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# Can anybody explain general relativity in a nutshell?

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# Can anybody explain general relativity in a nutshell?

30th Oct 2013, 18:07

Join Date: Jan 2003
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Can anybody explain general relativity in a nutshell?

Random thought occurred to me...

Specifically, travelling at or near to the speed of light, here's a hypothetical situation -

Light from Star X takes four years to reach Earth.

When it reaches Earth, it is like looking at Star X four years in the past, because light doesn't age. If light aged (not sure this makes sense but bear with it), then by the time it reached us it would have been travelling for four years, and it would have aged four years (during the four year transit), so it would be like looking at Star X EIGHT years ago, which is not the case. This is how I visualise the idea of time stopping for an object travelling at the speed of light.

Make of that paragraph what you will, I know the second half is nonsense but it is precursor to my real question -

How do we know that the quality of 'not aging' at the speed of light is something not just attributable to light photons? How do we know that it is the act of travelling at the speed of light that halts local time? As opposed to the act of a light photon (specifically) travelling at that speed, carries the attribute of its 'time' halting?

If that question can be phrased for a better answer, how about... Despite the formula (which I understand), WHY does 'local time' stop for an object travelling at that speed? I get that the theory states, in a mathematical format, that for 'A' to equal 'B', 'B' must equal 'A' etc etc, but WHY?

I haven't started drinking yet.
30th Oct 2013, 18:12

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Halfbaked:

Thanks for you little expose'. After reading it my brain burst into flames, causing my cubicle to spontaneously ignite as well.

Couldn't we discuss the relativity of big boobs instead?
30th Oct 2013, 18:16

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RG, I'd rather not talk politics in a thread with scientific material. It might cause a tear in the space-time continuum and render Hillary Clinton desireable via the photons reaching your eyes. You'd then need to poke them out.

Let's not go there, nor then.
30th Oct 2013, 18:18

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If anything rendered Hillary Clinton desirable to my eyes I would not only poke them out but seal them shut with crazy glue just to be sure! (Besides, I made mention of the relativity of big boobs. Hillary has no boobs. )
30th Oct 2013, 18:20

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rgbrock1,

We can call the object a boob, is that any good? The question still remains though, why does it stay eternally youthful instead of dropping like a wizard's sleeve?!
30th Oct 2013, 18:23

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Well, as far as the boob is concerned many do stay youthful in appearance whereas the host has gotten on in the years. However, gravity has they way of doing nastiness to some boobs. Which tend to droop like a bloodhound's ears.

Now, what this has to do with photons, protons, neutrons or neutrinos I have no clue. On the other hand, perhaps photons have a time-stilling effect on the non-drooping kind of boobs. Therefore, the more light of day a pair of boobs see the less likely for eventual droopiness.

Damn, I should have been Einstein.
30th Oct 2013, 18:25

Join Date: Jul 2005
Posts: 520
Talking of First Ladies, I did once have a dream that I was on the White House lawn, unfastening Michelle Obama's yellow dress.

(What I was doing wearing her yellow dress in the first place, I have ABSOLUTELY NO IDEA!!! )

But that was before she got all lardy, obviously...
30th Oct 2013, 18:25

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42...........
30th Oct 2013, 18:28

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Talking of First Ladies, I did once have a dream that I was on the White House lawn, unfastening Michelle Obama's yellow dress.
Hm. I wouldn't have considered that a dream but a friggin' nightmare. Unfastening her dress? Judging by the size of her arms she probably would kick the ass of the undresser from one end of Sunday to the next. And then rip your dick off just for the hell of it.
30th Oct 2013, 18:30
Dushan
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It depends...

The story goes something like this:

Young Albert was married to a Serbian woman from Novi Sad. On Sundays the couple would go to her parents fro lunch, and after lunch the men would sit around the table and smoke and drink coffee. The old man would say to young Albert: "it's all relative, you know", from which he later devised his theory.
30th Oct 2013, 18:54

Join Date: Feb 2001
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HB

Can anybody explain general relativity in a nutshell?
Err, no....."General Relativity" comes under the heading of "The really really difficult theory of life the universe and everything" - OTOH I think the question you pose comes under the heading of "Special Relativity" , as in the chunks of relativistic theory concerning a special/limited situation....so...

How do we know that the quality of 'not aging' at the speed of light is something not just attributable to light photons?
As an example I refer you to experiments surrounding the measurement of Muon decay, e.g.......

Wolfram Demonstrations Project

In a nutshell the faster they go, the longer they take to decay, as measured by a "stationary" observer.

Sorry for drifting off topic, now back to the boobs

Last edited by wiggy; 31st Oct 2013 at 10:07.
30th Oct 2013, 18:59

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When it reaches Earth, it is like looking at Star X four years in the past... If light aged then by the time it reached us it would have been traveling for four years, and it would have aged four years (during the four year transit), so it would be like looking at Star X EIGHT years ago ..
Nope, you're going to have to explain how you arrive at that conclusion. Are you saying that if I've spent 7 hours traveling from A to B I've actually aged by 14 hours because I've, er, aged?

Methinks you should be starting to drink ...
30th Oct 2013, 19:01

That's Life!!

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I'm not related to any Generals!
30th Oct 2013, 19:04

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Hmmm, for the photon leaving star x it arrived at your eyeball the instant it left star x,no time has passed at all, only the information it is carrying is four years old.
ere I think.

Last edited by tony draper; 30th Oct 2013 at 19:29.
30th Oct 2013, 19:23

Join Date: Aug 2009
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general relativity in a nutshell?
Seems to me, that if you were in a nutshell, you wouldn't be able to move very fast at all-just sayin'
30th Oct 2013, 19:41

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It's all magic but it responds to garlic.

...Or is that gravity...?

...Something that starts with a G in any case...
30th Oct 2013, 19:49

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Not only explained - but also to music !

Lid
30th Oct 2013, 21:37

Avoid imitations

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If you were traveling at the speed of light and someone held a big mirror in front of you, would you do a 180 and go back to where you came from, or would you just reflect on it?
30th Oct 2013, 22:07

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the photon leaving star x it arrived at your eyeball the instant it left star x,no time has passed at all, only the information it is carrying is four years old.
Nice..., butt. Even if photon is transmitted instantaneously, the aforesaid arriving info regarding said photon will - in your proposed calculus - be naturally incorporating not just the final integral but all the intermediate states of the path of the photon as it travels from source to observer, tracing a very complex set of wiggles and woggles as Mr. P is pushed and pulled off course in 3 or more dimensions enroute to one's eyeball. The entire history MUST exist as an information entity in continuum, because it is, inherently, we would surmise, associated with that particular photon making that particular transit in n-dimensional space at that one or set of instants in time. Were all the information of the transit not somehow preserved, the observed result could not possibly convey valid information that respects the true gravitational history of the intervening space -- a concept that is the moneyspot premise of modern cosmology and astronomy, n'est ce pas?

Last edited by arcniz; 30th Oct 2013 at 22:11.
30th Oct 2013, 22:10
Psychophysiological entity

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The music is a bit, War of the Worlds, innit?