Cosmology

[Plane]

http://en.wikipedia.org/wiki/Ekpyrotic


The troubble with tinking big is that there is no limit to it , but there are such tight limits on what we can observe or prove.

[Amianthus]

This is my favorite cosmological model.

[Plane]

This is my favorite cosmological model.

Why?

Doesn't it depend on several unobservable assumptions?

[Amianthus]

Why?

Because it's balanced and symmetrical.

Doesn't it depend on several unobservable assumptions?

So? I can't observe subatomic particles, but I don't disbelieve them because of it.

[Plane]

Why?

Because it's balanced and symmetrical.

Doesn't it depend on several unobservable assumptions?

So? I can't observe subatomic particles, but I don't disbelieve them because of it.

Subatomic particles can be observed , some museums even have cloud chambers available to the public so that you can observe the passage of cosmic rays yourself.

But no one as observed anything like a "brame" nor even its secondary effects.

How far can theory be taken seriously when it depends on speculation and observation of third effects?

[Amianthus]

But no one as observed anything like a "brame" nor even its secondary effects.

A brane detector is being worked on. It takes a bit of time to go from the mathematical model to detecting the evidence of it's correctness. Einstein published his General Theory of Relativity in 1915, it took a number of years to test various aspects of it (some wasn't tested until near WWII, 1934 or so, IIRC).

General Relativity was accepted by many before the final evidence was collected because of it's mathematical elegance. A similar situation exists with the various brane models.

[Plane]

But no one as observed anything like a "brame" nor even its secondary effects.

A brane detector is being worked on. It takes a bit of time to go from the mathematical model to detecting the evidence of it's correctness. Einstein published his General Theory of Relativity in 1915, it took a number of years to test various aspects of it (some wasn't tested until near WWII, 1934 or so, IIRC).

General Relativity was accepted by many before the final evidence was collected because of it's mathematical elegance. A similar situation exists with the various brane models.

Why do we suppose the reality to be elegant?

Or do we adjust our idea of elegance to fit reality?

Or perhaps we expect God to be elegant?

[Michael Tee]

The article didn't mention a single experiment in the works that might help to establish the theory.  IIRC, the Michelson-Morley experiment on the bending of light rays by gravitational fields was used to confirm aspects of Einstein's theories, although I don't recall the time lapse between the theory and the experiment.

This stuff is so far over my head that I wouldn't dare to express an opinion on it either way.  I don't even know what they mean by a 3D object "moving in multi-dimensional space."  It'd probably take a whole course in math just to get my head wrapped around that concept.

We had a very entertaining math teacher in Grade 11, a Clifton Webb look-alike with the same English accent, who gave a special lecture on "The Fourth Dimension," which was even taped for national TV once.  As I understood it, the Fourth Dimension was Time.  If a 3D object was moving, its dimensions had to be indicated on all three axes but also on a fourth (Time) axis because its position was always changing with the passage of time.  But there was no explanation for any dimensions beyond the 4th.

[Amianthus]

IIRC, the Michelson-Morley experiment on the bending of light rays by gravitational fields was used to confirm aspects of Einstein's theories, although I don't recall the time lapse between the theory and the experiment.

You don't recall correctly. That experiment disproved the idea of an "aether" that was a medium for light. And Michelson-Morley was about 30 years BEFORE Einstein published his works. I think Einstein was just being born around that time.

The article didn't mention a single experiment in the works that might help to establish the theory.

Because I get my information from sources other than this one article.

[Michael Tee]

Sorry.  You are correct.  Here's the experiment that I was thinking of that I had confused with the Michelson-Morley experiment (from Wikipedia article "Einstein:"

<<However, in May 1919, a team led by British astronomer Arthur Stanley Eddington claimed to have confirmed Einstein's prediction of gravitational deflection of starlight by the Sun while photographing a solar eclipse in Sobral northern Brazil and Principe.[29] On November 7, 1919, leading British newspaper The Times printed a banner headline that read: "Revolution in Science ? New Theory of the Universe ? Newtonian Ideas Overthrown".[34] In an interview Nobel laureate Max Born praised general relativity as the "greatest feat of human thinking about nature";[35] fellow laureate Paul Dirac was quoted saying it was "probably the greatest scientific discovery ever made".[36]

<<In their excitement, the world media made Albert Einstein world-famous. Ironically, later examination of the photographs taken on the Eddington expedition showed that the experimental uncertainty was of about the same magnitude as the effect Eddington claimed to have demonstrated, and in 1962 a British expedition concluded that the method used was inherently unreliable.[34] The deflection of light during a solar eclipse has, however, been more accurately measured (and confirmed) by later observations.[37]>>

My point was that whereas Einstein's theories were confirmed by experiments designed to test them, there seem to be no experiments designed to test the brane theory.

[Amianthus]

My point was that whereas Einstein's theories were confirmed by experiments designed to test them, there seem to be no experiments designed to test the brane theory.

And you'd be wrong in this as well.

Branes are detectable as gravity distortions over short distances. Here is a link describing a variety of tests underway to detect these distortions:

http://flux.aps.org/meetings/YR04/APR04/baps/abs/S690.html

[Michael Tee]

<<And you'd be wrong in this as well.>>

Try reading for comprehension next time.  I didn't say there WEREN'T any experiments designed to test brane theory, I said there didn't SEEM to be any, i.e., none of the posts in the thread mentioned any specifically. 

Not only that, the page of tests that you posted would have been invisible to a Google search - - the word "brane" or "branes" didn't appear once.  You'd have had to look for keywords such as TeV physics, which would never have occurred to a layman.

[Amianthus]

Try reading for comprehension next time.  I didn't say there WEREN'T any experiments designed to test brane theory, I said there didn't SEEM to be any, i.e., none of the posts in the thread mentioned any specifically. 

I guess you missed reading this post then:

A brane detector is being worked on. It takes a bit of time to go from the mathematical model to detecting the evidence of it's correctness. Einstein published his General Theory of Relativity in 1915, it took a number of years to test various aspects of it (some wasn't tested until near WWII, 1934 or so, IIRC).

General Relativity was accepted by many before the final evidence was collected because of it's mathematical elegance. A similar situation exists with the various brane models.

Not only that, the page of tests that you posted would have been invisible to a Google search - - the word "brane" or "branes" didn't appear once.  You'd have had to look for keywords such as TeV physics, which would never have occurred to a layman.

I also said that my information came from other sources than this article. In this case, I have a number of friends that work in this field.

[Plane]

Cosmology is fluid.

A great number of people are busy wondering why things are as we observe them and not otherwise the ones who attempt this on the grandest scale are cosmologists.

Making some of the highly mathematical and highfalutin theory's accessable to the common man is my hero Stephen Hawkins.

"A Brief History of Time" contains little math above grade school level but is still good at conveying concepts to make clear the most arcane musings of our intellectual elete by simplification.

Of course the details require some dense math but the basic concepts are simply fun to bat around.

http://www.generationterrorists.com/quotes/abhotswh.html

Any physical theory is always provisional, in the sense that it is only a hypothesis: you can never prove it. No matter how many times the results of experiments agree with some theory, you can never be sure that the next time the result will not contradict the theory. On the other hand, you can disprove a theory by finding even a single observation that disagrees with the predictions of the theory... Each time new experiments are observed to agree with the predictions the theory survives, and our confidence in it is increased; but if ever a new observation is found to disagree, we have to abandon or modify the theory.

[Michael Tee]

My apologies.  I DID read your post about the brane detector being "worked on."  I didn't equate that with devising an experiment to prove brane theory.  I guess designing and building a device to detect branes and then putting it to the test could be considered as one big experiment to test the brane theory, I just didn't see it that way at the time.