If "I" send a laser beam, that remains concentrated, with no interference, from point (A) to point (B), 1000 light years away, and simutaneously, a foreign craft departs point (B), but travels at 2.5 times the speed of light, to point (A), is it then plausable that the craft will arrive at point (A) before "I" actually even send the laser beam?
2007-02-11 06:51:10 · 10 answers · asked by newfoundlander 1 in Science & Mathematics ➔ Astronomy & Space
This is one of those thought experiments - we must first discount all of the reasons that light speed is not possible, let alone exceeding it - and go from there:
If we travel at light speed, time will slow to a stop - and distance will shrink to zero in the direction of travel. We would therefore reach our destination (by our reference) in no time or instantaneously. Einsteins formulas break down when our velocity (V) exceeds the speed of light (C). Mathematically, we find ourselves with negative square roots and division by zero - and who knows what that means.
It really depends on what happens after time stops at light speed and we continue to accelerate even faster - does time then go negative, i.e. backwards? Can we arrive even faster than instantaneously - i.e. in the past? Could we possibly arrive before we left?
Obviously, I have answered your question with more questions because neither I nor anyone else knows the answers - only speculation and theories.
Personally, I don't believe anything exists outside of a light cone - in other words, time travel into the future is a non-sensical question because the future doesn't exist - and the past exists only in our memories and recorded history.
Unfortunate because time travel is such an intriguing topic.
2007-02-11 10:28:33 · answer #1 · answered by LeAnne 7 · 0⤊ 0⤋
The craft will take about 400 years to reach point A. By that time the laser beam will have traveled 400 light years.
So the craft will meet the beam somewhere between point A (the beam's point of origin) and 400 light years away from A in the direction of B.
The word here is simultaneously, and not a 1000 years ago. However, if the craft departed 1000 years ago, then the craft would have arrived 600 years ago.
Of course, this is all speculation, since nothing that has actually been observed can travel faster than light.
2007-02-11 15:06:05 · answer #2 · answered by Tenebra98 3 · 0⤊ 0⤋
It's not plausible that a craft can travel 2.5 times the speed of light. As far as we know the speed of light is a hard speed limit on existence. Until we figure out if there's a way to break it so to speak, we can't really predict what kind of odd effects may come from doing so.
2007-02-11 14:55:02 · answer #3 · answered by Arkalius 5 · 0⤊ 0⤋
If Einstein is correct (and most of his theories are panning out in reality), not only does and object increase in mass to infinity at the speed of light (meaning you would need infinite energy to power any mass to the speed of light), but the time dilation thing goes to infinity.
That means that an object travelling a the speed of light would get everywhere instantly from the perspective of the traveller on it. So, if it was possible to travel the speed of light you could get anywhere in the universe instantly, so why would you consider travelling faster?
And since from the prspective of a light speed traveller, his speed is infinite, obviously, you cannot travel faster.
QED, as the mathematicians say.
2007-02-11 15:02:06 · answer #4 · answered by nick s 6 · 0⤊ 0⤋
No, your laser beam will be 400 light years on the way to point B when the craft arrives where you are.
2007-02-11 15:19:59 · answer #5 · answered by Anonymous · 2⤊ 0⤋
Seems like nonsense to me.
But since we're playing hypothetical, impossible nonsense games, answer this for me:
If you discovered a way to travel back in time and you couldn't return, did you ever exist in the current time? And was your time machine ever really invented? Not even your mother would know about you. All evidence of your existence disappears!
Come to think about it, there may have been many discoveries of time machines by people who keep negating their current existence by injecting themselves into the past... where they're probably apprehended and put into an insane asylum somewhere to die in anonymity!
If you think this is nuts, ask yourself what you'd do with me if I walked into a police station and said I just got here from the year 5659 and I need to speak to the authorities!
2007-02-11 20:10:55 · answer #6 · answered by idlebud 5 · 0⤊ 0⤋
Hi. If you could arrange to have the two events occur simultaneously then it should be obvious that no matter what speed the ship travels at (except infinite speed) the two events cannot have less than zero time between them. (Hey, if it's 'i' before 'e' except after 'c', no wonder Einstein had problems in school!)
2007-02-11 15:47:00 · answer #7 · answered by Cirric 7 · 0⤊ 0⤋
yes, in theory. but you have to "break physics law" when you say 2.5 times the speed of light..not allowed as we know it. even if you send a craft at 2.5x the speed of light, it seems to me that friction alone would vaporize the craft.
2007-02-11 15:13:43 · answer #8 · answered by cowboybabeeup 4 · 0⤊ 1⤋
to know the result of your argument, you should do it after preparing to pass it to at least 800 generation to complete the observation. human traveled 240,000 miles and back in five light days!
2007-02-11 15:26:23 · answer #9 · answered by Anonymous · 0⤊ 0⤋
actually, ion powered spacecraft can exceed the speed of light by a little bit. that is yesterday's technology. Stephen Hawking has been researching warp speeds for several years now and says he is making progress on achieving multiples of the speed of light.
2007-02-11 16:51:15 · answer #10 · answered by hot95spencer 2 · 0⤊ 3⤋