Ok. If I fly from NY to CA let's say it take 5hrs there and 5hrs back; so, when I return to NY I'm ten hours into the future of NY. If I ride a bike from said places and it takes a year there, year back, I'm two years into the future of NY. Isn't all just from a) what reference point and b) the speed of your transport vehichle? So, if I travel from Earth to planet X (light years away) at the speed of light, why would time durate longer than a) my journey (from my viewpoint) and b) planet X. Isn't it all relative? Yes, it would be later on earth when I get back but only by the same amount of time equal to the lenght of my trip. Just like ten hrs later flying from NY-CA and back. I just used a faster vehicle (one at the speed of light). All this time dialation, reference point stuff just isn't overly fancy mathematics? I don't get it!
2007-03-13 06:20:43 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
You *don't* get it. :wink:
The point is that for your airplane trip and bike trip, you, everyone in California, and everyone in New York continued to age along the same timeline.
If you took that same trip at near the speed of light, you would arrive in about 0.032 seconds, and the slowing of your aging relative to those "on the ground" would be by thousandths of a second.
However, if you traveled near the speed of light for 20 years (by your watch) and then returned, you would come back to a place that had aged much more than you.
The factor of "time expansion" is given by the Lorentz expression:
L= (1 - (v/c)^2)^(-0.5)
So if you are traveling at 90% the speed of light,
L= (1 -(.9)^2)^(-0.5) = 2.3
So those who remained behind while you took your 20 year trip will have aged 46 years.
http://en.wikipedia.org/wiki/Time_dilation
.
2007-03-13 06:38:45 · answer #1 · answered by Jerry P 6 · 1⤊ 0⤋
The time passge is different when traveling near c. So let's say you travel for 5 years at very very close to light speed and arrive at your destination. If you can somehow communicate instantly with home. You will find that the people there have aged 20 years. You travel back at same speed, the people have aged 40 years while you have aged 10.
They have done studies where an atomic clock on a 747 that travels for a few hours at 500 miles an hour actually slows down a few tiny fractions of a second compared to it's twin on the ground.
2007-03-13 13:25:34 · answer #2 · answered by Anonymous · 2⤊ 0⤋
If you stay in the frame of reference of the Earth's gravity well, and do not hit relativistic speeds, you will measure time like Earth measures time with unnoticeable-by-human-bodily perceptions' differences. Extremely accurate atomic-clocks have been used to conduct experiments by having two clocks synchronized, then taking one and putting it on a fast jet transport and flying it around. When the two clocks are brought back together and compared, there are differences of elapsed time in billionths of a second. No human could really count and determine that my count is a billionth of a second off from your count.
Now, the measure of time by an observer is relative to that particular observer's frame of reference and state of motion in that frame of reference. Say a ship travelling along at .99 c [the sped of light] goes around the galaxy for a galactic tour. By ship's clocks, it would take less than a human lifetime. When they arrived back in our solar system, Earth would be gone and our yellow sun would be in its final life stage as a white dwarf. If there was a working clock left here, it would have measured the same trip as having taken billions of years.
An observer in motion or in free space [away from a source of a gravity well], will measure the passage of time more slowly than a stationary observer or one that is closer to the source of a gravity well.
Both these aspects have been proven numerous times. Be glad we can do the fancy mathematics too. Otherwise the whole GPS would not work. To give a GPS receiver its coordinates, signals bounce from receiver to satellitets and back. The distance these signals traveled is computed based upon the time it took to get to the satellites and back. Well, the clocks on the satellites measure a second differently than a second as measured here on the Earth-or even for planes flying closer to the center of the Earth [i.e. the source of the Earth's gravity well] than the satellites are. If the computers did not use relativistic fancy mathematics, they would be unable to give accurate coordinates.
2007-03-13 14:11:01 · answer #3 · answered by quntmphys238 6 · 0⤊ 0⤋
Well...not exactly...a cesium clock in a fast travelling Supersonic jet does show a minute difference from a similar clock on the ground. Also, at near Light speeds, time does not slow down, it "Streches"...ie it would run sloweer for you than to a still object...hence causing the dilation effect
2007-03-13 13:35:01 · answer #4 · answered by Saber 1 · 0⤊ 0⤋
No if you accelerate to very close to the speed of light, the people in your old reference frame will see your clock slow down. Once you get to accelerating to very high speeds, things change.
2007-03-13 13:26:10 · answer #5 · answered by Gene 7 · 1⤊ 0⤋
your watch will go slower when your speed is higher. so its not 10 hours in futur of NY but a little bit less.
2007-03-13 13:25:00 · answer #6 · answered by gjmb1960 7 · 0⤊ 0⤋
Go hit the books again, slugger.
2007-03-13 13:44:21 · answer #7 · answered by stargazergurl22 4 · 0⤊ 0⤋