Antimatter is the inverse state of normal matter.When the antimatter meets the antimatter, the two sides will meet each otherAnnihilationOffset, explode and generate huge energy.
Positrons and negative protons are antiparticles. Compared with the so-called electrons and protons, they have the same electric quantity but opposite electrical properties.Scientists imagine that there may be matter completely composed of antiparticles in the universe, that is, antimatter.Electrons and antielectrons have the same mass, but have opposite charges.The same is true of protons and antiprotons.Particle and antiparticle not only have opposite charges, but also have opposite properties.
Zhao ZhongyaoHe was the first physicist to discover antimatter in the history of human physics and observed the annihilation of positron and electron pairs.[9]
Positrons and negative protons are antiparticles. Compared with the so-called electrons and protons, they have the same electric quantity but opposite electrical properties.Scientists imagine that there may be matter completely composed of antiparticles in the universe, that is, antimatter.
Electrons and antielectrons have the same mass, but have opposite charges.The same is true of protons and antiprotons.What is the difference between the properties of neutrons and antineutrons?In fact, particle experiments have confirmed that particles and antiparticles not only have opposite charges, but also have opposite properties.Here we will discuss the concept of baryon number.
Protons and neutrons are collectively referred to as nucleons.From the study of nuclear phenomena, people found that protons can be converted into neutrons, and neutrons can also be converted into protons, but before and after the conversion, the total number of nucleons in the system is unchanged.For example, when beta decay occurs, those that emit positrons are called "positive beta decay", and those that emit electrons are called "negative beta decay".In the positive beta decay, a proton in the nucleus is converted into a neutron, releasing a positron and a neutrino at the same time;In the negative beta decay, a neutron in the nucleus turns into a proton, releasing an electron and an antineutrino at the same time.In addition, electron capture is also a kind of beta decay, called electron capture beta decay.
Particle experiments since the 1950s have shown that there are still many kinds of particles heavier than nucleons, which belong to the same category as nucleons. This kind of particles was renamed baryons, and nucleons are only the lightest representative. The general rule is that when particles transform through interaction, the number of baryons in the system will not change.
Because of the conservation of baryon number, the collision of two protons will not produce a system containing three baryons, so how should anti nucleons be produced?Experiments show that antinucleons are always produced in pairs with nucleons in collisions.For example, p+p → N+N+N+N+N '+several π mesons, where N represents proton or neutron, and N' represents antiproton or antineutron.Once an antinucleon is produced, it often collides with a nearby nucleon and annihilates in pairs.for example
N+N '→ several pions.According to this argument, there must be an antimatter world somewhere in the universe.If the antimatter world really exists, then it can only exist if it does not meet with matter.But how can matter and antimatter not combine?Where is antimatter in the universe?This is still a mystery to be solved.
For baryons heavier than nucleons, the situation is exactly the same.Anti baryons are always born and annihilated in pairs with baryons.These experiences make people realize that the conservation law of baryon number needs to be re understood.Baryon number B is regarded as an electric charge describing the properties of particles.The positive and negative baryons not only have opposite charges, but also have opposite baryon numbers B.If any baryon has the baryon number B=+1, then any anti baryon has B=- 1.Non baryons such as mesons, leptons and gauge particles do not have baryons, that is, they have B=0.The conservation law of baryon number can be expressed as: any particle reaction will not change the total baryon number B of the system.This statement not only reflects that the number of baryons does not change when antiparticles are not involved, but also generalizes the paired production and annihilation of antiparticles and particles.We can easily understand the difference between neutrons and antineutrons. They have the opposite baryon number B. Therefore, antineutrons can collide with nucleons and cause annihilation, while neutrons cannot.
In addition, people also found the conservation of lepton number similarly.Although neutrinos are not charged and have no baryon number, they have the opposite number of leptons to anti neutrinos.According to the conservation of lepton number, the physical behavior of neutrinos and anti neutrinos is also very different. Experiments also show that the meson number and gauge particle number are not conservative.In this way, we can see that charge is only an attribute of particles, and there are other attributes described by physical quantities such as baryon number and lepton number.These attributes of positive and negative particles are also opposite.In 1928, British young physicist Dirac theoretically demonstrated the existence of positrons for the first time.This positron has all the same properties as an electron, except that its electricity is opposite to that of an electron.In 1932, American physicist Anderson discovered the positron predicted by Dirac in his laboratory.In 1955, American physicist Seagrey et al. obtained antiproton by artificial method.Since then, people have gradually realized that not only protons and electrons, but also all microscopic particles have their own antiparticles.
This series of scientific achievements make people increasingly close to the antimatter world.However, the problem is not so simple.First, antimatter is hard to find on Earth.Because particles and antiparticles collide, just like ice meets fireball, or disappear together, or change into other particles.So on Earth, antimatter will be absorbed once it meets other substances.Secondly, it is difficult and costly to manufacture antimatter, requiring high-tech instruments such as SSC or LHC, and even if antimatter is produced, it is difficult to preserve it, because everything on earth is made of matter.
The macroscopic matter around us is mainly composed of protons and neutrons with positive baryonic number.Therefore, such matter is called positive matter, and the matter composed of their antiparticles is correspondingly called antimatter.From the point of view of particle physics, the properties of positive particles and antiparticles are almost completely symmetrical. So why is there a lot of positive matter in nature, but almost no antimatter?This is exactly what we want to discuss.
Antimatter is the mirror image of normal matter. Normal atoms are made up of positively charged nuclei, while negatively charged electrons are outside the nuclei.However, the composition of antimatter is completely opposite. They have positively charged electrons and negatively charged nuclei.Fundamentally, antimatter is a form of inversion of matter.Einstein once predicted the existence of antimatter according to the theory of relativity: "For a matter with mass m and charge e, there must be a matter with mass m and charge e (i.e. antimatter)".According to physicists' hypothesis, at the beginning of the birth of the universe, there was an equal amount of matter and antimatter, and once they came into contact, they would annihilate each other to offset, explode and generate huge energy.However, for some reason, today's world is mainly composed of matter, and antimatter seems not to exist in nature at all.The problem of the asymmetry of matter and antimatter is a big challenge facing the physics community.[1]
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In the view of most theorists, the large-scale separation of matter and antimatter in the universe is impossible.Therefore, there is no antimatter object within the range of 30 million light years, which has shown that there is no massive antimatter in the universe.But theorists also believe that the amount of positive and negative matter in the very early universe should be equal.In this way, what needs to be done is to find a physical mechanism to explain how the universe can transition from a state of equal amount of positive and negative matter to a state of positive matter dominated.Here, theorists have also encountered very acute difficulties.
according toBig Bang TheoryThe temperature of the very early cosmic medium was very high.Thermal collisions between particles produce any elementary particles in pairs.When the pair annihilation and pair production of particles reach a statistical balance, the cosmic medium is the mixed gas composed of all basic particles, and any stable or unstable particle has nearly equal number density.Whether the number of baryons and antibaryons is strictly equal is not determined by physical laws, but by the initial conditions.
In the view of theorists, the positive and negative particles in the original universe should be equal in quantity to be natural.But it is easy to see that if this idea is correct, the conservation of baryons will immediately give a deduction that is obviously inconsistent with the facts.When the expansion of the universe causes the temperature of the gas to drop below 10 ^ 13K, because the thermal dynamic energy of the particles is not enough, it is impossible to generate baryons in pairs by thermal collision.thereforeAnnihilationThe process will make the number of positive and negative baryons decrease rapidly at the same time.In the end, there will be neither baryons nor anti baryons in the universe.This is obviously not a real cosmic scenario.In fact, there are the most photons in the universe today.The number of baryons is about one hundred thousandth of its number, and the number of antibaryons is probably many orders of magnitude lower.If the conservation of baryon number B is a strict physical law, it is impossible for the universe to evolve from a state of equal quantity of positive and negative baryons to today's state.Then, theorists can't believe that baryons would be more than anti baryons in the original universe, so where is the way out?
Is the conservation of baryon number a strictly valid physical law?It is true that the experiment of uncountable particles has not found a case of breaking the conservation of baryon number, but this does not mean that it must be a strict law.A review of the development of chemistry can be used for reference.Chemical reaction is the recombination of elements.Experience shows that the atomic number of each element is conserved before and after recombination, and countless chemical practices show that there is no exception.The failure of alchemy to transform mercury into gold has proved the opposite.But with the knowledge of nuclear reaction, people have clearly known that it is possible for mercury to become gold. The key is to have high energy to change the atomic nucleus.The chemical reaction is carried out under the condition that the particle energy is less than 1MeV. Under this condition, the atomic nuclei cannot contact each other, and the nuclear reaction cannot occur.If the energy of particles in the process exceeds 1MeV, the atomic nuclei can be sufficiently close to each other, then the atomic nuclei can change, and the conservation of atomic number will be destroyed accordingly.From this point of view, the conservation of atomic number in the chemical process is not accidental, but it is only a phenomenological law under low energy, rather than a universal natural law.Using the same principle for reference, the conservation of baryonic numbers may only be a phenomenological law in a certain energy range, rather than a universal law.When the energy of particles is higher, the conservation of baryonic number may not hold, which is exactly the way out that theorists today see.
Since the mid-1970s, the success of the unified theory of weak electricity in particle physics has set off a trend of studying interaction.According to this theory, the process of breaking the baryon number conservation at high energy is natural. This trend in particle physics coincides with the need of cosmology to solve the problem of asymmetric matter and antimatter.As a result, this difficult problem has made a lot of progress as the cross field of particle physics and cosmology.It has been clear that in order to evolve from the early universe with the same amount of matter and antimatter to the state dominated by today's matter, in addition to the possible destruction of the conservation of baryon number, there must be an appropriate amount of difference in the interaction properties of positive and anti particles.Since the laws of particle physics at ultrahigh energy have not yet been mastered, whether the nature really has these two elements is still unanswered. People are exploring and groping. If it is true that there are only positive matter objects in the universe today, whether the problem can be solved according to this idea is not completely certain.
In short, there is still a long way to go in order to completely reveal the mystery of cosmic antimatter.It can be expected that the solution of this problem is not only important for understanding the universe, but also will have a profound impact on physics.[2]
Research History
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Research History
The various macroscopic objects in nature are restored to their microscopic origins, and they are all created byproton、neutronAnd electrons.These particles are therefore called elementary particles, meaning that they are the basic bricks that make up everything in the world. In factElementary particleThe world is not so simple.In the early 1930s, someone discovered that the positively charged electronSubatomic particle]This is the first step for people to understand antimatter.In the 1950s, with the discovery of antiprotons and antineutrons, people began to clearly realize that any basic particle has a correspondingAntiparticleExists.
Antimatter is the inverse state of normal matter.When the positive and anti matter meet, the two sides will annihilate each other to offset, explode and generate huge energy.The energy release rate is much higher thanHydrogen bombExplosion.stayDan Brown's novel《Angels and Devils》The terrorists tried to steal 0.25 grams of antimatter from the European Nuclear Center, and then wanted to blow up the whole buildingVatican City(Finally, it explodes at high altitude).
But as for the 50 millionth gram of large-scale facilities destroyed and several grams of antimatter destroyed the earth spread on the Internet, it is just a rumor. It is just a fake news fabricated by online news to increase attention.The annihilation of 50 millionth of a gram of antimatter and positive matter can release 3.6 × 10 in physicssixJoule energy, but it is impossible to destroy large facilities.However, 1 gram of antimatter (calculated by annihilation of 1 gram of antimatter and 1 gram of normal matter) annihilates and releases 1.8 × 10fourteenJoule energy cannot destroy the earth.Their complianceEinsteinMass energy relation of E=mctwo。Where E is the energy generated by annihilation, m is the total static mass of participating positive matter and antimatter before annihilation, and c is the speed of light ≈ 3x10eightMeters per second.
The concept of antimatter is a British physicistPaul Dirac First proposed.In 1928, he predicted that every particle should have an antiparticle opposite to it, such asAntielectron, its mass is exactly the same as that of the electron, while the carrying charge is just the opposite (A).AntielectronicSpin quantum number- 1/2 instead of positive 1/2.
European Space AgencyThe existence of antimatter in the universe was confirmed by the Gamma Ray Astronomical Observatory.They made a careful observation and analysis of a region in the center of the universe.It is found that there is a large amount of antimatter in this area.In addition, the gamma ray astronomical observatory also proved that these antimatter sources are many, and they are not gathered around a certain point, but widely distributed in the universe.
Search process
1995European Centre for Nuclear ResearchScientists in the laboratory produced the world's first batch of antimatter——Antihydrogen atom。In 1996, the Fermi National Accelerator Laboratory in the United States successfully produced seven antihydrogen atoms.
In April 1997, American astronomers announced that they used gamma raysExploration satelliteFound onGalaxyThere is an antimatter source that continuously ejects antimatter about 3500 light years above, and the antimatter ejected by it forms an "antimatter fountain" up to 2940 light years.Since China has participated in this research, the news media have enthusiastically publicized it.Famous Chinese American scientistDing ZhaozhongWe are also committed to this.
On June 2, 1998, the US space shuttle Discovery launched with an alpha magnetic spectrometer.Alpha magnetic spectrometer is an instrument specially designed to find antimatter in the universe.However, this flight did not find antimatter, but collected a lot of valuable data.
On September 18, 2000, CERN announced that it had successfully produced about 50000 low-energy antihydrogen atoms, which was the first time that humans had produced large quantities of antimatter under laboratory conditions.
If we believe that there is an equal amount of matter and antimatter in the universe, then there should be a large area of anti galaxy regions 30 million light years away.There, the original cosmic rays should beAntiprotonAnd anti alpha particles.Some cosmic ray particles there will fly into our region of positive matter.Because most of the intergalactic space is empty, the density of gas is only about one proton per cubic meter.Therefore, anti atomic nuclei can fly freely for a long distance.In this way, the magnetic spectrometer placed outside the earth's atmosphere can receive it.This is it.Alpha magnetic spectrometerBasic idea of the plan.
As mentioned above, what is actually measured is not only the original ray particles, but also the secondary particles generated by the mid collision.Therefore, when we find antiprotons in cosmic rays, it does not mean that there must be an antimatter celestial region in the distance.These antiprotons are completely secondary.Antinuclei are different.It is a complex composed of several antinucleons, so it cannot be a secondary particle produced by collision.Therefore, if only one anti alpha particle can be observed from cosmic rays, it will be strong evidence that there is an antimatter object in the distance.The alpha magnetic spectrometer can simultaneously and accurately measure the mass and charge of particles flying into the instrument.When there are anti alpha particles flying into the magnetic spectrometer in space, it is easy to be identified.This is exactly what the designer expected.The Alpha Magnetic Spectrometer was launched in 2011, and the information it received is being sent back one after another. The results are undoubtedly very interesting.
If the observation of Alpha Magnetic Spectrometer confirms that there is a huge antimatter region in the distance, it must be a milestone achievement.Its significance is not only to confirm the existence of antimatter objects in the universe, but more importantly, it poses a serious challenge to physics.In the early universe, positive and negative particles must be mixed.According to the existing physical theory, no known force can make them separate in a large range.Therefore, if the observation confirms that there is indeed a large number of antimatter separated from the distance, physics will need a breakthrough change.
If there really is mysterious antimatter in the universe, where are they?The reporter learned from the Institute of High Energy Physics of the Chinese Academy of Sciences that in order to solve the mystery of this century, China and Italy will build the world's first 10000 square meter "carpet" type particle detection array experimental station in the Yangbajing area of Tibet, 4300 meters above sea level, to receive high-energy rays and antimatter particles from the universe.
According to Dr. Lu Hong, a researcher in the Astrology Laboratory of the Institute of High Energy Physics, cosmic high-energy rays are the only material samples that humans can obtain from outside the solar system.For a long time, it has been the research object for scientists to explore the mysteries of the universe.Since the appearance of the Big Bang theory, scientists have been working hard to find the mysterious antimatter from cosmic rays.But so far, scientists have failed to find traces of antimatter.
It is understood that Chinese and Italian scientists have set up particle detectors with scattered appearance like beehive in Yangbajing area, carried out research on cosmic rays and received them successivelypositron、Muon, л meson and other high-energy particles.The new "carpet" type detection array, in addition to its larger area, is also composed of square plates like glass plates, which can be spliced like carpets with almost no gaps, making up for the shortcomings of excessive spacing and loss of information in the past.
The 10000 square meter experimental hall containing particle detection display was completed in June.Scientists from China and Italy are laying "carpets", which will take about two years.It is reported that this scientific project with the highest altitude in the world has received about 80 million yuan of support from the Chinese and Italian governments.
Discovery history
Large Hadron Collider[3]
Scientists from the European Atomic Research Center said on November 17, 2010 local time in Europe that they had captured a small amount of "antimatter" through the Large Hadron Collider.Of course, these "antimatters" are only a small number of anti hydrogen atoms, but this discovery also triggered a great response from scientists.
be locatedGenevaThe European Nuclear Research Center (CERN) has been making unremitting efforts to solve this problem.CERN has the most powerful particle collider in the world——Large Hadron ColliderThe mission of this collider is to explore the origin of the universe and look for those unproven physical phenomena that may exist.
On the 17th, researchers announced that after unremitting efforts, the Large Hadron Collider has finally found dozens ofhydrogen atom'Antimatter'.Professor Rob Thompson said: "Although the discovery is only the tip of the iceberg of antimatter, it does not affect the importance of this discovery. This is a major breakthrough, which is conducive to our better understanding of the nature and origin of the universe".
Professor Rob Thompson is right to say that the discovery of antimatter will lead to human transformation, making the dream of interstellar travel a reality.Previously, in a large number of science fiction novels, spaceships used for interstellar travel were fueled by antimatter.To take the simplest example, if you want to send humans to Mars, you need more than ten million tons of chemical raw materials. If you use antimatter as fuel, you only need dozens of milligrams. At the same time, the time is also greatly shortened. It only takes six weeks to reach.
The new research will be published in the journal Nature. It also includes the important role played by CERN experts in this process, and discusses whether these scientific discoverers play the role of angels or demons.Professor Charlton from Swansea University in England finally made his own statement on this discovery: "The universe is basically monopolized by ordinary matter now, but we must understand the whole picture of the universe, otherwise we may be in danger but completely unaware that hydrogen is the most important element in the universe, and it is of great significance to discover its antimatter."
britainAccording to the research report published on the website of Nature on the 17th, scientists from the European Center for Nuclear Research (CERN) have successfully produced several antihydrogen atoms and used magnetic fields to make them exist for "a long time".This is the first time that scientists have successfully "caught" antimatter atoms.
The hydrogen atom is the simplest atom with only one proton and one electron.In fact, CERN produced the first antihydrogen atom as early as 1995, but it only lasted a few microseconds to collide with the positive hydrogen atom in the surrounding environment and annihilate.The breakthrough of this time is that after several antihydrogen atoms were manufactured, they successfully existed for the first time for a "long time" - about 0.17 seconds with the help of a special magnetic field.
This time seems to be still very short, but for scientists, this time length is very rare, and can conduct more in-depth observation and analysis of anti hydrogen atoms.Therefore, this achievement is regarded as a breakthrough in the field of physics, which will greatly promote the research on antimatter.
The Large Hadron Collider will have to collide for 1000 years to produce a microgram of antimatter.To get enough antimatter, several planets must be developed.Build giant particle accelerators around the whole planet.
Antimatter is a form of matter unfamiliar to human beingsParticle physicsIn, antimatter is an extension of the concept of antiparticle, and antimatter is composed of antiparticles.Antimatter and matter are opposite, just as particles and antiparticles combine, causing them to annihilate and releaseHigh-energy photonOr gamma rays.In 1932, Carl Anderson, an American physicist, confirmed thatpositronThe exists of.Then I found outNegative protonOpposite to spinAntineutron。So far, more than 300 kinds of basic particles have been found, all of which exist in pairs, that is, any particle may have antiparticles. On November 17, 2010, European researchers successfully "caught" trace antimatter for the first time in the history of science.In early May 2011,University of Science and Technology of ChinaCooperated with American scientists to produce the heaviest antimatter particle to date——Anti helium 4。On June 5, 2011, researchers from CERN announced that they had successfully captured the antihydrogen atom for more than 15 minutes.At the same time, there is also the dynamic energy efficiency of 'antimatter' in nature - reaction is antimatter condensation.Shanghai Institute of Optics and Fine Mechanics uses a femtosecond pulse laser device to interact with a high-pressure gas target to generate a large number of high-energy electrons. The high-energy electrons interact with a high-Z material target, and high-intensity gamma rays are generated by the bremsstrahlung radiation mechanism. The gamma rays then interact with a high-Z atomic nucleus to generate positron negative pairs.Through careful design, the positron spectrometer successfully solved the noise problem caused by gamma rays. Using the different deflection characteristics of positrons and negatives in the magnetic field, positrons were successfully observed in the experiment under single shot conditions.This is the first report of using laser to produce antimatter in China.
Some astronomers also believe that there is a possibility, but modern astronomy has not yet produced convincing evidence.There are many people who deny antimatter. The American cosmologist Schramm said: "Most theorists' intuition is that antimatter does not exist. This means that if you find it, it is a great discovery, proving that these theorists are wrong. But most probably, it means that you cannot find it."
The research led by Ding Zhaozhong has involved scientists from 16 countries, and the investment has reached more than 100 billion US dollars.Many scientists said that as long as the existence of cosmic antimatter can be found, it will be a well deserved Nobel Prize.The probe was launched in 2005 and stayed in space permanently. Southeast University will also establish a data receiving and analysis center and training center as supporting projects.Ding Zhaozhong believes that if antimatter does exist, it can generate huge energy when positive matter collides with antimatter.His research on "searching for dark matter and antimatter in the universe" has been carried out for many years and has achieved some important results."However, from the history of the development of this field, people should be prepared. Maybe we will find something unexpected that has nothing to do with what we originally wanted to study." Ding Zhaozhong said cautiously.
First capture of antimatter in nature
On November 17, 2010, some media said that antimatter was captured by human for the first time, and the energy of 500g could exceed that of hydrogen bomb.European scientists have successfully produced a number of anti hydrogen atoms and made them exist for 0.17 seconds, which is a breakthrough discovery in physics and the first time that humans have captured antimatter.The destructive power of 500g antimatter can exceed the world's largest hydrogen bomb.
Antimatter is still a big puzzle in the field of physics.The matter in our environment is positive matter, which is composed of atoms, which are composed of positively charged protons, negatively charged electrons and neutral neutrons.In contrast, the negativeprotonAnd positively chargedElectronicsThe constituent matter is antimatter.As long as antimatter meets normal matter, it will annihilate. Therefore, although the current theory believes that the universe produced the same amount of positive matter and antimatter when it was born from the Big Bang, it is difficult for us to find antimatter in the universe.Therefore, the search and research of antimatter has become a hot and difficult point in the field of physics.
Antimatter, the opposite state of normal matter, is extremely unstable and hardly exists in nature.The researchers made antimatter in the laboratory, but the antimatter annihilated as soon as it touched the wall of the container.If you can't catch it, you can't study it in depth.
According to a report released on the website of the British journal Nature on the 17th, European researchers successfully "caught" trace antimatter for the first time in the history of science.
"Grasp" for the first time and ingeniously set up "magnetic bottle" to overcome annihilation
Researchers created antihydrogen atoms in a vacuum environment in 2002, but they were annihilated within a short time.Now, for the first time, CERN researchers have successfully "caught" this antimatter.
Since antimatter disappears when it touches the wall of the container, researchers use special magnetic fields to capture antimatter.
Speaking of this invisible and intangible way of capture, Professor Jeff Hunt of Aarhus University in Denmark told the BBC that anti hydrogen atoms have "a little magnetism".
In addition, the anti hydrogen atom cannot move too fast, or it will be difficult to capture.Hunt's research team spent five years trying to reduce the temperature of the antihydrogen atom to 0.5 degrees Kelvin, which is equivalent to minus 272.65 degrees Celsius, or close to absolute zero, so that the antihydrogen atom is in a low energy state.
"If they don't move too fast, they will be 'caught'," Hunt said.
Theoretical calculation shows that 500g antimatter exceeds hydrogen bomb
In his best-selling book Angels and Demons, Dan Brown described antimatter as the most powerful energy source known to human beings.It can release energy with 100% efficiency, without pollution or radiation. A small "drop" can maintain the energy required by New York all day long.
Theoretically, the destructive power of less than 500g antimatter exceeds that of the world's largest hydrogen bomb.
However, for the first time, the researchers captured 38 antihydrogen atoms with a duration of one fifth of a second.This amount of antimatter is not enough to make a 100 watt bulb glow for 2 billionths of a second, let alone be used as a violent explosive.
Professor Hunt explained that after researchers master the technology of capturing antimatter, they can "fine tune" the specific operating procedures in the future, which is expected to produce enough antimatter with a long enough storage time, opening the door for further research.
Prospects help to solve the mystery of the origin of the universe
Einstein predicted the existence of antimatter.It explodes and generates huge energy.
The discovery of antimatter reminds people of many unsolvable mysteries of the last century, the most famous of which is“the Tunguska event ”。In the early morning of June 30, 1908, RussiaSiberiaTunguska region was hit by a "fireball" falling from the sky, and a large area of primitive forest was instantly reduced to ashes.As for the cause of the explosion, some people speculated that it was an asteroid impact, and some people speculated that it was an "annihilation" caused by antimatter.
The in-depth study of antimatter is an important part of solving the mystery of the origin of the universe.
"We hope to find out whether there are some differences between matter and antimatter that we don't know yet," said Hunt. "This difference may exist at a more basic level, or it may involve some high-energy activities at the time of the origin of the universe."
"That's why it's so important to 'catch' them (antimatter), because we need time to study them."
。Antimatter research is of great significance in high-energy physics, cosmic evolution and other aspects, and also has important applications. For example, positron emission tomography (PET) has been widely used in cancer diagnosis and other aspects.
Dynamic development
Mysterious "antimatter" may become mankind's "doomsday weapon".Through the Large Hadron Collider, they have captured a small amount of "antimatter", although only a small amount of antihydrogen atoms, but it has been regarded by the scientific community as a major breakthrough in the process of human antimatter research.
Time to live is key
In fact, as early as 1995, CERN produced nine antihydrogen atoms for the first time.However, as long as the antihydrogen atom meets the positive hydrogen atom in the surrounding environment, it will annihilate. Therefore, the antihydrogen atom created in the laboratory is fleeting, and scientists have no way to study its true nature.In 2002, the experiment of CERN further showed that antihydrogen atoms can be manufactured in large quantities, but how to make them last longer is still a problem.
Therefore, the breakthrough of this experiment is that 38 artificially manufactured anti hydrogen atoms exist for about 0.17 seconds.This time may seem very short to ordinary people, but for scientists, it has been substantially longer than before, enough for them to conduct more in-depth observation and research.
Use magnetic field as "trap"
CERN said that the reason why the antihydrogen atom could be captured for 0.17 seconds this time was due to a specialmagnetic field。 In the laboratory, antihydrogen atoms are produced in a vacuum environment. Normally, they will annihilate and disappear with positive matter in an instant.This powerful and complex magnetic field will "delay" like a trap, making the contact between antihydrogen atoms and positive matter slightly delayed.Experiments show that using this magnetic field can extend the time of "holding" anti hydrogen atoms to the order of one tenth of a second, which is "long enough" for observing and studying anti hydrogen atoms.
In the end, CERN successfully made 38 of the thousands of antihydrogen atoms produced by CERN exist for about 0.17 seconds.
Scientists say that the reason why we choose hydrogen atom to study antimatter is that hydrogen atom only contains one proton and one electron, which is the simplest atom, so it is regarded as the best research object in the field of physics.
An important step in antimatter research
Although the antimatter atoms were only made in the laboratory and captured briefly, the scientific community was still excited and believed that this was a breakthrough in the field of physics and was "a step closer" to the "truth" of antimatter.
The British journal Nature, which published this research achievement, said that after successfully "catching" the antihydrogen atom, scientists can test the basic symmetry theory at the core of the "standard model" of particle physics by comparing antimatter and positive matter.Rolf Hoyle, director of CERN, said in a press release released on the 17th, "This is an important step in the field of antimatter research."
"Grab" antimatter for thousands of seconds
The researchers of CERN reported in the British journal Nature Physics on June 5, 2011 that they successfully "caught" the antihydrogen atom for 1000 seconds, that is, more than 16 minutes, which is conducive to accurate research on the properties of antimatter.Antihydrogen atom is the antimatter form corresponding to ordinary hydrogen atom.Antimatter and ordinary matter will annihilate when they meet, and the antihydrogen atom produced previously can only exist for a few microseconds.In November 2010, CERN successfully bound the antihydrogen atom with the "magnetic field trap" for the first time by using the weak magnetism of the antihydrogen atom, lasting 172 milliseconds.The new research published on the 5th has made a great breakthrough in the bound time.In the paper, scientists said that in this round of research, they used magnetic traps to catch 112 antihydrogen atoms, and the time ranged from 1/5 second to 1000 seconds.The analysis also shows that most of the anti hydrogen atoms seized this time are in the ground state, that is, the lowest energy and most stable state.This may be the first ground state antimatter atom produced by human so far.If antimatter atoms can exist in the ground state for 10 to 30 minutes, it can meet the needs of most experiments.
In this round of research, scientists caught three anti hydrogen atoms at most once at a time.They hope that more antihydrogen atoms can be bound for a long time to make the measurement data more accurate in statistics.Antimatter is a substance composed of antiparticles. The quality and other characteristics of antiparticles are the same as those of the particles that make up ordinary matter, but the charge and other characteristics are opposite.The hydrogen atom is composed of a negatively charged electron and a positively charged proton, while the antihydrogen atom is just the opposite, consisting of a positively charged positron and a negatively charged antiproton.
Antimatter is still a big puzzle in the field of physics.According to the existing theory, the same amount of matter and antimatter were produced in the Big Bang when the universe was born.But in the universe observed by people, matter is absolutely dominant.Studying the characteristics of antimatter atoms and comparing whether they are equivalent to ordinary atoms in physical laws may help to solve the above doubts.
Anti helium 4
The United States with the participation of several Chinese scientistsBrookhaven National LaboratoryRHIC-STAR International Cooperation Group has detected the antimatter particle of helium nucleus - anti helium nucleus.This new particle is also called anti alpha particle（Alpha particle）Is the heaviest antimatter nucleus ever detected.The research results of STAR international cooperation group were published online in the journal Nature.
Brookhaven National Laboratory, Long Island, New YorkRelativistic heavy ion collider(RHIC) simulates the big bang of the universe by using two golden nucleus collisions that are close to the speed of light, producing a material form similar to the early universe.This violent collision produces about the same amount of quarks andAntiquarkMatter and some stable antimatter can leave clear signals in the STAR detector before annihilation with normal matter.[3]
STAR cooperation group is composed of 54 scientific research institutions from 12 countries, of which the members of STAR China cooperation group includeChinese Academy of SciencesShanghai Institute of Applied Physics, University of Science and Technology of ChinaInstitute of Modern Physics, Chinese Academy of Sciences、Tsinghua University、Central China Normal University、Shandong UniversityEtc.The "Large Time of Flight Detector" (TOF), jointly funded by the National Natural Science Foundation of China, the Ministry of Science and Technology, the Chinese Academy of Sciences and the U.S. Department of Energy, and installed on the STAR detector in 2009, played a key role in the identification process of antimatter helium 4.Contact of Sino US TOF cooperation projectUniversity of CaliforniaProfessor Huang Huanzhong of Los Angeles University said: "Finding antimatter helium 4 and other exotic substances is one of the physical goals of the TOF project. We not only have completed the hardware device excellently, but this discovery has opened a good beginning for realizing the physical goal of TOF."
Ma Yugang, a researcher of Shanghai Institute of Applied Physics and convener of STAR China Cooperation Group, said that the Chinese scientists in this importantscientific discoveryAnd made outstanding contributions.On the one hand, the discovery depends on the large time-of-flight detector with excellent performance developed by the Chinese cooperation group;On the other hand, the discovery benefited from the team led by Tang Aihong (the author of the article), a physicist at Brookhaven National Laboratory, who used "high-order trigger" technology to enable us toexperimental data The collision case containing antimatter helium 4 is selected in real time from.Xue Liang, a doctoral student of Shanghai Institute of Applied Physics, and Qiu Hao, a doctoral student of Institute of Modern Physics, made outstanding contributions in the process of using this technology to find anti helium 4.[4]
National NatureScience FoundationAcademician Shen Wenqing, Deputy Director of the Committee, commented that the older generation of Chinese scientists had done a lot of outstanding work in this field during the arduous process of mankind's search for antimatter, including the late scientist Zhao Zhongyao, who observed the anti electron signs predicted by Dirac in 1930, and the research team led by Academician Wang Ganchang, who discovered anti Sigma negative hyperons in 1960.This important discovery of anti helium 4 by STAR cooperation group is another breakthrough with important milestone significance after the discovery of antimatter super tritium nucleus. In these two important scientific discoveries, the team of nuclear physicists in China played a crucial role, highlighting thatBig scienceThe importance of international cooperation in basic research.[5]
Space-time warping effect
According to foreign media reports, physicists from the University of Warwick, UK, have established a space-time model covering the whole galaxy from the perspective of galaxy rotation, aiming to explain a prominent problem in particle physics: why matter and antimatter can coexist in the universe at the beginning of the universe.This question is like a door to the ultimate mystery of the universe. Behind the door may be hidden the "secret of God".Physicists have conceived a "pure" universe: in this conceived universe, all physical laws can be applied anywhere in the universe, with strong universality.The behavior of particles and antiparticles in the universe also moves in the same way.
However, particle physics experiments in recent years have found that K mesons and B mesons show significant differences in the decay of matter and antimatter.This is an evidence called "charge parity nonconservation". The discovery of this evidence should be an "embarrassing" phenomenon for particle physicists, because after the idea of parity nonconservation under weak interaction was proposed, physicists deduced“chargeThe concept of "parity conservation" (CP conservation) cannot explain why matter exists in our universe. In other words, in theory, the same matter and antimatter are produced after the birth of the universe. We also know that matter and antimatter will annihilate when they meet. If we extrapolate from this, everything in the current universe will disappear.
britainWarwick UniversityDr. Mark Hadley of the Department of Physics believes that he has found a testable evidence of charge parity nonconservation, which can not only maintain parity, but also enable the theory of charge parity nonconservation to reasonably explain the problem between matter and antimatter after the birth of the universe.
Dr. Hadley's paper has been published on the EPL (European Physics Letters), which mainly introduces a source of CP violation (CP symmetry is broken), which is related to the asymmetry of Kerr metric.At the same time, he also believes that researchers have neglected an important effect, that is, the rotation of our galaxy will have a significant impact on the attenuation of subatomic particles.
From the point of view of particle physics, our universe is fundamentally asymmetric, and there is an obvious left and right asymmetry in the weak interaction, as well as a smaller CP symmetry violation in the K meson system.The above views have been reflected in the existing particle physics experiments, but there is no explanation.One possible reason is that the effect of the rotation of our Milky Way Galaxy has caused the distortion of our space-time, which is enough to affect the evaluation of the experimental results.And if space-time distortion is enough to affect the experimental results, can we think that our universe is fundamentally symmetric to some extent.For this "strange" prediction, CERN has been collecting relevant data to prove how much the rotation of star system affects the results.
For the effect of galaxy rotation, this is a problem that is easy to be ignored.Because we have always been in the gravitational field of the earth and the sun, this is the most direct feeling, and it is not so significant for the impact of the entire Milky Way on our human beings in some aspects.Dr Hadley believes that the gravitational field generated by the whole galaxy will make the galaxyInternal space-timeDistortion, which naturally includes the solar system, and the influence of this space-time distortion effect cannot be ignored.The speed and angular momentum of the rotation of such a massive galaxy drag the space-time inside the galaxy, resulting in the deformation of the shape of space-time and the expansion effect of time.
The rotation of the whole galaxy has a 1000000 times stronger effect on the space-time around our earth than the rotation of the earth itself.When CP violation is observed in the B meson decay, it is a key phenomenon, which helps to explain that the splitting of matter and antimatter in the same particle is based on different decay rates.However, it is strange that even though researchers have observed large differences in decay, when these decay rates are added, researchers can get the same value as under the condition of splitting matter and antimatter in the same particle.
According to Dr. Hadley, the theory of the "drag" effect of the rotation of our Milky Way galaxy on space-time can explain all problems about observation.In the splitting of the same particle matter and antimatter, they can be symmetrical not only in the mirror image, but also in other structures.For the decay of those particles, this view is not completely unreasonable. The mechanism of this decay may start at the "mirror image" moment. However, the "drag" effect produced by the rotation of the Milky Way is significant, and the space-time distortion caused by it is enough to cause each particle to experience different structures and different time dilation effects,And that's why decay happens in different ways.
That is to say, when each particle decays, the overall effect of different time expansion caused by space-time distortion must be considered, and the disappearance of CP violation and symmetry conservation should also be related to this.Another highlight of this theory is that it can be tested and the predicted phenomena can also be tested.At CERN, a large-scale data array has been collected, which shows that CP destruction exists in the process of decay, and also examines the influence of the "drag" effect produced by the rotation of galaxies.
Particle physicists are proving similarGalaxyHow much does such a huge galaxy affect the CP violation observed in the experiment.At the same time, it also opens a door for those theorists to use CP destruction as a very useful tool to explain how matter and antimatter separated at the beginning of our universe and how to form the physical universe we saw.In fact, the effects of space-time drag and time expansion caused by the rotation of the Milky Way on particle experiments cannot be ignored.In the very early universe, there may be enough mass and rotation to generate space-time drag, and this effect will have a significant impact on the distribution of matter and antimatter.
Source of antimatter
The first source is the outer layer of the atmosphere above us.In the chargedcosmic rayUnder the bombardment of, positrons are constantly produced there.The second source is hidden in the atoms of radioactive material.Some unstable nuclei have excess protons, such as sodium 22, bromine 35 or iodine 122, which will eventually decay and release aneutrino, onephotonAnd a positron.The third one is composed ofthunderstormmanufacture.First, the storm cloud polarizes, then the lightning suddenly depolarizes the cloud layer, and the electrons in the atmosphere suddenly eject, and then gamma rays are generated. Finally, gamma rays hit other atomic nuclei in the atmosphere, producing electrons and antielectrons.[6]
Human antimatter
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Human antimatter
In addition to our common matter, there is also antimatter in the universe.Since the British physicist Paul Dirac predicted the existence of antimatter in 1928, antimatter has always been the "sweet cake" in the eyes of scientists.Scientists believe that the study of antimatter is of great significance in high-energy physics, the evolution of the universe, etc. The in-depth study of antimatter is an important part of solving the mystery of the origin of the universe.
Antimatter is also the "standard configuration" in many science fiction novels.For example, in the sister chapter of the movie The Da Vinci CodeAngels and DevilsOnly a bomb containing 0.25 grams of antimatter is enough to wipe the Vatican off the earth;In the movie Star Trek“Enterprise number”The spacecraft uses the powerful thrust generated by the annihilation of matter and antimatter to obtain the speed of flight beyond the speed of light.
In particle physics, antimatter is a special substance composed of antiparticles.Antiparticles and particles have the same mass but opposite charges and spins.These antiparticles combine to form antimatter.For example, a positron (the antimatter of an electron) and an antiproton can form an antihydrogen atom.
In addition, antimatter has many amazing features. The website of Symmetry magazine jointly founded by Fermi National Laboratory and Stanford Linear Accelerator Center (SLAC) lists ten things about antimatter that we may not know.[7]
Asymmetry of matter and antimatter
In 1928, Dirac predicted the existence of positron, the antiparticle of electron.
In 1932, American scientist Carl Anderson accidentally discovered positrons in the process of studying a cosmic ray from far space, which confirmed Dirac's prediction and caused shock and sensation in the scientific community.Is it accidental or universal?If it is universal, do other particles have antiparticles?As a result, scientists have added a search target in the research of exploring the micro world.
In 1936, Anderson won the Nobel Prize in Physics for the discovery of positron.Later, antiparticles of other basic particles were also found.In 1955, American researchers produced the first antiproton, the proton with negative charge.
Nowadays, there are a lot of matter composed of positive particles in our universe, but no stable antimatter composed of antiparticles has been found, which indicates that the positive and anti matter in the universe are not strictly symmetrical, otherwise all matter will annihilate.
According to the standard theory of the origin of the universe, matter and antimatter were produced in pairs or in equal quantities at the beginning of the Big Bang.When matter and antimatter meet, they will annihilate each other, leaving only energy.Therefore, theoretically speaking, we should all not exist, but in fact, most of the particles left today are positive particles, which is the so-called "symmetry breaking (symmetry breaking) of positive and anti matter". Although several particle collision experiments have found that the decay of positive particles is slightly different from that of anti particles,However, it is still not enough in quantity to explain why antimatter disappears today, which is still a big unsolved mystery in particle physics, and scientists have also put forward many explanations for this.
Physicists are now working hard to clarify this asymmetry. Perhaps the day when the answer is revealed, a new era of astronomy will begin.
Antimatter is closer to you than you think
A small amount of antimatter continues to fall on the earth in the form of cosmic rays and high-energy particles.These antimatter particles reach the atmosphere in the range of 1 to 100 per square meter.
But other antimatter sources are close at hand.For example, bananas also produce antimatter - it releases a positron every 75 minutes.This phenomenon occurs because bananas contain a small amount of potassium - 40.Potassium - 40 is a natural isotope of potassium, which releases positrons in the process of decay.
The human body also contains potassium - 40, which means that the human body will also release positrons.Since antimatter annihilates each other once it comes into contact with matter, these antimatter particles are very short-lived.[8]
Expensive but hard to reach
Although the annihilation of matter antimatter has the potential to release a large amount of energy, and one gram of antimatter may produce an explosion scale equivalent to a nuclear explosion, humans currently produce very little antimatter.
In 1995, scientists from the European Center for Nuclear Research (CERN) created the world's first batch of antimatter anti hydrogen atoms in the laboratory;In 1996, Fermi National Accelerator Laboratory successfully produced seven antihydrogen atoms.On September 18, 2000, CERN successfully produced about 50000 low-energy antihydrogen atoms, which is the first time that humans have produced large quantities of antimatter under laboratory conditions.At the beginning of May 2011, the University of Science and Technology of China cooperated with American scientists to produce the heaviest antimatter particle so far - anti helium 4.
However, so far, all antiprotons produced by Fermilab's Tevatron add up to only 15 nanograms (billionths of a gram);All the antiprotons produced by CERN add up to only 1 ng;The positrons produced by the German electron synchrotron (DESY) add up to about 2ng.Even if all these antimatter annihilate at once, the energy they produce is not enough to boil a glass of water.
The fundamental problem lies in the efficiency and cost of manufacturing and storing antimatter. At present, antimatter is produced by high-energy particles generated by accelerator hitting fixed targets and then decelerating to synthesize. The energy required in this process is far greater than the energy released by annihilation,And the rate of antimatter production is extremely low: only one gram of antimatter requires about 25 × 1015 kilowatt hours of energy.Therefore, considering the production cost, antimatter is the most expensive substance in the world.
Use "trap" to save antimatter
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Antimatter is also difficult to capture and store.Since antimatter will annihilate and explode as soon as it encounters positive matter, we cannot use any container made of positive matter to store it. We must build a special "home" for them.
Charged antimatter particles, such as positrons and antiprotons, can be stored in Penning traps.These devices can be regarded as small accelerators, which rely on magnetic and electric fields to prevent particles from colliding with the well wall and make them spiral.It is reported that scientists from NASA and Pennsylvania State University have been able to store 1010 antiprotons in Penning ion trap for a week.However, Penning ion trap has no effect on antihydrogen atoms, because antihydrogen atoms are not charged and cannot be "locked" by electric fields.Instead, they are kept in the commonly known "Yapu Well".
In fact, the earth's magnetic field is similar to some kind of antimatter trap.In 2011, an Italian scientific team used a cosmic ray detector to successfully discover the antiproton belt in the Van Allen radiation belt. The existence area is 350 to 600 kilometers away from the earth's surface. This study confirmed the theory that the earth's magnetic field can "capture" antiprotons.
Antimatter may fly upwards
Einstein's general theory of relativity tells us that gravity acts equally on any matter;The Standard Model theory also predicts that gravity should have the same effect on matter and antimatter.So does gravity make antimatter fall or fly upward?If antimatter's behavior is completely different, will they overturn the existing physical theory?CERN's ongoing "AEGIS" experiment and "ALPHA" experiment are all trying to find this point.
Of course, it is not as easy to observe the impact of gravity on antimatter as it is to see an apple fall from a tree.These experiments need to store antimatter in a well or slow it down by cooling it to a temperature above absolute zero to better observe it.Moreover, because gravity is the weakest basic force, physicists must use neutral antimatter particles in these experiments to prevent interference generated by stronger electric fields.
Particle decelerator slows down antimatter
Many of us are familiar with particle accelerators, but do you know there are particle reducers?CERN has a device called "Antiproton Decelerator".On August 10, 2000, CERN announced that this antiproton reducer was put into use.
This antiproton reducer is a circular concrete box with a circumference of 188m and a cost of 11.5 million dollars.It uses magnetic field to cool, decelerate and accumulate high-energy antiprotons and positrons, and finally forms a large number of antihydrogen atoms bound by electromagnetic field. The temperature of these "cold" antihydrogen atoms is only a few degrees higher than absolute zero, which makes it possible to study the characteristics and behavior of antiprotons, antihydrogen atoms and other particles in the future.
In 2014, CERN's "Low Speed Antiproton Atomic Spectroscopy and Collision (ASACUSA)" experimental team mixed positrons and low-energy antiprotons produced by the antiproton retarder, and successfully produced the antihydrogen atomic beam for the first time.They detected a 2.7 meter long antimatter beam consisting of 80 antihydrogen atoms.
Neutrino or its own antiparticle
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Material particles and their antiparticle partners carry opposite charges, making it easy for scientists to distinguish one from another.However, neutrinos have almost no mass, seldom interact with other substances, and even less charge. Therefore, scientists believe that neutrinos may be Mayolana fermions (the same particles as antiparticles).In the 1930s, Italian physicist Ettore Mayolana proposed that neutrinos could be used as their own antiparticles.
The Mayorana detector, which studies the nature of neutrinos, and the EXO-200 detection experiments in the United States are all aimed at determining whether neutrinos are Mayorana fermions by looking for a behavior called neutrino free double beta decay.Some radioactive nuclei decay at the same time, releasing two electrons and two neutrinos.If neutrinos were their own antiparticles, they would annihilate each other instantly after the double decay, and scientists would only see electrons.
Finding neutrinos may help scientists explain antimatter matter asymmetry.Physicists believe that some neutrinos are light and some are heavy.At present, there are light neutrinos, while heavy neutrinos only exist at the moment after the Big Bang.
Antimatter plays its role in the medical field
Today, although there are few antimatter particles found and produced, it is no surprise that antimatter like positron has been found and produced.Although it is not possible to produce and store a large amount of antimatter as described in science fiction, antimatter has been applied on a smaller scale. For example, positron emission computed tomography (PET) equipment used in many hospitals uses positrons to generate high-definition images of the body.
Positron emitting radioisotopes (such as potassium - 40 found in bananas) are attached to glucose and other chemicals, and then injected into blood vessels together.Glucose breaks down in the blood vessels and releases positrons, which meet the electrons in the body and annihilate each other.This annihilation process will produce gamma rays, which can be used to build images of the body to provide doctors with diagnostic evidence.
Scientists at CERN have been studying antimatter as a potential means to treat cancer.Physicists have found that they can use particle beams to attack tumors. These particle beams can release energy after safely passing through healthy tissues.Using antiprotons can add another beam of energy.Scientists have found that this technology is effective for hamster cells, but there is still no relevant research in humans.
Antimatter after the Big Bang may still be lurking
Scientists have always hoped to "find out" the antimatter left behind by the Big Bang, so as to solve the mystery of matter antimatter asymmetry.
On the International Space StationAlpha magnetic spectrometerThe mission of AMS-02 includes searching for these particles.This advanced detector, which was launched by Endeavour in 2011, is regarded as a scientific weapon that can make a "closing statement" on the antimatter mystery case.In the next ten years, it will explore the existence of antimatter and anti universe in the most ideal place in space.In addition, its mission also includes searching for dark matter in the universe and exploring cosmic rays.
AMS-02 is the largest magnetic spectrometer sent into space, which can identify an antiparticle from billions of events.This means that the accuracy of three orders of magnitude has been improved compared with previous experiments.With such precision, the detector will detect the composition of cosmic ray spectrum with unprecedented accuracy.
AMS-02 has a powerfulPermanent magnetCharged particles and antiparticles will deflect in the opposite direction under the action of charged particles and antiparticles, so that matter and antimatter will go their separate ways, instead of "meeting" and annihilating each other.
Cosmic ray collisions generally produce positrons and antiprotons, but the possibility of creating an antihelium atom is extremely low, because this process requires a lot of energy.This means that even if only one anti helium nucleus is found, it will become solid evidence that there is a large amount of antimatter somewhere in the universe.These substances were produced after the Big Bang, and their discovery will become a real breakthrough in understanding the universe today.
Antimatter propelled spacecraft is still a long way off
The potential and attractive use of antimatter is to make super fuel for interstellar rockets.
Scientists have long found that when antiparticles and particles collide and annihilate at high energies, a large amount of energy will be released.The release rate of this energy is far higher than that of nuclear bombs and hydrogen bombs. A few grams of energy generated is equivalent to a strategic nuclear bomb.Because of this nature, antimatter often appears as the fuel of starships in science fiction.In the Star Trek movies, the "Enterprise" spaceship can fly at warp speed and reach any place in the universe at the speed of light, relying on its antimatter power system.
The analysis results of Zhang Weiming, a senior researcher at Kent State University in the United States, and Ronan Keenan of Western Reserve College show that the speed of the antimatter rocket can reach 70% of the speed of light.Theoretically, it is possible to use antimatter as rocket fuel, but before this new idea is really put into practice, people must solve two major problems: the scarcity of antimatter and its storage.
At present, scientists still have no way to produce or collect enough antimatter on a large scale. After nearly half a century of research, humans can only save antimatter (anti hydrogen atom) for 1000 seconds at most.According to media reports, in 2011, CERN scientists successfully maintained 309 antihydrogen atoms for 1000 seconds, 5000 times the previous number.
However, scientists are a group of people who "know that there are tigers in the mountains and prefer to travel in the mountains". Many scientists are conducting research on the manufacture and storage of antimatter.If one day in the future, scientists can find a way to make or collect a large amount of antimatter, then interstellar travel propelled by antimatter may go from dream to reality.
But what is interesting is that when the antimatter rocket is really put into use, passengers must also get used to the so-called relativistic effect - when approaching the speed of light, space and time will not move so fast.To put it simply, the journey from Earth to Centaurus will take about 6 years for the Earth Clock to travel, but it actually feels that it has only taken less than 4 and a half years.
In fact, the human body also releases antimatter.It is believed that with the continuous development of science and technology and the deepening of scientific research, people's understanding of the role of antimatter will become more and more profound, and the antimatter world will make contributions to mankind.
