Is it possible to travel through time ?

[Nanovae]

Now, this is faster than light,

negative
I don't know what you try to explain with this picture, but it won't show anything going faster than c.

In fact, saying nothing can go faster than speed of light is an abuse.
no INFORMATION could go faster than light speed is true.

example : if you use a very powerfull laser on earth to paint the moon from one side to another, the beam speed on the surface could go faster than light speed.
but as there is no information shared beetween the first photon and the last one, there is no violation of the basic precept that no information could go faster than the speed of light.

[Jay]

negative
I don't know what you try to explain with this picture, but it won't show anything going faster than c.
In fact, saying nothing can go faster than speed of light is an abuse.
no INFORMATION could go faster than light speed is true.

You have absolutely forgot about the medium in which light travels defines the speed. Ever heard of Cherenkov light? what do you define as light? Is it the visible light or the entire electro magnetic spectrum?? I will agree if your defn is latter but not the former.

You also did not make the effort to search about the picture. I guess youve heard about ESA and their Newton observatory, they released this picture.

ESA's X-ray observatory, XMM-Newton, has imaged a spectacular set of rings which appear to expand, with a speed a thousand times faster than that of light, around the point in the sky where a powerful gamma-ray explosion took place in early December.

This is the first time that such a fascinating event, called an `echo', has been seen in X-ray wavelengths.

example : if you use a very powerfull laser on earth to paint the moon from one side to another, the beam speed on the surface could go faster than light speed.

Thats relative to a position and thats not what I'm talking about.

[omon]

If a train goes with speed of light and turns on its head light will light from a headlight go C(train)+C(of light itself)= 2C? Like person walking inside a moving train

[Nanovae]

which appear to expand


APPEAR to expand

I repeat : NO INFORMATIONS COULD GO FASTER THAN LIGHT
whether you like it or not, it's the formally definition, dude.
It's not "nothing could go faster than light" but only no informations.
There is only one exception i don't want to go in : about 2 photon emitted at the same time, and when you "read" one, you could deduct how is the second.
I gave you above an example of something that could go faster than light without violate the basic principle, it looks like you didn't get it ...

what do you define as light?

Basic principle => light : photon
You don't care about spectra, from gamma to kilometric waves

Ok, Jay ... I know you don't like me, but try to be not so agressive.
Just because on this subject, you will never teach me anything : this is my passion for 20 years, and each week for ten years, I could chat with some of the top astro scientist in France, and sometimes of the world.
You could teach me a lot about weapons and geopolitics, but you won't teach me anything in that matter.

Thank you to be a responsable man, able to have deep conversations, and not an exited child that want to show he is the best and the more intelligent guy around.

cheers

[Nanovae]

If a train goes with speed of light and turns on its head light will light from a headlight go C(train)+C(of light itself)= 2C? Like person walking inside a moving train

answer is ... no
to explain why, it's a bit complicated, it's a question of own reference.
but if you go near the speed of light and something come in front of you at the same speed, and if each one send a light beam to the other, anyway, when you will receive the beam, you will see a speed of light at 300.000km/s (in space)
It's explained by relativity.

[Jay]

Thank you to be a responsable man, able to have deep conversations, and not an exited child that want to show he is the best and the more intelligent guy around.cheers

Dude, WTF is your problem?? Cant you stop talking about me??

[Nanovae]

WTF <= this is my problem

[omon]

do we need to go with speed of light to travel in time? even if we build ship that is faster than C can it take us in lets say nov 9 204bc 17;00 and than back to when we left? I still think C isn,t the answer. and also if i go 1 day back and see shake hands with my self will it be a conflict? will both of us be like matter and antimatter?

[Jay]

which appear to expand

APPEAR to expand
I repeat : NO INFORMATIONS COULD GO FASTER THAN LIGHT
whether you like it or not, it's the formally definition, dude.

Thanks for the effort in making them big and bold, just to let you know, no one is blind here.
And yes, it says appear to expand, so I guess its just a relative measure, my bad.

I gave you above an example of something that could go faster than light without violate the basic principle, it looks like you didn't get it ...

I gave you another way by which you can make particles travel faster than light, Cherenkov light effect. If light travels at c in vaccum, it reduces to c/n in a dense medium (n being the refractive index of the medium itself). Havent you seen the blue glow from nuke reactors produced by eletrons travelling faster than light in water? The example you gave is an illusion, its a classic object and shadow example.

Basic principle => light : photon
You don't care about spectra, from gamma to kilometric waves

Ok, I agree with the definition. And I guess I should not bring in tachyons then.

Ok, Jay ... I know you don't like me, but try to be not so agressive.
Just because on this subject, you will never teach me anything : this is my passion for 20 years, and each week for ten years, I could chat with some of the top astro scientist in France, and sometimes of the world.

pff, what ever, I dont want to know your daily activities, nor I'm remotely interested in discussing about your personal life. It would be great if you do so as well.

Thanks

[Jay]

WTF <= this is my problem

Its very simple, then you should stop talking about me and just discuss the topic at hand.

[Nanovae]

I gave you another way by which you can make particles travel faster than light, Cherenkov light effect.

not light speed in space, so no more than 300.000 km/s ! the particule could go faster than light when light go under it's maximum speed.
here is your error : you couldn't say a particule is going faster than the speed of light => you have to say a particule is going faster than the speed of light in water ;)
Science doesn't like approximations, and you example shows your initial approximation lead you to believe something could go faster than light speed in the vaccum when it's just impossible.

So you came to a false conclusion because you didn't get all the factor, a thing to avoid in science where you need to take your time to understand all factors.

read that =>
http://hep.bu.edu/~superk/cherenkov.html
http://en.wikipedia.org/wiki/Cherenkov_radiation

Thanks for the effort in making them big and bold, just to let you know, no one is blind here.

let me laught about this one
I read you on the forum, and you use it so often you should have shame to tell me not to do what is your speciality

[Nanovae]

do we need to go with speed of light to travel in time?

if we could go faster than light, then, we could see the past =>
you go 2 ly away from earth at 2 times the speed of light then you could observe the earth before you leave it.

but ... nothing could go faster than light

even if we build ship that is faster than C

you cant' say that without giving us a new physic.
An assumption based on something impossible will give something impossible
So ... there is no "what if we could go faster than speed of light" because it's just impossible

It's the same to say, what if I am god ....
Not a scientific talk.

[Jay]

here is your error : you couldn't say a particule is going faster than the speed of light => you have to say a particule is going faster than the speed of light in water ;)
Science doesn't like approximations, and you example shows your initial approximation lead you to believe something could go faster than light speed in the vaccum when it's just impossible.
So you came to a false conclusion because you didn't get all the factor, a thing to avoid in science where you need to take your time to understand all factors.

I guess I have to bold my statements, to help you read. I'll just repost my previous arguements,

You have absolutely forgot about the medium in which light travels defines the speed. Ever heard of Cherenkov light?

If light travels at c in vaccum, it reduces to c/n in a dense medium (n being the refractive index of the medium itself).

So who came to a false conclusion? Read my posts and see, I have been very specific as to when/where can faster than light travel is possible. It you who extrapolated my arguement to include vaccum while in reality I never talked about vaccum at all.

let me laught about this one
I read you on the forum, and you use it so often you should have shame to tell me not to do what is your speciality

I guess you seriously need help in forming english sentences. Btw I have never increased the font size nor I use all caps in my posts, I do bold my posts. Do you even know what All Caps in an internet fora means? Prolly not, coz YOU ARE FRENCH!

[omon]

you cant' say that without giving us a new physic.
you are right i,ve read some books on this subject, our math and phicics can only be applied to real world to a certan extent, take decart's(flat) coordinate system x y z our world isn't flat and linear. coordinates should be spyral(so they say)or 5-7=-2 we can do it on paper but not in real world, it all this way so it,s easyer for us to work with,math, phycics are made by people, people make mistakes, tand to adjust things for our conviniance. our sciantific comunity has proven not to accept anything that didn't come from them.(examples like that everywhere). i know there is a logical explanation for everything, the thing is; logic could be very deciving.

[Nanovae]

You have absolutely forgot about the medium in which light travels defines the speed. Ever heard of Cherenkov light?

this one is for me, sorry
You mentionned it only once, and i miss it.
Anyway, as long as you are not talking about overruning c, which is a fixed value, I will agree.
In Cherenkov effect, nothing go faster than c

I guess you seriously need help in forming english sentences.

I know that, that's one of the reasons why I'm here.
But I don't think you could be a good teatcher for me, dude, you are not enought pedagogue ;)
Maybe on arsh language ...