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.
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.
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.
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