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josh
15-05-2006, 02:28 PM
Hey all. Just trying to wrap my head around a few bits of physics{im a bit slow at times} Say you were 4000 light years away and you had a scope powerfull enough ,does that mean you could watch the pyramids being built ? Then as you came rocketing closer you would see time progressing until you reached 0 light years away and then you would be observing the present?
Can i wave up at the sky:hi: ,jump in my space ship {beat the speed of light,i know, not possible and all that} then look through said telescope and see myself ? Does that mean theres two Josh's?. Good thing i dont have infinite energy at my disposal or id fill the universe with lots of me:D My brain get sore now:screwy:
This light stuff is kinda hard to understand.
Thought this is the best place to ask such questions as everyone at work is sick of me asking what they think.

ving
15-05-2006, 02:39 PM
i dont believe the speed of light can be beaten. if you beat it tho can you tell me

robagar
15-05-2006, 05:37 PM
it's not so much that you can't go faster than the speed of light, more that from your point of view light always travels at the speed of light, however fast you yourself are travelling.

So, even if you're bombing along at 0.9c (where c is the speed of light, 3x10^8m/s), the photons that just bounced off you waving will disappear away from you at c. You can never catch them up, let alone overtake them!

Einstein came up with the idea of a constant speed of light regardless of the observer's motion by imagining catching up with photons, and went on from there to invent Special Relativity and E = mc^2 :)

cjmarsh81
15-05-2006, 06:02 PM
I think if you could teleport yourself you would not need to be able to break the speed of light. Then yes I think you would be able to view the pyramids being built. It is just a matter of distance between you and Earth.

For the second one of watching yourself. Yes I believe you could see yourself jumping, however there is only one of you. You are simply looking back in time.

josh
16-05-2006, 10:39 AM
aww man
That puts quite a stumbling block on my path to dominating the universe with millions of me.
Physics/reality seem to spoil all my plans.
Id better do some more reading

astrogeek
16-05-2006, 11:37 AM
But how would you teleport yourself. You would have to send information from one point to another. This information also cannot travel faster than the speed of light so you end up back where we started, you can't wave then travel then see yourself waving. On another point, suppose you could travel faster than light. If you were to do this, the whole concept of causality breaks down and it is possible for an effect to preceed a cause. This is the basis for the postulate that you cannot travel faster than light, because we believe that causality is universal (but it might not be). So an observer wizzing past Earth faster than light might see the Earth explode before the evil alien spaceship in orbit fires the missile at us. I don't know about you but I think I need a Panadol :)

Leon

cjmarsh81
16-05-2006, 03:25 PM
I don't think teleporting will be a problem. When you teleport you don't 'send' yourself from one point to another. You pick a point and arrive immediately at it without any travelling time kind of like a worm-hole.

A few years ago(can't remember where) they managed to teleport a beam of light from one end of a room to another. They said distance isn't an issue, you simply dial up the coordinates and hey presto your there. Unfortunately though, they can't teleport humans yet.

robagar
16-05-2006, 03:38 PM
hmph. I don't think reproducing the quantum state of a single photon using entanglement really counts as teleportation.

And if I remember correctly, it couldn't transmit any actual information faster than light. You need faster than light information transfer to really mess up causality.

robagar
16-05-2006, 03:43 PM
by the way, there's a nice explanation (with lovely diagrams :)) of why special relativity & causality disallow faster than light travel at http://www.theculture.org/rich/sharpblue/archives/000089.html
(http://www.theculture.org/rich/sharpblue/archives/000089.html)

cjmarsh81
16-05-2006, 09:36 PM
At the bottom of the page you have linked to there is a forum of people who do not agree with causality.

I still disgree that you cannot teleport. You are not going faster than the speed of light, you are simply jumping from one point to another.

No one knows until it has been done. I remember a story they told me when I was in high school. When the automobile was being invented a leading scientist said you cannot travel at any significant speed because you would be rushing past the air so fast you would not be able to breathe.(I can't remember the scientists name but thought the story was funny.) Until someone physically attempts to teleport from one point to another who knows?

astrogeek
17-05-2006, 07:42 AM
And we also said that you couldn't travel faster than the speed of sound because the air in your lungs would be sucked out. I agree that we may not be correct in saying that you can't travel faster in light. The first thing I was taught in my science degree was that nothing can ever be proven in science, things can only be disproven.

[1ponders]
17-05-2006, 07:55 AM
And just when you though it was safe to go out in the light, scientists make it go backwards. Have a read here (http://www.rochester.edu/news/show.php?id=2544)

Lester
17-05-2006, 08:53 AM
I like the way you think Josh, Keep pushing the boundaries and stay as an indivual.

robagar
17-05-2006, 09:15 AM
As the author says, if you accept relativity you can either have faster than light travel OR causality. Personally I prefer causality. Paradoxes make me dizzy.

robagar
17-05-2006, 09:30 AM
Professor Dionysius Lardner (what a name!) warned that people wouldn't survive a 100mph trip through Brunel's new railway tunnel to Bath.

Also, coal fired steamers could never carry enough coal to cross the Atlantic.

And "men might as well project a voyage to the Moon as attempt to communicate electronically across or under the stormy North Atlantic Ocean".

In the end he eloped with an officer's wife and scarpered to the USA.

josh
17-05-2006, 10:20 AM
Thanks Lester
I remember hearing in that doc/movie.. what was it called..What the bleep, yep thats it. One of the crazy scientists said they had managed to break the speed of light, not with light itself but with information. Not that i understand how or what was really done. Was it something about the information of the light actually precedes it... could that be right? and would that then make teleporting possible?
Im not sure what kinda stuff that implies, that the path of light or matter may already be set and by predicting that path the speed of light may be anticipated, like it ... umm {is there something ahead of the light with the information of its coming ?} Raises all sorts of questions for some about fate, you know, that before everything happens one can read it {no idea how or what, just throwing ideas around and this is the best place for it.
its probably a stupid question, but i have heard there are no stupid questions, so please keep your brains churning for me, ill get it soon{i hope}
p.s I only mentioned that whole what the bleep stuff because that one point they talked about was interesting to think about... but hurt me mind
Thanks all

vespine
17-05-2006, 02:18 PM
Ok, here is my spin on teleportation:

The universe seems to us to work in "ways" that are governed by what we perceive as "laws".

To US, information can not travel faster then light, but what if the information is ALREADY THERE at the destination??

Just as some lizards can grow back an entire limb just from the genetic information contained in a single cell of their body. Scientists believe that human cells contain the same information even though we don't have the physical capability to recreate a whole limb. The genetic information contained in a single cell is enough to recreate the whole person, right? Not that it's possible, yet…

So is it such a leap of faith then to imagine that the whole universe could be recreated with one single particle of matter? Surely on some level, some very very deep level, the "laws of the universe" are contained in every single particle of matter. If that's the case then the information does not have to actually travel anywhere, it's already there…..
I'm not actually a student of any of this (beyond reading some Hawking and Schrödinger's cat ;) ) so there could be a massive flaw to my logic that I'm not seeing, please feel free to point it out.

ving
17-05-2006, 02:36 PM
5.

Gargoyle_Steve
18-05-2006, 01:10 AM
To arrive at a destination quicker than someone else you do not need to necessarily travel faster, but rather travel by a shorter path.

One theory was that it may be possible to arrive at a destination before the light that left your origin point at the same time you did arrives at he same destination if you were to travel through a conveniently local Einstein-Rosen bridge (ie wormhole). In theory you would not technically be travelling faster than light, you would simply be travelling fast through a very efficient "shortcut".

(http://www.krioma.net/articles/Bridge%20Theory/Einstein%20Rosen%20Bridge.htm)Sadly the theory has plenty of incongruities but still a popular idea ..... some interesting reading here (http://www.krioma.net/articles/Bridge%20Theory/Einstein%20Rosen%20Bridge.htm).

josh
18-05-2006, 12:09 PM
Thanks chaps
hey vespine, yeah thats what i meant,ie that the information for any part of the universe is already in every patricle (that ounds right to me),you just have to be able to look in a way beyond anything we have come up with. so if you assemble the info of something do you then have two of them ?or does the universe not alow it, therefore as you assemble the info ,the original is dissasembled ie teleporting. you summed it up clearer than i could.
And it makes me wonder...
Thank for the link steve, im off to have a look now