Roger Penrose Quotes

If you want fantasy... first of all, you have to believe in string theory... these extra dimensions and the D brains... and these D brains are supposed to have collided in the period before the Big Bang and there they come together and produced our Big Bang... and that expands... [T]he trouble... is a strong element of fantasy. We really haven't the remotest idea... what kind of physics is supposed to go on here, but there's a more serious problem... [T]his... has different forms, one... is... in terms of the 2nd law of thermodynamics... and it's related to a geometrical issue... [T]hese pictures are hard to draw.... because the singularity in the black hole doesn't really fit on the Big Bang singularity... It's a stretch of geometrical imagination... [I]t doesn't make them wrong, because... you really do need some fantasy, and this is an example of this possible kind of fantasy that you might need, but I want to give you a different kind which... has some greater plausibility...

[T]here's a version of this a version of this idea which John Wheeler has promoted, which is that in each of these cycles, since nobody really knows what goes on at the crunch, bang stage... you can... invent any physics you like, and one idea... is to suggest that the... fundamental constants of nature might get changed every time you go through one of these cycles... [T]his might help to explain... puzzles that... the constants have to be just such and such in order that life should exist...[etc.] I always have trouble with many of these arguments. It's not at all clear whether you need them or not. They might be true but we don't know. It may be that these numbers are fixed and they might change through each cycle...[etc.] but our current physics... doesn't allow this kind of thing. These are singular states according to classical theory. Maybe if we had quantum gravity... one could imagine such a scheme...

According to this view, the mind is always capable of this direct contact. But only a little may come through at a time. Mathematical discovery consists of broadening the area of contact. Because of the fact that mathematical truths are necessary truths, no actual 'information', in the technical sense, passes to the discoverer. All the information was there all the time. It was just a matter of putting things together and 'seeing' the answer! This is very much in accordance with Plato's own idea that (say mathematical) discovery is just a form of remembering! Indeed, I have often been struck by the similarity between just not being able to remember someone's name, and just not being able to find the right mathematical concept. In each case, the sought-for concept is in a sense already present in the mind, though this is a less usual form of words in the case of an undiscovered mathematical idea.

Understanding is, after all, what science is all about — and science is a great deal more than mindless computation.

The idea of having an ambient space-time of some specific dimension seems to play less of a role of string theory than in conventional physics, and certainly less than the kind of role that I would myself feel comfortable with. It is particularly difficult to assess the functional freedom that is involved in a physical theory unless one has a clear idea of its actual space-time dimensionality.

It seems to me that we must make a distinction between what is "objective" and what is "measurable" in discussing the question of physical reality, according to quantum mechanics. The state-vector of a system is, indeed, not measurable, in the sense that one cannot ascertain, by experiments performed on the system, precisely (up to proportionality) what the state is; but the state-vector does seem to be (again up to proportionality) a completely objective property of the system, being completely characterized by the results it must give to experiments that one might perform.

Does life in some way make use of the potentiality for vast quantum superpositions, as would be required for serious quantum computation? How important are the quantum aspects of DNA molecules? Are cellular microtubules performing some essential quantum roles? Are the subtleties of quantum field theory important to biology? Shall we gain needed insights from the study of quantum toy models? Do we really need to move forward to radical new theories of physical reality, as I myself believe, before the more subtle issues of biology — most importantly conscious mentality — can be understood in physical terms? How relevant, indeed, is our present lack of understanding of physics at the quantum/classical boundary? Or is consciousness really “no big deal,” as has sometimes been expressed? It would be too optimistic to expect to find definitive answers to all these questions, at our present state of knowledge, but there is much scope for healthy debate...

[T]he randomness is measured... by... entropy, and it's telling us that this entropy is increasing with time. ...[I]t can be given a clearer definition ...the idea due to Boltzmann ...we imagine... a ... a space... of a very large number of dimensions, where each point in the space represents a state of the system at one moment. In fact it contains both the positions of all the particles and the momenta (or velocities) of all the particles. So if you know where the point is in this large dimensional space at any moment that describes a particular thing... then the dynamics will tell you where that point moves. So that there will be a unique path through that point, wiggling around somewhere through this phase space.

General relativity is certainly a very beautiful theory, but how does one judge the elegance of physical theories generally?

How is it that mathematical ideas can be communicated in this way? I imagine that whenever the mind perceives a mathematical idea, it makes contact with Plato's world of mathematical concepts. ... When one 'sees' a mathematical truth, one's consciousness breaks through into this world of ideas, and makes direct contact with it ('accessible via the intellect'). I have described this 'seeing' in relation to Gödel's theorem, but it is the essence of mathematical understanding. When mathematicians communicate, this is made possible by each one having a direct route to truth, the consciousness of each being in a position to perceive mathematical truths directly, through this process of 'seeing'. (Indeed, often this act of perception is accompanied by words like 'Oh, I see'!) Since each can make contact with Plato's world directly, they can more readily communicate with each other than one might have expected. The mental images that each one has, when making this Platonic contact, might be rather different in each case, but communication is possible because each is directly in contact with the same externally existing Platonic world!

Beneath all this technicality is the feeling that it is indeed "obvious" that the conscious mind cannot work like a computer, even though much of what is involved in mental activity might do so. This is the kind of obviousness that a child can see—though the child may, later in life, become browbeaten into believing that the obvious problems are "non-problems", to be argued into nonexistence by careful reasoning and clever choices of definition. Children sometimes see things clearly that are obscured in later life. We often forget the wonder that we felt as children when the cares of the "real world" have begun to settle on our shoulders. Children are not afraid to pose basic questions that may embarrass us, as adults, to ask. What happens to each of our streams of consciousness after we die; where was it before we were born; might we become, or have been, someone else; why do we perceive at all; why are we here; why is there a universe here at all in which we can actually be? These are puzzles that tend to come with the awakenings of awareness in any one of us—and, no doubt, with the awakening of self-awareness, within whichever creature or other entity it first came.

Whereas originally the hopes for string theory, and its descendants, were that some kind of uniqueness would be arrived at, whereby the theory would supply mathematical explanations for the measured numbers of experimental physics, the string theorists were driven to find refuge in the strong anthropic argument in an attempt to narrow down an absolutely vast number of alternatives. In my own view, this a very sad and unhelpful place for a theory to find itself.

In its simplest form, the 2nd law of thermodynamics... You imagine... a glass of wine sitting on a table... it falls off and wine splashes out onto the carpet...[etc.] If you just think of this as a Newtonian situation, as the system evolves the thing proceeds according to Newtonian laws, but Newtonian laws are reversible in time... What's not so agreeable [about the reverse] is that it violates the 2nd law...

[S]ome of these regions may be... indistinguishable, for example the air in the room. We might have molecules in some other places. You might like to say we don't care where the individual molecules are. We just care about overall parameters, and so we lump together the systems which look very much the same. ...[L]et's say with regard to macroscopic parameters we lump them together, and so we have these things called course graining cells in the phase space... [Y]ou then say, well let's measure the volume of these regions... <math>V</math>... and the logarithm of that volume is the entropy. This is a marvelous formula due to Boltzmann. This [<math>k</math>] is Boltzmann's constant, the only thing in the formula that wasn't due to Boltzmann... This was named afterwards. I don't think he was particularly interested in constants...

Somewhat more exotic is the idea... by Lee Smolin in his book... [T]hese pictures are a little hard to draw... The difficulty seems... a... drawback. It may mean... something... troublesome about the geometry. ...[W]e have black holes forming ...You must imagine each one of these forming ...take this funnel ...that's supposed to represent the universe ...which expands from the Big Bang and ...its expansion accelerates because of ... or, if you're more boring like me, the cosmological constant ...and according to Smolin, all these black holes, which form at various places, could be the origins of new universes, and you see them sprouting off at various places... [Y]ou can adopt the Wheeler idea of maybe having the constants of nature changing to reach one of these phases.