h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

If it really doesn't apply at all, none. But sometimes the applications are indirect, and sometimes they are only discovered after the event. I mean, who'd have thought imaginary numbers (like the square roots of negative numbers) would be useful, but in fact they make certain types of computation tractable (so they tell me).

Noggin

But the 'imaginery' numbers still apply in the real world. Or have I missed something?

az

Well they *do* apply in the real world (in that indirect sense), but mathematicians invented them for fun and *then* found a use for them afterwards. So you can never be sure that something that seems to have no application now won't acquire one in the future.

Noggin

Well, except maybe to say that something that is discovered to have a real application *now* always did except we didn't realize it previously?

az

Madent.

By definition there is NOT!

< I understand that space is infinite but bounded. Time is also probably infinite but bounded.>
I take it that they are finite but unbounded!

Well, we can see why we're bound to disagree while our assumptions are so diametrically opposed. Would anyone else care to put in their two cents worth on these basic ideas?



The point is so 'elementary' that you have misunderstood it. The author changed his mind after writing the paper to the (in my opinion, mistaken) view that one of his arguments that time doesn't have a beginning doesn't work, but that the others still do! So he's still saying that time has a beginning.

The rest of your message depends on the false assumption that the universe and time are infinite but bounded. Perhaps you would care to explain. I will happily come back with an explanation of the sense in which they are finite but unbounded in my next message.

toxx

Madent. I think we might be at cross-purposes in that you might mean by 'the first Planck time' the moment AFTER 10^-43 seconds of time, while I mean that period of 10^-43 sec. Either way, what does it matter whether we call the change from nothing to something a 'transition' or a 'beginning' of something? It is clearly a beginning and if it is also a transition of sorts, that doesn't affect my argument.

toxx

Hi, az. Good to see you again.



So let us suppose that we invent the apparently useless concept of zero before we have any money. Later, we come to use money and find that zero helps with our calculations. Did it really have an application from the beginning? I don't think so!

toxx

I think Madent has got his negatives crossed; infinite but bounded seems to be the only one of the four combinations that *can't* be the case. Finite but unbounded is the "state of play" at the moment, but as I've said before I'm not entirely sure what a finite but unbounded time might be.

Noggin

Thank you, Noggin. I was beginning to feel somewhat beleaguered by opponents. Here is my 'take' on finite but unbounded time. Possibly it is shared by nobody else!

Time had a beginning about 14 billion years ago, but it continues into the future without any theoretical limit. It is a potential infinite, although it is actually finite.

The finite extent of time reflects the period from its beginning to the present. Its unbounded nature consists in the fact that it has no limit to its continuation.

toxx

But *I'm* thinking of a finite time unbounded in *any* direction.

Noggin

Member. The idea of infinity derives from mathematics. There is no real world example. Quantum mechanics derives from observation so, of course, the equations and concepts apply in the real world. Hence it is not sound to allege that these ideas are equivalent in some way. We apply quantum theory successfully, but we don't divide by zero lest we get infinity which will only screw up the calculation!

You complain that I refuse to accept that anything counter-intuitive can exist (although I accept quantum theory). Then you say that I suggest the existence of an extra-temporal God which you dub 'supernatural' - presumably on the grounds that the idea of extra-temporality is counter-intuitive to you! It seems to me, Member, that you are hoist by your own petard!

toxx

"I'm not entirely sure what a finite but unbounded time might be."

Well... it *might* be a simple loop (although it probably isn't - nothing in nature is simple). If time isn't simply what stops everything happening at once... if you consider it as an actual dimension, one, single dimension, like length, width or height, then it could quite easily be finite but unbounded. It need only form a continuous loop. It is then, albeit unimaginably large, *actually* finite (if you must...) but has no boundary, because it folds imperceptibly back on itself. You may choose to say there is a "join" at a point singularity in the other dimensions, but to say that is to miss the point a bit, in that (here I go again) you can draw a line anywhere you like and it's equally right/wrong.

The head-splitting thing about this concept is that if time IS finite and unbounded by the fairly simple expedient of being a self-contained loop, then it makes absolutely no sense at all to ask how long it's been like that. It just IS like that. There's nothing outside it, by definition.

The problem is - it solves NOTHING about a creator, because an omnipotent extra-universal creator *could*, if it wanted to, create such a universe, complete with looped finite time. It would have to be created whole, with its time loop complete in every detail - in which case, whither free will?

Or, alternatively, the loop, and everything in it, simply is. It is "eternal", in the sense that it makes no sense to ask "how old is it?", because the very medium you use to measure the age of things loops back on itself. It only makes sense to measure the age of things from the last singularity.

<>

Why would a creator only have created things part-way? Imperfect? Not understandable? Meanwhile, is this creator creating every thought you have ever had or will have, every word you have ever spoken or will speak, every feeling . . .

Why would this creator bother with such a bunch of imperfect bumbling beings such as ourselves? Why didn't the creator create us perfect?

Why do we keep seeing the creator as having human characteristics?

Why do we feel we need to know the origin of the universe? Why do we create gods? Why can't we just accept that it works and we work within it the best we can?

az

Why don't we just go back to the Stone Age? Those were the days!

toxx

Dunno about nothing in nature being simple, Member. The most complex thing around is the human brain, so it ought to be able to understand the rest.

This looped time thing: that's turning it from a continuum into a modulus. We can know that the time is half past, but not half past what. Even if we don't have one it makes logical sense to suppose the existence of the hour hand! Do events repeat the second and nth times round the loop or not? If not, then we have finite but unbounded time that started at the point in the loop where the first lap began and goes on indifinitely. If so, how do the initial conditions get set back for the n+1th circuit that were disturbed on the nth loop? We need to know the answers to these things for an even half-way coherent theory.

I think we should be told.

toxx

"we have finite but unbounded time that started at the point in the loop where the first lap began"

But if there's a finite but unbounded time of this sort, there is no "first lap", any more than you can say that Silverstone has a "first lap". Silverstone is a circuit. It has a lap. It's not the first lap, the second lap or the last lap, it is THE lap.

Yeah, I understand the general idea Member; it just has the same effect on me that putting brown sauce on lobster has on Kryten



I think for all practical purposes that's what we do do; not much option, really. But it's still fun to push at the boundaries from time to time.

Noggin

Member. The course, if never travelled, has no laps. That is like proposing an empty time dimension. That is implausible, as is space with nothing in it.

Once the dimension is populated, we have a race (or a procession, more plausibly) which does have laps. It is up to you to say whether we have the same lap over and over again - in which case, how do altered features of the track like oil slicks and debris get removed for the next repeat of the lap?

Alternatively, events differ between laps and it makes sense to discriminate between them.

toxx

"If, on the other hand, we imagine seeing someone dancing to ballroom music, we may infer that the movements have been deliberately planned, instead of being the twitchings of someone with Tourette's Syndrome!"

But if I see (some)modern dance, or listen to (some)modern music I can detect no deliberate planning, Noh theatre also baffles me. Probably because I don't understand the rules. Other people find opera unendurable.........

On the other hand I read an interview with some people with Tourette's the other day. One of them had a tendancy to shout out inappropriate, but not necessarily obscene, words - for example "monkey". He said other people quite often shouted the words back - in a friendly way.

I think that, knowing me, that's exactly what I'd do.

And if you were in the street, and someone suddenly shouted "monkey!", and someone else (up to that point seemingly unconnected to the former) shouted "monkey!" back, and then the two engaged in a rapid rally of simians, before smiling and going their separate ways........

You might well suppose it was some bizarre form of performance art.

What this says about the argument from design I have no idea,

Can I join as an agnostic pantheist?

Hi gadarene.



Hmmmm, precious little I suspect. You can join as a Catholic Satanist if you like, I guess. I sure won't attempt to deter you!

toxx