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"Hawking, Tough Physics and (Conspiracy) Theories"

Did anyone else watch the Hawking program on BBC 2 last night?
For a closet physics fan like myself it was great viewing.
Not only did we get to learn a bit about the fella in question, but it was nice to have someone explain his (early) work fairly clearly. Books are all well and good, but they can be hard work at the best of times.
Which brings me on to Roger Penrose - I was quite shocked to see him crop up in the story. I'm actually reading one of his books at the moment (very slowly), The Emperor's New Mind. Actually I think I picked it up after seeing someone post about it on these forums...
A bit of a surprise though - the title of the book suggested to me he would be a fresh voice standing up to point out the nudity of modern physics theories, in fact it turns out he was part of the discovery of those theories!

Then again I suppose a few decades ago he was pointing out nudity...


So, the begining of the universe* according to Hawking et al (stop me if I'm wrong):
A singularity (where matter, energy space and time collapse under gravity), running in reverse to a black hole, effectively spews everything out.

- But when you ask what was before that 'big bang', you have to remember that, if the theories are correct, time itself collapses in a singularity, and so would only begin from the 'big bang'.
Presumably then can't we vastly simplify to this analogy:
The universe 'before' the big bang is like a paused video tape. The paused video doesn't show what came before in the film, perhaps for the universe there was no earlier film. Nevertheless, you press play and the universe begins.
Hmm...


- Why just one 'big bang'? In an infinitely vast universe we have many black holes (presumably). Why not many reverse black holes?
If that's so, then while time was 'paused' 'before' our big bang, it could have been running for one, or many, other reverse singularities and their resultant galaxies and stuff.
Hmm, clearly we need a name for the 'level' above galaxies but below the universe, to denote all the stuff from one particular singularity. In the absence of another name (that I know of) for this, I'll call it a 'Pin'.
So, planet < solar system < galaxy < pin < universe.
And from our big bang came our pin.

Hang on, wasn't space itself supposed to come from the big bang?
Like for time, there are issues with how one set of space fits in with another in practice which don't really sit comfortably...


Oh well, enough for now. I'll get back to my Penrose book :^)



* Disclaimer - This topic is not about religion, it doesn't preclude or implicate a god in the creation or running of the universe, and doesn't comment on his relationship to the universe in any new way.
If you want to discuss the relationship between your god and physics please start a new thread for it.

Did anyone else watch the Hawking program on BBC 2 last night?
For a closet physics fan like myself it was great viewing.
Not only did we get to learn a bit about the fella in question, but it was nice to have someone explain his (early) work fairly clearly. Books are all well and good, but they can be hard work at the best of times.
Which brings me on to Roger Penrose - I was quite shocked to see him crop up in the story. I'm actually reading one of his books at the moment (very slowly), The Emperor's New Mind. Actually I think I picked it up after seeing someone post about it on these forums...
A bit of a surprise though - the title of the book suggested to me he would be a fresh voice standing up to point out the nudity of modern physics theories, in fact it turns out he was part of the discovery of those theories!

Then again I suppose a few decades ago he was pointing out nudity...


So, the begining of the universe* according to Hawking et al (stop me if I'm wrong):
A singularity (where matter, energy space and time collapse under gravity), running in reverse to a black hole, effectively spews everything out.

- But when you ask what was before that 'big bang', you have to remember that, if the theories are correct, time itself collapses in a singularity, and so would only begin from the 'big bang'.
Presumably then can't we vastly simplify to this analogy:
The universe 'before' the big bang is like a paused video tape. The paused video doesn't show what came before in the film, perhaps for the universe there was no earlier film. Nevertheless, you press play and the universe begins.
Hmm...


- Why just one 'big bang'? In an infinitely vast universe we have many black holes (presumably). Why not many reverse black holes?
If that's so, then while time was 'paused' 'before' our big bang, it could have been running for one, or many, other reverse singularities and their resultant galaxies and stuff.
Hmm, clearly we need a name for the 'level' above galaxies but below the universe, to denote all the stuff from one particular singularity. In the absence of another name (that I know of) for this, I'll call it a 'Pin'.
So, planet < solar system < galaxy < pin < universe.
And from our big bang came our pin.

Hang on, wasn't space itself supposed to come from the big bang?
Like for time, there are issues with how one set of space fits in with another in practice which don't really sit comfortably...


Oh well, enough for now. I'll get back to my Penrose book :^)



* Disclaimer - This topic is not about religion, it doesn't preclude or implicate a god in the creation or running of the universe, and doesn't comment on his relationship to the universe in any new way.
If you want to discuss the relationship between your god and physics please start a new thread for it.

Hurrah! A topic to really get one's teeth into. I'll post something more considered tomorrow, when I get the chance to, but one thing I will say is that I cannot conceptualise nothingness, yet I cannot conceptualise that something has existed forever.

Maybe "nothing" and "everything" exists together in one instance. If you had two (or more) sigularities connected to each other then wouldn't time flow between the two? Maybe we are in a cosmic version of ping pong, galaxies being spewed out from one singulatity and eventually sucked into another one.

Then when it is "full" it spews out the universe and it all begins again. Hence a set of definable laws, gravity and so on. Maybe if there were more than one universe the laws of physics would be different in each instance.

I read "The emporor's new mind" just before my uni interviews (that was 2 years ago) and i remember it being pretty tough to understand. i did actually finish it but if you were to ask me the basis of penrose's argument towards why humans can never be replicated by AI then i wouldn't be able to tell you it. I remember the first chapter or so was alright but once he got onto turing machines it got a bit too much. Actually the only bit of the book i can really remember is where thermodynamics is brought into it because i did a whole project on maxwell's demon. I may endeavour to start reading it again sometime in the not too distant future.

a brief history of time is a really interesting and easy to read book (well in comparison to all these other sciency books). I already knew that penrose and hawking worked together a lot because they wrote "the nature of space and time" together -i started it but then stopped pretty early on.

Physics is pretty interesting stuff...especially quantum mechanics which in my opinion is a bit of a mind f**k. but i think i'll stick to engineering which is far more practical and useful.

Two or more suingularities would have to have space between them. Since space does not exist at the beginning if the universe then they cannot be separated. If in some event they were separated and no other energy was present then the massive gravity from both of them would attract them together and they would become one anyway.

Electrum wrote:
> Two or more suingularities would have to have space between them.
> Since space does not exist at the beginning if the universe then they
> cannot be separated.


Then again, if space doesn't exist at the beginning, they can't really be together either... can they?

However, if one big bang occured, then could it not be possible that somewhere in the space it created (in part of the first one's pin ;^) ), another one occured?



> If in some event they were separated and no
> other energy was present then the massive gravity from both of them
> would attract them together and they would become one anyway.


Of course you'd expect a gravitational pull between the two, but that needn't have yet had the effect of pulling the two together. We don't know what kind of forces or distances are involved...


But if space itself collapses in a singularity, and so forms from a big bang - presumably 'expanding' from the origin(?), it does seem to re-introduce 'what happens at the edge of space?'

Assuming there really is nothing at all inside the event horizon of a black hole, then the matter, radiation, and even time has to go somewhere, or so the theory goes :

"Energy cannot be destroyed, it can only be changed from one form to another"

But of course, we are also told that the laws of physics CANNOT be applied to singularities (black holes). The reason for this is unclear, and unless we fly into a black hole, we'll never know. Of course, this would be certain death using any known methods.

There are other theories that the matter is not really destroyed at all, it is simply transported either to another part of the universe, via a 'wormhole' in the center of the singularity, or transported to another universe entirely (or another dimension). If we were to view this event occuring from the other dimension in question, matter, radiation and time would be exploding outwards from the singularity that exists there.

To me this opens up a plethora of other theories, such as maybe the big bang was one of these events occuring! In another universe/dimension, all of the matter, radiation and time had been sucked into a singularity, and was forced into what we now know as our universe, in one collossal event.

I really don't know enough about physics to know whether any of this is valid, but one of the statements hawking made in his first book was to the effect that only the lay-person knows little enough to ask the really big questions, rather than concern himself with what is possible or impossible.

I'm quite interested in the whole fuss around the speed of light:
Why mass increases with speed, why relative speeds don't 'add up right', stuff like that.

I assume when physicists talk about the speed of light, they mean the speed in a vacuum?

You remember that high school experiment where you pass light through a prism to split it into component colours? Which works by slowing the light within the prism, and so seperating the wavelengths...

And one thing that occured to me.. if gravity attracts light, then surely when light is moving away from a star, that star's gravity slows the light down?

I expect science has explanations for everything, but I want to know them!

Anyone know any books (or anything else) about the details of light physics? Is it covered well in Hawking's Brief History of Time?

read into quantum mechanics...that throws in the idea of light wave/particle duality.
the thing is we know that newtonian laws and quantum mechanics aren totally correct because they conflict with each other.

Loquacious Duck wrote:
> And one thing that occured to me.. if gravity attracts light, then
> surely when light is moving away from a star, that star's gravity
> slows the light down?

it does slow it down. if a car passes you with its horn blaring, as it passes the tone drops. it is the same with light waves, as something emitting light passes you, its wavelength becomes longer and it changes colour (I think from red to violet). this is because the wavelength for violet is far longer than the wavelength for red.

in a black hole, light cannot escape, so we cannot see it at all from outside, but if light travels near a black hole, it can be bent to ridiculous angles, or spiral in to the center and never escape.

> I expect science has explanations for everything, but I want to know
> them!

so much to learn and so little time. and too much beer.

> Anyone know any books (or anything else) about the details of light
> physics? Is it covered well in Hawking's Brief History of Time?

light physics is covered, but it's a while since I read it so I can't remember how much. good books though, both of them.