Sunday, November 19, 2017

Should We Be Here?

Why are we here? That question could be answered from many perspectives including philosophical, theological, and scientific. From a scientific perspective we are here partly because the early universe had an excess of matter over antimatter. If the amount of matter and antimatter had been identical, their interactions would have annihilated both, resulting in a universe with energy but no matter, so we would not be here. Physicists have been investigating why there is excess matter in the universe, and in particular, if there is a discernible difference between matter and antimatter. When a recent very precise measurement at CERN found no difference in a certain property of matter and antimatter, the headlines across the globe, such as in Cosmos, Space.com, and The New York Post, proclaimed "The Universe Shouldn't Exist."

The fact that we have more matter in the universe, the "matter-antimatter asymmetry," is a problem in physics that has not been solved. In 1967 the Russian physicist, Andrei Sakharov, wrote a paper listing three necessary conditions for baryonic matter1 to be produced at a different rate than antimatter2. These are
  1. Baryon number violation
  2. C-symmetry and CP-symmetry violation
  3. Interactions must occur out of thermal equilibrium
The first criteria has never been observed, but is expected to be true at some level. Baryons are particles like neutrons and protons that are made of three quarks each. Baryon number violation simply means that a reaction can occur in which the number of baryons at the end of the reaction is different than the number at the beginning where matter (baryons) are counted as +1 baryon and antimatter (antibaryons) are counted as -1 baryon. The second criteria has two parts. C (charge) conjugation reverses the sign of the charge of a particle (from minus to plus, for instance) and reverses the magnetic moment of the particle, changing a particle to its antiparticle. In essence, then, C-symmetry means that the laws of nature seem to be the same for both particles and antiparticles. CP-symmetry violation means that when both a charge conjugation and a parity (P) operator are applied, the laws of nature seem to be slightly different. The Parity operator changes a left handed-object into a right-handed object, as if you are looking in a mirror. So together, the second criteria says the laws of nature seem identical for particles and antiparticles, but not quite the same when you observe particles that have changed to antiparticles in a mirror. The third criteria means that the system is in a state where there are different temperatures throughout and heat can flow from one area to another.

So the first criteria has not been observed but is likely true. The third criteria was almost assuredly true in the early universe. The second criteria has been observed to be true as well, but only at levels that are far far less than what would be necessary to produce the known amount of matter in the universe. Because the known and observed CP-symmetry violation is well below that needed to explain the matter in the universe, the search for other sources of CP violation remains a very active area of physics research.

Although we see a difference in matter and antimatter as observed in the known CP violation, we have not yet seen a fundamental difference in matter and antimatter at the level of their basic properties. As far as we have measured the antimatter particle of any particular matter particle has exactly the same mass, magnitude of the electric charge, and magnitude of magnetic moment (the intrinsic magnetism found in particles). The most recent measurement at CERN was made by the BASE (Baryon Antibaryon Symmetry Experiment) collaboration and published in Nature.(3) The collaboration made the most precise measurement of the magnetic moment of the antiproton, the antimatter partner to the proton, and found that the antiproton has exactly the same magnetic moment as the proton.

As is often the case, the headlines seem to be slightly sensationalistic. Of course there is a real scientific mystery as to why matter dominates over antimatter in our universe. Although the known CP violation accounts for some excess matter it doesn't account for all that we actually observe. The newsworthy announcement is that we still can't find a fundamental difference in the magnitude of the properties of matter and antimatter. Of course these unsolved mysteries mean that we do not yet know the process that led to the amount of matter in the universe necessary for our existence. Given our current knowledge it is true that we don't yet know why the universe should exist as it does. But our search for answers is not yet finished.

When the popular press published articles about this latest measurement by the BASE collaboration in late October many of my Christian friends forwarded me copies of the articles and asked what we know about the origin of matter in the universe. Many followed the suggestion from the headlines and asked if God must have performed a miracle since "The Universe Shouldn't Exist" and if this was evidence for God's direct intervention into our universe. Of course, many of the posts in this blog have pointed out aspects of the universe that show God's hand in its creation and design. Certainly, whatever mechanism God used to create the exact amount of matter needed for our existence would have to be finely-tuned so that the universe did not have too much or too little matter to expand at just the right rate and form galaxies, stars, and planets. My opinion is that God did not supernaturally create more matter in the universe than antimatter but rather created a natural mechanism that is tuned just right to give us the necessary matter — a mechanism we have not yet discovered. After all, we usually see God's work in nature through the finely designed universe he made rather than through supernatural intervention. Many times in the past we have discovered that the laws of physics show characteristics of design and fine-tuning and it is that precision in the laws that ultimately points to a designer.

The result from BASE will spur us on to continue to explore this unsolved mystery of how we got the excess matter over antimatter that we see in the universe. Further sources of CP violation and more precise measurement of the properties of matter and antimatter should eventually give us insight into the processes that led to our existence. Though I don't believe this particular feature of the universe will require God's supernatural activity, his fingerprints remain imprinted all over the universe apparent in its remarkably designed features that give a universe precisely created as a suitable home for our existence.


The bottom figure is a picture of the BASE experiment at CERN.
1Baryonic matter is anything made out of baryons including all the material in the universe that we are familiar with in the periodic table that have neutrons and protons in the nucleus. 
2A. D. Sakharov (1967). "Violation of CP invariance, C asymmetry, and baryon asymmetry of the universe". Journal of Experimental and Theoretical Physics Letters. 5: 24–27.
3C. Smorra, et.al., "A parts-per-billion measurement of the antiproton magnetic moment". Nature 550, 371374 (19 October 2017).

4 comments:

  1. My understanding is that the community states that vast empty space is not empty but rather replete with particles of every type and "gender" constantly zipping in and out existence by QM rules and understanding. Maybe the now proposed early hyper expansion at the beginning means there was an early headstart of greatly excessive real particles or the positron type...something had to energize the super expansion. Once this head start was in place it would likely not phase out.

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  2. But where does the antimatter exist? Right along side matter? Are they like isomers of the elements or exact replicas? What makes them antimatter? You mention their forces are equal in measurement. Do they have the same amu equal to a corisponding element but with an opposite nuclear charge or something? Also, I think about the analogy you told me all the time, that the universe is like a clock that God set the gears in motion. So then I wonder if you believe God takes an active role in our daily life, intervening when it's necessary and whatnot. That's my understanding of the modern Christian belief system, but it sounds like that's not your understanding. I personally have a hard time with that idea. Again I'll apologize for the elementary questions ahead of time. Thanks!

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  3. There is no antimatter left because. It has been annihilated and the extra matter remains. When we create antimatter in the lab it exists only for a short period of time before it interacts with matter and annihilates into energy (like the power source for star ships on Star Trek). Antimatter has the same mass as the matter counterpart but different charge and opposite quantum numbers. As I said in my reply to your other post, I think God takes an active role in the universe so he can relate to us on a personal level, not because he needs to in order to keep the clockwork of the universe going. Your questions are great.

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    1. Crazy! okay I'm trying to wrap my brain around this. If n=2, l=1, ml=-1, ms=-1/2, l+s=3/2, l-s=1/2, ml+ms=1/2 what does the opposite of that look like? And are you saying the electron has a positive charge as antimatter? My understanding is when you guys create these particles, we don't know where they are being created from. Is that right? If so, and they are creating energy like you say, does that imply our universe might not be a closed system? Or does annihilate into energy mean assimilate, not necessarily create. And is that why they theorize different universes? I feel kinda bad asking all these questions. I am planning on attending OU by fall of '18 and I have intentionally not taken physics yet so I can attend your class. Please feel free to tell me to wait until then for answers. I'm so anxious to learn it all though. I will ask my question about the God aspect in the other post

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