# Is antimatter present on Earth?

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As we all know, antimatter is present across all of space. Is it also present on Earth? If it is present on Earth then by the interaction of matter and antimatter, why don't we feel the energy around us?

Antimatter is present on Earth and is being naturally created all the time (by Beta decay) as well as being created as product of cosmic ray collisions and in particle accelerators.

However the universe appears to be principally made of matter and so the antimatter thus created is annihilated: and although the production of antimatter through nuclear decay is essentially continuous, it is not of a high volume so the energy created in this way is not significant in the normal course of events. The real question is why is matter so much more abundant than antimatter: which is an open question though various theories have been proposed about why we might live in such a universe.

## There's Almost No Antimatter In The Universe, And No One Knows Why

The colliding galaxy cluster "El Gordo," the largest one known in the observable Universe, showing . [+] the same evidence of dark matter and normal matter as other colliding clusters. There is practically no room for antimatter in this or at the interface of any known galaxies or galaxy clusters, severely constraining its possible presence in our Universe.

NASA, ESA, J. Jee (Univ. of California, Davis), J. Hughes (Rutgers Univ.), F. Menanteau (Rutgers Univ. & Univ. of Illinois, Urbana-Champaign), C. Sifon (Leiden Obs.), R. Mandelbum (Carnegie Mellon Univ.), L. Barrientos (Univ. Catolica de Chile), and K. Ng (Univ. of California, Davis)

When we look around at the Universe:

• at the planets and stars,
• at the galaxies and clusters of galaxies,
• and at the gas, dust and plasma populating the space between these dense structures,

we find the same signatures everywhere. We see atomic absorption and emission lines, we see matter interacting with other forms of matter, we see star formation and stellar death, collisions, X-rays and so much more. There's an obvious question that cries out for an explanation: why is there all this stuff, rather than nothing at all? If the laws of physics are symmetric between matter and antimatter, the Universe we see today should be impossible. Yet here we are, and no one knows why.

On all scales in the Universe, from our local neighborhood to the interstellar medium to individual . [+] galaxies to clusters to filaments and the great cosmic web, everything we observe appears to be made out of normal matter and not antimatter. This is an unexplained mystery.

NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

1.) Every interaction between particles that we’ve ever observed, at all energies, has never created or destroyed a single particle of matter without also creating or destroying an equal number of antimatter particles. The physical symmetry between matter and antimatter is even more stringent than this:

• every time we create a quark or lepton, we also create an antiquark or antilepton,
• every time a quark or lepton is destroyed, an antiquark or antilepton is also destroyed,
• the created or destroyed leptons and antileptons must balance across each lepton family, and
• every time a quark or lepton experiences an interaction, collision or decay, the total net number of quarks and leptons at the end of the reaction (quarks minus antiquarks, leptons minus antileptons) is the same at the end as it was at the beginning.

The only way we’ve ever changed the amount of matter in the Universe has been to also change the Universe's antimatter by an equal amount.

The production of matter/antimatter pairs (left) from pure energy is a completely reversible . [+] reaction (right), with matter/antimatter annihilating back to pure energy. When a photon is created and then destroyed, it experiences those events simultaneously, while being incapable of experiencing anything else at all.

Dmitri Pogosyan / University of Alberta

And yet, there’s this second fact:

2.) When we look out at the Universe, at all the stars, galaxies, gas clouds, clusters, superclusters and largest-scale structures everywhere, everything appears to be made of matter and not antimatter. Whenever and wherever antimatter and matter meet in the Universe, there’s a fantastic outburst of energy due to particle-antiparticle annihilation.

But we don't see any signatures of matter annihilating with antimatter on the largest scales. We don't see any evidence that some of the stars, galaxies or planets we've observed are made of antimatter. We don't see the characteristic gamma rays that we'd expect to see if some antimatter parts were colliding (and annihilating) with the matter parts. Instead, it's matter, matter everywhere, in the same abundance everywhere we look.

The matter and energy content in the Universe at the present time (left) and at earlier times . [+] (right). Note the presence of dark energy, dark matter, and the prevalence of normal matter over antimatter, which is so minute it does not contribute at any of the times shown.

NASA, MODIFIED BY WIKIMEDIA COMMONS USER 老陳, MODIFIED FURTHER BY E. SIEGEL

It seems like an impossibility. On one hand, there is no known way, given the particles and their interactions in the Universe, to make more matter than antimatter. On the other hand, everything we see is definitely made of matter and not antimatter.

We've actually observed matter-antimatter annihilation in some extreme astrophysical environments, but only around hyper-energetic sources that produce matter and antimatter in equal amounts, such as massive black holes. When the antimatter runs into matter in the Universe, it produces gamma rays of very specific frequencies, which we can then detect. The interstellar and intergalactic medium is full of material, and the complete lack of these gamma rays is a strong signal that there aren't large amounts of antimatter particles flying around anywhere, since that matter/antimatter signature would show up.

Many examples of stars, nebulae, gas, dust, and other forms of matter can be seen interacting both . [+] within the Milky Way and beyond. In every instance, we see lots of evidence for absorption and emission, but no evidence that any astrophysical object is primarily made up of antimatter as opposed to matter.

Hubble Heritage Team (AURA / STScI), C. R. O'Dell (Vanderbilt), NASA

If you threw a single antimatter particle into the mix of our galaxy, it would only last for about 300 years before annihilating with a matter particle. That constraint tells us, within the Milky Way, the amount of antimatter can be no more than 1 part in a quadrilliion (10 15 ) compared to the total amount of matter.

On larger scales — of satellite galaxies, major, Milky Way-scale galaxies and even the scales of galaxy clusters — the constraints are less stringent but still very strong. With observations spanning distances ranging from a few million light-years away to over three billion light-years distant, we’ve observed a dearth of the X-rays and gamma rays we’d expect from matter-antimatter annihilation. Even on large, cosmological scales, 99.999%+ of what exists in our Universe is definitely matter (like us) and not antimatter.

Whether in clusters, galaxies, our own stellar neighborhood or our Solar System, we have tremendous, . [+] powerful limits on the fraction of antimatter in the Universe. There can be no doubt: everything in the Universe is matter-dominated.

Gary Steigman, 2008, via http://arxiv.org/abs/0808.1122

So how did we get here today, with a Universe made of a lot of matter and practically no antimatter, if the laws of nature are completely symmetric between matter and antimatter? Well, there are two options: either the Universe was born with more matter than antimatter, or something happened early on, when the Universe was very hot and dense, to create a matter/antimatter asymmetry where there was none initially.

That first idea is scientifically untestable without recreating the entire Universe, but the second one is quite compelling. If our Universe somehow created a matter/antimatter asymmetry where there initially wasn't one, then the rules that were at play back then should remain unchanged today. If we're clever enough, we can devise experimental tests to uncover the origin of the matter in our Universe.

The particles and antiparticles of the Standard Model obey all sorts of conservation laws, but there . [+] are slight differences between the behavior of certain particle/antiparticle pairs that may be hints of the origin of baryogenesis.

E. Siegel / Beyond The Galaxy

In the late 1960s, physicist Andrei Sakharov identified three conditions necessary for baryogenesis, or the creation of more baryons (protons and neutrons) than anti-baryons. They are as follows:

1. The Universe must be an out-of-equilibrium system.
2. It must exhibit C- and CP-violation.
3. There must be baryon-number-violating interactions.

The first one is easy, because an expanding, cooling Universe with unstable particles (and/or antiparticles) in it is, by definition, out of equilibrium. The second one is easy, too, since "C" symmetry (replacing particles with antiparticles) and "CP" symmetry (replacing particles with mirror-reflected antiparticles) are both violated in many weak interactions involving strange, charm, and bottom quarks.

A normal meson spins counterclockwise about its North Pole and then decays with an electron being . [+] emitted along the direction of the North Pole. Applying C-symmetry replaces the particles with antiparticles, which means we should have an antimeson spinning counterclockwise about its North Pole decay by emitting a positron in the North direction. Similarly, P-symmetry flips what we see in a mirror. If particles and antiparticles do not behave exactly the same under C, P, or CP symmetries, that symmetry is said to be violated. Thus far, only the weak interaction violates any of the three.

E. Siegel / Beyond The Galaxy

That leaves the question of how to violate baryon number. Experimentally, we've seen that the balance of quarks to antiquarks and leptons to antileptons are each explicitly conserved. But in the Standard Model of particle physics, there isn't an explicit conservation law for either one of those quantities individually.

It takes three quarks to make a baryon, so for every three quarks we assign a baryon number (B) of 1. Similarly, every lepton has a lepton number (L) of 1. Antiquarks, antibaryons, and antileptons all have negative B and L numbers, correspondingly.

But according to the Standard Model, it's only the difference between baryons and leptons, B - L, that's conserved. Under the right circumstances, you could not only make extra protons, you can make the electrons you need to go with them. Those exact circumstances may be unknown, but the hot Big Bang gave them an opportunity to arise.

At the high temperatures achieved in the very young Universe, not only can particles and photons be . [+] spontaneously created, given enough energy, but also antiparticles and unstable particles as well, resulting in a primordial particle-and-antiparticle soup. Yet even with these conditions, only a few specific states, or particles, can emerge.

Brookhaven National Laboratory

The earliest stages of the Universe are described by incredibly high energies: high enough to create every known particle and antiparticle in great abundance via Einstein's famous E = mc 2 . If particle creation and annihilation works the way we think it does, the early Universe should be filled with equal amounts of matter and antimatter particles, all interconverting into one another as the available energy remains extremely high.

As the Universe expands and cools, unstable particles, once created in great abundance, will decay. If the right conditions are met — specifically, the three Sakharov conditions — they can lead to an excess of matter over antimatter, even where there was none initially. The challenge for physicists is generating a viable scenario, consistent with observations and experiments, that can give you enough of an excess of matter over antimatter.

When the electroweak symmetry breaks, the combination of CP-violation and baryon number violation . [+] can create a matter/antimatter asymmetry where there was none before, owing to the effect of sphaleron interactions working on a neutrino excess.

There are three leading possibilities for how this excess of matter over antimatter could have emerged:

1. New physics at the electroweak scale could greatly enhances the amount of C- and CP-violation in the Universe, leading to an asymmetry between matter and antimatter. Standard Model interactions (through the sphaleron process), which violate B and L individually (but still conserve B - L) can then generate the right amounts of baryons and leptons.
2. New neutrino physics at high energies, of which we have a tremendous hint, could create a fundamental lepton asymmetry early on: leptogenesis. The sphalerons, which conserve B - L, could then use that lepton asymmetry to generate a baryon asymmetry.
3. Or GUT-scale baryogenesis, where new physics (and new particles) are found to exist at the grand unification scale, where the electroweak force unifies with the strong force.

These scenarios all have some elements in common, so let's walk through the last one, just as an example, to see what could have happened.

In addition to the other particles in the Universe, if the idea of a Grand Unified Theory applies to . [+] our Universe, there will be additional super-heavy bosons, X and Y particles, along with their antiparticles, shown with their appropriate charges amidst the hot sea of other particles in the early Universe.

E. Siegel / Beyond The Galaxy

If grand unification is true, then there ought to be new, super-heavy particles, called X and Y, which have both baryon-like and lepton-like properties. There also ought to be their antimatter counterparts: anti-X and anti-Y, with the opposite B - L numbers and the opposite charges, but the same mass and lifetime. These particle-antiparticle pairs can be created in great abundance at high enough energies, and then will decay at later times.

So your Universe can be filled with them, and then they'll decay. If you have C- and CP-violation, however, then it's possible that there are slight differences between how the particles and antiparticles (X/Y vs. anti-X/anti-Y) decay.

If we allow X and Y particles to decay into the quarks and lepton combinations shown, their . [+] antiparticle counterparts will decay into the respective antiparticle combinations. But if CP is violated, the decay pathways — or the percentage of particles decaying one way versus another — can be different for the X and Y particles compared to the anti-X and anti-Y particles, resulting in a net production of baryons over antibaryons and leptons over antileptons.

E. Siegel / Beyond The Galaxy

If your X-particle has two pathways: decaying into two up quarks or an anti-down quark and a positron, then the anti-X has to have two corresponding pathways: two anti-up quarks or a down quark and an electron. Notice that the X has B - L of two-thirds in both cases, while the anti-X has negative two-thirds. It's similar for the Y/anti-Y particles. But there is one important difference that's allowed with C- and CP-violation: the X could be more likely to decay into two up quarks than the anti-X is to decay into two anti-up quarks, while the anti-X could be more likely to decay into a down quark and an electron than the X is to decay into an anti-down quark and a positron.

If you have enough X/anti-X and Y/anti-Y pairs, and they decay in this allowed fashion, you can easily make an excess of baryons over antibaryons (and leptons over anti-leptons) where there was none previously.

In the early Universe, the full suite of particles and their antimatter particles were . [+] extraordinarily abundant, but as they Universe cooled, the majority annihilated away. All the conventional matter we have left over today is from the quarks and leptons, with positive baryon and lepton numbers, that outnumbered their antiquark and antilepton counterparts.

E. Siegel / Beyond The Galaxy

That's one example illustrating how we think it must have happened. We started with a completely symmetric Universe, obeying all the known laws of physics and beginning with a hot, dense, rich state full of both matter and antimatter in equal amounts. Through some yet-to-be-determined mechanism, one that obeys the three Sakharov conditions, these natural processes generated an excess of matter over antimatter in the end.

The fact that we exist and are made of matter is indisputable the question of why our Universe contains something (matter) instead of nothing (from an equal mix of matter and antimatter annihilating away) is still an unanswered one . This century, advances in precision electroweak testing, collider technology, neutrino physics, and experiments probing beyond the Standard Model have a chance to reveal exactly how it happened. Until then, we can be certain that there's almost no antimatter in the Universe, but no one knows why.

## Source of Mysterious Antimatter Found

Antimatter,which annihilates matter upon contact, seems to be rare in the universe. Still,for decades, scientists had clues that a vast cloud of antimatter lurked inspace, but they did not know where it came from.

Themysterious source of this antimatter has now been discovered — stars getting rippedapart by neutron stars and blackholes.

Whileantimatter propulsion systems are so far the stuff of science fiction,antimatter is very real.

Allelementary particles, such as protons and electrons, have antimattercounterparts with the same mass but the opposite charge. For instance, theantimatter opposite of an electron, known as a positron, is positively charged.

Whena particle meets its antiparticle, they destroy each other, releasing a burstof energy such as gammarays. In 1978, gamma ray detectors flown on balloons detected a type of gammaray emerging from space that is known to be emitted when electrons collide withpositrons — meaning there was antimatter in space.

"Itwas quite a surprise back then to discover part of the universe was made ofantimatter," researcher Gerry Skinner, an astrophysicist at Goddard SpaceFlight Center in Greenbelt, Md., told SPACE.com.

Thesegamma rays apparently came from a cloud of antimatter roughly 10,000 light-yearsacross surrounding our galaxy's core. This giant cloud shines brightly withgamma rays, with about the energy of 10,000 suns.

Whatexactly generated the antimatter was a mystery for the following decades.Suspects have included everything from exploding stars to darkmatter.

Now,an international research team looking over four years of data from theEuropean Space Agency's International Gamma Ray Astrophysics Laboratory(INTEGRAL) satellite has pinpointed the apparent culprits. Their new findingssuggest these positrons originate mainly from stars getting devoured by blackholes and neutron stars.

Asa black hole or neutron star destroys a star, tremendous amounts of radiation arereleased. Just as electrons and positrons emit the tell-tale gamma rays uponannihilation, so too can gamma rays combine to form electrons and positrons, providingthe mechanism for the creation of the antimatter cloud, scientists think.

Billions and billions

Theresearchers calculate that a relatively ordinary star getting torn apart by ablack hole or neutron starorbiting around it — a so-called "low mass X-ray binary" — could spewon the order of one hundred thousand billion billion billion billion positrons(a 1 followed by 41 zeroes) per second. These could account for a great deal ofthe antimatter that scientists have inferred, reducing or potentiallyeliminating the need for exotic explanations such as ones involving darkmatter.

"Simpleestimates suggest that about half and possibly all the antimatter is comingfrom X-ray binaries," said researcher Georg Weidenspointner of the MaxPlanck Institute for Extraterrestrial Physics in Germany.

Nowthat they have witnessed the death of antimatter, the scientists hope to see itsbirth.

"Itwould be interesting if black holes produced more matter than neutron stars, orvice versa, although it's too early to say one way or the other rightnow," Skinner explained. "It can be surprisingly hard to tell thedifference between an X-ray binaries that hold black holes and neutronstars."

Weidenspointner,Skinner and their colleagues, detailed their findings in the Jan. 10 issue ofthe journal Nature.

## Are antimatter stars firing bullets of antihelium at Earth?

Fourteen possible antimatter stars (“antistars”) have been flagged up by astronomers searching for the origin of puzzling amounts of antihelium nuclei detected coming from deep space by the Alpha Magnetic Spectrometer (AMS-02) on the International Space Station.

Three astronomers at the University of Toulouse – Simon Dupourqué, Luigi Tibaldo and Peter von Ballmoos – found the possible antistars in archive gamma-ray data from NASA’s Fermi Gamma-ray Space Telescope. While antistars are highly speculative, if they are real, then they may be revealed by their production of weak gamma-ray emission peaking at 70 MeV, when particles of normal matter from the interstellar medium fall onto them and are annihilated.

Antihelium-4 was created for the first time in 2011, in particle collisions at the Relativistic Heavy Ion Collider at the Brookhaven National Laboratory. At the time, scientists stated that if antihelium-4 were detected coming from space, then it would definitely have to come from the fusion process inside an antistar.

However, when it was announced in 2018 that AMS-02 had tentatively detected eight antihelium nuclei in cosmic rays – six of antihelium-3 and two of antihelium-4 – those unconfirmed detections were initially attributed to cosmic rays colliding with molecules in the interstellar medium and producing the antimatter in the process.

Subsequent analysis by scientists including Vivian Poulin, now at the University of Montpellier, cast doubt on the cosmic-ray origin, since the greater the number of nucleons (protons and neutrons) that an antimatter nucleus has, the more difficult it is to form from cosmic ray collisions. Poulin’s group calculated that antihelium-3 is created by cosmic rays at a rate 50 times less than that detected by the AMS, while antihelium-4 is formed at a rate 10 5 times less.

### The mystery of matter and antimatter

The focus has therefore turned back to what at first may seem an improbable explanation – stars made purely from antimatter. According to theory, matter and antimatter should have been created in equal amounts in the Big Bang, and subsequently all annihilated, leaving a universe full of radiation and no matter. Yet since we live in a matter-dominated universe, more matter than antimatter must have been created in the Big Bang – a mystery that physicists have grappled with for decades.

“Most scientists have been persuaded for decades now that the universe is essentially free of antimatter apart from small traces produced in collisions of normal matter,” says Tibaldo.

The possible existence of antistars threatens to turn this on its head. “The definitive discovery of antihelium would be absolutely fundamental,” says Dupourqué.

The 14 candidates were identified from a total of 5787 gamma-ray sources catalogued over 10 years by Fermi’s Large Area Telescope, and have allowed Dupourqué, Tibaldo and von Ballmoos to calculate constraints for the possible populations of antistars in the Milky Way.

If antistars formed in the spiral disc of the galaxy alongside normal stars, then they calculate that there is one antistar for every 400,000 ordinary stars. If, on the other hand, antistars are primordial, dating from the early universe when the Milky Way was just forming, meaning that they are located in the oldest part of the Milky Way (the galactic halo), then as many as a fifth of the stars there could be antistars.

“Locking up antimatter in antistars would be a plausible way to spare antimatter from being annihilated,” says von Ballmoos. “Particularly if they hide away in regions of relatively low densities of normal matter, like the galactic halo.”

### Balloon mission

Poulin, who was not involved in the detection of these 14 candidates, agrees that if antistars are real, then a primordial origin is most likely, since clouds of antihydrogen “would have annihilated on very short time scales,” he says. Instead, “they would have formed in the very early universe.”

Given the speculative nature of antistars, it is quite possible that all 14 candidates will turn out to be something more mundane. Dupourqué, Tibaldo and von Ballmoos suggest that a possible next step should be to check whether the 14 candidates emit electromagnetic radiation at other wavelengths that could reveal them to actually be active galactic nuclei or pulsars.

Record-breaking gamma ray is smoking gun for Milky Way cosmic rays

Meanwhile, the GAPS experiment, a balloon mission set to launch later this year, will join the search for antimatter cosmic rays. One of its aims is to independently confirm the AMS’ antihelium detections, which for now should be treated with caution because they are a statistically low sample, say Dupourqué, Tibaldo and von Ballmoos.

“The conventional claim is that the detection of antihelium-4 is a smoking gun for new physics, and the existence of antistars,” says Poulin. If antistars can be shown to be real, then they promise to alter our view of cosmology, astrophysics and particle physics.

## JimsAstronomy

- 3152 - ANTIMATTER - is there another world? - Antimatter particles have the opposite charge of normal matter particles. When particles of matter and antimatter meet, they destroy each other. Otherwise, antimatter behaves similarly to ordinary matter.

----------------- 3145 - ANTIMATTER - is there another world?

- An antihydrogen atom, consisting of an antiproton and a positron (the antimatter counterpart of an electron), is the antimatter version of a hydrogen atom. Using the Antiproton Decelerator at CERN's ALPHA (the Antihydrogen Laser Physics Apparatus) instrument, researchers combined antiprotons with positrons to form antihydrogen atoms.

- Researchers trapped hundreds of antihydrogen atoms in a vacuum and used laser pulses to excite the atoms, prompting them to jump into a higher energy state. Prompting or measuring this change, known as the Lyman-alpha transition, is a method used frequently in astronomy to study dark energy, that unseen, yet abundant force that makes up about 68 percent of the total energy of the universe.

- When the antihydrogen atoms drop back down to a lower energy state, they release photons. The researchers measured these photons, which revealed that the antihydrogen emissions were the same as those one would expect from a normal hydrogen atom.

- The researchers plan to use this approach to test how antimatter and gravity interact. This gets us just a bit closer to answering some of these big questions in physics. Over the past decades, scientists have been able to revolutionize atomic physics using optical manipulation and laser cooling, and with this result, we can begin applying the same tools to probing the mysteries of antimatter.

- Antimatter is just like normal matter, with all the same properties and all the same abilities to make up atoms and molecules, except for one crucial difference: It has an opposite charge.

- The electron, for example. Mass of 9.11 x 10^-31 kg. Quantum spin of 1/2. Charge of -1.6 x 10^-9 coulombs.

- It has an antimatter evil twin, the “positron“. The positron has a mass of 9.11 x 10^-31 kg. Quantum spin of 1/2. Charge of … 1.6 x 10^-9 coulombs.

- It is the same for every other particle. There's a dark-side twin for the top quark, the neutrino, the muon and all the fundamental particles that make up our daily lives have a partner, living just on the other side of the charge fence.

- Our universe ought to be swimming with antimatter, existing in equal parts with normal matter. Whole planets, stars and galaxies made of antimatter.

- When matter and antimatter meet just as the pairs are produced in perfect symmetry in fundamental interactions, they are destroyed in symmetry as well. When a particle finally gets to meet with its antiparticle all their combined matter is converted into energy, usually in the form of high-energy gamma-ray radiation.

- The universe is filled with constantly-interacting particles. High-energy particles zipping across light-years. Fountains of material escaping from galaxies and new material drifting in. Stars colliding. In our universe, stuff mixes with stuff all the time. If some decent proportion of that was antimatter, the universe ought to be a lot more energetic than it is.

- If the antimatter isn't here anymore, where did it go?

- One possibility is that our universe was simply born this way, with an abundance of matter and a severe lack of antimatter. Something in the early universe caused an imbalance between matter and antimatter.

- An imbalance. A strange process that produced more matter than antimatter. Most of the pairs would be annihilated, but a few normal particles would remain. It wouldn't have to be much: Just one particle in a billion would be enough to lay the foundations for all the stars and galaxies that we see today.

- Whatever interaction, whatever process, led to matter's ultimate victory had to be strange indeed. It had to start with producing not just an excess quantity of regular matter, but also an excess quantity of charge to counterbalance it.

- This process had to happen during a sharp boundary, when the infant cosmos was transforming rapidly from one state to another. It's only there that the physics would permit such a rule-breaking violation to take place otherwise a universe in equilibrium would just end up balancing all interactions out.

- Is there anything in all of known physics that could make the antimatter go away? There are some hints and suggestions buried in rare particle interactions involving the weak nuclear force. We understand these interactions only dimly, especially the way they would occur in the early universe, but even there our best guess for its matter-favoring ability put it far, far below the minimum needed to explain our present situation.

- The origins of the asymmetry between matter and antimatter is an outstanding problem in physics. A problem that pushes the boundaries of current knowledge and pushes our understanding of the universe into some of its earliest moments.

- New discoveries are needed. Innovative laser experiments at the CERN lab in Switzerland has brought physicists one step closer to understanding mysterious antimatter.

- An antihydrogen atom, consisting of an antiproton and a positron (the antimatter counterpart of an electron), is the antimatter version of a hydrogen atom. Using the Antiproton Decelerator at CERN's ALPHA (the Antihydrogen Laser Physics Apparatus) instrument, researchers combined antiprotons with positrons to form antihydrogen atoms.

- The researchers trapped hundreds of antihydrogen atoms in a vacuum and used laser pulses to excite the atoms, prompting them to jump into a higher energy state.

- Prompting or measuring this change, known as the “Lyman-alpha transition“, is a method used frequently in astronomy to study dark energy. This unseen, yet abundant force that makes up about 68 percent of the total energy of the universe.

- When the antihydrogen atoms drop back down to a lower energy state, they release photons. The researchers measured these photons, which revealed that the antihydrogen emissions were the same as those one would expect from a normal hydrogen atom.

- The Lyman-alpha transition is the most basic, important transition in regular hydrogen atoms, and to capture the same phenomenon in antihydrogen opens up a new era in antimatter science.

- The researchers plan to use this approach to test how antimatter and gravity interact.

- More antimatter particles stream toward Earth than scientists can explain and new research from a mountaintop observatory in central Mexico deepens the mystery by crossing off one possible source.

- The Earth is constantly showered by high-energy particles from a variety of cosmic sources. The recent finding, November 2020, concerns positrons, the antimatter complements of electrons. High-energy particles, usually protons, traveling across the galaxy can create pairs of positrons and electrons when they interact with dust and gas in space.

- In 2008, the space-based PAMELA detector measured unexpectedly high numbers of earthbound positrons. This was about 10 times what they were expecting to see. After years of work, camps coalesced around two distinct explanations.

- One hypothesis suggests the particles come from nearby pulsars, rapidly spinning cores of burnt-out stars, which can whip particles like electrons and positrons to incredible speeds.

- The other group posits a more exotic origin for the excess positrons, perhaps involving dark matter, an unknown yet pervasive entity that accounts for 80 percent of the universe's mass.

- Particles like positrons that carry an electric charge are difficult to detect on Earth since they can be deflected by the planet's magnetic field. But scientists have a workaround. The particles also interact with the cosmic microwave background, an ever-present stream of low-energy photons left over from the birth of the universe.

- The high-energy electron, or positron, will kick the low-energy photon . so this the photon becomes a high-energy gamma-ray. These gamma-rays, which have no electric charge, can pass right through the magnetic field and make it all the way to Earth's surface.

- Scientists used the High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory, located about 4 hours east of Mexico City. HAWC comprises more than 300 tanks of extra-pure water.

- When gamma-rays plow into the atmosphere, they create a cascade of high-energy particles. As this shower of particles passes through HAWC's tanks, it emits flashes of blue light, which scientists can use to determine the energy and origin of the original cosmic ray.

- The data from HAWC revealed that particles are streaming away from the pulsars too slowly to account for the excess positrons.

- The measurement do not decide the question in favor of dark matter, but any new theory that attempts to explain the excess using pulsars will need to match the new data.

- By observing the rotations of galaxies, scientists determined that the universe contains more mass than the objects we can observe. They call this mysterious extra mass dark matter. Aside from seeing dark matter's gravitational influence from afar, no one has directly detected it otherwise.

- However, a popular model of the substance involves weakly interacting massive particles, or WIMPS, which interact with regular matter solely through gravity. If these proposed particles were to decay, or be annihilated somehow, they could conceivably generate pairs of electrons and positrons.

- There are other astrophysical processes to consider. Supernova remnants and micro quasars, extremely bright objects formed as matter spirals toward a blackhole, can produce positrons. And there's the possibility that the initial model of particle interactions with the cosmic microwave background is inaccurate.

- May 9, 2021 ANTIMATTER - is there another world? 3152

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## A letter to the Minister for Education

On Friday evening, I gave a public talk on the big bang at Blackrock Castle in Cork. I always enjoy giving public science talks, but this one was special (slides here). The venue was a beautiful castle overlooking the sea and I was enormously impressed with the science outreach work being done there by Dr Niall Smith, director of research at Cork Institute of Technology. I was equally impressed with the new observatory at the castle and the astronomy program of Niall and his postgraduate students. Superb work in a fantastic location, surely an inspiration for generations of young students.

Blackrock Castle in Cork: the white dome above the tower is the observatory

I left Cork early on Saturday morning in order to travel to Dublin to catch the High Flyers conference of the Institute of Physics (this is what physicists get up to on bank holiday weekends!). On my way to the meeting, I heard the Irish Minister for Education interviewed on RTE Radio One (Marian Finucane show, May 5 th ). The Minister had many interesting things to say on subjects such as RTE, the Catholic Church, a recent libel case in Ireland and the near-paralysis of political process in the United States (the latter is a most unusual topic for a politician over here). However, I was taken aback to hear him refer to “problems of productivity in the third level sector, particularly in the Institutes of Technology”, and disappointed that the interviewer didn’t seek some clarification on the comment.

I would very much like to know what the Minister meant by this comment. What do we understand by ‘productivity’ in the context of the third level education? How is it measured? Is it the number of students taught? Number of Noble prizes for research? Perhaps some Soviet-style quota of engineers graduated? Like all Institute lecturers, I have a heavy teaching load we produce legions of exactly the sort of science, computing and engineering graduates that Ireland so desperately needs. I must say I grow weary of generalizations like this about third level academics from journalists and politicians, and such a comment from the top man in education is pretty serious. Not a scintilla of evidence was offered by the Minister in support of his remark, just a casually delivered public insult to my colleagues and I.

Here’s the thing, Minister Quinn: like almost all lecturers in the Institutes of Technology (IoTs), I teach between four and five different courses per semester to degree level, a larger teaching load than any third level college in the world as far as I know add research and outreach activity to this and it is no surprise I am in the office until 9 pm at least four days a week. In terms of prep, each semester typically presents at least one new module to teach, involving months of preparation over the summer, where I would hope to be concentrating on research, finishing my book and attending conferences. (I teach diverse courses in mathematics and physics to students in the departments of computing, engineering and science, not to mention more specialized modules in quantum physics, cosmology and particle physics – how many Harvard professors can boast such a wide teaching portfolio?).

‘Yes, but what about other IoT lecturers?’, the Minister will ask. I imagine I have a more accurate view of the work of my colleagues than the Minister’s advisors and I have no complaints. Indeed, the limited time I have for research arises because other lecturers take on the bulk of student administration (the large number of classes in the IoTs necessitates a great deal of admin Year Tutors and Course Leaders spend a great deal of time keeping track of attendance, assessments, lab performance and exam results). There are no easy lecturing jobs.

I love my job and stopped counting the overtime years ago. However, it is frustrating to hear the work of lecturers in the institutes and the universities denigrated by politicians who know nothing of what we do. The tragedy is, I suspect the binary system of universities and institutes has served Ireland very well, although few in charge of education seem to realize it. As they consider the future of the third level sector, I hope politicians and their advisors will make an effort to understand the current system, rather than indulge in unsupported generalizations.

## Have Astronomers Found Antimatter Stars?

For more SpaceTime visit https://spacetimewithstuartgary.com or the all new www.bitesz.com
The Astronomy, Technology and Space Science News Podcast.
SpaceTime Series 24 Episode 55
*Have astronomers found antimatter stars
Astronomers have identified 14 .

For more SpaceTime visit https://spacetimewithstuartgary.com or the all new www.bitesz.com

The Astronomy, Technology and Space Science News Podcast.

SpaceTime Series 24 Episode 55

*Have astronomers found antimatter stars

Astronomers have identified 14 potential candidate stars that -- just maybe &ndash might be made out of antimatter rather than normal matter.

*Ingenuity and Perseverance head south on the Red Planet

NASA&rsquos Ingenuity helicopter has completed its first one way flight above the surface of the red planet landing at a remote location 129 metres south of its take off point.

*Mapping the Milky Way&rsquos galactic magnetic fields

Astronomers have created a 3D map of the magnetic field in a small wedge of the Milky Way galaxy.

*SpaceX successfully launches the same Falcon 9 rocket for the tenth time

SpaceX has carried out a successful tenth flight using the same Falcon 9 first stage booster with Elon Musk saying it&rsquos showing very little wear.

*The Science Report

Fission reactions discovered smouldering away in the wreckage of the Chernobyl Nuclear Power plant.

The earliest known deliberate burial by modern humans.

Studies show people are consuming up to four milligrams of plastic for every 100 grams of rice they eat.

Skeptic's guide to Prince Philip&rsquos interest in aliens and UFOs.

SpaceTime is an independently produced podcast (we are not funded by any government grants, big organisations or companies), and we&rsquore working towards becoming a completely listener supported show. meaning we can do away with the commercials and sponsors. We figure the time can be much better spent on researching and producing stories for you, rather than having to chase sponsors to help us pay the bills.

That's where you come in. help us reach our first 1,000 subscribers. at that level the show becomes financially viable and bills can be paid without us breaking into a sweat every month. Every little bit helps. even if you could contribute just $1 per month. It all adds up. By signing up and becoming a supporter at the$5 or more level, you get immediate access to over 230 commercial-free, double, and triple episode editions of SpaceTime plus extended interview bonus content. You also receive all new episodes on a Monday rather than having to wait the week out. Subscribe via Patreon or Supercast. and share in the rewards. Details at Patreon www.patreon.com/spacetimewithstuartgary or Supercast - https://bitesznetwork.supercast.tech/

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See acast.com/privacy for privacy and opt-out information.

SpaceTime Series 24 Episode 55 AI Transcript

[00:00:00] This is space time series 24 episode 55 for broadcast on the 17th of May, 2021. Coming up on space time, have astronomers found anti-medic stars, ingenuity and perseverance head South. As the begin, their exploration campaign on Mars and space X successfully launches the same Falcon nine rocket for a 10th time.

Any Elon Musk says they'll continue pushing the envelope. All that and more coming up on space time. Welcome to space time with Stuart, Gary.

Astronomers have identified 14 potential candidates stars that just maybe might be [00:01:00] made out of anti-matter rather than normal matter. One of the biggest problems with sciences understanding of the universe and cosmology is that equal amounts of matter and anti-matter would have been created in the big bang.

When the universe came into being 13.82 billion years ago. Now other than in science fiction, there's really nothing special about anti-matter. It simply has the opposite electrical charge of so-called normal matter. So the anti-medic counterpart to the positively charged proton is the negatively charged anti-proton and the anti-medic counterpart to the negatively charged electron is the positively charged positron.

The problem is that when matter and antimatter come into contact, they Nile at each other. So with equal amounts of matter, and anti-matter being created in the big bang, the universe should have annihilated itself in a bright blue flash of gamma rays, as soon as it came into existence, yet, clearly that didn't happen.

And we live in a universe composed mostly of [00:02:00] matter rather than anti matter. Of course, that doesn't mean there isn't any anti-matter out there. We see it all the time. It just doesn't hang around very long. And they may be significant regions of anti-matter in the observable universe. But so far we haven't found them finding huge regions of anti-matter would require looking for the high energy gamma Ray glow being generated on exporters where matter.

And anti-matter coming to contact this annihilation. Radiation would feature a characteristic spectrum picking around half the massive and mutual pion with a cutoff around the mass of a proton. But the failure to detect this annihilation gamma Ray radiation, as virtually excluded the existence of at least significant amounts of baryonic anti-matter in our cosmic neighborhood.

However, the alpha magnetic spectrometer experiment AMS to aboard the international space station has on several occasions. Tentatively detected anti helium, nuclei, not many somewhere around one [00:03:00] in every hundred million helium atoms. Now all of the events that have been reported six, a compatible with being at a helium three and two with Addie helium four.

So that raises the question about whether this represents a sort of smoking gun for the existence of anti-medic stars or anti stars, and possibly even anti-medic galaxies to try and resolve the question as traumas have turned to NASA's Fermi gamma Ray space telescope. Again, looking for that tilt Taylor nine Alation radiation.

The other is analyzed data from a gamma Ray catalog known as four FGL out to now for FGL DHEA two is based on 10 years of observations, looking at the 50 mega electron volts to one Terra electron volt energy range. It contains some 5,787 gamma Ray sources, including their special parameters, spectral energy distributions, light curves, and multi wavelength associations.

Reporting in the journal, physical review, [00:04:00] D the authors were able to identify 14 possibly stars whose properties were spectrally compatible with a top of signal, likely to be generated by matter. Anti-matter in isolation. Now the authors stress, this doesn't mean they've found a bunch of anti-matter stars.

These things are just as likely to simply be POS or stellar mass black holes. Still, if they were anti-medic stars or anti stars, you could extrapolate that out to indicate the Milky way contains as many phase five anti metastatic for every 2 million regular stars. And the authors say that to be the source of the annihilation nuclear.

I tentatively detected by the AMS to experiment these anti stars. If they do really exist, probably between around 30 and a thousand light years away, which means they could be hiding in the galaxies disk or at most in the gallery. Hello, it's certainly not proof of anti-matter stars, but you've got it mid.

It does deserve further investigation. [00:05:00] This is space time still the calm messes, ingenuity, and perseverance head South on the red planet. As they begin their scientific mission and astronomers have created a three-dimensional map of magnetic fields in the small wedge of the Milky way. Galaxy. Oh, that in much more store the calm on space time.

Masses the helicopter has completed its first one way. Flight above the surface of the red planet landing at a remote location, 129 meters South of its takeoff point. Ever since ingenuity arrived on Mazi, mid February tucked beneath the perseverance Rover, the tissue box size twin rotor aircraft has never ventured far from home base, an area which has been dubbed Wright brothers field in honor of [00:06:00] oval and Wilbur Wright who undertook the first powered controlled flight in history.

And after H of ingenuity is for test flights, it's always returned to the same spot each night. Now with these tests, White's completed proving to mission managers at the 1.8 kilogram autonomous helicopter really can fly in the Martian atmosphere. Its fifth flight transitions, the rotor craft into a new role.

One of supporting perseverance and its mission to study the geology of the river Dota region of Jethro crater and search for signs of past microbial life on Mars. The 108 second flight took ingenuity South Miami to an altitude of 10 meters and surveying the surrounding terrain, taking high resolution color images of the area before attaching down at the new site for its first overnight.

Stay away from Wright brothers field, the ingenuity team at NASA's jet propulsion laboratory in Pasadena, California chose the new site based on information gathered during the previous flight. The first stereo [00:07:00] scout mission on another world. That flight generated digital elevation maps indicating almost completely flat terrain with virtually no major obstructions.

The flight represents the rudder crafts transition to its new operations demonstration phase. Focusing on the type of capabilities or rotorcraft operating on mosque can provide such as scouting ahead for the best terrain and the taking aerial observations of areas not accessible by Rover. And of course, detailed aerial imaging.

These operations and the lessons learned from them will significantly benefit, feature, Errol exploration of Mars and other worlds, including the upcoming dragon fly mission to the stanchion moon. Titan. Of course, this new phase also brings with it added risk to ingenuity with more one way flights and more precision maneuvering required by the autonomous aircraft.

Having successfully land that at its new site, ingenuity will now await future instructions relayed by way of the perseverance row from mission [00:08:00] manages. Meanwhile, these six wheeled car size perseverance is also heading South towards its first primary science and sample collection spot. Not far from where the helicopter is sitting, the Rover teams need to him.

Strategy won't require any long drives that would leave the helicopter far behind. Thereby allowing ingenuity to continue supporting the primary mission as they move together through new terrain. But for the media back home on earth, some 317 million kilometers or 18 light minutes away, the highlight of the past week as being the ability to actually hear that sounds of ingenuity is whirling rotor blades, cutting through the thin mash and atmosphere.

[00:09:00] The sound of human encroachment on the surface of another world, the initial rumble in the background is the Marsh and wind or the hum, which takes over other helicopters blades spinning it 2,537 RPM with a sound being greatly muffled by the thin mash and atmosphere. Perseverance used one of its two microphones to listen as the ingenuity helicopter that some 80 meters away flew out on its fullest mission back on the last day of April, it's the first time a spacecraft on another planet as recorded the sounds of another spacecraft on that world.

This space-time. Still the calm astronomers create a three-dimensional magnetic field map of part of [00:10:00] the Milky way. Galaxy and space X reaches a major milestone successfully launching the same Falcon nine rocket for a 10th time, all out of more store to come on. Space time.

Astronomers have created a three dimensional map of the magnetic field and a small wedge of the Milky way. Galaxy the research reported in the astrophysical journal paves the way for discoveries, improving sciences, understanding of the evolution of the Milky way, the formation of stars and planets and the early stages of the universe lead researcher.

Dr. from Australian national university says the work was the first to Tama graphically measure the strength of that Galaxy's magnetic field. The Milky ways, magnetic field and cosmic dust act like a veil that obscures the [00:11:00] radiation from the early stages of the universe known as the cosmic microwave background.

And it's prevented scientists from testing cosmological models for the investors evolution. Trisha says the research provides a means to map the strength of the magnetic field for all regions of our galaxy, enabling astronomers to better understand the universe has evolution. The authors found that the Galaxy's magnetic field strength was much higher than previously thought.

Most models that predict the strength of the Galaxy's magnetic field for every location and distance from the sun, uh, based on observations that can't probe the magnetic field in three dimensions, the study is also an important step in understanding how ultra high energy cosmic rays travel through the galaxy.

Galactic cosmic rays are very high energy particles. Often with energy is far greater than what can be produced in even the biggest particle accelerators on earth. Trisha says that by understanding the structure and strength of the magnetic field, astronomers can improve their chances of finding the locations of the sources of these extremely [00:12:00] energetic particles and thereby probe new physics at extreme the magnetic field plays an important role.

In many of these processes, the importance is more or less straightforward. So first you have a cosmic rays, which are very, , uh, much more, uh, than what we can eat with our accelerators. Right. Then, because these pockets of we are elected from the magnetic tree. Why is it important to know how cosmic rays are deflected by magnetic fields?

Okay. We want to know the show. She's second. We want to know their, their, their nature, how heavy these product are in a sense, right? And, uh, as a result, we can test our models of particle physics in very, very high energy. By that you find out more about the properties of cosmic rays, as well as where they're coming from.

Yes, exactly. And of course that's not the only issue is that also we want to find out more about the cosmic microwave background radiation 2.7 [00:13:00] degrees above absolute zero. Now it's often described as the leftover light from the big bang itself, some 380,000 years after the big bang occurred. The thing is that all over or galaxy?

Uh, there are some dust grains, and this does go into line with the magnetic field and they act like, like a veil that prevents us from studying all the properties of the CMV and some properties that we haven't yet padded hold the potent clues. About the sales stages of the universe. This includes things like the Hubble constant, because there are different ideas as to what the Hubble constant actually is.

There are two primary ways of looking at the Hubble constant and they're giving different figures. One of those ways is the CMB, right? So it's not directly without in the center. So some theory can cause more logical models from inflation. So inflation was a period of a universe where the universe grew exponentially.

Right? And so some of these theoretical models [00:14:00] predict the certain part and to be present in the CMB. And, uh, one who confirmed that we can't detect me in the same day. They have a questions, but, uh, the magnetic field and the dusk games are in the way and understanding cosmic inflation would tell us all about.

Well, the moments of the big bang itself. Yes, exactly. Which is about as far back as you can see, as far as, like you said, you said it, right? Yes. The magnetic field is very, very important for the evolution of molecular clouds, which are the places where I start at formed. So a 3d map of the magnetic field of the galaxy would just give us really important information regarding a star implant information.

So we'll find out more about where we came from. Yeah. Yeah. So we'll actually find where the university and from. Where we came from what's happening in the most innovative coordinates of our cosmos. We will learn a lot of things. It's just the magnetic release time. It's funny, isn't it? When you think about it, because astronomy has, haven't really focused as [00:15:00] much on the magnetic field as they should have over time.

I've always looked at just the optical light, but they haven't looked at the other side of the electromagnetic spectrum, the, the magnetic field. To nearly the same degree if he needs. It's very, very hard to observe and especially in a, in three dimensions. So, so there was a saying one would observe certain phenomena and investigated what part of the phenomenon could be explained.

And then the unexpected unexplained parts were starting to show the effect of the magnetic fields. So, uh, the lab is one ignorance, the stronger the magnetic field. I've heard that expression myself. Yes. Yes. So how did you, how were you able to map the magnetic? Okay. So the way we did that is by examining the clouds, the clouds threaded by the magnetic field and some magnetic waves and these waves, the imprint.

In the, in the clouds. So by studying the clouds, we study these magnetic waves and by studying the magnetic waves, we can [00:16:00] find the value of the over the magnetic field. And the cool thing is that we can do that in three dimensions, which has never been done before. we now have a method to map the magnetic field.

You can see the, so out of the two dimensional world. And into the full city. What did you use? What instruments were used to do that? Uh, so I used, uh, some, uh, observation, some radio observations, looking at the H one, any specific telescopes or just whatever archival many surveys, so that, so there were a couple of surveys.

The past decade and compilation of observations called the and way to now, you want to increase that map? I'd take it. Yeah. Our next plan is to increase, increase that map and do the entire galaxy and have you over the magnetic field of our entire galaxy would, would be, which would be. Uh, shoot the important, what did you choose?

The two slices of the pie you chose? Were there any particular reasons for that or is that something in that [00:17:00] direction, those directions or interest? Yes, actually there was. And so in that general direction, we also observe the so-called the Academy gray hotspot. Which is basically an excess of, uh, what's like headed in that direction.

so that's where we think the cosmic rays are coming from, or some of them, uh, we, we don't know. Because, uh, the, the, the fact that we see them project, the sky with w direction doesn't mean it doesn't necessarily mean that they're coming from like the galaxy and right behind that, that, uh, uh, region, this guy, because of a deflection from the grant, am I going to defeat it?

I think in that direction that, uh, we've selected to generate the moment specific, uh, specifically extra large supermassive black holes. Uh, we're looking, we're looking into that. We're not sure yet time will tell you exactly. from the Australian national university. [00:18:00] And this is space time, still the com a major milestone for space X as they launch the same Falcon nine rocket for the 10th time and later in the science report, vision reactions discovered smoldering away in the wreckage of the Chenault bowl, nuclear power plant, all that, and much more still to come.

space X has passed the major milestone, carry out a successful 10th flight using the same Falcon nine first stage booster. The booster numbered B 10 51 was used to launch the 27th of cluster of 60 styling, broadband telecommunication satellites. The mission was flown from space launch complex 40 at the Cape Canaveral space for a station in [00:19:00] Florida after Mika or managing cutout and the state separation, the boosters successfully returned to worth landing on the drone ship.

Just read the instructions, which was pre-positioned 630 kilometers down range in the North Atlantic ocean. Space X originally designed the block five version of the FACA nine first stage for 10 launches. But they're now considering extending that as pre-phone rockets all appear to be doing well, the company says it's using its internal Starlink missions to test the limits of the boosters reliability.

As for this booster, be 10 51, it's only a required minor refurbishment between each flight. Space X bossy. Elon Musk says there's been no significant wear and tear of any of the magic components. Meaning that with engine replacement, H Vista could theoretically I'll have to 100 times be 10 51 first floor back in 2019, watching the unmanned crew dragon capsule on the demo.

One mission to the international space station. It's also [00:20:00] launched a trio of Canadian earth, observation satellites, a Sirius XM, broadband telecommunication, satellite, and seven different styling missions. Space X is so confident with the reliability they had boosters. And now equipping the 70 made a toll rockets with a series of upgrades, including more robust thermal protection systems are more durable and a stage.

That's the bit between the top of the core stage and the upper stage. They're improved that the Tanium grid fins used to control the boosters during their re-entry into its atmosphere. And they're being given more powerful engines. Last year space X also positioned both of their drone ships. Of course, I still love you and just read the instructions on the East coast, thereby allowing loans, frequencies to be increased to less than a week between flights.

In fact, this latest 27th Starlink mission launched just five days after the last and like the last 60 satellites on board. This mission we're all safely deployed into a 580 kilometer high orbit. For the record, the turtle number of [00:21:00] Starlink satellites now launched stands at 1,625 of which 1,554 of the turned and 60 gram spacecraft is still in orbit space.

XC is hoping to eventually launch over 30,000 styling satellites, providing broadband internet coverage over match of the planet. This mission was also the 14th Falcon nine launch so far this year. This is space time.

And Tom had to take a brief look at some of the other stories making use in science this week, where the science report increased levels of neutrons emanating from an inaccessible basement area at the Schnabel nuclear power station indicate that fission reactions are again, smoldering away at the side.

The number four reactor at the Chernobyl nuclear power plant in the Ukraine exploded during a failed test in 1986 in what's become known as the [00:22:00] world's worst nuclear disaster. Now a report of the journal science claims new readings are showing that radioactive neutron emissions have increased by 40% since 2016.

And that suggests a growing fusion reaction is underway deep inside the wreckage of the plant. The focus of attention is the Magwood reactor hall basement known as room three Oh five, two. It's in tomb, deep, under hundreds of tons of highly radioactive steel and concrete rubble. And it contains a congealed mixture of highly radioactive melted lava, including about 170 tons or 95% of the number four reactors uranium fuel load, as well as the fuel rods or conium cladding, the graphite control rods and hundreds of tons of sanding concrete, which was dumped on at the core to try and extinguish the fire.

The deadly black molten lava mixture that's resulted slowly oozed into the basement. After the meltdown, computer modeling suggests that [00:23:00] neutrons in the lava, a splitting uranium nuclei causing fission to take place the specter of self-sustaining Fision or criticality in this highly radioactive ruin has long haunted scientists.

So what's gone on. Well it's thought the giant sarcophagus hardly constructed over the reactor site. After the explosion was riddled with holes, allowing water to seep in, and that water moderated neutron reactions in the uranium lover. However, a far more massive concrete instilling casement is now in term of the entire number four reactors site.

And that's prevented further water seepage and with the water level and the basement dropping there is nothing to sufficiently slow the neutrons down. And it's that, which their fear is causing the increases in radiation. On the other hand, once the water dries up completely, the neutrons will be moving too fast to be captured, and that should prevent fishing from occurring for now.

However, the radiation continues to seep out and levels continue to increase. Now [00:24:00] it's important to point out that there's no chance of a repeat of the 1986 explosion with center radioactive cloud over much of Europe. However, there are concerns that the fission reaction now underway and the wreckage will accelerate exponentially.

And that could lead to a smaller, uncontrolled, explosive reaction, which could bring down unstable structures inside the sarcophagus spreading a massive cloud of radioactive dust. Scientists are looking at a couple of possible solutions. One would involve drilling into the basement and then spraying the entire area with the neutron absorbers, such as ghetto lineage.

Another option would involve developing a robotic drill, capable of withstanding the intense radiation long enough to drill directly into the lava itself and insert a series of boron control rods in order to restrict the neutrons activities, whatever happens for now and for the foreseeable future, the number four reactive side at Chernobyl will remain the deadliest place on earth.

[00:25:00] As the horrific COVID-19 death toll and infection rate continues to spiral across India scientists. They're working to try and understand the Corona virus variants now circulating across the subcontinent, the countries recording some 400,000 new infections every day. Taking the Tuttle from this ferocious latest wave to more than 22 million.

A report in the journal nature claims there's growing evidence that a new variant known as B one six one seven, which was first detected in India might be more transmissible and better at evading immunity than other variants. The studies are also suggesting that this Indian variant might be causing more severe disease.

Almost three and a half million people have now been killed by the COVID 19 Corona virus with another 160 million infected since the deadly disease first emerged in Warhammer, China and was spreading around the world. The earliest known yeah, liberate burial by modern humans in Africa has been discovered with the [00:26:00] body of the young child and researchers have named Metallica, which means childhood Swahili.

A report in the general nature is dated Totos burial in a cave in Kenya to around 78,000 years ago, with the arrangement of the bone fragments, suggesting that two and a half to three year old was buried on its side in a fetal position. Anthropologists found the body was covered in dirt from the cave floor, and it appears to have been rapidly covered, would suggest that it was a burial.

Sad to say this burial shows clear differences from those of, in the NFL's and early modern humans in Eurasia providing new insights into the evolution of homo sapiens in Africa. Yeah. And do you study as well that people are consuming up to four milligrams of plastic for every 100 grams of rice. They ate with that number jumping up to 13 milligrams per serve for instant rice.

Findings by scientists from the university of Queensland is the first to quantify levels of microplastics and rice. But there is some good news, a report in [00:27:00] the journal of hazardous materials found that washing rice, before cooking reduced plastic contamination between 20 and 40%, it's been revealed that the late Prince Philip, the Duke of Edinburgh had a keen interest in aliens.

UFO's. Cementum from Australian skeptic says, then you shouldn't be a big surprise as members of the Royal family have also shown interest in things like home. Apparently he did. They, the truth can be revealed. Royal family is not particularly well-known for being the most scientifically literate. They have been certainly Prince Phillip.

And I think the queen as well has been supporters of a certain amount of alternative medicine, cures and things like that. But Prince Philip apparently had a big belief in. UFO's aliens had some stuff. He was a subscriber to a magazine called flying social review. He had lots of books on extraterrestrial and campus and that sort of stuff.

And it was, it was a big thing for him. He used to write to a famous, a urologist UFO, ologist analytically named Timothy. Good to describe yourself as the leading authority [00:28:00] on UFO's and alien presence. And Phillip wrote to this guy good that there are many reasons to believe that extraterrestrials exist.

Because there so much evidence from reliable witnesses. Well, unfortunately the evidence from witnesses is not particularly reliable and the sightings and other manifestations are subject to a lot of dismissive debate. Did Phil to any well-known physicist about this topic? That's what I'd like to know.

It's hard to say because I mean, not that much about Phillip's personal life, but I dare say he was in touch with some scientists, et cetera, but it's often through his Eckery who was his offsider, who. Moderately he's conduit to some of these things he gave way back when this guy, the go ahead to look into any credible accounts of alien and cannabis or USI siding.

So it was a big deal. It was an ongoing thing paying for a lot of his life. Obviously he had the UFI movement where he got a boost up after the second world war and the early fifties, et cetera. And that's really when he started sort of making a lot of inquiries to Penn, apparently sort of having his beliefs [00:29:00] because the guy was a pilot.

He should have known better. Well, the thing you find that there's no guarantee that people aren't going to believe something when yes, you would hope that pilots would see more things, less prone to such things. But I mean, people keep writing, Oh, he's a policeman. He must know what he's talking about.

Policemen don't deal with Eileen. Fairly often. They have time for pilots, pilots reports saying things that they. Kind of explain them that makes it a flying saucer or an alien followers of UFOs. The Hypertherm flying saucer. Fair enough. You can blame the media for that. They're the ones who invented flying Sosa.

Um, the guy who was Arnold was a surname guy who said he saw objects moving near Mount Rainier in Washington state, I think. And that was the source of a lot of the, yeah, the mania. He didn't say. He said that he decided there was social shapes. It was something halfway. They, and that was then picked up by the media was saying though, flying sources and ever since then, that became the shape of the classic shape as these alien craft.

Now you can [00:30:00] say an identified flying object, but that implies flying implies some sort of control and identified this objects means it is a thing, but flying as a program, unidentified aerial phenomenon, which is the UAP, which is one of the other alternatives, it's a bit broader. But it can also mean I'm identified up in the sky and it's a phenomenon that could be a cloud clamped that only identified.

But you know, it's not something you can say way up there that I don't know whether it is, but it's up there and it could be way up in spice. It could be Venus. I'm sure all your, all your listeners are well aware of Venus being one of the major things. Ubiquitous. Venus. Yes. It was definitely not Venus. I want to say, Oh, you could see Venus think.

Could you, uh, Oh, it was in the way of me. Yeah. So, you know, if you look that way, you should have seen that Venus anyway. I'm sure. Um, Prince Phillip is now sort of, he she'll be able to, unfortunately we probably have going to have to wait a while to hear back from him though. He's also, he's he's uncle [00:31:00] Louis Mountbatten.

Believer in flying sources, maybe he passed on the, on the dream Mendham from Australian skeptics.

And that's the show for now. Spacetime is available every Monday, Wednesday, and Friday through Apple podcasts, iTunes, Stitcher, Google podcast, pocket casts, Spotify outcast, Amazon music bites.com, SoundCloud YouTube favorite podcasts download provider and from space-time with Stewart, gary.com space times also broadcast through the national science foundation on science own radio and on both iHeart, radio and tune in radio.

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## What is antimatter and why does it matter?

The place is England. The year is 1928. One of the founding theorists of quantum mechanics, Paul Dirac, is scratching his head because solutions to his equations have yielded unexpected results. For the solutions to make sense, he reasons, there must be a particle that has the mass of an electron but the opposite charge. At the time, such a thing was not known to exist.

Several years pass before American physicist Carl Anderson observes a "positive" electron, or positron that confirms Dirac's prediction.

Almost 80 years later, positrons and other antiparticles are still studied to try to answer fundamental questions about the universe and the matter it contains. Antimatter, as the name implies, can be described as the opposite of ordinary matter. Every particle in the universe has characteristics such as mass and charge. With antimatter, the mass remains constant, but the sign of the charge is reversed. All particles have an antimatter counterpart, even the chargeless neutron (Its constituent quarks do have a charge the antineutron is composed of antiquarks).

Unlike matter, antimatter is not common. Unless you're in the upper atmosphere, or inside a particle accelerator, you're not going to stumble across it. "Antimatter was not always so rare," Stéphane Coutu, Penn State particle physicist says. There was a time when it was as prevalent as matter itself. "Right after the Big Bang," Coutu explains, "we believe there must have been exactly the same amounts of matter and antimatter…and yet owing to some small asymmetry in the laws of particle interactions, all of the antimatter and most of the matter in the early universe was annihilated. We are left today with the resulting matter-dominated universe." So the study of matter-antimatter interactions is a glimpse at the first few moments of a nascent universe.

To conduct his antimatter research, Coutu sends sophisticated detectors to the edge of the atmosphere on high altitude balloons. He looks for antimatter in the cosmic radiation that rains down upon the earth. This antimatter sprinkle can be a signature for all sorts of particle interactions that occur within our galaxy.

Some physicists, instead of observing antimatter produced via nature, study it by making their own in a particle accelerator. When ordinary particles are accelerated to very fast velocities and then collide with each other, Coutu explains, antiparticles can be borne out of the ensuing high-energy explosions. These antiparticles are short lived, however, and invariably meet their ordinary-matter match in a destructive process called annihilation.

Annihilation doesn't mean that the particles completely disappear, it just means that their energy is transferred to a different form, he adds.

Science fiction is rife with tales of high-energy particle annihilation, and indeed, antimatter weapons have appeared in current bestselling novels. This is unrealistic, Coutu says. "[It] would be very impractical owing to very great difficulties in producing and maintaining significant amounts of antimatter."

Technology that uses the properties of antimatter is actually feasible outside of science fiction, however. Positron emission tomography (PET) is a medical technique that can be used to detect cancer, measure blood flow and detect coronary artery disease. In PET scans, "a small amount of radioactive substance is injected into a person, which produces positrons upon decaying within the body," Coutu explains. "By detecting the high-energy photons (gamma rays) produced in the annihilation of positrons with electrons in the body, a map can be made of where the substance has spread within the body." While antimatter may never be used as a bomb, it certainly has a positive future in life-saving medical diagnostic tools, the anti-weapon.

## Is antimatter present on Earth? - Astronomy

Could Earth’s ring of antimatter power spacecraft?
KEITH COOPER
ASTRONOMY NOW
Posted: 19 August 2011

A belt of antimatter has been discovered circling the Earth, which in future could be used to fuel voyages that race at breakneck speeds to other planets in the Solar System.

Antimatter has properties that are opposite those of normal matter – for example the positive charge on a proton is negative in an antiproton. When antimatter and normal matter come into contact, they annihilate spectacularly, releasing energy. The Italian-run PAMELA (Payload Antimatter Matter Exploration and Light Nuclei Astrophysics) satellite, launched in 2006, has found thousands of times more antiprotons than expected in a region of the innermost Van Allen radiation belt called the South Atlantic Anomaly. The anomaly appears to be a concentrated region of a much larger antimatter belt, and is the point at which the innermost radiation belt is nearest the Earth’s surface (an altitude of about 500 kilometres) and Earth’s magnetic field lines, which confine the belts, are at their weakest.

An artist’s impression of an antimatter powered spacecraft. Such craft would be capable of making the round trip to Jupiter in just one year. Image: NASA.

James Bickford, the senior member of the technical staff at Draper Laboratory in Cambridge, Massachusetts, USA, has calculated that Earth’s antimatter belt contains 160 nanograms of antiprotons. This in itself doesn’t sound much – pure annihilation of this antimatter would produce just ten kilowatt-hours of energy – but it dwarfs the amount of antimatter that we can create in particle accelerators on Earth. (As an example, the Fermi National Accelerator Laboratory in Illinois, USA, would take an entire year, running up costs of millions of dollars, to create just one nanogram of antiprotons if the lab was used exclusively for that purpose.)

The antiprotons are produced via Earth’s interaction with incoming cosmic rays from beyond the Solar System. Cosmic rays are charged particles moving at close to the speed of light, ejected from phenomena such as supernovae and their remnants. When they encounter Earth’s atmosphere they collide with atmospheric molecules and decay via pair production into antiprotons and antineutrons. Because of their charge, the antiprotons are trapped on the magnetic field lines in which they form those that form deeper into the atmosphere quickly annihilate with a particle of normal matter. However, antineutrons with no charge can escape back into space where they decay into antiprotons and become trapped in Earth’s magnetic field at much greater altitudes, where they can survive for years.

PAMELA discovered an over-density of antiprotons within the 60� MeV energy range contained within the South Atlantic Anomaly, but this may only be the tip of the iceberg.

“PAMELA’s orbit is limited to altitudes between 350� kilometres and the antiproton radiation belt is expected to extend up to thousands of kilometres,” says Alessandro Bruno, a co-author on a paper describing the results that will appear in Astrophysical Journal Letters. “Some of these particles are produced in the confinement region of the magnetosphere and become trapped, especially in the exosphere where the density is low enough to allow antiprotons to be gathered, since losses due to annihilation or ionisation are significantly reduced.”

A simplified version of Earth’s magnetic field. Earth acts like a bar magnet, with an internal magnetic dynamo generated in its molten iron core that produces a magnetic field that enshrouds our planet. The Van Allen radiation belts are rings of charged particles trapped within the magnetic fields above our heads. It is within these belts that the antiproton belt has been discovered. AN graphic by Greg Smye–Rumsby.

What practical use is 160 nanograms of antimatter spread hundreds to thousands of kilometres above our heads? Dreams of science fiction have depicted spaceships running on antimatter reactions, but Bickford, as part of a study for NASA’s Institute for Advanced Concepts (see here for more), has looked at how antiprotons could instead instigate nuclear fission reactions to produce the energy to propel a spaceship. For example, 30 nanograms of antiprotons collected from the radiation belts around Earth would be sufficient for a nuclear powered spacecraft to reach Mars in just 45 days, compared to the nine months that it will take NASA’s Curiosity rover after it blasts off this November. The trick, however, is catching the antimatter in the first place.

Bickford envisages something called a plasma magnet. It would be installed on the space vehicle, which would have to orbit Earth, fuelling up as it passes through the antimatter belts (alternatively, a craft could dock with an orbiting fuel depot that does the same thing). An electric current running through four giant 100-metre loops, arranged perpendicular to one another, would create a rotating magnetic field that induces another electric current in a surrounding plasma (ionised gas) that creates a second, stronger magnetic field that traps and stores the antiprotons. “When you want to turn the engine on and annihilate the antiprotons, you would have them collide with a dense target near the high strength region of the magnetic field,” says Bickford. This induces a fission reaction of the atoms within the target, generating energy that can be used to power the ship. “Under the correct conditions [the magnetic field gradient] will act like a nozzle and propel the vehicle forward.”

In his NASA report, Bickford speculates that missions not just to Mars but Jupiter (10 micrograms of antiprotons would be sufficient to fuel a 100 ton payload on a one-year round trip to the giant planet), or fast missions to the ‘heliopause’ at the edge of the Solar System (only just reach by the Voyager spacecraft after three decades) or to the Sun’s gravity focus point (550 times further from the Sun than the Earth, from where distant light magnified by the Sun’s gravity in a gravitational lens focuses would create a giant natural telescope) would be feasible. Although there isn’t enough antimatter around the Earth to power all these missions (it replenishes at a rate of two nanograms per year) it could fuel some prototype spacecraft, while other planets could also be mined for their antimatter – Bickford’s report states that Saturn is the most copious producer of antiprotons, with 240 micrograms per year. Antimatter could ultimately be used to fuel flights to nearby stars such as Alpha Centauri, and could be of use to starship designs such as Project Icarus, which is a long-term joint venture by the British Interplanetary Society and the Tau Zero Foundation. However, it’s going to take a long time before we are in a position to harness the power of the antimatter belts.

There are so many issues involved in antimatter as a potential propulsion technology that right now solar sails, laser and microwave beaming and nuclear rate ahead of it in the feasibility arena,” says journalist Paul Gilster, who runs the Centauri Dreams website that is affiliated with the Tau Zero Foundation, of which he is a director. “This is not to say that it’s not an extremely promising idea, given how much energy is unlocked when matter and antimatter annihilate each other, but the antimatter belt near Earth provides nowhere near enough antimatter for an Icarus-style mission. Here we are talking about just enough antimatter to ignite a fission or fusion reaction for a mission within the Solar System.”

Bickford agrees. “There is a significant amount of overhead associated with doing this for the first precursor interstellar missions,” he says. “In contrast, there are still many missions within our Solar System that are much easier to complete that would not need the level of infrastructure development that we’re talking about here. I suspect people will focus on these options first.”