A former member
Post #: 3
I enjoy reading popular science and a new book is coming shortly from Roger Penrose, entitled 'Cycles of Time'. I was able to acquire a signed copy from him at the Royal Institution where he spoke this week.

The great man has come up with a highly original and mind-blowing idea about the creation of our universe. I haven't yet read the book but I got the idea from what he said. His idea comes from a careful study of entropy - the measure of randomness and disorder in physical things. The 2nd law of thermodynamics says entropy increases. Going back in time towards the Big Bang, entropy decreases into the past and must have been incredibly low at the Big Bang: where did this extremely high degree of symmetry and order in the universe come about? Cosmic inflation is usually given as the answer but there are some problems with that and it may be a partial explanation or just wrong. Penrose thinks the real explanation is that if we tracked back in time through the Big Bang we would find ourselves in a previous incarnation of the universe in which entropy just carries on decreasing as you go on backwards in time. In other words entropy really does increase with time, from one incarnation of the universe to the next. How? I think he said that our accelerating cosmic expansion, which will continue for billions of years, is identically the same as the start of the Big Bang of the next incarnation. Never mind that our expanded universe will be gigantic and of immense age whilst the next will start off tiny and in nanoseconds - space and time are relative and it makes no sense to compare time or distance scales from one universe to another!

In other words the new Penrose cosmology is a sort of steady-state ever-expanding universe in which, from the point of view of any occupant, there was just one Big Bang but in reality they iterate. He said that this could be a testable hypothesis because closer examination of the cosmic background radiation could indicate effects of gravitational waves emanating from the previous aeon.

I might be able to comment more when I've read the book but I like this new idea so much that I thought I'd mention it now.
Andrew Wise
lan B.
user 10895495
London, GB
Post #: 90

Sorry I missed this mail and therefore didn't make any comment at the time.

Camilla and I were lucky enough to be able to attend one of Sir Roger's less-publicly-accessible talks on this very subject, in a room containing about 20 physicists, in the Physics Building at Queen Mary College at Mile End in east London. It was clear that the vast majority of them couldn't follow it, but regarded it as quasi-obligatory to intercept as much as they could. However the talk's convener was very much on top of the subject. Penrose -- already in his seventies -- was even upstaged regarding some of the technical niceties of symbol manipulation when writing down his own calculus: the so-called Twistor Theory. He was unable to carry through an operation and the convener was well ahead of him!

Sir Roger himself admitted that a talented Doctoral student of his, Lane Houston, had effectively overtaken his, Penrose's, own creation.

The concept behind it as far as I am able to understand is an application of conformal invariance. There's an interestingly positivistic twist behind it as well. (A little philosophy. Apologies, but it is in truth a sharply anti-philosophical school of philosophy!) The idea is that, effectively, a run-down, thermally fully equilibrated cosmos ..

(i.e. a cosmos asymptotically near to the condition of maximum entropy, or in the beautiful phraseology of scientific author William Poundstone "the universe will have stabilised"; one estimate being that it will take at least 10^123 years for the largest black holes to convert entirely into highly stretched radio-wave photons via Hawking evaporation, and around 10^1200 years for, say, a diamond to assume a spherical shape as a consequence of "random quantum walks" of its own constitutive carbon atoms!)

.. has no metric. I.e. it no longer has any physical markers -- much less life, machines or "intelligence"; not even matter. Markers whose change of state in any respect whatsoever might act as a clock, and given the constancy of the speed of light, no measure of distance either. That is, even if, per impossibile, one were on board a functioning, fuelled-up space vehicle, the universe would be observed to manifest just one inertial frame: the one in which the spaceship can be regarded as "at rest"!


A former member
Post #: 14
Yes...


I bought "Cycles of Time" a year or so ago, and so far I have read it twice.

I do not yet claim to understand it

lan B.
user 10895495
London, GB
Post #: 92

Well as far as I am able to understand, each maximum-entropy "empty cosmos" hovering near to the Absolute Zero of temperature constitutes the condition for the Big Bang of a successor cosmos, but that offers no consolation to those of us rapidly running out of steam and freezing to death in the "old" universe, losing consciousness, never to return! Due to the lack of metric, we could never "travel through".
A former member
Post #: 17
Indeed. I think I recall that bit.

It's what happens in between that is a bit more challenging.



Peter
lan B.
user 10895495
London, GB
Post #: 93

True. IMV it would be interesting to explore not only the solar system, but also our own galaxy. It couldn't, of course, be "us" who will do it, because evolution hasn't designed us to be able to tolerate a life from birth to death trapped in some stale-smelling tin can amidst utter blackness, breeding successors for a Biblical genealogies'-length of time so that by the time the ship reaches its intended destination the descendants will look back on those who started the voyage through the same distance haze of accreted myth as that from which we today regard Moses.

No. The feat would have to be accomplished by non-biological machines. The future -- "sub-light speed" -- counterparts of the U.S.S. Enterprise will be, not Kirk, Spock, Scottie and Uhura but mechanisms more closely resembling R2D2. My guess is that they'll need to be actually conscious (in the biological sense that we are, but alas no-one else on this Board except Camilla even agrees with me even as to the subject-matter which should form the basis of any investigation into "how consciousness works").

So that's why we need to develop a properly testable, scientific understanding of what consciousness is.

Alternatively, the human race could continue to just sit and moulder here on this planet alone -- and also, just maybe, the Moon, for commercial and military reasons. (Read Henlein's The Moon is a Harsh Mistress. I can't understand why no ambitious director has yet made a blockbuster state-of-the-art special effects science fiction movie from it yet.) Like rats, we're too technically resourceful, numerous, widespread and biologically ruthless to become actually extinct, and so neither wars nor natural disasters will succeed in wiping us out. Continuing the way we have been doing, however -- in what one might describe as the purely "biological/religious" phase, we are merely destined for long-range, homeostatic more-and-more-of-the-sameness. If we wish to achieve anything interesting or worthwhile beyond beinf simply top-dog occupiers of an undistinguished planet, then we can best find a sense of "transcendent" purpose by deliberately designing the culture which will succeed us. (Don't worry; we can design into them some constraining axioms resembling Asimov's famous Three Laws of Robotics!)


A former member
Post #: 18
Speak for yourself Ian...


"It couldn't, of course, be "us" who will do it, because evolution hasn't designed us to be able to tolerate a life from birth to death trapped in some stale-smelling tin can amidst utter blackness, breeding successors for a Biblical genealogies'-length of time"

That sounds exacty like like racing yachts offshore which is one of my hobbies.


lol


Peter
lan B.
user 10895495
London, GB
Post #: 94

Stale air?

Do you do your yachting on the surface of some underground reservoir, Peter?

Puzzled, of Whitechapel


(Replies to your somewhat extended parallel "Consciousness" posting hopefully later today, but I may not have time. Definitely tomorrow though.)
lan B.
user 10895495
London, GB
Post #: 95

Just a minute: It's just struck me that your phrase "it's what happens in between that's interesting" refers not to the period extending into "our" future between now and the time at which the last animals, conscious beings and machines are no longer able to continue functioning, but instead to the transition between one old, clapped-out precursor cosmos and the "next", new, zero-entropy Big Bang and all the cosmic history which will ensue "for it". Is that what you were getting at? Or were you after all referring to the paragmatic challenges which we and our descendants will face?

Clearly, the former question is the one which holds the "frontier challenge" for scientific thinking .. if Penrose, Houston et al are on the right lines, that is!

A former member
Post #: 19

Stale air?

Do you do your yachting on the surface of some underground reservoir, Peter?



You have to understand that the interior of a racing yacht is designed for the stowage sails not currently in use, and the storage of safety equipment required by the safety regulations (but never used).

(Nobody would ever consider carrying safety equipment not required by the regulations, however useful, of course - Save Weight!)


They mean "Save Mass" of course.


The interior of a racing yacht is emphatically NOT designed for the storage of humans (or other intelligent systems)

So it will have an atmosphere to suit the (un-intelligent) life forms it needs to nourish, such as the carbon fibre and kevlar worms that repair the sails.


Of course it is "stale" to human senses:

Salt water and diesel oil, most likely...


Peter
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