Is the electromagnetic constant a constant? Could yet another universal constant, the value assigned to the electromagnetic force, be less constant than we thought? And could variability of the constant help explain life in the universe? That’s the tantalizing hypothesis offered by Australian astronomers, who believe that the value alpha, referring to the strength of …
Well, that would depend very much on what we're looking at. The force of gravity varies depending on where you stand, but the underlying process that causes this is the same everywhere (as far as we can tell, anyway) and the rules that govern that process remain constant. Varying values of alpha could be the visible effects of some underlying mechanism in the same way, no?
What is rather more interesting to contemplate is whether this underlying phenomenon might represent a universal frame of reference, something which does not fit very well with our understanding (see also, relativity).
The anthropic principle may be unsatisfying in many ways, but it is naive to say it is a circular argument. A circular argument is one which proves its premise by using its premise as an axiom. The anthropic principle doesn't suffer from this. It is answering a question of the form "why does B occur" with the answer "we know A occurs, and !B => !A, therefore B", which is absolutely mathematically sound. (B being the fact that the universe is "tuned for life" and A being the fact the universe contains life.)
The problem with the anthropic principle is that it tells us nothing we didn't already know and it adds no insight into the deeper question of why both A & B occur in the first place. There's also this uneasy feeling that it's essentially a bitch-slap response from physicists who don't think it's an appropriate question to ask.
Most serious theoretical physicists (including Neil Turok) to whom I've had the opportunity to put the question dislike invoking the anthropic principle, regarding it as a bit of a cop-out. To misquote Rutherford: "If your theory relies on the anthropic principle, you should have thought of a better theory".
I always considered universal constants to be over rated. The only reason we need 83% of the known universe to be made up of matter that we can not prove the existence of, is because without it, some of our 'constants' wouldn't be constant. Well guess what fellow physicists, beware of interesting times ahead!
Newtonian physics gave us a concept of gravitation that related attraction to mass over the square of distance, and we knew of no reason to doubt why that should not be univeral, so it was called the - all together now - Universal Constant of Gravitation. Einstein however, missed a golden opertunity. He came up with something that showed that the measurement of mass and of distance was not absolute but relative to velocity, so instantly, Big G should have become suspect.
When I fell in love with physics, it was its simplicity and honesty that attracted me. If the evidence proved a theory wrong, you dropped the theory and tried to come up with a better one. Dark matter and super string theories are not, in my humble and outdated opinion, better theories, they are attempts to bodge disproven theories and should have been strangled at birth.
There's two.
The Strong Anthropic Principle says "the universe has the behaviour it does in order that we can be here to talk about it". Basically creationism.
The Weak Anthropic Principle is the one quoted here, which says "if the universe didn't have the behaviour it does, we wouldn't be here to talk about it". Sure, this may seem like handwaveyness. But if the boffins are correct that there's actually an infinity of universes out there with different settings, being able to put limits on the range of settings that give rise to a "working" universe is a valid exercise. It's not just an "it is because it is" bitchslap. Instead it's a thought experiment where you say "what if it wasn't" and find the result is a dead universe, so you can put much tighter limits on what values are valid.
Think TVs for an example. It's a safe bet that everyone's brightness and contrast settings are within a few percent of midway. You could ask "why do people use those values?" and be told "bcos it works", which might not seem very helpful. But if you rephrase the question as "why don't people use other values?" and find the answer is "bcos you can't see the picture", then you can put much tighter limits on what's a working range of values.
Those aren't the generally accepted forms of weak/strong AP. Weak AP is saying that, within the space/time universe as we observe it, we must expect to find ourselves in that part of it which permits the existence of intelligent life forms. This can be used to explain why we find ourselves in orbit around a G1 dwarf rather than a black hole or a pulsar.
Strong AP is the claim that 'universal' constants must be such as to allow for the existence of intelligent observers. If you allow for a multiverse, then it's simply an extended form of the weak principle (universes with all possible values of fundamental constants exist, and we naturally find ourselves in one which is congenial for complex lifeforms). If there's only the single observable universe, then you must account for why the universal constants appear to be fine-tuned to allow complex (intelligent) observers to exist.
If your system has an easily-computed invariant (such as total energy) then compute it after each iteration and compare it with the previous value. You expect small changes because of floating-point rounding errors. An unexpectedly large change meant one of two things:
You'd introduced a bug into the program, or
The floating-point hardware was flaking out.
In the days of the CDC 7600 and Cray-1, it was commonplace for a scientist to phone the computer centre and tell them the latter. They'd assert the former. It was most gratifying to say "told you so" on the occasions that the system went down for hardware maintenance a few hours or days later.
Notes.
1. the need to check your invariants hasn't gone away. It's just that with modern technology you usually own the whole CPU, and it isn't mend-able any more.
2. Who says that the observable universe isn't just a sim in $deity's computer? And that it doesn't have any bugs?
The universe may be very much bigger than the observable universe. The latter is the part of spacetime from which light is today reaching us. It's pretty much a 3D section of a 4D spacetime (since we have observations over a few milennia only, and good ones only over a decade or two). The rest might be (a) forever unobservable, (b) inferrable from its effects on the observable at an earlier time, or (c) capable of becoming observable in the deep future if anything can brake the observed (and probably accelerating) expansion of the observable bit of the universe.
I've long had a pet idea that the topology of the entire universe is torroidal . That's based on the non-observation of magnetic monopoles and the everyday observation of magnetic fields. The simplest topology within which those facts do not essentially contradict each other is the torroidal. Such a topology might also eliminate the need for the birth of the entire cosmos from a big-bang singularity. What's physics like in the "hole" in the donut, if the observable universe is on the "outside equator"? Different, for certain. BTW that's a 4-torus, or possibly one of higher dimensionality if string or brane theories are correct. It would imply time and space are both eternal but cyclical.
A torroidal universe would have to be anisotropic (different in different directions) but the observable bit of it might look very close to isotropic. Very close, but maybe not so close that we can't find a slight hint of a built-in directionality?
Talking of religion and circular arguments, religion is the classic circular argument.
God exists because it says so in the bible (which is the only 'proof' one has of anything relating to religion).
And of course the bible must be true because 'it is the word of God'.
There really is no arguing with religious types. It's pointless. Their logical arguments for the existence of god apply just as well to it being a large green frog or some dude with the head of an elephant or jackal or whatever. But of course, *their* holy book is the truth, and everyone else's is full of nonsense.
Many sophisticated thinkers have attempted to demonstrate the existence of a deity* from first principles. St Anselm of Canterbury (1033-1109) demonstrated his "ontological argument", serious discussion of which continues to this day. Descartes found it necessary to assume the existence of a benevolent deity in order to move beyond solipsism.
Of course, philosophers exist within their cultural milieu just like the rest of us. An apparent logical proof for the existence of god was widely welcomed prior to the enlightenment, whereas a similar argument today is usually taken to demonstrate an error in the chain of logic. But nonetheless ...
* this is not necessarily equivalent to Jehovah/Allah/Brahma/Zeus/Wotan/whatever
If you want to make a physicist twitch, ask him *why* 1 over alpha has the value 137.035999...
It's a dimensionless number cooked up by God, The Universe, or whatever you call it.
And whereas numbers like e and PI are readily calculable, no mathematician has ever found a way of creating alpha by deduction.
If I were God, I'd perhaps consider making a multitude of universes with a multitude of alphas along an alpha dimension. Or something like that. Then it wouldn't hurt my head if someone happened to find one somewhere that had the value that we see and started moaning that he couldn't work it out.
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Generally speaking the word "chemical" is reserved for compounds, usually molecular in nature.
It's *elements* that are synthesized in stars, but only up to atomic number 56, iron. Heavier elements are synthesized only in supernovas.
Indeed, "chemical" is a weasel word in this case. "Atoms" would be more suitable and more precise.
Get your nomenclature right, Mr. Chirgwin.
The atomic number (the number of protons in the nucleus) of iron is 26. The element with atomic number 56 is barium.
The atomic weight of iron is about 56 (naturally occurring iron is a mixture of stable isotopes, and the atomic weight is an average [weighted, so to speak] by abundance) of the atomic weights of those isotopes found in any particular sample - although there is not a lot of variation between samples). The weight of any particular isotope is *approximately* the number of nucleons (protons + neutrons, so iron-56 has 26 protons and 30 neutrons making 56 nucleons in all) in the nucleus. The approximation there is because both the proton and the neutron weigh slightly more than 1 unit, and we have to subtract out the binding energy of the nucleus. The atomic or isotopic weight also includes the weight of enough electrons (outside the nucleus) to make the atom electrically neutral, and subtracts out the binding energy of those electrons. The net result is that the isotopic weight of iron-56 is slightly less than 56 units.
The atomic mass unit is standardised such that the isotopic weight of carbon-12 is exactly 12 units.
Webb's findings are very interesting in their own right. Inconclusive, maybe, but that is the nature of science. Rather than settling on a dogma it constantly seeks new evidence.
Inasmuch as it impacts on "anthropic principles" and the like, however, it does not really have much to say one way or another.
The strongest evidence for the "fine tuning" of the universe, or at least the locality, within which we find ourselves actually lies well downstream of cosmology and the physical constants.
It is to be found in abundance n the strong directional patterns (and the inevitability thereof ) which are observed in chemistry and biology.
Moreover, there is no need to invoke any kind of "creator" or "designer", or, for that matter, extravagant multiverse notions, in order to account for this pattern.
A far more economical approach is the wide evolutionary model (which extends well beyond biology ) outlined very informally in my latest book : "The Goldilocks Effect: What Has Serendipity Ever Done For Us?" (free download in e-book formats from the "Unusual Perspectives" website)
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