Would you go back in time to prevent your own birth for $1b?
- Thread starter warpus
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Crezth
i knew you were a real man of the left
Actually it'd be very helpful if you went to any "troubles" because as it stands you're incomprehensible.
No, it was you who claimed that Einstein said that time was defined as a speed, whatever that is supposed to mean anyway. When we asked you what it meant and where he said that, you decided to ignore the point, and now you are claiming we said these things?
I have also never claimed that gravity does not influence light. If you were to actually read just a couple of points up, you will see me talk about how light moves alongs the geodesics of curved space time. Of course, these geodesics are determined by gravity.
Don't put words in my mouth please.
The last time I had this discussion with a doctor of mathematics and student of physics he agreed more or less on my crude definition of time and even commended me on some of my thought processes although he of course disagreed. I am not knowledgeable enough to debate the formulas and admit my weakness there. I would love to study this further but I don't have the time. Although I agree with almost everything I hear about in physics right away and love to dibble in it, even the most complex of things, this is one of the few things that goes straight against everything I know and every bone in my body.
http://hubblesite.org/explore_astronomy/black_holes/encyc_mod3_q11.html
About gravity and light bending.
If you want an explanation that befits your theory google it, there's tons of youtube videos showing the matrix of spacetime bending and stuff going around other stuff .
So what was bollox about my statement about gravity? I'm totally confounded now.
Crezth
i knew you were a real man of the left
"Common sense" has people reckoning the Earth is flat, so this is really not a point in your favor.
Again I ask: how can gravity bend light if light has no mass?
The answer is not "refraction" because there is no medium to speak of which could induce this effect in space.
Ah I see. I never said that mirrages are caused by gravity in a lens. I just merely commented on that light can be bent and that this does not necessarily mean that we are bending time and space (what the hell is space anyway, can you define it at all to me?)
That is if you re-read my statement and stop looking for flaws and instead try to understand my point of view you will see that my suggestion was: Light can be bent, by gravity AND by other things.
Nice site, did you click the "Do black holes obey the laws of gravity?" link on the right?
My common sense does not stem from my filthy little butthole but from books I've read, people I've spoken to and documentaries I have seen.
Since the physicist agrees with me he can explain it if he can be bothered. I don't agree with your theory, remember?
Again early on I mentioned gravity and Newtons thoughts about it. An entirely correct calculation but an entirely incorrect assumption on what it was and what was causing it. Todays modern asssumption is the bending of space-time.
As space-time is bent then particles who were going straight start going around. Even particles without mass
Crezth
i knew you were a real man of the left
Refraction is caused by a change in the medium that light is traveling through.
By no token is this similar to gravity's apparent bending of light. As I explained (and you ignored, in keeping with your theme of putting your fingers in your ears and singing loudly), since light has no mass there is no reason that gravity should be able to impart a change of momentum on light. As this is how gravity is typically seen as interacting with the universe, it is disproven by this apparent fact and was shelved in favor of the space-bending idea.
edit: It doesn't matter where your common sense stems from, it is no suitable replacement for critical study or examination.
Nice site, did you click the "Do black holes obey the laws of gravity?" link on the right?
I did now, why?
Both refraction and light bending by black holes can easily be explained using the same principle. Light will always take the fastest path* between two points. When the medium changes, the speed of light in both media is actually different (this explanation is rather rough and macroscopic, microscopically one could see it as light travelling at the speed of light through the "empty parts" of the medium and being absorbed and emitted again by atoms. This interactions cause the average speed of the light to be lower. Of course, this treatment is still rather rough and to really explain it you need a full QFT treatment), a bent route will be the fastest, leading to Snell's law. In the presence of gravity, space time itself will be bent and the light will follow the shortest route through this bent space time.
*more rigorosly, the path of least action
Crezth
i knew you were a real man of the left
^ I don't really see how that disagrees with what I said?
You shouldn't be arguing against a theory you don't understand and continually and comically misrepresent.
As stated, until you start rolling out objections of any relevance, your posts are essentially just useless fodder.
You shouldn't be arguing against a theory you don't understand and continually and comically misrepresent.
As stated, until you start rolling out objections of any relevance, your posts are essentially just useless fodder.
Re: Crezth
Well, thinking about it some more, momentum can be useful in explaining the difference between refraction and the effects of general relativity. The amount of bending in refraction depends on the momentum (~energy~frequency~wavelenth~color) of the light, leading to the fact that a prism will split up a white light beam into several colors. Refraction is caused by interactions between light and matter (the medium) and these interactions depend on the energy
The effects of general relativity don't depend on the properties of the photon though. Red and blue light follow the same geodesics. The image of a star can be changed by passing near to a black hole, but the red and blue will end up in the same place in the image. (Of course, both could be Doppler shifted). This indicates that the effects of relativity are not effects of the photons themselves, since the effects don't depend on the properties of the photons, but of the space time they propagate through.
Well, thinking about it some more, momentum can be useful in explaining the difference between refraction and the effects of general relativity. The amount of bending in refraction depends on the momentum (~energy~frequency~wavelenth~color) of the light, leading to the fact that a prism will split up a white light beam into several colors. Refraction is caused by interactions between light and matter (the medium) and these interactions depend on the energy
The effects of general relativity don't depend on the properties of the photon though. Red and blue light follow the same geodesics. The image of a star can be changed by passing near to a black hole, but the red and blue will end up in the same place in the image. (Of course, both could be Doppler shifted). This indicates that the effects of relativity are not effects of the photons themselves, since the effects don't depend on the properties of the photons, but of the space time they propagate through.
Crezth
i knew you were a real man of the left
It's important IMO to outline why we can't just say "gravity bending light is a type of refraction," but fair enough. I admit I'm taking a roundabout tack. The point remains that it demands a new model of gravity, which general relativity happily substitutes.
e: yeah, your new post is very helpful, especially the second paragraph.
Don't let the door hit your ass on the way out.
Well, if you want to show the difference between Newtonian gravity applied to light and General Relativity, then the Eddington expedition is usually the answer. General relativity predicts twice the Newtonian value for the bending. Already in 1919 Eddington tested this prediction. General Relativity was right. Of course, this requires formulas and number and trust in "the scientific community", which might be problematic in some discussions.
See e.g.
http://en.wikipedia.org/wiki/Tests_of_general_relativity#Deflection_of_light_by_the_Sun
http://en.wikipedia.org/wiki/Arthur_Eddington#Relativity
See e.g.
http://en.wikipedia.org/wiki/Tests_of_general_relativity#Deflection_of_light_by_the_Sun
http://en.wikipedia.org/wiki/Arthur_Eddington#Relativity
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