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Our future, our universe, and other weighty topics

Sunday, February 16, 2014

Is There Any Flab in Nature's Fundamental Blueprint?

An interesting question to consider is whether the universe is built on a kind of blueprint that has a significant amount of excess or flab. If we look at the fundamental layout of particles, and find a great deal of excess and waste, this might perhaps tend to confirm the suspicions of many pessimistic thinkers that the universe is the daughter of pure blind chance.

Below is a typical diagram used to illustrate the Standard Model of particle physics, which is the closest thing we have to nature's fundamental blueprint. 

Where here can we find some flab in nature – something that is hanging around, but is not needed?

We certainly could not get along without the Up quark or the Down quark, because they are the constituents of the protons and neutrons that make up the nucleus of an atom. There are two Up quarks and one Down quark in a proton, and two Down quarks and one Up quark in a neutron.

We also could not get along without the electron, as it is a vital part of any atom. As for the photon, that is certainly needed, as sunlight itself consists of photons. The gluon is needed because it is believed to play a key role in the strong nuclear force that holds together the nucleus of the atom.

There are also reasons (much less obvious) why we need the three types of neutrinos in the Standard Model (the electron neutrino, the muon neutrino, and the tau neutrino). Although they might seem to be useless “ghost particles,” neutrinos are a critical element in supernovae explosions, the explosions of stars which create and spread around all of the heavier elements that are used in our civilization. Among the elements believed to be created entirely by supernova explosions are nickel, copper, zinc, germanium, selenium, tin, silver, gold, lead, and uranium. According to this link almost all of the energy of a particular supernova was transmitted through neutrinos. So we can't classify any of the neutrinos as being flabby parts of nature's blueprint. Living in an advanced industrial civilization, we can't dismiss as “useless” particles such as neutrinos that help to spread around the heavy elements needed for an advanced industrial civilization.

As for the W boson and Z boson particles, they are believed to play a crucial role in the weak nuclear force, which is believed to be important in supernova explosions. Such explosions are very useful for any industrial civilization needing heavy elements such as the elements listed above. This scientific paper says that there would not be enough oxygen if we did not have the weak nuclear force.

Not shown in the diagram above (but shown in other diagrams of the Standard Model) is the Higgs boson. That particle is believed to be vitally necessary because it helps to give mass to other vitally needed particles, as explained here.

So far we have found everything in the Standard Model to be useful. But we still have not discussed some particles that have sometimes been described as superfluous particles: the Charm quark, the Strange quark, the Top quark, the Bottom quark, the tau particle, and the muon particle.

Here is an example of a scientist (Sean M. Carroll) who makes an argument that some of these particles show a case of flab or excess in nature, perhaps suggesting a poor design:

But in fact there is a better reason to be skeptical of the fine-tuning claim: the indisputable fact that there are many features of the laws of nature which don't seem delicately adjusted at all, but seem completely irrelevant to the existence of life. In a cosmological context, the most obvious example is the sheer vastness of the universe; it would hardly seem necessary to make so many galaxies just so that life could arise on a single planet around a single star. But to me a more pointed observation is the existence of ''generations'' of elementary particles. All of the ordinary matter in the universe seems to be made out of two types of quarks (up and down) and two types of leptons (electrons and electron neutrinos), as well as the various force-carrying particles. But this pattern of quarks and leptons is repeated threefold: the up and down quarks are joined by four more types, just as the electron and its neutrino are joined by two electron-type particles and two more neutrinos. As far as life is concerned, these particles are completely superfluous. All of the processes we observe in the everyday workings of the universe would go on in essentially the same way if those particles didn't exist. Why do the constituents of nature exhibit this pointless duplication, if the laws of nature were constructed with life in mind?

The previous paragraph is very densely packed with absurd and misleading reasoning. The first ludicrous claim (strangely referred to as “most obvious”) is that the vastness of the universe is somehow an argument against the idea that it is fine-tuned, with the lame suggestion that an intelligent designer would only be interested in creating one planet with life on it (rather than many planets with life). That is one of the silliest arguments I have ever heard, and makes as much sense as arguing that if there were a writer he would write no more than one sentence, being forever satisfied with having created just one. The next mistake is in insinuating that the second and third “generations” of quarks are somehow an example of superfluous excess. Carroll knows full well that the second and third “generations” of quarks have lifetimes of less than a millionth of a second, and that they decay into the very Up quarks and Down quarks that make up protons and neutrons, and are therefore absolutely necessary for our existence. More than 99.99999999999% of the quarks that actually exist in our galaxy are Down quarks and Up quarks (the other types never existing for more than a millionth of a second, and only in particle accelerators and a few freaky stars). The same thing is true for the tau and muon particles, which last than less than a second, and decay into the electron particle that is essential for our existence. So to complain of “pointless duplication” is wrong. There is no such duplication. The particles that Carroll calls “completely superfluous” particles are the direct ancestors of the vitally necessary particles, and are no more superfluous than your grandmother was superfluous to your existence.

For physicists to speak of “generations” here is very apt to give you the wrong idea, because when you hear the term generation you think of the forty years of a human generation. But in reality the second and third “generations” of quarks exist for less than a millionth of a second before decaying (directly or indirectly) into the vitally necessary first generation. Complaining about that length of time as some example of wastefulness is like complaining if a short-order cook takes a millionth of a second to make your food.

As for the neutrino particles, it may be technically correct to say “the processes we observe in the everyday workings of the universe would go on in essentially the same way if those particles didn't exist.” But that is a very misleading turn of phrase, because as discussed earlier, if those neutrinos hadn't existed, supernova explosions (not an everyday occurrence) wouldn't work, the heavier elements would not have got spread around, and we wouldn't have here on Earth many of the elements used for industrial civilization. So neutrinos also cannot at all be classified as useless excess particles, some flab in nature's blueprint.

I will now introduce two tables that will help to clarify these points. The first table is an improved table showing the particles of the Standard Model, a table that will make clear which particles are stable particles lasting longer than a second, and which particles are short-lived particles lasting less than a second. The stable particles are shown in blue. All other particles have lifetimes of only a tiny fraction of a second.

Standard Model

In judging whether there is flab in the Standard Model, we really need concern ourselves only with the particles shown in blue above. For the reasons given earlier, all of these particles are necessary. We know that neutrinos are necessary for the production of heavy elements in supernovae explosions. I don't think any one has ever done an analysis judging whether we would have as many heavy elements if one of these three types of neutrinos did not exist, so we should assume for now that all three are necessary for a universe with as many useful heavy elements as we have.

Another useful table is the table below. In this list I list each type of particle in the Standard Model, and I explain why each type of particle is relevant to life or civilization (in the sense of either being directly necessary itself for life or advanced civilization, or a particle that is a predecessor of some other particle that is relevant to life or civilization). The decay paths shown are typical decay paths, among the most common (a particle will often have multiple ways of decaying). To save space, I have not listed all the particles produced in the decays described, but only the relevant ones. 

Standard Model

Notice the important summary at the bottom of the chart. Considering only regular matter (not antimatter), and considering a particle to be relevant to life or civilization if it is either directly relevant or decays into some other particle that is relevant to life or civilization, I find that there are zero unnecessary stable particles, and zero particles irrelevant to life or civilization.

Like most tables summarizing the Standard Model, these visuals do not depict any antiparticles. But what if we were to consider antiparticles? Aren't antiparticles a great example of pure flab in nature's fundamental blueprint?

There are two reasons why antiparticles should not be considered as flab in nature's fundamental blueprint. The first reason is that there seem to be subtle reasons why our universe would not work right or not be stable if antiparticles did not exist. In his book Symmetry and the Beautiful Universe (page 234), Nobel Prize winning physicist Leon M. Lederman suggests complicated reasons why “the whole universe could not be stable” if antiparticles were not part of the overall blueprint.

The second reason is simply that antiparticles don't exist in nature for more than a tiny fraction of a second. This is because whenever an antiparticle comes into contact with a regular particle, both are converted into energy. As there seems to be no evidence that even 0.00000000001 percent of the universe is antimatter, one can't plausibly cite antimatter as an example of flab in nature's fundamental blueprint.

Could we perhaps cite dark matter or dark energy as an example of flab in nature's fundamental blueprint? No, not at all. Neither dark matter nor dark energy is covered by the Standard Model, so we are pretty “in the dark” here (pardon the pun). But scientists do think that dark matter seems to be a vital element in explaining the current structure of the universe, and that galaxies would not even hold together without it. Scientists also say that galaxies would not have expanded at a suitable rate (and galaxies would not have formed) if dark energy did not exist.

So we have looked for flab in nature's fundamental blueprint, and we have come up short. The blueprint seems to be flab-free. We might say that nature's fundamental blueprint is lean and mean. Metaphorically, we might say it is composed essentially of nothing but muscle and bone.

We can easily imagine a universe with lots of flab in its fundamental blueprint, a universe with thousands of different types of stable particles cluttering up space, with only a few of them being the type that combine together to make atoms. Our universe has no resemblance to such a universe.