Theory of relativity, Big Bang, Time, Random etc..

[James]

If like me you are stoopid, but interested, when it comes to physics you may find this useful ...

 

http://www.plunks.free-online.co.uk/

 

I know we asked this question on the old board but ...

 

Who believes in the Big Bang theory ? Do you believe that there has always been a universe, or do you believe that there was once a beginning - and if so do you believe there will be an end ?

[nuthead53]

I believe that the universe started somehwere, i doubt the big bang theory is correct, and there is many versions of it anyway, but something along those lines started everything.

 

But its something very hard to pathem, for instance, how could a god exist before everything? likewise how could the dust or whatever created the big bang come about? all very confusing and above my normal level of thinking

Edited April 15, 2004 by nuthead53

[James]

agreed mate ! I'm moving away from this concept of a god again but for some strange reason i do feel as though some is in 'control'

 

:s

[Lizard]

QUOTE (James @ Apr 15 2004, 17:29)

agreed mate ! I'm moving away from this concept of a god again but for some strange reason i do feel as though some is in 'control' :s

I'm like that...I don't really believe in 'god' per-sé...but believe in 'something' spiritual and all that...perhaps it's my paralysing fear of death that's influencing my ideas here

[Lisa]

Im a great believer that everything has a beginning & an end!! you cant get something from nothing, it has to have an intial start IMO!!

[Chris Hutchinson]

I believe in Hawkings 'big bang' proof....I personally cant see anything wrong with what he has said (although a lot of it is waaaaaaay over my head!), but I disagree with there being a point where time and space do not exist

 

I just dont understand how something can appear out of nothing - especially the size of the universe, and if nothing existed before it, how can space even exist on a planar level??

[Chris Hutchinson]

QUOTE (Lisa @ Apr 15 2004, 18:26)

Im a great believer that everything has a beginning & an end!! you cant get something from nothing, it has to have an intial start IMO!!

yeah - they think the universe will start collapsing again over the next billion years or so (the rate of expansion is slowing down) which means it must eventually have an end...does it??

[russelldust]

I once had a kind of moment of revelation whilst watching a science programme in a Japanese hotel room when I was utterly jet-lagged.

 

In a nutshell:

 

Einstein 'proved' that on the scale of incredibly large things (i.e. the universe and space and time), that time is effectively fixed (i.e. past, present and future already exist- time is merely the movement from one state to another. So if we could travel at or faster than the speed of light (which is also impossible because only objects with no mass can do so) then we could travel back in time.

 

He made time trave possible (at least in theory).

 

Using logic, this therefore means that all things are pre-determined (as past, present and future pre-exist). i.e. Fate is true- at least for the scale of massive things.

 

 

Quantum mechanics...

 

deals with the movement of incredibly small objects. And what this seems to prove is that many things are entirely dependent on the movement of electrons as they 'jump' from one energy level to another.

 

And electrons act in a ramndon manner (they can be 'observed' over time and a 'probability graph' drawn to see more-or-less where they are likely to be, however, predicting exactly where they can go next is impossible).

 

This means that on the very very small scale randomness exists.

 

 

So how is it possible that on the scale of the universe for things to be pre-determined, but on the sub-atomic scale things to be random?

 

 

I'm not a scientist so this is not supposed to be comprehensive but it's my understanding of the programme and the fundamental paradox between the theory of general relativity and quantum mechanics (both of which have been tested and 'proven' to be accurate).

 

I don't actually believe in god, but I suspect the closer we come to discovering the meaning of everything, the more likely that there really is a higher power behind things...

 

(most 'major' scientists have been deeply religious people).

 

R

 

 

[Alex]

Random isn't all that random.

[LiquidEyes]

QUOTE (russelldust @ Apr 15 2004, 19:47)

This means that on the very very small scale randomness exists... ...the fundamental paradox between the theory of general relativity and quantum mechanics (both of which have been tested and 'proven' to be accurate)

Well-placed inverted commas, Russ.

 

I have never managed to get my head around how you can "prove" that something is random. You can only hypothesise that things are random.

 

Everything appears random until you understand its inner workings ... so we can't possibly know that (for example) electron behaviour is truly random unless we know everything that there is to know about electrons. We have only hypotheses.

 

It is my belief that there is only "pseudo-randomness" - things appear random because the rules that govern them are so complex... in the spirit of chaos theory, "butterfly effects", etc.

[Scream]

to question the random thing, i believe there is no thing as random as eventually give it enough time it will repeat the same pattern. It's just the way it is. So i agree with Andrew in that there is only "pseudo-randomness".

 

But to question the big bang, we can also look at the M-Theory. Time is dynamic. For example if you stood on the side line watching the 100m sprint your time perception would be different to those who are running the race. There time would be in fact slower than yours. This is what gives rise to one of the "possible" ways of time travel. But as mentioned before about the M-Theory it also ties in with the SuperString Theory. This goes into i think 14D now. 14D i believe is another form of time. This is how we explain other universes of different shapes and sizes floating about in what they hypothise is anti-matter i think.

 

It's hard for us to think that something just is, it has no start and has no end. We know the universe is slowing down in size, which suggests it's growing, so it must of had a starting point.

 

but then again what is that background hiss we detected that is all around us? The start of the universe?

[Guest Kether]

The reason we can't comprehend what was there before the big bang is because we only have the ability to think in 4 dimensions: the 3 dimensions we exist in, and time.

 

How theoretical physicists have managed to come up with 14 dimensions is beyond me, but then I'm a chemist.

 

Russ> I disagree slightly with your description of the behaviour of electrons. AFAIK, They don't behave randomly.

 

Firstly they, have their own wavefunction to describe their motion as outlined by Schrodinger. Secondly they exhibit particle behaviour and are subject to all the forces that we are subject to such as gravity/repulsion and the spin of other quantum objects.

 

It's the sum of all these interactions which makes it hard to calculate just exactly how an electron will behave. It's usually quite possible in systems such as in a Hydrogen atom but as you go up through Heliem and the heavier elements we find it impossible.

 

Also, the way electrons behave, the energy is quantised. They have to obey particulary strict rules regarding what energy levels and quantum numbers they can attain.

 

I think what you were trying to get at is the heisenberg uncertainty principle which states you cannot know where an electron is with any certainty at any time and know its kinetic energy. The trade off is the wave function where you can draw an electron density map and say that the electron is likely to be here a certain amount of the time.

 

The behaviour may seem random as we're unable to provide the models to predict it but as electrons are subject to the same forces as everything else. How is this random behaviour?

[LiquidEyes]

QUOTE (Kether @ Apr 15 2004, 22:52)

The behaviour may seem random as we're unable to provide the models to predict it but as electrons are subject to the same forces as everything else. How is this random behaviour?

Cheers Kether. Essentially that was my gut feeling, but clearly you have a much greater depth of knowledge than do I on this subject!

[alasdairm]

QUOTE (Chris Hutchinson @ Apr 15 2004, 11:36)

...and if nothing existed before it, how can space even exist on a planar level??

you have to go back to hawking for the explanation.

 

assume time "started" with the big bang. asking what happened "before" the big bang is like asking what's north of the north pole. there's no (simple) answer because the question doesn't make any sense.

 

alasdair

[James]

hey, some excellent replies and certainly more for me to think & read about.

 

I find as I get older questions like this are becoming more and more important to me - not because I want to live forever or anything - I just find it much more facinating now.

 

"Random" - never really thought about this until I read your replies - I agree, I dont see how anything could be truly random - everything is being affected by the forces around us (as someone said above). I guess we should question the root cause - the force - is that random ? :S

 

Time - agreed that past/present/future all exist at the same time - i believe one day it will be possible to manipulate time (not sure whether for ourselves or just for other matter :s)

 

Everyone keeps going on about the size of the universe in terms of how large - what about how small - is it possible that an atom contains other sub-universes :S