Evidence for Big Bang cosmology

ISAW

anyone know about evidence for the Big Bang?
Far as I can remember
1. CMB radiation
2. H/He ratio of nueleosynthesis
3. cosmological red shift

there is a 4 isnt there what is it?

ISAW

ISAW wrote:

anyone know about evidence for the Big Bang?
Far as I can remember
1. CMB radiation
2. H/He ratio of nueleosynthesis
3. cosmological red shift

there is a 4 isnt there what is it?

there is the recent Cosmic Neutrino Background but thats just the same as 1 isnt it?

Flukey

Funnily enough, I was reading about this last night. I have a book, which I'd reccommend, called "The Natural History of the Universe" by Colin A. Ronan. It says there are 3 pieces of evidence, much as you have it.

• The fact that the galaxies are all moving away from each other.
• Radiation coming towards us from all parts of the Universe, with equal intensity.
• The expected ratio between deuterium and helium that should exist from the way chemical elements would have evolved since the Big Bang, has been verified.

There is no fourth one mentioned.

ISAW

Flukey wrote:

Funnily enough, I was reading about this last night. I have a book, which I'd reccommend, called "The Natural History of the Universe" by Colin A. Ronan. It says there are 3 pieces of evidence, much as you have it.

• The fact that the galaxies are all moving away from each other.
• Radiation coming towards us from all parts of the Universe, with equal intensity.
• The expected ratio between deuterium and helium that should exist from the way chemical elements would have evolved since the Big Bang, has been verified.

There is no fourth one mentioned.

I met greg B of B squared FH last night! he gave a talk in dublin Castle.

Burbridge, E. Margaret, G. R. Burbridge, W. A. Fowler and F. Hoyle, "Synthesis of Elements in Stars," Reviews of Modern Physics, Vol. 29, No. 4, pp 15-69, Oct. 1957.


In 1957, after years of steady work- aided by advances in nuclear physics and stellar observations- Margaret and Gregory Burbridge, William Fowler and Hoyle published a comprehensive and detailed theory showing how stellar systems could produce all the known elements in proportions very close to those observed to exist.

He added three more. I dont know what he referred to as the theta z and M z relationship. Is Z red shift or atomic number?
And he doesnt accept Big Bang cosmology!

He pointed out that nobody really knows for sure how or when galaxies formed and whether the active nuclei are creating more matter all the time. also he spoke of the "ossilating" theory without a Big Crunch.

Heres something on where the other elements come from. Thats what his (Burbridge) breakthrough was.
http://jan.ucc.nau.edu/~doetqp-p/courses/env440/env440_2/lectures/lec2/lec2.html

He tended to ramble and not get to the point. I love that! But another related issue was that the culture the money the bullying mindset all against any opposition to the Big Bang. It is anti science. and I accept the Standard Model. there are too many tweaks for my liking however. I mean infaltion for example. Okay it makes sense but we add it things when the Universe is too small or too cool. then again everything has to balance but wouldnt exist without "symmetry braking". And I get into arguments here with people who say you have to go and learn the maths before you can talk about it.
To me this is not acceptable. I dont mean that a Lawyer or doctor or priest without maths or physics can have their own pet theory, I mean that the theories are underpinned by philosophical assumptions, some of which we have to accept e.g. homogenity isotropy the speed of light, but others we dont e.g. inflation, early galaxy formation, stars before galaxies etc.
to say "it is right because the maths say so" is not good enough for me!

albertw

ISAW wrote:

To me this is not acceptable. I dont mean that a Lawyer or doctor or priest without maths or physics can have their own pet theory, I mean that the theories are underpinned by philosophical assumptions, some of which we have to accept e.g. homogenity isotropy the speed of light, but others we dont e.g. inflation, early galaxy formation, stars before galaxies etc.
to say "it is right because the maths say so" is not good enough for me!

There is no onus on science to prove theories in such a way that you (or I) will understand them. If I prove a geometric proof and tell someone the conclusion then they can either believe me or go learn geometry to work it out for themselves.

Proponents of the Big Bang need to make the maths work, and that leaves them needing inflation. Opponents of the theory need to prove that that is wrong, or alternativly come up with a theory that explains things without needing to invent inflation.

I don't see why accepting the speed of light is any different from accepting the theory of inflation. I don't understand either in detail, but am happy to accept them and see where that leads. If it goes into a dead end we backtrack to our assumptions and fix them, which may happen with the big bang question.

Flukey

The very nature of science in some ways decrees that we can't prove anything. Every answer leads to another question. We come up with a theory, conduct experiments to prove it which give our predicted results and we accept that. We still could be wrong of course.

The history of science is that time and time again it has overturned things that had been accepted for a long time. Some of Einstein's work overturned Newton's much as Newton's had changed the ideas of those before him. Maybe a century or more from now, scientists will laugh at the ideas we have now and disprove them, much as many past ideas have been shown not to be the case. So, we don't really know, but then that in itself is the beauty of science and what keeps us pursuing it. If we had all the answers, and they were correct, science would die.

ISAW

albertw wrote:

There is no onus on science to prove theories in such a way that you (or I) will understand them.

I dont think I suggested they did. I suggested that what is accepted is underpinned by philosophical assumptions.

Proponents of the Big Bang need to make the maths work, and that leaves them needing inflation. Opponents of the theory need to prove that that is wrong, or alternativly come up with a theory that explains things without needing to invent inflation.

I wasnt saying that either. I was saying more like. Proponents of the Big Bang accept the maths work. But there are many solutions to the equations. the standard solution suggests the Universe should be smallewr and hotter. And that leaves them needing inflation.

I don't see why accepting the speed of light is any different from accepting the theory of inflation. I don't understand either in detail, but am happy to accept them and see where that leads.

so are you just as happy to accept retatder or "tired" light and see where that leads. Or reject homegenity and isotropy and see where that leads?
One could reject inflation and have oscillating universes and other theories and still stay within a philosophical construct bound by the cosmological principles.

If it goes into a dead end we backtrack to our assumptions and fix them, which may happen with the big bang question.

So whay not backtrack before the Big Bang theory? Why not fix it with oscillating universes or "spontaneous creation" of matter?

albertw

ISAW wrote:

I dont think I suggested they did. I suggested that what is accepted is underpinned by philosophical assumptions.

I wasnt saying that either. I was saying more like. Proponents of the Big Bang accept the maths work. But there are many solutions to the equations. the standard solution suggests the Universe should be smallewr and hotter. And that leaves them needing inflation.

Then feel free to learn the maths, resolve the equations and argue that point.

so are you just as happy to accept retatder or "tired" light and see where that leads. Or reject homegenity and isotropy and see where that leads?
One could reject inflation and have oscillating universes and other theories and still stay within a philosophical construct bound by the cosmological principles.

Light works as it is. There is no philosophical construct. If you want to advance oscillating universes then again feel free to add to the literature. http://www.arxiv.org/abs/gr-qc/9510041 or Penrose for a start.

So whay not backtrack before the Big Bang theory? Why not fix it with oscillating universes or "spontaneous creation" of matter?

Because the theory still hasnt ran into a dead end. Research is still ongoing into other less media friendly theories. The best at the moment is still the big bang.

Cosmologists are the greatest 'theory savers' going, but even they eventually will realise that sometimes they are wrong!

ISAW

albertw wrote:

Then feel free to learn the maths, resolve the equations and argue that point.

One does not have to have a degree in theology to say they have solid reasons for not believing the philosophical underpinnings of a belief system.

Science is a belief system. You may well argue about the formal language of mathematics but most of science is not in this realm and even in scientific cosmology there are a myriad solutions. As I pointed out coming into that ther are three piects of evidence that point to an expanding universe which might have been created in a Big Bang. Having a tidy mathematical solution is NOT the proof that that one solution is correct.

Light works as it is. There is no philosophical construct.

Photons are philosophical constructs!

If you want to advance oscillating universes then again feel free to add to the literature.

I think I already stated I am a proponent of the Big Bang. But I referred to the "bully my neighbour" mentality. It isnt healthy.

Because the theory still hasnt ran into a dead end. Research is still ongoing into other less media friendly theories. The best at the moment is still the big bang.

How do you judge "best"?

Cosmologists are the greatest 'theory savers' going, but even they eventually will realise that sometimes they are wrong!

You do of course mean "scientific" cosmologists? Otherwise I would suggest it is turtles all the way down.