Years in the making
Gravity Probe B was to launch today, but due to weather was held off, Dreamed up in the 60's, and taking over 30 years to actually launch. Another attempt will be tomorrow Go watch it tomorrow on the live webcast (click on the link Watch NASA TV now).
A Boeing Delta 2 will launch NASA's Gravity Probe-B to measure how space and time are warped by the presence of the Earth, and how the Earth's rotation drags space-time around with it. The spacecraft will test the predictions of Albert Einstein's general theory of relativity.
Is einstein correct? Or should we say how correct?... obviously Newton wasnt, he was a generalizer, how much a generilization of the universe was Einstein? Better understanding on blackholes? What all will this prove/ imply?
You may remember we talked about this once before, when this was to launch previously... go to the old post to read about the mission.
Comments
Relativity is about the coolest thing out there, It was one of the most facinating things that I learned from my physics classes,
hey Javin, if you were traveling close to the speed of light you might actually be as short as us in our stationary frame :)
lets see if he is 2 for 2, well it is probably more, but here you go...
===snip snip from http://www.geocities.com/Athens/Forum/1755/my_relat.html===
Comments: Here is a simple way of viewing 'time dilation,'followed by some emperical data to support it's existence. Time slows down when soaring through space at close to the speed the light. How 'much' time depends on the velocity of the travelling object. All clocks, mechanical and biological, tick more slowly in space while stationary clocks tick at the same rate. Any change in your internal sense of time will 'not' be noticed; you will not detect any 'time delta' till you return home. And then, you will ha e a 'big' surprise waiting for you! Now to an example of 'the parodox of the twins.' One twin soars into space at close the speed of light and does not experience any feelings different than that of his brother on Earth. However, the elapsed time on board the space craft will be about 'ha f' of the elapsed time his brother experiences on on Earth. If the space twin travels for 10 years, earth time, when he returns, he will only be 5 years older while his brother will have aged 10 years. There is one significant thing missing from this ex mple; the velocity of the space craft. So, using one of Einstein's equations, and working backwards, we can compute the velocity of the space craft. It turns out to be 86.6 % the speed of light. Or, 161,076 mi/sec. Some 74 years after Einstein published his Special Relativity, out of which came,'time dilation, his theory was proven by the Naval Research Laboratory (NRL)in Washington D.C. In June, 1977, NRL launched a satellite, Navigation Technology Satellite-2 (NT -2), to verfy Einstein's theory. The NTS-2 had on board, two atomic (cesium-beam) clocks. The clocks provided an accurate measure of the effects of relativity on the frequency of a clock in an orbiting satelitte compared to a similar clock on the ground. From an NRL News Media Release, #22-8-77c, dated 4 August, 1977, 'the two atomic clocks on board NTS-2 provided preliminary measurements showing an apparent frequencty shift of 4.45 parts per 10(sup)10 with an uncertainty of plus or minus .02 parts per 1 (sup)10 compared to a predicted value of plus 4.448 parts per 10(sup)10. About the cesium clock, they work on the principle of a resonate cavity containing cesium atoms in their lower energy state. Radiation is fed to the atoms at a 'frequency' that corresponds to the energy needed to raise the atoms to their higher state of nergy. It is the measurement of this "frequency" that yields the "time." All of the above, and much more, are from my essay which I call, "How Fast Is Fast, The Cosmic Speed Limit."
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Posted by: Master Priddy | April 19, 2004 12:51 PM
Yes gravity bends our space time continuum... therefore, after you've studied it in reality, time is going slower at your feet than at your head, because your feet are closer to the center of the earth. (Like how time goes slower in (or near) a black hole)
I theorize that is why we have to get hair cuts for the hair on our heads, but not the hair on our toes. (And also why our fingernails should grow faster than our toenails) I call it the Myers-Nail Theory.
Posted by: itzjerm | April 19, 2004 02:57 PM
The difference in the speed of light between your feet and your head is approximately .001
"ninny-nano" seconds.
this was tested in an aisle at a local Walmart
with beams from a flashlight.
It's not exactly as scientific as Einstein but it produced an "enlighting" result.
Posted by: Martha | April 19, 2004 08:38 PM
Hey Jerm, can you give the class a lecture on "Frame Dragging."
That would be great... Thanks
[I just have a hard time believing that the earth pulls time, or something like that]
Posted by: case | April 20, 2004 03:32 PM
Gravity probe B completed its succesful launch!
Whats it all about?
Frame Dragging: A rotating massive body drags space and time around with it.
Geodetic Effect: According to Einstein's General Theory of Relativity, space and time in the vicinity of a massive body is distorted.
So in other words... time and space is relative... aka Relativity
Posted by: itzjerm | April 21, 2004 10:30 AM