"As time flows, this structure of fixed past, immediate present and open future gets carried forward in time. This structure is built into our language, thought and behavior. How we live our lives hangs on it. Does mans concept of time meaning, seconds, minutes, hours, days, weeks etc etc fit in with the flow of the universe" - giveme
I am impress. Anyway, time is tricky.
In a recent experiment, scientists placed two atomic clocks on two tables, then raised one of the tables by 33 centimeters, and found out that the higher clock was running faster than the lower one at a rate of a 90-billionth of a second in 79 years.
This is called time dilation, and it happens because (as Einstein's theory of relativity predicted) gravity warps time as well as space. The closer you are to the ground, the more you are affected by the Earth's gravity and the slower time moves. On the other hand, as you get higher, gravity's pull weakens and time speeds up.
Keep in mind that this is an insignificant amount of time we're talking about here. It has absolutely no bearing on your life, unless you rely on GPS equipment. Because a clock inside a GPS satellite runs at 38 microseconds per day faster than the same clock would run on Earth, a computer has to constantly adjust everything to make up for that difference. Otherwise the consequences would be disastrous: In only one day, the entire system would be off by 10 kilometers, and it would just get worse from then on.
Oh, and by the way, gravity isn't the only thing that can mess up time ...
Another thing GPS satellites have to take into account is speed, the faster you travel, the slower time moves. Scientists have proven that the same thing happens to you every day, on a much smaller scale. Making one of the clocks move at only 20 mph caused it to slow down its tick by almost 6 x 10-16. In numbers we can understand, that translates to "Not a whole lot, but still".
So, let's say you're driving to work at around 40 mph, that right there is apparently enough to cause time to move 0.0000000000000002 percent slower than it would if you were standing still.
In another experiment, one atomic clock was taken on a plane trip around the world while the other one stayed home. Even though the clocks were perfectly synchronized at first, the traveling clock came back from its 50-hour, 800-kilometer trip missing 230 or so nanoseconds.
So the clock gained time from being farther from the Earth than the other one, but it lost even more just by going faster. What's even weirder is that from the perspective of the clock on the plane, the clock back home is the one that's running faster than normal. You don't actually feel time slowing down or speeding up: Only someone outside your conditions can tell the difference.
People can witness the same events happening at different speeds. Einstein claimed that events that appear simultaneous to a person in motion may not look simultaneous to someone who is standing still. So reality may actually be a mess of people walking around in slightly different timelines that sometimes synch up or intersect, depending on their conditions.
Last, but not least. One day, time itself must die. So how long have we got? In four out of five possible calculated scenarios, time is most likely to end in about 3.3 to 3.7 billion years. In the fifth scenario, time could end before you finish this sentence.
So it turns out we live in a reality that's like an old pocket watch, and one day it's just going to wind down. In fact, when it happens, we won't even see it coming. The scientists describe it like watching someone falling into the event horizon of a black hole. Things slow down and eventually just ... stop.
We won't even be aware of what's happened. Everything will work one second and won't the next. We'll all just be frozen in place, completely still. Forever and ever.
Ismael
http://www.wired.com/2010/09/ordinary-relativity
http://m.sciencemag.org/content/329/5999/1630.abstract
http://en.m.wikipedia.org/wiki/Time_dilation
http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html
http://www.phys.unsw.edu.au/einsteinlight/jw/module4_time_dilation.htm
http://www.nature.com/news/2010/100923/full/news.2010.487.html
http://www.npr.org/templates/story/story.php?storyId=130077353
http://www3.open.ac.uk/media/fullstory.aspx?id=19636
http://www.bartleby.com/173/8.html
http://www.telegraph.co.uk/science/large-hadron-collider/3319218/Time-is-running-out-literally-says-scientist.html
http://m.phys.org/_news205133042.html