Time And Light Just simple Physics?

[dodgerblue 0]

I've always been interested in this particular topic. It's sorta related to time travel (but I don't really wanna time travel... )I think it's interesting how we can't measure time without light. Like the very first time measurements (the sundial) were based on the changes in shadows - which are made by blocking light.And also how we can't measure light without time. How do you define light? Scientifically you can only say it's photons which travel at a certain speed. And speed is distance/time.There you have it.

[switch 0]

yeah now that's interesting. i've heard something similar in physics... and that if you travel faster than the speed of light you can go forwards in time. but that doesn't make sense to me. to me it just implies that you would travel very VERY quickly ^_^i'm doing Astrophysics as part of physics this year, so if that sheds any light (no pun intended) i'll let you know.cheers

[Cerb 0]

Actually, the theory is that once you hit the speed of light, time will stop. As you progressively move faster than the speed of light, time will begin to move backwards.

[sportytalk 0]

Hey I study physics at college and even I have to say that It's a pretty confusing topic.Lets just simply say that without light, the life on Earth wouldn't be possible. Light is essential for plant growth as well as human growth. Without light there wouldn't be a need for time because no one would be alive to experience it.I think this must be the easiest thing to say!

[dodgerblue 0]

Actually, the theory is that once you hit the speed of light, time will stop. As you progressively move faster than the speed of light, time will begin to move backwards.

197795[/snapback]

Is there anything that can move at the speed of light? Well, apart from light itself, duh...

 

So if you can dissolve yourself into photons you can travel at the speed of light, and then you reassemble yourself at the other end, and you've just time travelled whee!

[wild20 0]

Great topic. You are right. Time annot be measured without light. But I do find it fascinating on how some time is measured by the turns of a planet. Seems kind of weird. But it probably is the most accurate. Do you think a solar or lunar calendar are more accurate though. Time is measured by light, but you can also measure by the orbits of lunar and solar movements. Interesting? Yes. Does anyone know any info about which is more accurate, lunar or solar? While we are on the subject I have been fascinated with it. If you couldpost it it would be great. Again, great topic.

[dodgerblue 0]

Time is measured by light, but you can also measure by the orbits of lunar and solar movements.

198562[/snapback]

Maybe 'coz the sun is the source of light. I dunno, I'm grasping at loose threads here. I'm not a big fan of physics. Ironically.

[Cerebral Stasis 0]

Time isn't necessarily a static value; it's dependant on perception and doesn't really have a specifically measurable value. We consider time to be the order that certain patterns occur, but it may be much more (or less) than that.And I rather doubt that time travel (at least in the classical science fiction defition) is possible. There are too many strange questions tied to it. Furthermore, if time travel was avaliable, chances are some kind of crazy radical faction would have already destroyed reality as we know it using a time machine.I fail to see how light and time are directly related, save in theoretical concepts, like those mentioned about reaching and passing the speed of light. Save that one may be (or have been) perceptionally based off of the other, there is no direct connection.

[Saint_Michael 3]

but you must remember gravity is part of that equation as well, and its impossible to catch up with light even at a molecular level, even if you could slow it down still won't be able to catch up with it, it's just one of those unsolved mysteries that won't get solved, unless a supreme being or aliens stop by and tell someone.

[Unregistered 015 0]

Actually, the theory is that once you hit the speed of light, time will stop.

Why would this happen?

Speed of light © is ~300.000km/s (c=300.000km/1s). If time "stops" then the speed would be ~300.000km/0s (0s since there is no time), and that is infinite. Infinite speed sounds bizarre to me.
Looks like nothing is going to catch you.
(looks like I'm lost in tougths)

Anyway, here is the question: If I'm aboard the spaceship traveling at the speed of light, and ship "fires" me in a capsule at the starting speed of 1000km/h, at which speed am I going to travel?

(c+1000km/h)???

[Erwin_X 0]

Speed of light Š is ~300.000km/s (c=300.000km/1s). If time "stops" then the speed would be ~300.000km/0s (0s since there is no time), and that is infinite. Infinite speed sounds bizarre to me.

Looks like nothing is going to catch you. 

(looks like I'm lost in tougths)

Time is not stopping for you. Time is relative. Time will go faster for you, than for someone not in your frame of reference.

 

Actually, the theory is that once you hit the speed of light, time will stop.

Time will not stop. Remember that time is relative to people or object in another frame of reference than you. If you go at lightspeed for a few seconds, and then return to earth, everyone you know is dead. It's like you stand still, and they live on, or reverse. So time will not stop. For someone in another frame of reference you go just extremely fast (if he's slower than you).

 

Nothing (not yet ) kan go faster than light. In theory we can not travel at the light ot speed, because there's no mass and size anymore.

Light is also a constant, you cannot ad other speeds to the speed of light.

 

Notice from saint-michael:

edited bbcode

Edited November 5, 2005 by Saint_Michael (see edit history)

[Saint_Michael 3]

also to add on the space travel due to the time differance if you call it that, it was said that if you where traveling for 50 years 25 from earth 25 back to earth everyone except you will be 50 years older, mind you I don't think this was ever tested but only in theory.

[Unregistered 015 0]

also to add on the space travel due to the time differance if you call it that,

This is called time dilatation

 

There is also another concept concerning lenght called lenght contraption

 

Those are part of special theory of relativity. Actually it's nothing "special" if you consider speeds way below the speed of light. But, if you go for higher speeds, those count.

 

The point is that every spot in the universe has it's cordinates given by P(x,y,z,t) not by P(x,y,z). That means, that every spot has it's own frame of reference and its own time.

[dogomchawi 0]

One of the things that fascinates me more than anything is the idea of Black Holes. why bring up a black hole in this topic? well its quite simple really - a black hole can bend light!The gravity of a black hole is soooo strong that even light cannot escape it.SInce physicists think that time and light are related it would be reasonable to suspect that the gravity of a black hole is so strong that it might even be able to bend time.The actual definition of what time is, is rather sketchy. When people talk about time they often are actually referring to how we as humans keep track of time. But what is time really? The dictionary says that time is basically the indefinite continued progress of existence both past and future, regarded as a whole. Time is NOT hours minutes and seconds. That is just how we measure time.When someone is in a plane that can travel at supersonic speeds (alot faster than we are travelling here on earth) time will pass slower for them. If someone were to go into space travelling faster than light and then be able to come back to earth, they would see that time passed slower for them in thier "warpspeed (faster than light speed)."Einstein believed that speed of light was the fastest in the universe and so far we havent been able to prove him wrong.One interesting thing to think about is that when we look at a star - we are actually looking at the past. In the time it takes for the light from that planet to travel to earth. the star itself might have been destroyed! If we were able to (for theoretical purposes) travel at 1,000,000 times the speed of light and we went out from the earth and looked back - then we would be able to see the earth as it existed a million years ago!!!Interesting stuff.. i could go on and on this stuff fascinates me

[LocalSeer 0]

From what I've studies time travel does happen due to weird quantom mechanics. Black holes radiate Hawking radiation, from what I remember a quark gets distorted larger then the size of the black hole, at the edge of the whole it splits into two parts, the anti-quark and quark. The quark falls back into the black hole, while the anti-quark escapes by traveling back in time(a very small quanton miniscule ammount) and turns into a normal quark. So time travel is possible .Long time ago my physics teacher told me of an experiment. Take a beam of light and get on a moving train, point the light from the ceiling to the floor and measure the speed, it'll be approximatly 300.000km/s. Now have someone outside the train standing still measure the speed of your light, he'll get 300.000km/s. In order for you both to measure the exact number there is only one explanation, the person in the train had his time slowed down to account for the extra speed, cause otherwise he'd have 300.000km/s plus train speed. So now imagine your proceding at 300.000km/s and represent your brain as two molecules. Those molecules cannot communicate because if one sends a signal to another it would go faster then the speed of light, therefore your atoms don't communicate, you don't age in fact time dosen't pass(I consider time to be communication between fundamental particles). Yet you still travel so if you measure distance(from a outside source) and use your time you would be traveling at infinite speeds, it's all frame of reference.I hope that this explanation helps someone cause it took quite a bit of time traveling forward to write it.