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Originally posted by Grandmaster baterWow! Very interesting idea! You knowledge indicates you keep up with the latest discoveries on this stuff. Me too. So I'd like to comment on your theory.
one theory that I have is that black holes are simply galaxy's that are travelling away from us at a combined speed which is faster than the speed of light, thus the light from stars in that galaxy never reaches us and the whole galaxy would appear to us a black hole.
As yet, scientists have not disproved Einsteins original theory that nothing travels faster than the speed of light. Yeah, I know they're searcjing for quarks and stuff that might do that, but when you talk about a galaxy moving faster than the speed of light, I don't think the laws of the universe allow that.
Comment?
Originally posted by arrakisTwo galaxies travellling awy from each other at slightly more than half the speed of light each. \but both in the opposite direction. relative velocity????
Wow! Very interesting idea! You knowledge indicates you keep up with the latest discoveries on this stuff. Me too. So I'd like to comment on your theory.
As yet, scientists have not disproved Einsteins original theory that nothing travels faster than the speed of light. Yeah, I know they're searcjing for quarks and stuff that might do that, but when yo ...[text shortened]... faster than the speed of light, I don't think the laws of the universe allow that.
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Originally posted by BowmannWHOA! The speed of light is CONSTANT! It doesn't change between a vacuum and air!
The former is "the speed at which light travels", and that speed varies depending on the medium: fastest in a vacuum, a little slower in air, two thirds as fast in glass etc.
The latter is generally used to mean "the universe's speed limit". This is "the speed of light in a vacuum".
Example: In water, light travels at about 0.75 c. Other particles can therefore go "faster than light".
Ridiculous? I don't think so.
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Originally posted by arrakisQuarks? Presumably you mean "Tachyons".
Wow! Very interesting idea! You knowledge indicates you keep up with the latest discoveries on this stuff. Me too. So I'd like to comment on your theory.
As yet, scientists have not disproved Einsteins original theory that nothing trav ...[text shortened]... t, I don't think the laws of the universe allow that.
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Galaxies at the edge of the Universe do indeed appear to be travelling faster than c (or "the speed of light," as you like to call it).
How so? Well, it has to do with General Relativity and the expansion of spacetime itself...
Originally posted by BowmannHmmm. So you ARE SAYING THAT (oops) at the outer edges of the cosmos, that everything is moving at a greatly accelerated rate to the more central parts, therefore, perhaps enrgy light matter are also moving faster in a relative way?
Quarks? Presumably you mean "Tachyons".
Galaxies at the edge of the Universe do indeed appear to be travelling faster than c (or "the speed of light," as you like to call it).
How so? Well, it has to do with General Relativity and the expansion of spacetime itself...
Originally posted by BowmannB> Quarks? Presumably you mean "Tachyons".
Quarks? Presumably you mean "Tachyons".
Galaxies at the edge of the Universe do indeed appear to be travelling faster than c (or "the speed of light," as you like to call it).
How so? Well, it has to do with General Relativity and the expansion of spacetime itself...
A> I said quarks and stuff... there's not just Tachyons either.
B> Galaxies at the edge of the Universe do indeed appear to be travelling faster than c (or "the speed of light," as you like to call it).
A> NO, they don't!
B> How so? Well, it has to do with General Relativity and the expansion of spacetime itself...
A> This question refers to what?
Originally posted by jimslyp69Sort of. It's like a stretching of the "fabric" of the cosmos itself. Taking that into account, there is in fact no violation of the speed-limit, c.
Hmmm. So you ARE SAYING THAT (oops) at the outer edges of the cosmos, that everything is moving at a greatly accelerated rate to the more central parts, therefore, perhaps enrgy light matter are also moving faster in a relative way?
And LET'S NOT FORGET (you've got me at it now!), this expansion appears to be accelerating...!
Originally posted by arrakis'Quarks and stuff' - And that makes your statement clear?
B> Quarks? Presumably you mean "Tachyons".
A> I said quarks and stuff... there's not just Tachyons either.
B> Galaxies at the edge of the Universe do indeed appear to be travelling faster than c (or "the speed of light," as you like to call it).
A> NO, they don't!
B> How so? Well, it has to do with General Relativity and the expansion of spacetime itself...
A> This question refers to what?
'NO, they don't' - Ohhh, yes they do!
'This question refers to what?' - It was a rhetorical question, connected with the line immediately above.
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Originally posted by BowmannBowmann, sorry you felt the need to shoot me down in flames. I was simply trying to get a conversation going about the universe.
There's a lot of nonsense written in this thread.
[b]The bods seem to think that at the centre of each galaxy is a black hole that regularly, every few 100,000 billion years, sucks all matter into it, compressing it and then spits it all out again as stars in a great big bang.
If they do then they're wrong. And do you realize just how much "time ...[text shortened]... ed to read up on Special Relativity.
As you can tell......I'm bored!
I can indeed.[/b]
And despite your efforts I seem to have succeeded. This forum does have a heading general topics. I was not aware that I have to be a professor on a subject to post something?
I was reporting what I had read on the Hubble website. There is an interesting report re. stars from a galaxy which IT says an astronomer has discovered the light seems to be diminishing and THEY say that it proves that galaxies are moving away from each other at a combined speed of more than the speed of light.
I also said that I don't pretend to know about this stuff.
Obviously, with your comments you know everything about the universe!
PS. Did I read somewhere that your great grandad once replied 'poppycock' when someone suggested that the earth was round and not flat!
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Originally posted by Grandmaster baterApologies if I seemed rude, but I do read an awful lot of gibberish on this subject.
Bowmann, sorry you felt the need to shoot me down in flames. I was simply trying to get a conversation going about the universe.
And despite your efforts I seem to have succeeded. This forum does have a heading general top ...[text shortened]... ck' when someone suggested that the earth was round and not flat!
Could you post the URL of the page where you read this? I'll take a look at it.
Originally posted by BowmannB>'Quarks and stuff' - And that makes your statement clear?
'Quarks and stuff' - And that makes your statement clear?
'NO, they don't' - Ohhh, yes they do!
'This question refers to what?' - It was a rhetorical question, connected with the line immediately above.
A> My statement was more correct than your criticism of it. 😛
B> 'NO, they don't' - Ohhh, yes they do!
A> Only to the uneducated...
B> 'This question refers to what?' - It was a rhetorical question, connected with the line immediately above.
A> Sounds like you need to read more about how to write clearly.
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Originally posted by Bowmannhttp://curious.astro.cornell.edu/question.php?number=575
Apologies if I seemed rude, but I do read an awful lot of gibberish on this subject.
Could you post the URL of the page where you read this? I'll take a look at it.
Cornell uni. Some ineresting questions and answers on the site. This is the one I was talking about. The previous web address posted earlier was about the 'fast star' which has been discovered that appears to have been shoot out of the centre of our galaxy.
Originally posted by Grandmaster baterThat is not the 'Hubble website'. No wonder I couldn't find anything at hubblesite.org.
http://curious.astro.cornell.edu/question.php?number=575
Cornell uni. Some ineresting questions and answers on the site. This is the one I was talking about. The previous web address posted earlier was about the 'fast star' which has been discovered that appears to have been shoot out of the centre of our galaxy.
However, I've read through this page at "Curious About Astronomy" and feel you would be unwise to take too much of what is written on board. I noticed a number of contradictions there. But unfortunately, that's one of the natural downsides of the Web: lots of misleading information and spurious articles.
If you're interested, take a look here for a good basic guide...
http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/FTL.html
Originally posted by ark13
Alright. I get it, but you have to admit, you really pulled that out of your @ss.
Actually, that isn't incorrect. c is the speed of light in a vacuum. Light does actually travel slower through a medium inversely proportional to the refractive index of the medium.
This is what causes effects like refraction. Refraction is caused when light bends when going from a medium of one refractive index to another due to part of the beam reaching the boundary between the mediums before the other which slows down first (or speeds up, depending on going from lower to higher or higher to lower refractive index) before the rest of the beam goes in (not easy to explain without diagrams) hence causing the beam to bend.
It is also possible for subatomic particles to exceed the speed of light within a medium (like water). This causes a bow shock wave which is equivalent to the shock wave you get when breaking the sound barrier. Highly radioactive materials tend to get a bluish glow surrounding it when immersed in water. This effect is called Cerenkov Radiation.
http://dept.physics.upenn.edu/balloon/cerenkov_radiation.html
It is c (speed of light in a vacuum) that is constant.