Is all space antimatter or not

Antimatter in the universe

In the Big Bang, matter and antimatter should have been created in equal parts. But where has the antimatter gone? Are there possibly whole galaxies made of antimatter in the universe?

The current understanding of physics includes the existence of antimatter. If the CPT invariance is maintained - provided that antimatter and matter behave in exactly the same way - all properties of antimatter can be predicted from those of matter. Matter and antimatter annihilate each other to form energy or are generated simultaneously from energy. But if this symmetry applies to the creation and annihilation of matter and antimatter, then it should also have applied at the time of the creation of the universe, at the time of the Big Bang. Or have the laws of physics changed on the way up to today and in the beginning of all becoming different laws than today applied? Where has the antimatter gone, which must have originated in the Big Bang?

We know that antimatter does not exist naturally on earth. Cosmologists tell us that there is a high probability that antimatter does not exist within a radius of thirty million light years around us. Furthermore, speculation remains that distant galaxies could be made of antimatter.

Fundamentally, such considerations are not that new, because Aristotle already led in his work Across the sky - on becoming and passing away from: "The Pythagoreans claim that across from this earth there is a second one, the so-called invisible" counter-earth ", invisible because it is diametrically opposite to the earth, beyond the fire, but otherwise the same down to the smallest detail."

The Alpha Magnetic Spectrometer

The Alpha Magnetic Spectrometer at the ISS space station

Antimatter created in the Big Bang could have been left somewhere to this day. The aim of the Alpha Magnetic Spectrometer (AMS) is to investigate this.

With this detection device it should be possible to locate nuclei of antiatoms from antigalaxies, if any. In particular, nuclei such as anti-oxygen or anti-carbon would prove the existence of stars made of antimatter, because such heavy nuclei can only have been formed by processes of nuclear fusion within structures made of antimatter.

The use of the AMS experiment on the ISS was initially delayed due to difficulties at NASA. Now, however, the experiment took a decisive step forward: On August 26, 2010, it set off on its penultimate stage on the journey to the international space station by flying from the CERN research center in Geneva to the Kennedy space center in Florida. Before that, it had to withstand extensive series of tests, which also led to decisive technical changes. Once on the ISS, there is no longer any possibility of significant mechanical intervention; because the AMS experiment will literally be transported into space on the last ferry of the space shuttle at the end of February 2011.

Possible explanations

Test of the AMS at CERN

In 1967 Andrei Sakharov formulated three central conditions that formed the basis for all further attempts to explain the excess of matter and the lack of antimatter observed in our universe:

  • There must be processes that change the number of matter particles made up of quarks (the so-called baryons).
  • The laws of nature known to us must be designed in such a way that there is an excess of matter compared to antimatter, i.e. there must be a violation of the C and CP symmetry.
  • Processes that violate the preservation of the baryon number must take place or have taken place in thermal imbalance, since in thermal equilibrium the secondary products of a decaying particle would also recombine back into their original particle with the same frequency.

As has meanwhile been proven beyond doubt, there is a CP violation. This may have been partly responsible for the formation of the surplus of matter in the early times of the development of the universe, even if the part of its strength that is known today does not seem sufficient to explain the entire effect. An alternative to the three Sakharov conditions, which - even in thermal equilibrium - could lead to high baryon asymmetry is a baryon number violation when the CPT invariance is broken.

The task of the scientists is now to identify complementary processes or new sources of the CP violation, and / or determine whether all interactions between the particles are really invariant to the CPT operation. For this purpose, a number of measurements were made on different particle systems, and experiments are currently being planned and carried out at many experimental facilities.

This is where the goals of AMS, LHC and the AD particle accelerator at CERN meet (see article Experiments with anti-hydrogen). Even if the ways and methods are very different: The search for exotic particles in space with AMS, the observation of exotic new particles in collisions of highly energetic particles at the LHC and the measurements of exotic antiatoms at the AD with the highest precision at the lowest energies - that The decisive scientific aim of these complementary experiments is to investigate the fundamental forces that rule our world.

In this context, it is particularly noteworthy that the management of CERN not only had the LHC built so successfully and put into operation, not only actively supported the AMS experiment in its completion, but is also currently advancing planning, the AD accelerator through one additional, further braking ring - called ELENA (Extra Low ENergy Antiprotons) - to increase its efficiency by two orders of magnitude.

New insights into the laws of the universe?

The evolution of the universe

In any case we have to ask the question of the cause of the excess of matter over antimatter in nature. We will also get an answer - the more precisely we formulate the question, the more precise it will be, and it will allow us to penetrate deeper into the secrets of nature in our understanding.

The situation today seems similar to that at the beginning of the twentieth century, when - after the Maxwell equations for electromagnetism had been established - there seemed to be an almost uniform picture of physics and the phenomena of nature, and only a few small effects could not yet be fully explained. Just as a closer look at the time led to fundamentally new descriptions and findings, which initiated a real renaissance in physics, so a clear answer to the question of the asymmetry of matter compared to antimatter is still waiting to be given today - an answer that may possibly give us will provide fundamentally new insights into the laws of the universe. Because the world view of physics, as it is summarized in the standard model of particle physics, can describe a CP violation, but cannot explain it quantitatively.

Questions on the microscopic scale are used to explain the macrocosm; the phenomena of the microcosm and the macrocosm complement each other. In response to the question of whether we can expect a significant explanation of our existence at all, reference is made to the considerable successes that physics has already achieved, and to conclude Stephen Hawking:

“Mankind has always wanted to look beyond the horizon ... On each side of us, the universe has structures on scales that are up to a thousand billion billion billion times larger or smaller than we are. Because this range is not quite infinite, there is hope that one day we will fully understand the structure of the universe. The search for the almost infinite. "

("The human race has always wanted to look beyond the horizon ... On either side of us, the Universe has structure on scales up to about a thousand billion billion billion times bigger or smaller than our own. Because this range is not quite infinite, there is hope that we may one day completely understand the structure of the Universe. ")