Aeschylus

umm, i'll look round for some sources. einstien did not 'make' the equations although he did put soo much work into prooving it, deriving at it and so on that it is regarded as his because without him it wouldnt have been much use in that it wouldnt have been proved etc, however it was not him who 'made' it.

e = mc^2 is Einstein's, the Lornetz transformations and Lornetz-FitzGerald contraction and time dialtion aren't. What Einstein did was to to gather up all these sets of equations and but them into a single self-consistent theory in which they can derived from more basic axioms.

Wouldn't it be possible to polarize the spin alignment of an entangled particle located at one end' date=' then check the polarization on the other end at a different time? Then if so, someone could continue changeing the spin on location 1 at a set time interval (not observing, but changing the spin alignment with polarization), and location 2 would observe the spin, moments after the assumed polarization was done at location 1. Continuing this process should result in binary data unidirectional. For a return response you could use the same proccess in reverse using another entangled pair.

 

Example:

 

Time Action

-------------------

16:04:01 Loaction 1 polarize spin axis x up

16:04:02 Location 2 observe spin axis x

16:04:03 Loaction 1 polarize spin axis x down

16:04:04 Location 2 observe spin axis x

16:04:05 Loaction 1 polarize spin axis x up

16:04:06 Location 2 observe spin axis x[/quote']

 

No it's not possible, though you alter the combined wavefunction of the two particles, polarizing one of them does not affect the expectation value of the other.

Yeah' date=' after seeing that I remember thinking up something similar a while ago now. The idea I had would be to just travel outside our galaxy and come to a dead stop, you wouldn't need to travel to the centre of the universe. Since you were at a dead stop the opposite time dilation effect of slowing should play more of a role on you, because you'd be travelling as slow as possible from the speed of light.

 

Wouldn't that be the time frame used on a universal scale?? Adding the speed of whichever heavenly body you were examining to find it's relative time or something like that?? [/quote']

 

read my reply to the post you quoted.

I am amused at the fact that many of the world's greatest scientists routinely use the term "space-time continuum" because it sounds like words from fools.

Well small things please small minds. The term "spacetime continuum" refers to a mathematical construct, not some vague cod-philosophical concept.

Lukis Whayn

Very good, now go away and learn some physics.

[math]t=\frac{t}{\sqrt{1-\frac{V^2}{c^2}}}[/math]

 

[math]m=\frac{m}{\sqrt{1-\frac{V^2}{c^2}}}[/math]

 

[math]d=d{\sqrt{1-\frac{V^2}{c^2}}}[/math]

 

and' date=' of course, the famous one: [math']E=mc^2[/math]

 

How did Einstein derive these equations?

It should be:

[math]t = \gamma t_0[/math]

etc.

The formulas for time dialtion and lenght contraction were not Einstein's. The formula for Length contraction (usually known as Lorentz-Fitzgerald contraction after the two phycists that discovered it independtly) precedes the theory of special relativty by 10 years, I believe time dialtion came only a yera before the STR.

All these equations can be derived from the Lorentz transformations (indeed the formulas for Lorentz-Fitzgerlad conbtarction and time dialtion really are just incomplete versions of the Lorentz transformations), the first and third ones are very easy to derive.

The second equation, these days wold be considered to be wrong as mass m is taken as the rest mass and thus invariant. E = mc^2 is not particualrly easy to derive, but can be derived by considering the absrption of a photon.

E=mc^2 is not einstiens own formulae

 

not everyone is aware of this and there are not many sites which say it plainly and simply' date=' here are two though:

http://www.vttoth.com/emc2.htm

http://www.100megsfree4.com/farshores/rm04ein.htm[/quote']

 

The first article complains about people calling it 'Eisntein's equation' (if it's called anything it's called the mass-energy equation) it does not say that Einstein w3as not the first to derive it. the second artilce is a load of crap E = mc^2 is a relativistic euation and yet the article tries to attribute it to Newton! As far as know Einstein was the first to derive this equation (actuially there was recently some controversy over whether an unknown itlain physicst may of just got their first).

Did I not just describe it? I just said that R is an infinite number.

In that case you are certianly not talking about the real numbers.

Buy a book on analysis. The real numbers are closed under additon so for any x, x + 1 is also a number of the rela numbers, further x < x + 1, therefore there is no largest real number (of course it's not enough just to say this, it must be proven from the axioms of the real numbers, which is why I suggest you buy a book on mathematical analysis).

I agree' date=' and have no problem with your logic in the above truths

 

I don`t find them at all helpfull in my understanding of this thread though ([/quote']

 

You see a + 0 = a is what defines zero (in a field), so using this (and the other field axioms) you can show that divison by zero is undefined.

it all looks quite perverted logic to me' date=' Zero = 0 aka NOTHING, and any "proof" to the contrary must be flawed somehow. Hovever convincing it may seem to be on paper.

 

I`m no maths student/grad of schollar in this field, but Zero is just that, Nothing, or at best a symbol to represent "No Content" as in the number 10 = 1 TENS unit and Zero content in the ONES unit, and so on into the kazillions [/quote']

 

Zero is the additve identity that is for any number:

 

a + 0 = a

 

also:

 

a + (-a) = 0

It's usually called Occam's razor, which is the way that the French spelt his name. The person for who it is named is usually called William of Ockham as that is how the village is spelt nowdays, both are acceptable spellings. You have to remember that in the days of William of Ockham there was no such thing as standardized spelling and in England manuscripts were more often written in Latin or French than English.

it doesn't matter which way it is going, matter can't travel at c. who told you it could if it was going the other way?

:Sigh: it's a genral relativistic effect and what do you mean by the 'other way'? Recession velcoties may be greater than c as they are not due to local cooridnate velcoties, but the expansion of the universe itself. Davis and Lineweaver (2000), showed that there must be galaxies in the observable universe with recession velocities greater than c for any reasonable cosmological model.

how does a galaxy travel faster than c? link plz

It's recession velocity is greater than c. Y'know you can google yourself it's not as if there are not a wealth of websites about this.

what makes you think the universe expands at the speed of light? afik, it only contracts at c. it expands @ sub c.

Think carefully what you mean by the universe expands at such and such a speed. Really the rate at which the universe expands is not a speed, it's measrued in units of s^-1. You can certainly talk about recssion velcoties, which may certainly be greater than c (infact the recession velcoties of the furtherest galaxies are greater than c) but these are dependent on distance, so they're not a measure of how fast the universe expands as a whole.

Yup. Not in violation much like firing a single photon in opposite directions causes their motion relative to one another to equal 2c.

Not strictly true as the two photons do not have relative speeds as they do not have refrence frmaes. Taking the limit of the compostion of velcoties law you actually get an answer of c.

I was recently thinking about this as well. And the answer seems quite logical now. Consider this:

 

The sun is not the center of the universe. Nor is it stationary. The speed that pluto is moving' date=' in relation to the earth, is not much different, considering the speed that our sun is moving in the galaxy. And the speed our galaxy is moving. Etc. Etc. I have no idea how *absolutely* fast we are moving, relative to the center of the universe, but might it be theoretically possible that something at the center of the universe, at a perfectly relativistic standstill, would be accelerated through time at a rate directly proportional to the rate at which we age, divided by the ratio of our absolute speed through the universe to the speed of light?[/quote']

 

All motion is rrelative; there is no sauch thing as a 'relativstic standstill', 'absolute speed' or the centre of the universe.

ok, relative to himself, b sees a as ticking slower. relative[/i'] to himself, a sees b as ticking slower. they cant both be right. or are you talking "relative" on some other level.

I am tlaking about the fact that the relative rate at which clocks 'tick' is itself relative.

a is correct for a's frame and b is correct for b's frame there is infact no contradiction.

ok, thanks for the info. but the exact numbers dont really matter much for what i was saying(i think...). because either way, "a" sees "b" as moving away from him, and therefore going through time slower (1.15 seconds per tick) and "b" sees "a" as the one that is moving so from his perspective "a" is ticking slower. it doesnt work out. one of them has to be ticking slower than the other.

It does work, because the rate at which they tick is relative.

with the clocks that were flown around the world, how did they know which one would come out ahead? from the planes perspective the one on the ground was moving away very fast behind it. if speed is reletive then why isnt the one on the ground the one that went slower?

 

if the guy on the plane looked at the ground clock would it look to him like the ground clock was the slower one? because thats the only way i could see this actually working.

if a and b are both travelling with constant velcoity there is symmetry between them,howvere when the clock was flown around the world it was subject to acceleration, so the two obserevrs were not symmetric. It is easy to show that an unaccelarted observer experinces more time between two events than an accelarted observer.

I don't know if this is right or of any help but...

Isn't light speed like a universal time keeper??

The rate that time passes at light speed being universal time' date=' the slower you move the faster you feel like you're moving through time.[/quote']

 

No it's not quite right, there is no universal time and you must remeber that all speed is relative, except that is for the speed of light. Objects travelling at the speed of light don't have refrence frames tho'.

why is that the quote of the week? i go on to mention all the people i tried to talk to about it... i read a book' date=' i asked a bunch of smart people, was there something else i was supposed to do?

 

and no, im not looking for an analogy. i have heard dozens of analogies. i understand the idea(or at least i think i do), i know what the effects supposedly are, i want to understand why.

 

consider the following:

 

a------b------c

 

person "a" is moving left at 1/2c with repect to person "b", person "c" is moving right at 1/2c with respect to person "b". in person "b"s eyes, they are both moving 1/2c faster than himself and will there for experience the effects of time dialation. in person "a"s eyes, "b" is moving 1/2c faster than himself and "c" is moving a full c faster than himself. so "a" thinks "b" is aging at 1/2 speed and "c" isnt aging at all. "b" thinks "a" and "c" are both aging 1/2 speed. who is right? this could work if time dialtion factored in direction. if "a" could be going negative and "c" positive then it would all match up. am i missing something?[/quote']

 

Well strsaight away you have made one mistake, you have assumed velocity is a vector in relativity - it isn't. What this means is that you can't combine two velocities by vector addition, you must use somehting called the compostion of velcoties law and you find that 'a' will actually view 'c's' velocity as 0.8c .

 

You've also got a little muddled about time dialtion, the dialiton factor is not beta (the velocity of the object as a fraction of the speed of light), but gamma given by:

 

[math]\gamma = \frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}[/math]

 

i.e.

 

[math]t' = \gamma t[/math]

 

which means from the point of view of b one tick of both a's and c's clocks will both take about 1.15 secs as opposed to one secs in the rest frma eof the clock.

 

But from the point of view of a, his clock will not appear to be slowed down and he will infact that both b's clock and c's clock will be running slow (one tick on b's clock to him will take 1.15 secs, and c's clock will be even slower taking about 1.67 secs; c will also see the same except it will be a's clock that is running the slowest).

 

Now this may seem like it's paradox, but it's not, as they all see different things as they are in different frames of reference and all of them can consider their measurements of time to be correct in their own refrence frames. This is a very counterintuitve result of relativity, however the effects of time dialtion have been experimentally observed and the explantion is self consistent.

 

To summarize: time is frame dependent.

If your asked to find the raidus of a circle of say radius 9m, then you should alewyas express your answer as 81*pi m^2, of course if for some reason (I relaly can't think of any reaosn though) you need to know wherre it approximatley lies on the real number line then you would approximate pi.

Why do you need to approximate' date=' eh? How about pi being an irrational number.

 

Btw, World Record: Goto, Hiroyuki | Japan | 42195 digits, World Rec since -95[/quote']

 

You should never approximate unless you have to, the decimals are only one representation of the real numbers.