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Could they send a probe into space that would come back 3 hours later after it had been in the universe for millions of years? I saw an old tv show. How they would manage changing the future..Is time travel possible? Could they designate a landing area that would always be reserved for the probes? Maybe area 51? g Maybe a radio channel that would always be reserved. Maybe the History Channel from 300 years from now would click on. Could something land in Ben Franklins back yard or Mount Vernon? What they would do with the data from now back? (Back to laughing at the subway window....)

yes he's cute

Maybe the Asgards will know?

I want to go back to stop my mom from ever being born...

Pattison said: "I want to go back to stop my mom from ever being born..."



You've just exemplified "The Grandfather Paradox"
The paradox is this: suppose a man traveled back in time and killed his biological grandfather before the latter met the traveller's grandmother. As a result, one of the traveller's parents (and by extension, the traveller himself) would never have been conceived. This would imply that he could not have travelled back in time after all, which in turn implies the grandfather would still be alive, and the traveller would have been conceived, allowing him to travel back in time and kill his grandfather. Thus each possibility seems to imply its own negation, a type of logical paradox.

If you've read Stephen Hawking (like "The Universe in a Nutshell"), you'd know he's not entirely against backwards time travel, but he admits there are countless arguments against it.

I want a TARDIS!!

drakutis saidI want a TARDIS!!

I want a stare Gate.

I want ice cream!

I want to go back to 1988 and buy stock in Microsoft and Starbucks

CuriousJockAZ saidI want to go back to 1988 and buy stock in Microsoft and Starbucks

If only I could!!

CuriousJockAZ saidI want to go back to 1988 and buy stock in Microsoft and Starbucks

I want to go back to 1980, and buy shares in condoms.

But then I would also like to go back to may off 1999, and have groundhogs day.

I would love too go back and meet Catherine the Great, and the last Tsar Nichlas II. What those peasants did to him and his family was so wrong.

I would also like to go back and meet the Lat Emperor of France, oh what those peasants did to him and his family was so wrong. They got the wrong people, and made the wrong people suffer.

Scientists at NEC Research Institute in Princeton, N.J actually made something exit before it entered, and no this is not a trick statement. Since the speed of light was exceeded by a significant margin, they were able to have something exit before it entered...freaky

I don't know... but I'm sure The Prophets, from Star Trek: DS9 would find a colorful puzzling way of getting all those things answered by those historical figures... Unless of course they're not looking at your through some tranportation of their own laughing, thinking they're going crazy :S - lol j/k.

typo

E=MC squared..
relativity is the key.

its very simple: mass, which is highly condensed energy, causes space to bend, or warp, which is what causes time, essentially. now since all mass warps space (and therefor exerts gravitational force on all other mass, no matter how small), it follows that light, which walks a thin line between being energy OR mass, would have that effect on the fabric of space- and in fact, it does. light, having mass and weight, exerts a gravitational field, which is essentially the warping of space; since mass and energy are one and the same, it follows that energy can cause a warp in space/time as well.

the theory is this: if you can warp space enough with a large enough energy level/mass/gravitational force, as in a black hole, you can actually bend it back upon itself; and where it touches itself, a 'wormhole' would form- essentially forming a circuit loop in the space/time continuum and bypassing a large chunk of it in a return to an earlier point. it'd be like taking a straight string, forming a large loop in it, tying the loop off at its base, and cutting the ring of looped string off, shortening the string considerably, and connecting two points on it which would otherwise have been spaced far apart- though of course the actual theory is more complex than this, as time and space have more than the the two dimensions in this model.

back to light- since we obviously don't have the mass required to generate a black-hole effect and spawn a worm hole lol, its been theorized that light may be used to form significantly less impressive wormholes, more akin to the ones formed constantly at the scale of the 'quantum foam,' amid the chaos of probability, where time doesn't really hold any sway. lasers have successfully been used to form a column of revolving light, which 'stirs' up the space within, similar to the revolving air of an eddy in the atmosphere- a cyclone effect- only in this case, with space, and therefor potentially with time. one wouldn't think that a column of light formed by lasers could stir anything, let alone the air.. let alone space itself, as a thing very different from the air that occupies it; but this is just the case. an electron let loose inside this column begins to spin around in a circular motion- evidence that a gravitational field has been generated sufficient to stir space in a vertical column. since Einstein's theory of relativity decrees that space and time are more than intimately related, a warp in space is also potentially a warp in time. theoretically, if one can warp space hard enough, which is possible using this technique, time will form a loop.

the problem with this 'time machine,' however, is that one would only be able to use such a mechanism to 'travel' back in time to the point in time in which the machine was switched on- and it should never be turned off. in this way, a person could use such a machine turned on today to travel back to today, after a thousand years of it running, or to any point in time between now and then; but one could NOT travel back to yesterday, or any point in time before the machine being turned on.

side note: theories abound on why time travel SHOULDN'T be possible, such as the infamous 'grandfather theory,' which postulates that if you COULD go back in time, and you were to, say, kill your grandfather- you would never have been born, and therefor you couldn't exist to go back in time.. and therefor couldn't exist to kill your grandfather! this seeming paradox, however, can be overcome by the theory that in every instant of existence, an infinite number of alternative realities are spinning off to form their own universes, all super-imposed over our own. this would be due to the chaotic nature of reality on the quantum scale, where things only exist as probability and as energy, which only 'solidifies' into a more concretized, newtonian 'reality' at our significantly larger scale after all of the probabilities have mostly canceled each other out, influenced in no small part by the effect of our own consciousness. Technically though, this means that in the realm of probability in the quantum sense, all possibilities of how a thing can 'be' are realized simultaneously. In essence- you would probably be traveling back in time to an alternate reality within the same universe, and your actions would have, while unpredictable, decidedly non-parallel effects on the 'future' of that reality, possessing no bearing on the time from which one came.

and of course there's also the nifty idea that if it ever WERE to become possible for man to physically travel backwards through time, there would be time travelers present amongst us today, or have been in our past. ;)

in response to the original question though- i think it refers to the way time moves when one is traveling extremely fast- no, one can't move back in time by moving at high speeds- only forward, so to speak. and we are ALL moving physically through time, in the forward direction- we're all 'time-travelers.' lol

time is relative and malleable, being a product of the warping of space, which in turn depends on a number of factors. as far as the nature of one's experience in it, think of it this way: one is ALWAYS moving, and one HAS to spend all of the energy one has available on movement- imagine that you have x amount of energy to spend, but it must all be used. you have your choice of moving simultaneously through any of the four (known) dimensions as percentages of a whole- up/down, right/left, forward/backward, and time. just as in when moving diagonally, you are moving through a percentage of two or more of the first three dimensions at the same time- one must remember that one is also always traversing the fourth dimension of time simultaneously, which is intimately tied together with space. if you're moving MORE through space (the first three dimensions), you're moving LESS through time, in terms of the percentages of the total energy you have to spend that you're using on each dimension- so the faster you move through space, the less of an effect time has on you, essentially 'slowing down for you.' the LESS one moves through space, the MORE one moves through time- if you were to not move at all, your existence would be even less of a blip in time than it already is. though in reality, you're ALWAYS moving through space, even when standing still, because you're standing on the surface of a plant that is revolving through space and relatively high speeds, and which is rotating around our sun pretty swiftly.. the sun, in turn, is whirling around the center of our galaxy with mind numbing speed, and the galaxy is moving outward from the center of the universe with all the momentum of the 'big bang.' you can't avoid moving through space, and that is why time has the ability to unfold from a single instant and give the impression of linearity and progression for you. now, to clarify something- if you WERE to attain to even higher speeds, in relation to those known on Earth, time would pass more slowly for you from the perspective of those moving more slowly.... but it would seem to pass at the same speed for you- therefor, while you'd live much longer, and may return to the planet after a 'brief' flight several thousand years later, without aging, its not like you'd actually enjoy the benefit of living all of those 'extra years.' This is more than possible though, lets be clear: its how things naturally work in the universe.

an interesting fact: light, existing as a wave and a particle (the photon), is THE fastest moving thing in the universe. nothing can move faster than light through space (except, theoretically, tachyons)- this is because as matter approaches light-speed, it becomes increasingly massive, due to a somewhat confusing principle, in an exponential kinda way- and the more massive an object is, the more energy it takes to make it move faster- energy taken from its commitment to movement through time. because the increase in its massiveness as it approaches light speed is exponential, so is the energy required to get it to light speed- therefor, for matter to travel at light speed... it would require INFINITE ENERGY to do so! light can only do it because its also a wave. we will never travel at light speed, and there is no such thing as additional speed after 'lightspeed.' if we COULD though, we would achieve immortality, because, as light uses ALL of its available energy to travel through space, it expends NO energy on movement through time- TIME STANDS STILL AT LIGHT SPEED! light is as old as it was when it was created when it strikes the earth's surface after millions of years of travel to us from a distant star! fun stuff, huh?

and btw, the only way some'thing' could exit before entering would be use of a nano-wormhole, as 'things' obviously can't hit light speed, and there is nothing faster. the only way to get anything other than light to travel at light speed, is to convert it to light- as with 'information.' information is energy, and can therefor be neither created nor destroyed, only transmuted- a book thrown into a black hole, though utterly destroyed, COULD be reconstructed with the right knowledge of how to do so, by back-peddling the process of its destruction. if you convert information into light (as with flashing a light using morris code, for example) you can cause that information- energy originally NOT light- to travel at light speed, and then be converted back into energy at its destination. using this logic, as all matter is condensed energy, theoretically, matter COULD be converted to light and travel at light speed- but as i said, it requires conversion, as nothing can travel completely through space, with no energy spent on traversing time, but light.

the effect mentioned of a thing coming out of something before entering it would have to be a quantum effect utilizing a warping of space/time in a wormhole, and wouldn't specifically involve travel at super-light-speeds.

YOU'RE A WORMHOLE!!!!!!!!

It's easier with a TARDIS!!

Czaro....I am so in love with you right now. so in love....

tommysguns2000 saidCzaro....I am so in love with you right now. so in love....

Talk dirty to him!!!!

Czaro's posts are like love poems to a geek.

drakutis - what would constitute dirty talk in this circumstance? Quantum mechanics?

lmao thanx guys :p

oooh yeah baby, lets talk quantum entanglement! raar ;)

czarodziej saidlmao thanx guys :p

oooh yeah baby, lets talk quantum entanglement! raar ;)

Hehe, I wonder how many people will get that?

That supposes that tachyons don't exist, eh? We thought light was just light at one point, but it's just a part of the same lump that everything is, was, or will be. Harnessing gravity would certainly change the world.

WTB Skyhook

ShawnTO said[quote][cite]czarodziej said[/cite]lmao thanx guys :p

oooh yeah baby, lets talk quantum entanglement! raar ;)

Hehe, I wonder how many people will get that?[/quote]

I did! :-P

Tachyons (hypothetical things that travel faster than the speed of light and cannot travel any slower) cannot permit information to travel faster than the speed of light... so they wouldn't be very useful.

ShawnTO saidCzaro's posts are like love poems to a geek.

drakutis - what would constitute dirty talk in this circumstance? Quantum mechanics?

How about Quantum Thrusting?

I was refering to quantum entanglement - the quantum states of two objects being linked together even if they're physical separated (which made me think of c2c because of the dirty talk comment).

Was it only funny in my head?

ha, no, its what i was implying, as a joke :p

czarodziej saidan interesting fact: light, existing as a wave and a particle (the photon), is THE fastest moving thing in the universe

I love unified duality .. it makes so many ideas possible



The Way is empty, yet adds fullness to everything,
The Way is hidden, but seen throughout the universe ..

well, everything is duality in unity- division, multiplicity, separation, differentness, distance, time and space are all illusionary constructs- at the deepest and most fundamental level of 'reality,' all is truly One. metaphysically, you could take it a step further to suggest that that One is really None, for reasons that it'd almost be too much effort to put down here. ;)

Czaro, :swoon:

x

czarodziej saidwell, everything is duality in unity- division, multiplicity, separation, differentness, distance, time and space are all illusionary constructs-

The Way that can be spoken
is not actually the Way

When you have names and forms,
know that they are provisional.
When you have institutions,
know where their functions should end.

czarodziej saidat the deepest and most fundamental level of 'reality,' all is truly One.

The Way creates the One.
that creates the Two.
that create the Three.
that creates all things!

czarodziej said metaphysically, you could take it a step further to suggest that that One is really None, for reasons that it'd almost be too much effort to put down here. ;)

I'm good with that!

"The Way ..
The more you use it, the more it produces;
the more you talk of it, the less you understand."

all very well said

maybe I should stop then

I have a question for the science/physics guys ..

Is matter mostly space or substance? http://www.pa.msu.edu/sciencet/ask_st/051894.html

So what is all the space between [sub]atomic particles in matter called .. what is it?

matter is mostly space. its comprised of atoms, which don't actually ever touch, and the make up of an atom is almost entirely emptiness. 99.9% of an atom's mass is contained within its nucleus of protons and neutrons, with the electrons occupying a 'field' (not rings) around it, wherein its impossible to define their position or energy level, because they have been smeared out into psi waves of potentiality in a quantum sense. atoms never touch because they interact with each other using electrostatic fields, and so nothing you 'touch' actually touches you; you're only interacting with the object's electrostatic field- and the same is true for the internal structures of atoms. atoms are 99.999999999999% empty space, and if the nucleus were the size of a basketball, the nearest likely position of an electron could be as far away as several miles, and would be smaller than pea sized. this empty space, however, is not truly empty, as it contains more potential energy than matter itself. the amount of energy bound up in 'empty' space is so mind-bogglingly great, that i can't even think of a good enough analogy- google it on your own lol. the empty space, if you zoom in far enough, is a 'quantum foam' of absolute chaos and unbridled energy, where all of the 'laws' of physics that hold true at our scale completely cease to apply, and a truer, albeit basement level reality is revealed. matter pops in and out of 'existence' randomly, forming from the raw potential energy of the vacuum, and in the incalculably small amounts of time they 'exist,' they break every 'law' of Newtonian physics by their actions. though at this scale, time breaks down too. truly, all logic fails when faced with fundamental reality at the plank scale of the empty space within an atom.

i also suggest watching the movie 'What the Bleep and Down the Rabbit Hole'- it goes into this a little bit, and gives a good introductory presentation of it all.

czarodziej saidmatter is mostly space ...

the make up of an atom is almost entirely emptiness.

and so nothing you 'touch' actually touches you;

Look, and it can't be seen.
Listen, and it can't be heard.
Reach, and it can't be grasped.

czarodziej saidthis empty space, however, is not truly empty, as it contains more potential energy than matter itself. the amount of energy bound up in 'empty' space is so mind-bogglingly great

I don't need to Google .. I like the way you explain things!
"Wu" is nothingness or emptiness
Wheels are spokes,
but they come together at an empty hole,
that allows it to usefully spin.
A cup is solid clay,
but it is the empty space inside
that makes it so useful.

The Way is empty like a bellow,
in that emptiness is great fiery power.

czarodziej saidi also suggest watching the movie 'What the Bleep and Down the Rabbit Hole'- it goes into this a little bit, and gives a good introductory presentation of it all.

I wonder if this is on net-flix:

Czarodzei saidlight...which walks a thin line between being energy OR mass...

I'm sorry, Czaro is wrong. Light does not have mass. It is not walking some thin line. Light is energy, and converting the mass by the speed of light squared to energy is converting it to light.

Your love is premature.

Objects traveling near the speed of light experience a time dilation effect, not related to the mass of light.

Light does not influence gravity. It's the other way around: gravity influences light. By warping space-time.

No true geek would ever miss that. Shame on you wanna-bes.

i'm sorry you've been misled into thinking that- but light exists, not just as waves of electromagnetic radiation, but as photons- its true that gravitational fields bend light's trajectory path, but light HAS successfully been used to warp space, by Professor Mallett (http://www.physorg.com/news63371210.html). yes, light IS energy, but so is everything, after a fashion. " though light has no REST MASS (because it can never be at rest!), it does have an effective mass which (it turns out) has all the properties one expects from MASS - in particular, it has weight in a gravitational field [photons can "fall''] and exerts a gravitational attraction of its own on other masses. The classic Gedankenexperiment on this topic is one in which the net mass of a closed box with mirrored sides increases if it is filled with light bouncing back and forth off the mirrors!"

and the time dilation effect on matter approaching (theoretically) light speed certainly has nothing to do with light's mass- i don't know where you read that in my post- as i said before it has to do with the fact that matter actually becomes innately more massive as it speeds up, and more energy is needed to perpetuate that acceleration. light's ability to ACT as matter OR as a wave, depending on how you look at it, due to its being both, is what allows it to travel at the speed it does. i'm sorry you're understanding is so basic... but don't take it out on us.

Some theorists have hypothesized that dragging a spinning black hole behind an as-yet-impossible spaceship by tractor-beam to near light-speed would create a time dilation effect on the "wormhole" created by the spinning black hole, where its entry end would remain in the (present) past and the emptying end would move into the future (at normal rate).

Flying an as-yet-impossible probe or spaceship through the wormhole, the traveler could enter the future (present) and end up in the past, before they entered the entry end of the wormhole.

As yet, no wormholes have been detected, no test for detecting wormholes has been created (or imagined), and were such a thing possible in the least, no spaceship could withstand the sheering tidal forces of nearing or passing the black hole's event horizon.

Without qualification, I could say with great certainty that we'll never see this kind of time travel (in the lifetime of our species).

czarodziej saidwell, everything is duality in unity- division, multiplicity, separation, differentness, distance, time and space are all illusionary constructs- at the deepest and most fundamental level of 'reality,' all is truly One. metaphysically, you could take it a step further to suggest that that One is really None, for reasons that it'd almost be too much effort to put down here. ;)

Czaro, you are so hot Love the geek talk, being one myself, but I have a question. You wrote: "the more massive an object is, the more energy it takes to make it move faster." This comes from special relativity (and the position of objects in the Lorentz transformation). Does this input of energy apply to just accelerating masses or masses that have already achieved those velocities. What I mean is, if it were possible to jump to a specific velocity rather than accelerate there slowly (so the derivative of velocity would be a step-function), could an object with real mass (not just relativistic mass) theoretically be able to "jump" to the speed of light.

Did that make sense?

czarodziej saidand the time dilation effect on matter approaching (theoretically) light speed certainly has nothing to do with light's mass- i don't know where you read that in my post-

Didn't say you said that. Re-read my post.

As far as my understanding being basic, just try me, hot stuff.

The experiment you cite by Professor Mallet is an experiment he HOPES to get funding for, not an experiment he proved.

And proof will require replication.

His conjecture is intriguing, but as you can tell from the article, he's proved nothing.

javaman: it made sense, though, being an interior design major, it is a bit beyond what understanding i've attained to in pursuit of my personal interests... i'd bet 'no' though, in response. i don't think anything could withstand the force on it in such a situation- the thing would probably be torn atom from atom.

mickey: im not here to 'rumble,' i just disagreed with everything you said. and what you postulate involving the towing about of black holes with alien spacecraft and traction beams just seems a bit ridiculous for the tone of this thread, where we're discussing the possibilities, not what captain kirk would do.


ps: "Objects traveling near the speed of light experience a time dilation effect, not related to the mass of light." yes, you did liken the acceleration of mass somehow, illogically, to the mass of light. i still don't understand how you were trying to do that though...

ActiveAndFit said

So what is all the space between [sub]atomic particles in matter called .. what is it?

I think this is called "dark matter".
Though 18th century scientists called it ether!!!lol

javaman9999 said[quote]could an object with real mass (not just relativistic mass) theoretically be able to "jump" to the speed of light.

Some sort of incredible force would have to create the jump. Equal to the "incremental" force you're trying to avoid using.

agreed- so its likely possible, but not probable, and probably unseen since the 'big bang.'

with that im off to bed ;)

swimbikerun saidI think this is called "dark matter".
Though 18th century scientists called it ether!!!lol

Ahhhh! Matter .. Dark Matter .. Don't matter .. we'll call it either
Actually I must confess, I asked the question just so I could talk about "wu" the utility of emptiness

BTW, dark matter really gas nothing to do with what I am talking about though http://en.wikipedia.org/wiki/Darkmatter

czarodziej said
mickey: im not here to 'rumble,' i just disagreed with everything you said. and what you postulate involving the towing about of black holes with alien spacecraft and traction beams just seems a bit ridiculous for the tone of this thread, where we're discussing the possibilities, not what captain kirk would do.

ps: "Objects traveling near the speed of light experience a time dilation effect, not related to the mass of light." yes, you did liken the acceleration of mass somehow, illogically, to the mass of light. i still don't understand how you were trying to do that though...

The Captain Kirk scenario isn't my invention, if you read the literature. This was in response to the original poster, who asked about time travel. See Scientific American, August 2002 or http://www.sciam.com/article.cfm?id=how-to-build-a-time-machi-2002-09

I did not "liken" the acceleration of an object to near-light-speed to the mass of light. The words I used were "not related." Check your quote above. Of course you don't understand, or think it's illogical, because somehow "liken" and "not related" appear to mean the same thing to you. They don't to me.

As far as disagreeing with everything I said, great, go on and cite your sources, you must have a degree that eclipses my own. As far as rumbling, please!

micky, do you smoke?

Are you saying I need to have a smoke? Maybe I will.

lol

According to my (admittedly simple) understanding of the theory of relativity, the slowing down of time increases inversely with velocity, until it essentially comes to a halt at the speed of light, which is why the theory predicts that light-speed is the ultimate barrier.

If that's true (and if I understood it correctly), then to travel backward in time would require a decrease in velocity. However, relative to the earth, we're already at zero velocity. No decrease is possible. So no traveling backwards.

This whole topic has got me scratching my head.

You guys might as well be speaking sanskrit to me.

well, as i mentioned earlier, standing still on earth isn't zero velocity (except for in relation to the earth- one always has to ask 'relative to what?' when talking about velocity lol)- since the earth itself is actually moving incredibly fast through the universe. i guess if you were in space it'd be possible to station yourself as being completely still in reference to the calculated center of the universe, but you'd look like you were hurtling through space, as everything else is still exploding from that center.

slowing down won't give you any more control over your regular movement through time though, i don't think, aside from changing the apparent span of your existence in reference to everything else.

btw i correct myself- in an earlier post i said it was 'impossible' for anything to move faster than light speed, however while nothing but light CAN reach light-speed, we HAVE apparently caused lasers to accelerate their speed as much as 318x the speed of light before it was seen to exit a cesium filled chamber before entering it (thanx for the elaboration, YngHungSFSD xoxo). of course, in keeping with my earlier comment, this was light and not matter that traversed through time unnaturally, and so my original point remains in-tact.

Wysiwyg60 saidThis whole topic has got me scratching my head.

You guys might as well be speaking sanskrit to me.

Rii JB, asya sinduura. Yogya mandahaasa uta zirah caalayati!

Time is a human construct. It is just a way for us to help describe the change in a molecule's position.

Right?..... ummm....

czarodziej said
btw i correct myself- in an earlier post i said it was 'impossible' for anything to move faster than light speed, however while nothing but light CAN reach light-speed, we HAVE apparently caused lasers to accelerate their speed as much as 318x the speed of light before it was seen to exit a cesium filled chamber before entering it (thanx for the elaboration, YngHungSFSD xoxo). of course, in keeping with my earlier comment, this was light and not matter that traversed through time unnaturally, and so my original point remains in-tact.

Yes, I read about that experiment and the result, but (as of the last time I read about this) despite numerous attempts, no one has been able to replicate the results. A number of theorists have suggested that there was experimental error somewhere in there.

WyoLifter saidTime is a human construct. It is just a way for us to help describe the change in a molecule's position.
Right?..... ummm....

Maybe it is a construct to sell watches

czarodziej said
btw i correct myself- in an earlier post i said it was 'impossible' for anything to move faster than light speed, however while nothing but light CAN reach light-speed, we HAVE apparently caused lasers to accelerate their speed as much as 318x the speed of light before it was seen to exit a cesium filled chamber before entering it (thanx for the elaboration, YngHungSFSD xoxo). of course, in keeping with my earlier comment, this was light and not matter that traversed through time unnaturally, and so my original point remains in-tact.

Gah, I have to step in here and correc this misconception. I think what Czaro meant in his original post is that nothing can move faster than light speed in a vacuum. It's been noted for a long time that you can observe Cherenkov radiation (an example of something moving faster than the speed of light) in the water of nuclear reactors. But the speed of light in water is actually slightly slower than the speed of light in a vacuum.

In the experiment you mentioned above (with cesium atoms), the observed lasers traveled faster than light in the cesium chamber, but not faster than light in a vacuum. So far there has been no recorded object that has traveled faster than light in a vacuum.

Has anyone read "Faster Than the speed of light" by Joao Magueijo? I have only started, but besides what the title suggests I am finding its subtitle "the story of scientific speculation" very interesting.

javaman9999 said[quote]
In the experiment you mentioned above (with cesium atoms), the observed lasers traveled faster than light in the cesium chamber, but not faster than light in a vacuum.

In fact, by slowing light to a near standstill with a Bose-Einstein condensate, you can in fact outrun it!

ShawnTO said[quote][cite]Wysiwyg60 said[/cite]This whole topic has got me scratching my head.

You guys might as well be speaking sanskrit to me.

Rii JB, asya sinduura. Yogya mandahaasa uta zirah caalayati!
[/quote]

I had this feeling by mentioning sanskrit someone was going to respond in that language. Am I surprised it was you ShawnTO? Nooooooooooooooooooooooooooo.

TigerTim saidIn fact, by slowing light to a near standstill with a Bose-Einstein condensate, you can in fact outrun it!

Really? Even if I can't run worth a damn? I would get a chuckle if I could outrun light .. something to write home about.

mickeytopogigio saidAre you saying I need to have a smoke? Maybe I will.

Well while it is true you are "smokin'" I actually just saw that one of your pictures looked like you were smoking.

Wysiwyg60 said[quote][cite]ShawnTO said[/cite][quote][cite]Wysiwyg60 said[/cite]This whole topic has got me scratching my head.

You guys might as well be speaking sanskrit to me.

Rii JB, asya sinduura. Yogya mandahaasa uta zirah caalayati!
[/quote]

I had this feeling by mentioning sanskrit someone was going to respond in that language. Am I surprised it was you ShawnTO? Nooooooooooooooooooooooooooo. [/quote]

Yeah, I'm so predictable.

regarding time travel, are we thinking in terms of Back To The Future rules or Terminator rules?

well yeah the speed of light, while 'constant,' is also relative to the medium through which it's traveling- its why water refracts light and bends it- the light slows and changes trajectory when it hits the water's surface. diamonds, being the hardest thing known, actually slow light more than any other physical medium is capable- which is what makes them so pretty

i'm not very thoroughly knowledgeable on this particular area though- i wonder stupid things to myself like, if water (for example) slows light down, where does light get the energy required for it to 'speed up' again upon exiting the water? this is obviously a product of gross ignorance, for i'm sure the answers are well known in the right circles lol- perhaps, i may speculate to myself, light never actually slows down relative to some constant- it only appears to when it is made to move through mass, from an outside perspective, because mass inherently warps space and time... or it probably has more to do with the fact that light is electromagnetic radiation- waves- and all that changes when it travels through mass is that its energy must be re-appropriated somewhat to oscillate as a wave through the denser medium, vibrating its heavier/denser molecules, and taking energy from what would normally be spent on travel through space- no longer traveling 100% through space and not at all through time, time would begin to have an effect on light and it would appear to slow down; such that upon exiting the denser medium, that appropriated energy would return to its original application in movement through space alone, and time would loose its hold on light? i haven't read enough about this, and these are just weak musings...

if anyone here has a clearer, more lucid understanding of light's movement through mass as opposed to vacuum, it'd be welcome..

"regarding time travel, are we thinking in terms of Back To The Future rules or Terminator rules?"

lol i think earlier references to the TARDIS evoke the theoretical fun of Doctor Who

:p

czarodziej saidwell yeah the speed of light, while 'constant,' is also relative to the medium through which it's traveling- its why water refracts light and bends it- the light slows and changes trajectory when it hits the water's surface. diamonds, being the hardest thing known, actually slow light more than any other physical medium is capable- which is what makes them so pretty

i'm not very thoroughly knowledgeable on this particular area though- i wonder stupid things to myself like, if water (for example) slows light down, where does light get the energy required for it to 'speed up' again upon exiting the water?

if anyone here has a clearer, more lucid understanding of light's movement through mass as opposed to vacuum, it'd be welcome..

Well the first point isn't quite true... diamond's refractive index is very high, but there are things (like the bose-einstein condensate I referred to) that can slow light down *more* drastically. And hardness doesn't necessarily mean high refractive index... it is more true to say that diamond's particular structure and electronic properties are responsible for *both* it's hardness and refractive index.

And as to the second point, these sort of questions require a quite sophisticated picture of what light is and are best addressed within the framework of Quantum Electrodynamics (you should read Richard Feynman's excellent and very accessible book QED for an introduction).

Briefly: Light, in a sense, does not exist at all! Underneath the Maxwell equations, it's easy to forget that what are really being described is the motion of *charges* that are a property of 'real' particles like electrons and protons, and that the continuous field-theory of electromagnetism is just a convenience: the magnetic or electric field at some point in space is nothing more than a (lengthy!) sum of the position and movement of all charges in the universe. Those far away obviously contribute very little and one has to take care of some details to ensure charges far away don't have an immediate effect on some distant location.

Analogy: think of a Newton's cradle. At one end, the first hammer moves a great distance to strike the row of balls. These move very little and then the last hammer moves a great distance.

This is not so far from what happens with light interacting with a solid. The light photon comes in from far away and so the charges in the solid are at first barely affected by it, but as it hits charges in the solid begin to move. But they interact with each other as well, and this is in effect what causes the apparent wavelength to be increased (as if the light had slowed down). You can also view it as being in effect the light is continuously absorbed and re-radiated within the solid. These processed must be described in detail by QED.

ah, kewl, that actually makes a lot of sense- the newton's cradle analogy helped- thanx

czarodziej saidah, kewl, that actually makes a lot of sense- the newton's cradle analogy helped- thanx

Having reread that, if it was clear to you then you're a better man than I!

ha well im not saying i suddenly understand it all :p but it clears a few things up for me- i love suddenly looking at things from a new angle

czarodziej saidha well im not saying i suddenly understand it all :p but it clears a few things up for me- i love suddenly looking at things from a new angle

No I meant I did a pretty bad job of explaining it! Read the Feynman book QED. You'll enjoy it.

Has anyone seen the new movie Southland Tales (It got Sarah Silverman! Wooo)





DON'T LET THOSE TWO KITTIES TOUCH EACH OTHER!

that looks REALLY GOOD is it out yet? i've never heard of it

that looked really good! I totally want to see that, too. Anything with Buffy is a must-see

Yes it was actually released 2007. It's a dystopian and cyberpunkish, so might not be for everybody. But it's good.

And it's the first movie I've seen Justin Timberlake in.

With services like T-VO and I-pods, does it mean we coming out of the era of the "CD" and "DVD"?

Bought the DVD of Southland Tales...watched the first hour and i literally felt time slowing down as i watched it. Still have another hour and a half to watch..i just cant bring myself to do it. I'm hoping the movie gets better but then there's the nagging thought of "what if the best part of the movie already happened"

Reminds me of a Clapboard.

Just as a brief mention for those interested in the subject; there is a book I read a number of years ago that was quite interesting on this topic. Although the book is now somewhat dated, it is a good read, and when you can get it for 40 cents on amazon, why not.

Faster Than Light: Superluminal Loopholes in Physics by Nick Herbert

A few years back, MIT held a time travel conference inviting everyone from the future (or the past), human or alien to attend. Unfortunately no one with a time machine showed up, but it was an interesting try...