One of the most amazing facts in science is how the universal laws of nature. Each particle is subject to the same rules and experiences the same force exists in the same fundamental constants, regardless of where and when. From the point of view of gravity each individual particle of the Universe is experiencing the same gravitational acceleration or the same curvature of space-time, no matter what the properties.
In any case, it follows from the theory. In practice, some things to measure can be very difficult. Photons and ordinary particles are equally stable fall, as expected, the gravity field and the Earth makes any massive particle to accelerate towards its center at a speed of 9.8 m/S2. But no matter how we tried, we never managed to measure the gravitational acceleration of antimatter. It is bound to accelerate as well, but until we measure it, we can’t be sure. One of the experiments intended to find the answer to this question, once and for all. Depending on what he finds, we may be a step closer to the scientific and technological revolution.
Is there antigravity?
You may not realize it, but there are two very different methods to represent weight. On the one hand, there is a mass that accelerates when you apply the force: is the m in the famous equation of Newton, where F = ma. It’s the same in the Einstein equation E = mc2, from which you can calculate how much energy you need to create a particle (or antiparticle) and how much energy you will get when it annihilates.
But there is another ground: gravity. A mass, m, which appears in the equation of weight on the surface of the Earth (W = mg) or the gravitational Newton’s law, F = GmM/r2. In the case of ordinary matter we know that these two mass — inertial and gravitational mass must be equal with an accuracy of 1 part in 100 billion, due to experimental restrictions, established over 100 years ago by Laurent University.
But in the case of antimatter, we could never measure all this. We applied non-gravitational forces to the antimatter and see how it accelerates; we create and destroy antimatter; we know exactly how it behaves inertial mass the same as inertial mass of ordinary matter. F = ma and E = mc2 works in the case of antimatter the same as with ordinary matter.
But if we want to know the gravitational behavior of antimatter, we can’t just be based on theory; we have to measure it. Fortunately, at the present time the experiment is carried out, the task is to find out exactly that: the ALPHA experiment at CERN.
One of the biggest breakthroughs occurred recently, was the creation of not only particles of antimatter, but neutral, stable bound States in them. Antiprotons and positrons (antielectrons) can be created, dragged down and forced to interact with each other with the formation of neutral antihydrogen. Using a combination of electric and magnetic fields, we can limit these in which anti-atoms and keep them in a stable state far from matter, which will lead to annihilation in the event of a collision.
We were able to successfully maintain them in a stable condition for 20 minutes at a time, which is much higher than the microsecond time scales, which tend to experience unstable fundamental particles. We fired at them with photons and found that they have the same spectra of radiation and absorption as the atoms. We determined that the properties of antimatter are the same as predicted by standard physics.
Except gravity, of course. New detector ALPHA-g, built in the canadian factory TRIUMF and shipped to CERN at the beginning of this year, should improve the limits of the gravitational acceleration of antimatter to a critical threshold. If antimatter is accelerated in the presence of a gravitational field on the Earth’s surface to 9.8 m/S2 (down), fall 9.8 m/S2 (up), 0 m/S2 (in the absence of gravitational acceleration) or to some other value?
Both theoretical and practical point of view, any result that is different from the expected +9.8 m/S2, will be absolutely revolutionary.
Analogue of antimatter for every particle of matter must have:
- the same weight
- the same acceleration in a gravitational field
- opposite electrical charge
- opposite spin
- the same magnetic properties
- should communicate the same in atoms, molecules and larger structures
- should have the same range of positron transitions in a variety of configurations.
Some of these properties was measured over time: the inertial mass of antimatter, electric charge, spin and magnetic properties are well known and studied. Linking and transitional properties was measured by other detectors in the experiment ALPHA and coincide with the predictions of particle physics.
But if the gravitational acceleration would be negative, rather than positive, it will literally turn the world upside down.
Currently, there is no such thing as a gravity conductor. In a conductor, free charges reside on the surface and unable to move, redistributing themselves in response to any charges nearby. If you have an electric charge outside of the electrical conductor, the inside conductor will be shielded from this source of electricity.
But to defend against the forces of gravity there’s no way. There is no way to set a uniform gravitational field in a certain region of space, such as between parallel plates of an electric condenser. The reason? Unlike the electric force, which is generated positive and negative charges, there is only one type of gravitational “charge” is mass/energy. Gravitational force always attracts and it does not change.
But if you have negative gravitational mass, everything changes. If antimatter actually manifests anti-gravity properties, falls up, not down, in the light gravity it consists of intimacy or antienergy. According to the laws of physics that we know of intimacy or antienergy does not exist. We can imagine them and imagine how they will behave, but we expect that antimatter will have a normal mass and normal energy, when talking about gravity.
If antimass really exists, many technical achievements, dreamed of by science fiction writers for many years, will suddenly become physically feasible.
- We can create a gravitational conductor, distancing themselves from the gravitational forces.
- We can create gravitational capacitor in space and create artificial gravity field.
- We could even create a warp drive, as would the ability to warp space-time as well as required a mathematical solution of General relativity, proposed by Miguel Alcubierre in 1994.
This is an incredible opportunity, which is considered almost impossible by all physicists-theorists. But no matter how wild or unimaginable was not your theory, you should back them up or disprove exclusively experimental data. Only measuring the Universe and subjecting it to checks, you can see exactly how to apply its laws.
Until we measure the gravitational acceleration of antimatter with a precision necessary to determine whether it falls up or down, we should be open to the possibility that nature does not behave as we expect it. The equivalence principle may not work in the case of antimatter; it can be 100% anyprincipal. And in this case opens a world of brand new possibilities. The answer we will know in a few years, having conducted a simple experiment: place antiatom in a gravitational field and see how he will fall.
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