The Theory Of Relativity What does it mean for space travel?

[mitchellmckain 0]

You're right, I should have thought of that with the aging...  But I still don't agree with you saying "We can get anywhere as fast as we would like." The theory of relativity forbids that - which you fully agree with later... 

For the people on the ship they can get anywhere as fast as they would like, it is just for the for the people back on earth watching that it takes so long. So "would be space emperors" must either stay on a planet to rule it while space ships crawl among the stars like snails or go on the space ships themselves where the people on the planets can pretty much ignore him. Of course the scavenger like aliens in the sci fi hit "Independence Day" would certainly be a be a problem (at least if relativity were the only obstical).

Are you sure of this? I could have sworn that many scientists saw the tachyons as a possible solution to many observations, including the accelerating expansion of our universe.

Well the last class I had two years ago when I finished my masters in physics was a pretty up to date class on String Theory. And one of the key historical developments was solving the "tachyon problem" (which meant figuring out how to make sure tachyons don't show up in the theory).

But nevertheless in 1973 Philip Crough and Roger Clay fell over an interesting observation using a large particle detector. They saw what some expects to be a superluminal particle (a particle that travels faster than light). This result has never been reproduced so we canât make any conclusions upon that. My intension was only to show, that some people still believe in these particles.

The essence of science is that it can be reproduced. Here in Utah we had that cold fusion fiasco/scandal where some scientists had people convinced they had found evendence for cold fusion, but it turned out to be a scam. Reproducible results is the only thng that seperates science from fraud (or big blunders).

As for believing in tachyons I and all the physicists in the world are completely outnumbered by the star trek fans.

[YudzzY 0]

relativity is what differentiate us! like everyone is beautiful, but some are more beautiful and some less, hence its relative as you are talking to your distance topic! about the limits, well what has a definite limit?! thats is how life is! oh well..

[mitchellmckain 0]

Well I think this thread has proved my point that many people put more faith in science fiction than in science. Many people do not even bother understanding what limitations are implied by the theory of relativity before they are looking for some crazy way to get past the speed of light. Relativity does not restrict our ability to travel long distances in space. You can go accross the galaxy (100,000 light years) in as short a time as you like provided you can supply the enormous energy required and endure the tremendous acceleration. HOWEVER, if we restrict ourselves to reasonable accelerations and energy then it will take a few years to get anywhere (like the nearest star 4 light years away) just because it takes a couple years just to get near the speed of light at a reasonable acceleration (1 g = 9.8 m/s^2), but once this is done we can cross large distances fairly quickly.4 light years will take about 4 years on board ship10 light years will take about 6.5 years on board ship100 light years will take about 19 years on board ship1000 light years will take about 62 years on board shipSince there are over a hundred stars known to be within 20 light years, a 10 year trip can get us to many destinations. And if we can manage higher accelerations we can cut these times down tremendously. For example at four times the acceleration 39.2 m/s^2 we cut these times in half. But anyway the problems here are with engineering not with relativity!What relativity does mean for interstellar travel is that it is basically a one-way trip, in the sense that you cannot come back in time for dinner, or even for your friend's next birthday. Although you can get where you are going pretty fast, time passes much faster for those you leave behind. during the 4 light year trip about 6 years will pass on earthduring the 10 light year trip about 12 years will pass on earthduring the 100 light year trip about 102 years will pass on earthduring the 1000 light year trip about 1002 years will pass on earthRelativity isolates the locations from one another so that what happens at one location cannot effect another location for a long time. This makes things like government and trade very difficult and unlikely over inter-stellar distances. This rules out star trek and star wars but not interstellar travel.

[Vicious_AD 0]

I've been having a debate with a few friends lately about this sort of thing. I can walk on my hands, so I have deduced that standing on my hands, by the theory of relativity, is in fact me carrying the earth. Since there is no up or down in space, and there is no motion in space because relatively everything is in constant motion, then while the mass of the earth is drawing me towards it's center, it is coming towards me as well (both are moving towards eachother according to Einstein). Holding something is defined basically as stopping something from falling by impeding it with another material object. so since there is no "falling" in space, I am technically holding the earth as it holds me, right? Considering the earth and I as two material bodies rather than the earth being my home and planet, instead thinking of it as two marbles in the same ocean.Does anyone agree with this? I can't get some of my friends to understand.

[yobster 0]

am I right in thinking that time even passes at a different rate when you are on a train, or a plane?I remember reading that if you throw a ball in the air when you are on a train it will seem to be in the air for longer if you are watching from a stationary point..would this mean that time passes ever so slightly differently if I was jogging? could someone explain to me how this works? - or is it just one of those things which just happens, without any explaination.. I'm just confusing myself now.