The Two Huge Asymmetry Mysteries Scientists Can't Solve

Among the many mysteries scientists cannot solve, two of them involve gigantic asymmetries that scientists cannot explain. The first such asymmetry is what is called the matter/antimatter asymmetry. Scientists believe that when two very high-energy photons collide, they produce equal amounts of matter and antimatter, and that when matter collides with antimatter, it is converted into high-energy photons. Such a belief is based on what scientists have observed in particle accelerators such as the Large Hadron Collider, where particles are accelerated to near the speed of light before they collide with each other. But such conclusions about matter, antimatter and photons leads to a great mystery as to why there is any matter at all in the universe.

Let us imagine the early minutes of the Big Bang about 13 billion years ago, when the density of the universe was incredibly great. At that time the universe should have consisted of energy, matter and antimatter. The energy should have been in the form of very high energy photons that were frequently colliding with each other. All such collisions should have produced equal amounts of matter and antimatter. So the amount of antimatter should have been exactly the same as the amount of matter. As a CERN page on this topic says, "The Big Bang should have created equal amounts of matter and antimatter in the early universe." But whenever a matter particle touched an antimatter particle, both would have been converted into photons. The eventual result should have been a universe consisting either of nothing but photons, or some matter but an equal amount of antimatter. But only trace amounts of antimatter are observed in the universe.

It would be incredibly inconvenient if matter and antimatter were equally distributed. So much energy is released when matter makes contact with antimatter that if there were trace amounts of antimatter lying about, you'd have “oops, someone blew up Europe because he stepped on a tiny piece of antimatter” situations all over the place.

The asymmetry of matter and antimatter (the fact that matter and antimatter do not exist in equal amounts) reminds us of the fact that the Big Bang theory is not quite a successful theory, in the sense of making only predictions that match reality. We read in the popular press triumphalist talk like the statement below by cosmologist Ethan Siegel:

This picture is part of what’s known as the hot Big Bang, and it makes a whole slew of predictions. Each one of these predictions, like a uniformly expanding Universe whose expansion rate was faster in the past, a solid prediction for the relative abundances of the light elements hydrogen, helium-4, deuterium, helium-3 and lithium, and most famously, the structure and properties of galaxy clusters and filaments on the largest scales, and the existence of the leftover glow from the Big Bang — the cosmic microwave background — has been borne out over time.

Siegel here fails to mention that the Big Bang theory predicts a universe with either equal amounts of matter and antimatter, or all energy and no matter (which is what would result from all the matter combining with antimatter). That is a gigantic prediction of the theory that does not match reality. We don't patch up this problem by adding the “cosmic inflation” speculation to the Big Bang theory, as that also predicts a universe with either no matter or equal amounts of matter and antimatter. So rather than engaging in such triumphalist talk, our cosmologists should be saying, “There must have been something far more going on at the beginning than we understand.”

Every several years we hear about some type of result (typically preliminary) which we are told may hold an answer to the mystery of matter/antimatter asymmetry. But such results don't hold up over time. The latest report of a promising preliminary result came in 2017, but by 2018 news stories were throwing cold water on such results, saying they did nothing to explain the mystery of matter/antimatter asymmetry.

There's another gigantic mystery involving asymmetry that scientists don't understand: the mystery of homochirality. Chemicals such as amino acids and sugars can be either left-handed or right handed. A left handed amino acid looks like a mirror image of the right-handed amino acid. Homochirality is the fact that in living things essentially all amino acids are left-handed, and all sugars are right-handed. But when such things are synthesized in a laboratory, or experimentally produced in experiments such as the Miller-Urey experiment, you see equal amounts of left-handed and right-handed amino acids or equal amounts of left-handed and right-handed sugars.

A left-handed amino acid and its right-handed counterpart

Based on the fact that it is just as easy for left-handed amino acids to form in the laboratory as right-handed amino acids, and just as easy for left-handed sugars to form in the laboratory as right-handed sugars, we would expect for there to be a symmetry in the handedness of amino acids, with an equal amount of left-handed and right-handed amino acids. We would also would expect a symmetry in the handedness of sugars, with equal amounts of left-handed sugars and right-handed sugars. But what we see is an asymmetry, with living things having only left-handed amino acids and right-handed sugars.

I can give an analogy for why homochirality is such a mystery. Let us imagine a stack of cards. On one side is a particular word.

And on the other side is the mirror image of that word.

Now, let us imagine someone tosses this stack of cards into the air, and the cards randomly arrange into a long, elaborate instruction. Let us also imagine that all of the cards show only one side: the side with the intelligible word, and not the side with the mirror image of that word.

We would have two great problems in explaining such a thing. The first would be that this elaborate set of instructions had formed randomly. The second problem would be explaining how all the cards had landed in a way so that all of the regular words had appeared, without any of the mirror image words appearing. A similar problem comes with explaining the origin of life. We have to explain not merely the “organization explosion” in which huge amounts of functional information appeared, but also the fact of all the amino acids being left-handed and all the sugars being right-handed. The fact of this homochirality greatly compounds the problem of explaining the origin of life.

There was in the news recently a goofy news story on this topic, which stated the following:

Homochirality, or one-handedness, plays a key role in cellular chemical reactions, and all living organisms (that we know of) contain the ‘left-handed’ molecules. Scientists aren’t sure why this is, but some believe the answer may have something to do with the molecules’ cosmic origin. In 2016, researchers found propylene oxide, a chiral molecule, in Sagittarius B2, which is a massive molecular gas cloud roughly 25,000 light years from Earth, near the center of our Milky Way Galaxy. The findings suggest that the chiral molecules necessary for life may have come from space, particularly from star-forming regions.

This is hardly helpful in explaining the mystery of homochirality. What we want to know is why sugars and amino acids display homochirality, and the fact of a “chiral molecule” of the biologically irrelevant propylene oxide modecule does nothing to explain that. The existence of a chiral molecule does not explain homochirality, just as the existence of a two-sided penny does not explain 300 consecutive coin flips that were all heads rather than tails. The problem isn't the existence of chiral molecules (molecules that can be left-handed or right-handed). The problem is why in living things we see only left-handedness in amino acids and right-handedness in sugars.

A much better article about homochirality is “The Origin of Homochirality” in the Chemistry World magazine. The article points out why homochirality is necessary for living things, saying, “No homochirality, no life.” The article says that according to a London chemist, “understanding homochirality is still completely unresolved.”

It would seem that once we consider homochirality, we need three miracles for life to appear from non-life. The first miracle is just for you to get all of the genetic information needed for life to begin, at least 160,000 DNA base pairs arranged in just the right way (with also the proteins that correspond to such a genome). The second miracle is for you to have homochirality, so that all of the amino acids have the same handedness, and all of the sugars have the same handedness. The third miracle is for the genetic code to originate, a complex symbolic system of representations in which particular combinations of nucleotides represent particular amino acids. Similarly, it would be a triple miracle if your 2-year-old in America were to start speed typing well-written how-to books in French. The first miracle would be that he could understand enough to write how-to-books, the second miracle would be that he could write in French, and the third miracle would be that he could do speed typing on a keyboard.