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feck
08-03-2005, 05:52 PM
Hi people,

Just a stupid thought really, that's been bugging me for some time, like some other ridiculous thoughts i have sometimes.

Light speed and its applications has confounded me, since i heard that when traveling at this speed (if possible) that time seems to change for the person or object traveling at that speed.
Now i do not know if their are any other thoughts on this published and would like to read them if anyone knows of any.
What Ive heard is that say a person traveled at this speed for say one year, thereby traversing one light year, then when they return then, everyone they knew could infact be older or dead.

So if i was an observer of someone who had traveled at light speed for one year there time, I would have to wait something like 50 years for them to return.
Now this brings me to my confusing thought, if we have scientifically proved that on observance that light takes 8 minutes to arrive to us from the sun, how long if i was actually sitting as a passenger on a light particle from the sun would it take for me to arrive on earth?

Darren.

BenDuckett
08-04-2005, 01:42 AM
Hi Darren,
You are talking about Time Dilation (a consequence of Relativity) and something called the Twin Paradox. If one of a pair of identical twins goes on a long journey at near light speed and the other just lazes around on the beach then the one who has been in the spaceship will arrive back and be younger (I think - it could be older) than his/her twin. The concept is quite simple to explain, but the mathematics behind it needs people like Einstein to figure out. I did have a book written by Einstein that was for 'average' people. I didn't get past chapter one! Any good Physics website should be able to do animations to explain further.
As for the light particle, time is defined by the frame of reference of the observer, so (if my memory is correct) your clock on the light particle would appear to be normal to you, but a clock outside of the light particle would be wrong (fast or slow) and to an outside observer your clock would be wrong and theirs would be correct.
Hope this helps!
Ben

feck
08-04-2005, 12:40 PM
Thanks Ben,

what I'm trying to get at is that as an observer it takes 8 minutes for light to arrive from the sun, but how long would it take as a traveller at the speed of light to arrive from the sun, from the inside as an observer and not as an observer from the outside?

thanks again ben

ESimmons
08-04-2005, 01:21 PM
I guess it would be instantaneous, assuming you could travel at the speed of light without actually being some kind of electromagnetic energy. If you somehow manage to travel faster than the speed of light, you've just violated causality and will actually arrive at your destination before you left.

Psy-Kosh
08-04-2005, 02:11 PM
Hello all. A couple things, first, the basic stuff from special relativity, ie, time dialation, length contraction, and so on, you really don't need that much advanced math for. Once you accept the axiom "the speed of light is the same for all observers" (and this can be derived straight from Maxwell's equations) you don't need much more than basic algebra and geometry. (Now, _general relativity_, on the other hand, is mathematically intense. Tried to teach myself it, will try again, got stuck early on in a derivation of some stuff)

But, the point is, time dialation itself can be derived relatively simply once you bend your mind around the idea that it actually happens. Admittedly, to get more sophisticated with it, can then get into messier stuff (which is what actually knocked me out of that book. I went "guh" at an attempt to derive electrodynamics from electrostatics via SR. ouch, my head a splode)

It's not exactly true that if you went faster than light you'd arrive before you left so much as if you go faster than light, from _someone's_ perspective you would. (Who's perspective would depend on the details of how yer moving and how they're moving)

BenDuckett
08-04-2005, 03:04 PM
Hi all,
From what I remember is that as you get towards moving at the speed of light all of the answers either tend towards zero or infinity, neither of which is a big help. I hate not being able to remember things like this!
I'm going to get my textbooks, a calculator and a big pad of paper. I am going to work out the answer and get back to you. Say in about 4.2 billion years?
I'll get back to you on that one
Ben
(who wishes he'd paid more attention at University...)

feck
08-04-2005, 07:12 PM
Hi people,

thanks for all the responses so far. One other thing that bugs me about the speed of light, is that its supposed to be a constant, in that Einsteins theory and also modern science's view is that nothing in the universe can travel faster than light, well what about the pulsar beams that get prescribed in a huge circle across the sky?.

These pulsar's apparently sweep a huge conical circle across space, well if these beams are picked up by different star system's, and the beams are picked up as regular as an atomic clock, thousands of times a second, then surely the ends of those beams are travelling faster than light? while sweeping across star systems that are light years apart.

Darren

Psy-Kosh
08-04-2005, 07:51 PM
Hi people,

These pulsar's apparently sweep a huge conical circle across space, well if these beams are picked up by different star system's, and the beams are picked up as regular as an atomic clock, thousands of times a second, then surely the ends of those beams are travelling faster than light? while sweeping across star systems that are light years apart.

Darren

Not the same thing. Nothing is actually moving from one side of the sky to the other. Think about the direction the actual photons are moving and you'll see what I mean.

Also, the speed limit idea is often intepreted nowadays more as the "speed of information" or "speed of causality" ie, how fast you can cause an effect at point B from a cause at point A

DustinAcuff
08-05-2005, 07:47 PM
I could be way way way off here and happily bow to anyone who disagrees. But...

That seems pretty fine with me. I remember in the quantum section of physics they were mentioning the particles involved and chronotons (time) were mentioned in relation to gravitons (gravity), the theory as stated (in my mind anyway) was that from some experiments that had been made time seemed to be more of a function of gravity than a constant thing. If this were true, based on the data of the experiment and some conjecture on my part, the faster you moved the less you would be effected by gravity and therefore time. So if you were traveling the speed of light you would not be swayed by time.

As I mentioned before, I expect I am wrong and willingly accept any corrections. My physics knowledge is a couple years old and pretty incomplete.


And there are a few diffrent ways to determine speed depending on the circumstance and the variable you are concerned with.

feck
08-06-2005, 04:00 AM
Hi josef,

Sorry but the way i understand it is that the beam of a pulsar, sweeps accross the earth and is picked up as a pulse, just like a lighthouse beam sweeps across your field of view. Now if a lighthouse light only turns on its axis ( say 6 ft diameter ) every 2 seconds, but 20 miles away your observance of the light is moving many miles a second.
Now as ive already stated ( and too me this is the confusing part ) if you as an observer on our earth pick up a pulse from these stars every second and another planet on another star system pick up the pulse then surely the end of the beam is travelling faster than the speed of light?

BenDuckett
08-06-2005, 02:55 PM
Hi Again,
From what you are describing (I wish we could sit with a piece of paper and a pencil) I think you are forgetting something. In everyday life the distances over which we observe things is small enough for the speed of light to make things appear instant. i.e. we think that we see things the instant they appear. But remember the old way of working out how far a lightning storm is? You can count the seconds between the flash and the thunder and divide? This works because the light travels the distance 'instantly' whereas the sound is slower. Now think about a distance so huge that not even light is fast enough to travel it instantly. We don't see things as they HAPPEN, we see them as the light ARRIVES. It takes light 8 minutes to get here from the Sun - we are seeing the Sun as it was 8minutes ago. So with a Pulsar the beams of light are not moving faster than the speed of light.
The other thing to remember is that something spinning must have the same angular velocity at the edge as at the centre. So, if something is spinning at, say, 45 degrees per second then the outside must also be spinning at the same rate - think of a bike wheel. The rim must spin at the same rate as the hub or the spokes would bend! And, to quote the old Physics cop-out, there will be a point at which Newtonian mechanics (on which 'common sense' is based) breaks down and Relativistic mechanics takes over.
Hope this helps!
Ben
:)

Psy-Kosh
08-06-2005, 09:12 PM
Dustin:
Gravity does affect time, but that's sort of a seprate issue from velocity affecting time. er... sort of. First, the thing you need to know is we do _not_ yet have a unification of quantum stuff and general relativity... in other words, the quantum nature of gravity is still a big mystery... perhaps either string theory or loop quantum gravity will be the solution, perhaps neither of those. The point is though that the time distortion stuff is all currently in terms of relativity. Don't worry about quantum here, especially with regards to gravity.

Now, when you're moving fast, you're not escaping gravity or anything. The time distortion with respect to velocity happens even in a gravity free environment. One way of thinking of it though is this: "interval" in spacetime is computed in terms of the square root of the _difference_ between the squares of distance and time. That is, that'll be the value that's constant for all observers. but when you're moving fast relative to a certain observer, you're doing more "space per unit time" then you are from your own perspective. your own perspective is yer standing still, and are just "moving" in time. but since it's based on the difference instead of the sum, from the other guy's perspective, you have to "take up" more time to make up for the extra space.

curvature of spacetime basically means "instead of just a simple difference, calculate the 'metric' my multiplying various values by these other constants here, then take the square root.", ie, when spacetime is bent, what that means is the "rule" for determining, well, "spacetime distance" (ie, the thing that will be the same for all observers" changes.

Darren: the light from the pulsare is radiating straight out from it. any single photon isn't moving in circles around it but going straight out. the only thing that's changing is which direction it's spitting photons in at any point in time.

Another way to phrase this is the whole "phase velocity vs group velocity" thing. Again, the best way to think about it is to ask yourself the question "could something use this somehow do something at point A such that it would have some effect at point B before light could get from point A to point B?"

ie, think of the speed limit as ruling the speed of "cause and effect"

DustinAcuff
08-07-2005, 01:01 AM
Thanks Josef! That makes sense. In some obscure fashion it sounds like rotational dynamics, ie 1 degree is one degree but the further from the center you are the more distance 1 degree covers. I realize just how vast an oversimplification it is. But if the closer to the speed of light you are going the more distortion takes place to "reality" as seen by someone else, the principle seems pretty on target. Relativity lost me way way back at you can get a 20 ft pole in a 15 ft room stage so most of the rest of it was gibberish.

I really hate to take a risk on bumping this thread off of its origional course, but what is the problem with the unification of quantum and relativity??? I realize that that is probably a rather huge question, just point me in the right direction or nutshell it if it is possible.

Psy-Kosh
08-07-2005, 06:10 PM
Thanks Josef! That makes sense. In some obscure fashion it sounds like rotational dynamics, ie 1 degree is one degree but the further from the center you are the more distance 1 degree covers. I realize just how vast an oversimplification it is. But if the closer to the speed of light you are going the more distortion takes place to "reality" as seen by someone else, the principle seems pretty on target. Relativity lost me way way back at you can get a 20 ft pole in a 15 ft room stage so most of the rest of it was gibberish.


The 15 foot in 20 foot is a similar thing... you can get most of this just from twiddling basic algebra and geometry... it's really not as bad as it sounds... the later stuff is that bad, but the basic stuff isn't. :)


I really hate to take a risk on bumping this thread off of its origional course, but what is the problem with the unification of quantum and relativity??? I realize that that is probably a rather huge question, just point me in the right direction or nutshell it if it is possible.

The problem is we don't really know how to do it yet?

There are a couple candidate theories, but still it's a big question mark. This is simply one of those areas in which we simply aren't sure how it works. Is the curvature of spacetime itself quantized? does the superposition principle apply to it? but if so, wouldn't that mess with other stuff since other wavefunctions work "in" the spacetime? or something like that. There's still alot I myself don't know, even if "we" know it. *scratches his head*

Tis simply a tough one.

Reitan
08-23-2005, 06:12 AM
I'm not so sure the speed of light is a cosmic speed limit.If a star is 100 light-years away, we see it as it looked 100 years ago. However, if we imagine ourselves at that star as it is now, our mental projection is instantaneous, or cause and effect together without seperation. I would imagine a human being could cause an action at a distance with intentions instantly,no matter the distance.

Psy-Kosh
08-27-2005, 08:23 PM
I'm not so sure the speed of light is a cosmic speed limit.If a star is 100 light-years away, we see it as it looked 100 years ago. However, if we imagine ourselves at that star as it is now, our mental projection is instantaneous, or cause and effect together without seperation. I would imagine a human being could cause an action at a distance with intentions instantly,no matter the distance.

If we imagine ourselves at the star as it is now, that's all we're doing, imagining it. ie, do you have any reason to believe that act of imagining is anything more than simply a model or a made up picture in your head? (to put it crudely.)

I mean that as a serious question though, why do you suspect that a human can cause an effect instantly at a distance? Even if simply by willing/intending something to happen elsewhere, it would happen, there _still_ would be a problem with the "instantly" bit.

It's just that the concept of "right now" is kind of meaningless over large scale distances. When physicists say spacetime, it isn't just because they're too lazy to say space and time, it's because the two aren't really seperable. The short version is that "now" isn't really physically meaningful in an absolute sense, though "here and now" is.

rob_liberti
08-28-2005, 09:40 PM
To play the devil's advocate - isn't there some interesting quantum physics about entanglement that would suggest otherwise? I believe the zen folks talk about the same concept (philosophically) when they talk about 'mutual causality'. This kind of stuff is interesting to me, but I just barely grasp the surface level understanding of such things... - Rob

Psy-Kosh
08-29-2005, 09:14 PM
To play the devil's advocate - isn't there some interesting quantum physics about entanglement that would suggest otherwise? I believe the zen folks talk about the same concept (philosophically) when they talk about 'mutual causality'. This kind of stuff is interesting to me, but I just barely grasp the surface level understanding of such things... - Rob

Ehhhhh...... Weeeeeeeellllllllllllllllllllllllllll...

Entanglement's funny. The short version is as far as I know, normal everyday information can't really be transmitted via it. Quantum information can be transmitted with it, but that's not the same thing, and can't really be used to send a message on its own.

For instance, in so called "quantum teleportation", what you basically do is split the thing in question into classical and quantum information. The quantum information is transmitted via the entanglement. However, that, on its own, is useless, until the classical information arrives at the destination, and _THAT_ is bound by the speed of light.

To go into more detail would require for me to have better grasp of quantum information theory than I currently do (which is basically a very teeny understanding)

But, short version is, as far as we know, you don't get to use entanglement to cheat the light limit. :)

Reitan
09-02-2005, 04:39 AM
Here's an interesting article. It's on the bottom of the page. http://www.livescience.com/technology/050819_fastlight.html Another interesting thing in quantum physics is the fact that an observer of an experiment actually influences the outcome based on their expectations, and this occurs regardless of distance, and it occurs instantaneously. In quantum physics, cause and effect are one and the same, coinciding in time and space.

Psy-Kosh
09-02-2005, 03:36 PM
Here's an interesting article. It's on the bottom of the page. http://www.livescience.com/technology/050819_fastlight.html Another interesting thing in quantum physics is the fact that an observer of an experiment actually influences the outcome based on their expectations, and this occurs regardless of distance, and it occurs instantaneously. In quantum physics, cause and effect are one and the same, coinciding in time and space.

Well, yes, but again, although the wave, in a sense, is faster than c, the speed of information isn't.. (alternately, a classical cause at point a isn't going to have a classical effect at point b before a photon could get from a to b)

Yes, it'd help them process it, but still afaik, no way you get to actually get information from point A to point B before faster than c.

Now, again, with the quantum instant entanglement thingie, that's a sortakinda. As far as I know, there's no way, even in theory, to actually use this to get information from point a to point b faster than light would go. It's more like A and B make some observations, then later come together and notice certain patterns in common with those observations showing that there was a link.

But it's not something that could be modulated in a way that could actually be used for communications, as far as I know.

Yes, this stuff is weird. :)

Reitan
09-03-2005, 03:29 PM
Granted, the link I posted does not say the speed of light was transcended,but they just actually slowed part of the light down and made the remaining portion appear to be travelling faster than the whole. I am not looking at this from the viewpoint of trying to transmit info in the contemporary sense, but in using energy and intentions to generate physical results. I have been floored by sensei on many many occasions without being touched,and I think if a person's energy and intentions create reality, that distance would be a meaningless factor. I could see the argument that the transmission of sheer willpower was done at the speed of light, and it only appeared instant because of the short distances involved, but something inside me tells me this is not the case. I would like to see some experiments done in this area.

Psy-Kosh
09-03-2005, 09:26 PM
Granted, the link I posted does not say the speed of light was transcended,but they just actually slowed part of the light down and made the remaining portion appear to be travelling faster than the whole. I am not looking at this from the viewpoint of trying to transmit info in the contemporary sense, but in using energy and intentions to generate physical results. I have been floored by sensei on many many occasions without being touched,and I think if a person's energy and intentions create reality, that distance would be a meaningless factor. I could see the argument that the transmission of sheer willpower was done at the speed of light, and it only appeared instant because of the short distances involved, but something inside me tells me this is not the case. I would like to see some experiments done in this area.

Again, this stuff is funny... The short version is even though it may kind of look like in some situations that the wave is going faster than c, actually having a cause at point A have an effect at point B sooner than the speed of light would allow wouldn't be helped by this.

As for the no touch throws, I admit I am an extremely inexperienced student, but I do remain skeptical as to their natures. I've seen some theories about them that may explain them in terms of psych and conditioning instead, so, I appologise, but at this time I really must remain a bit skeptical about the mechanisims behind such techniques. On the other hand, haven't ever experienced them directly at all, nor even witnessed them, so what I can say on them is rather limited.

However, even if "will" can be thrown as energy or something to produce an effect at a distance, well, it may be that something inside you tells you that it was instant, but remember, a several hundred years ago we used to to think light was instant, IIRC.

Ie, it "felt" instant.

Heck, when I flick the switch to turn on the light in my room, it feels instant, even though I know the effects of flicking the switch have to go through the wiring, the filiment in the bulb has to heat up, and the light has to reach me, and all three of those things have to happen in sequence.

However, your willingness, nay, eagerness, to see expermimentation done in this area is good in my opinion. But, here's the tricky question: how?

ie, the likely delay between starting the clock/telling the thrower to do it, and the actual doing would likely dwarf the time it would take for a lightspeed effect to arrive at the throweee.

I would suggest first determining if "no touch throws", or any effects like them could be done reliably to inanimate objects. If yes, then that would be stronger evidence as to the reality of these things. (alternately, if the no touch throw can be done silently, with uke not being able to see when it's being done (Say, by facing away, or having some barrier in between thrower and throwee), and it still working, may also be evidence stronger evidence. (depending on how it's done)

However, even if confirmed, it would still leave the question of measuring the speed, if it's anywhere near lightspeed or faster. I am having trouble imagining a plausible way to construct such a test. Any ideas?

Reitan
09-08-2005, 04:41 AM
I have heard of a japanese scientist who found out that water droplets viewed under a microscope would change their physical construction in the presence of different emotions. For example, when anger was projected at the droplets, they would organize into spike-like shapes, etc. I was thinking if 2 people on opposite sides of the planet could run an experiment affecting water molecule organization, there might be enough of a distance to calculate whether the speed of light is a limiting factor in the projection of intentions. Then I thought about how someone would have to push a timer button, and in terms of 300,000 meters per second, that would be severely innacurate. I also don't know how to isolate the receiving obsever's intentions and expectations from corrupting this experiment. This could prove to be very,very difficult. I bet if someone figured out how to perform an experiment on this subject, no matter the outcome, they would be in every schoolbook for the next 100 years.

Berney Fulcher
09-11-2005, 05:05 PM
I think a link to your water droplet source would be in order here :) I have not heard of any such experiment / reaction...

Edit: I got interested enough to search:

Masaru Emoto was born in Yokohama in July 1943. He graduated from the Yokohama Municipal University where he studied International Relations. In 1986, he established the I.H.M. Corporation in Tokyo. In 1992, he received certification from the Open International University as a Doctor of Alternative Medicine. Subsequently, he was introduced to the concept of micro cluster water and Magnetic Resonance Analysis technology. He is currently the head of the I.H.M. General Research Institute, Inc., the President of I.H.M., Inc., and the chief representative of I.H.M.'s HADO Fellowship. In his first book, The Message from Water (in three volumes), Emoto documents his findings of what he calls "the true nature of water," discovered in his study of the effects of human vibrational energy, thoughts, words, ideas, and music on the molecular structure of water. He has also published The Hidden Messages in Water, and his work was popularized through the movie, What the Bleep Do We Know!?

Explanation (http://www.life-enthusiast.com/twilight/research_emoto.htm)

Sounds a bit out there to me...

Kevin Leavitt
09-12-2005, 03:19 PM
I think the problem we all have with the concepts is that we see ourselves as individual beings, not connected, stationary. This allows for the concepts of time, space, and distance....however, if we see ourselves as a part of the "fabric"...interconnected to it, then really does all this become "irrelevant"?

I think this is the concepts you find in many meditation practices or enlightment. If we can transcend our own self and become aware of the connections..then we can see ourselves connected to every other thing...and things like time, space, distance, life and death become simply concepts that allow us to self identifiy!

It blows my mind!! :)

anyway, if we are all simply protons/neutrons, and particles bouncing around, constantly organizing and holding together for about 70 or 80 years (100 if you are lucky! :))...then we are all traveling on those wave lengths of light already!!

Dude..I can't wait till I am out of the military and can start smoking some of the good stuff :)

Dante
09-16-2005, 08:14 PM
Good discussions here. I've read Brian Greene's 'Elegant Universe' and 'The Fabric of the Cosmos.' They were both a tough read, but thoroughly enjoyable - if you like the mind-blowing aspects of space-time, M theory and 11 dimensions.

What's interesting to me is the aspect of gravity compared to light speed. If light from our Sol takes 8 minutes to reach Earth, and if suddenly the Sun were to disappear or vanish, would the Earth spin out of the solar system as soon as the Sun disappeared, or would it take 8 minutes before gravity is lost and the Earth spins out? Apparently it's the latter - it would take 8 minutes for the gravitational effect to also reach the Earth because of the nature or physics of our universe's space/time fabric.

Mind boggling, don't you agree? I think Newton would be insulted by this - or thoroughly enjoy it. :-)

Cheers.