is it possible to travel at speed greater than light
By sidharth07
@sidharth07 (6)
India
January 24, 2007 11:05am CST
well it has always been a dispute it can be done or not ....
but it shld be possible because we can take nothing as granted as someday a person might be able to travel at speeds greater than light
2 responses
@mx_aman (2101)
• India
8 Mar 07
I thinks it's not possible...
Recalling the very famous second postulate of Special Relativity declared by Einstein (1905): "The velocity c of light in vacuum is the same in all inertial frames of reference in all directions and depend neither on the velocity of the source nor on the velocity of the observer". Einstein's theory of special relativity says that the speed of light in vacuum is always the same (at 299,792.458 km/s) but this is true only for systems that are inertial, which means not accelerating. From Newton's second law: if forces exist implies acceleration exists; this means that special relativity is valid only when no forces are acting; thus it cannot be used when there is a gravitational force present. Albert Einstein himself emphasized this in his paper written in 1917: "The results of the special relativity hold only so long as we are able to disregard the influence of gravitational fields on the phenomena". Therefore for the results of special relativity to hold the systems should not be accelerating (no gravitational forces).
In 1915 (10 years after special relativity) Einstein developed another theory called General Relativity that deals with gravitational fields and according to this latest theory the velocity of light appears to vary with the intensity of the gravitational field. For example, an observer outside gravitational fields measures the speed of light locally (in his location) at 299792.458 km/s but when he looks towards a black hole he sees the speed of light there to be as slow as a few meters/sec. At the same time an observer freefalling into that black hole (zero-g) measures the speed of light locally (in his location) at 299792.458 km/s; when he looks towards the black hole he sees the speed of light there much slower; when he looks away from the black hole he sees the speed of light there much faster. If he tries to resist his freefall into that black hole (by firing his rockets for example) he will not measure the speed of light locally anymore at 299792.458 km/s; instead the stronger the g-force that he feels the faster light appears to him. Again when he looks towards the black hole he sees the speed of light there much slower; when he looks away from the black hole he sees the speed of light there much faster. In any case, freefalling or not, he will never see the speed of light outside gravitational fields at 299792.458 km/s. Finally, there is no difference between the effects of g-forces experienced from these rockets and the effects of g-forces experienced when standing on planets, stars... hence an observer standing on a black hole measures the speed of light locally (in his location) much faster than 299792.458 km/s; when he looks towards outside gravitational fields he sees the speed of light there a zillion km/s.
1 person likes this
@redyellowblackdog (10629)
• United States
8 Mar 07
"hence an observer standing on a black hole measures the speed of light locally (in his location) much faster than 299792.458 km/s; when he looks towards outside gravitational fields he sees the speed of light there a zillion km/s."
I'd like to read more about this quote. Could you give me a reference?
@haze06 (241)
• Philippines
25 Jan 07
I don't think it's possible to travel faster than light. All I know is that the term faster-than-light, which is also called superluminal or FTL, is used in communication and travel which refers to the propagation of information. But, it's more likely FICTION. Generally, it is impossible by the mainstream physics community due to special relativity.