Development of the universe

The French have always had an affinity for developmental models of historical processes. Comte famously argued that societies had four stages to go through. Lamarck held that species were like individual organisms that had a youth, maturity and senescence. And more recently Teilhard held that evolution was heading towards a single goal. It's the philosophy of the Great Chain made temporal...

But maybe there are more general properties of historical processes that might be empirically determined to be either evolutionary (contingent) or developmental (systematically predictable)? After all, stellar "evolution" is regular and predictable. Well, that's the idea behind Evo-Devo Universe, a conference on which is being held in Paris, 8-9 October. If they pay for my flight and accommodation, I will submit a paper by the deadline, 30 July.

But I think that evolution is best characterised not by the notion of contingency or "hasard", but by the notion of common descent, in which there is contingency, but also retention of the past and modification to it, allowing us to identify some of the history and group things naturally.

While there may be a useful set of contrasts here, I do not think we can generalise to physics from biology. Instead we learn how physics plays out in one particular part of the universe, as biology on earth. Fundamentally, it is a category error to talk about the (biological sense of) evolution of the universe. It's too much like the Macrocosm/Microcosm error of the alchemists: as above, so below, and vice versa. The universe is under no obligation to behave everywhere the ways that it does on earth, nor in studying the local do we always learn about the global...

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The universe is under no obligation to behave everywhere the ways that it does on earth, nor in studying the local do we always learn about the global...
Quick someone dig up Einstein and tell him there's no obligation on light to maintain constant speed in a vacuum.....

By Brian English (not verified) on 25 Jun 2008 #permalink

Whoops. My bad. I must say that 'I didn't expect you...' rhetorical phrase has reminded me of school when I used to muck about. Have you considered being a teacher?

Still your first clause suggests that we can't rely on measurements taken on Earth to have any generalization throughout the rest of the universe. The second clause doesn't change that.

By Brian English (not verified) on 25 Jun 2008 #permalink

I am a teacher. Sure, they're undergraduate and honours university students, but I still use the same techniques that my sixth grade teacher, Mr Dewan, used.

And I think the first clause is correct. We need to take measurements elsewhere in the universe to be sure that the same properties apply. Consider the strength of graviation: we measure it locally to many degrees of precision, but there is some dispute about whether it applies more generally (MOND), and the only solution is to take exact measurements directly or by proxy elsewhere.

I'm not disputing the first clause. Just joking that perhaps we can question relativity theory where it requires that light have the same speed in a vacuum throughout the universe.

We can measure it here on Earth, and possibly do a good job in our solar system too, but the universe is a tad larger than that, so to justify relativity theory's insistence that light does indeed travel at a certain speed in a vacuum at any given point in the universe wouldn't we need to test it if we are not justified in assuming that universe behaves the same way in all places?

Anyway 'twas a bad attempt at humour on my part. And probably my understanding of relativity theory is way off anyhow.

By Brian English (not verified) on 25 Jun 2008 #permalink

Part of the problem is that the word "evolution" has also has an older meaning which is essentially equivalent to what biologists now call "development" - the unfolding of an inbuilt plan (with possible effects from the external environment). "Stellar evolution" makes perfect sense so long as you interpret the "evolution" using the older meaning. The hypothesis that _universes_ evolve to produce baby universes better fitted to produce more baby universes is, ah, speculative.

Now John, your statement "The universe is under no obligation to behave everywhere the ways that it does on earth ..." is a rather strong denial of the principle of uniformity. I'm quite sure that the large majority of physicists would disagree with you, even though it is true that physics types are continuing research to assure themselves that this principle does, indeed, obtain.
Recent research conducted by an international team of astronomers shows that one of the most important numbers in physics theory, the proton-electron mass ratio, is almost exactly the same in a galaxy 6 billion light years away as it is in Earth's laboratories - approximately 1836.15. The paper is Murphy et al., Strong Limit on a Variable Proton-to-Electron Mass Ratio from Molecules in the Distant Universe, Science Vol. 320. No. 5883 (20 June 2008), pp. 1611-1613.
MOND does not dispute the uniformity of the gravitational constant; it simply questions whether or not Newtonian dynamics is a sufficiently good approximation at all scales,

Now John, your statement "The universe is under no obligation to behave everywhere the ways that it does on earth ..." is a rather strong denial of the principle of uniformity. I'm quite sure that the large majority of physicists would disagree with you

Wouldn't that depend on whether or not "everywhere" lies outside our light cone? If the location under consideration hasn't been causually connected to us since the moment of the big bang...

jeff, the light cone associated with your particular coordinates in four dimensional space time may be considered to be a set, say set A. If, within that set a physical principle applies at one position, say principle z at your position, then the principle of uniformity says that z will apply at all other positions within set A. Now consider an observer at some position different from yours, in space time. That observers light cone can be considered to be set B, a set that is not coincident with set A, but intersects set A. Within the intersection of set A and set B physical principle z must apply. Again, the principle of uniformity states that if principle z applies anywhere in B, then it applies everywhere in B, and hence to anywhere in the union of A and B. By extension, to sets C, D, etc. principle z applies everywhere within the four dimensional space time that is our universe.
Of course if cosmologies like eternal inflation, string theory, etc. that posit multiple universes are more than elegant mathematical exercises, there may exist other universes with different principles.