I think the answer is quiet simple...
Whenever I turn my back the entire world does turn to ham. Or turkey sometimes. But the catch is that when I look back, it changes back into the world I know. Therefore why do I care that the world turns into ham? Does it really matter at all?
" I talk of physics because i know what i am talking about, not just to sound educated. "
High school physics does not mean you know what you are talking about....... you clearly don't. I know you don't understand physics because of what you say; anyone who understood physics would not say the nonsense that you have done.
"Yes. I'm not sure I get your point?"
You have studied calculus yet you don't know how probability can be applied to an infinite set?
Inifinity is not a problem at all, you can apply probabilities to infinite sets mathematicians do it all the time.
"It's not that belief A has a greater or lesser probability (in the strict sense) than belief B, just that all my experience confirms belief A and not B."
Those two statements are exactly the same, your experience confirms belief in A and not B making A the more probable occurance.
"as I think you said earlier, there an infinite number of possibilities, then there is no difference between a 1/infinity prob and a (really big #)/infinity prob. It just does not make sense to take the probabilities over the infinite set. "
Yes, it does, and like I said mathematicians do it ALL the time, just as you can integrate over an infinite set, you can apply probability over an infinite set. Your problem is you don't understand infinity; there IS a difference between 1/ infinity and 200 / infinity, they both give an infinitely small number, BUT those two numbers are different. Yes, you can have two infinite numbers and one can be larger than the other. This scenario arises quite often: consider integrating between 0 and infinity a y = x line, the area will be infinite, now consider integrating between 0 and infinity a y = 2x line, the area will also be infinite but a "larger" infinity than the first one.
Infinities can cancel out, infinitely large numbers multiplied by infinitely small numbers yield constants. (In some senses that is why light has a mass)
Last edited by Clyde; 05-20-2002 at 05:40 AM.
if light has a mass, why do we explain the gravitational lensing effect by using the distortion of space-time, not just simple Newtonian effects ?????
Steve
"if light has a mass, why do we explain the gravitational lensing effect by using the distortion of space-time, not just simple Newtonian effects ?????"
You are asking I think, why we explain gravitation lensing in terms of space-time distortion rather than gravity?
Well they are the same thing, light gets bent around a mass because the mass distorts space, that distortion IS gravity, (atleast according to relativity it is).
Light does not have what's known as a "rest mass" that is to say if light stopped moving it would not have a mass, the only mass it has is associated with it's energy.
We can observe light's mass experimentally by using an extremely sensitive mirror and firing photons at it, the mirror can be deflected.
a little knowledge is a dangerous thing for me...sorry
actually i was just confused about something...looking into it....
from 'the grip of gravity' book i have...
it seems that the path of light is deflected according simply to Newtonian mechanics, but the deflection is approx. doubled when you also account for the effect of the curvature of space-time ie einstein relativity.
the differences in measurement are due to measuring lights mass simply by gravitational mass compared to measuring by the 'equivalence principle' - relatavistic deflection of light....
ie the mass of light is not just subject to gravitation in the same way as ordinary matter, but is deflected in accordance with einstiens relativity theory....
does that make any sense ????
anyway, forget it, i will know what i'm talking about when i finish this book(if ever)....or mebe not, in any case the fact is that nobody actually knows what gravity is when you get a bit deeper than just saying its warping of space time...gravitational radiation waves, string theories....oh my poor little head !!!!
Last edited by stevey; 05-20-2002 at 12:43 PM.
Steve
"it seems that the path of light is deflected according simply to Newtonian mechanics, but the deflection is approx. doubled when you also account for the effect of the curvature of space-time ie einstein relativity. "
I didn't know that, damnit now i have to teach you some history! :P
"does that make any sense ????"
Looks like you know quite a bit more than me on the topic.
"in any case the fact is that nobody actually knows what gravity is when you get a bit deeper than just saying its warping of space time...gravitational radiation waves, string theories...."
Yea, there is still major disagreement between quantum mechanics and relativity over the nature of gravity, the hope is that the theory of quantum gravity will coem along and solve these problems and a bunch of other ones too.
Can someone please explain to me what space-time is?
I remember hearing about it in Astronomy all the time, but never quite understood it...
There are 3 spacial dimensions, (x,y, &z) and one temporal dimension (time), collectively they are known as space-time.
its possible to treat time as if it were a spatial dimenion, therefore motion of a body is regarded as a curve made of 'events' identified by 3 spacial co-ordinates and the 4th coordinate, time. this 4th dimentional space is called space-time.
its a rigidly flat continuum, similar to the rigidly flat space of euclidian geometry. all bodies are moving in space-time, a non moving body is stationary in 3 coordinates but always moving in the 4th, time. the sum of the motions in the 4 dimensions is always constant, so a spacially moving body slows down in the time dimension or its 'clock' slows down. this is time-dilation.the 3 spacial dimensions can be +ve or -ve, but time can only be +ve. as regards the 'clock' - eg a muon particle with a lifetime of 2X10^6 secs at rest may have a lifetime increase of X200 at close to the speed of light.
gravity is thought to be a distortion of space-time, like a heavy ball on a flat sheet, curving it in, so the gravity pull is like a smaller ball falling into the 'well' so created. thats why gravity is always positive, always pulls towards.
a regards the speed of light/mass of light, i thought light has no mass. i was confused.
at the speed of light mass becomes infinite, so only bodies with zero mass ie a light photon can travel at the speed of light. the mass increases with speed due to relativistic effects, so in fact light can be considered as having mass, but only at light speed.
increase of mass with speeds close to light speed have been confirmed, in fact need to be accounted for ie in electron microscopes where relativistic mass of electrons can equal 10,000 times rest mass at 99% speed of light.
so we can never travel faster than light (boo hoo) unless we can 'warp' the space-time continuum (warp drive) or travel thru a worm hole - a hyperthetical tunnel joining 2 points in curved space-time. a worm hole would actually allow faster than light travel and also possibly traveling backwards in time but probably not.
anyway thats space-time !!!!
goddamn it i popped out !!!
that was me(i aint writing that essay and not getting a credit for it !!!)
btw i would heartily recommend stephen hawkins books "brief history of time" and "universe in a nutshell" - good stuff for laymen, not that i'd pretend to understand it all !!!
Steve
Wow, a little over my head but I've got to admit it makes my mouth water it's so interesting.
>gravity is thought to be a distortion of space-time, like a heavy ball on a flat sheet, curving it in, so the gravity pull is like a smaller ball falling into the 'well' so created. thats why gravity is always positive, always pulls towards.<
Hehe, I remember watching a video (yeah, in Astronomy) about this. It had Homer Simpson (gotta love that) getting sucked into a black hole.
>btw i would heartily recommend stephen hawkins books "brief history of time" and "universe in a nutshell" - good stuff for laymen, not that i'd pretend to understand it all !!!<
I've gotta check at least one of those out. This type of stuff I love reading and learning about...
these stevey hawkins books seem to come in 2 versions, crappy paperback with just text, and hardback with lots of big colourful piccies. i'd recommend the latter. us laymen need all the help we can get!!
i think its fascinating stuff though, time travel, faster than light, black holes, worm holes, dark matter, the hubble telescope looking so far distant we can see almost to the creation of the universe.....
at least you can understand star trek when u get a basic grasp of it !!!!
i must warn u its very baffling !! i mean eg this thing about gravity, what i said is true, but gravity is 'carried' by particles called gravitons !!
every atom in our bodies was made in stars, we are stardust, we are part of the universe, we are the universe trying to understand itself !! oops getting carried away......
i do believe eventually, i hope in my lifetime , that finally we will unify all the theories, we will have what they call 'the theory of everything'. not that me and you would understand it !!!
stephen hawkins a big star trek and simpsons fan btw - hes been on both !!!!!
Last edited by stevey; 05-20-2002 at 07:25 PM.
Steve
>every atom in our bodies was made in stars, we are stardust, we are part of the universe, we are the universe trying to understand itself !! oops getting carried away......<
Heh, yeah I remember learning that.
If I get some money sometime, I'll buy those books (in hardback edition).
Damn! Is BeOS open souce now?? (question about hillbillies signature)
>Damn! Is BeOS open souce now??<
No. BeOS got bought from Palm along with the rest of Be's IP. There's an open-source effort (dubbed OpenBeOS) that is working to recreate BeOS. It's actually closer than people think. A lot of things are working. Some are even completed.
