Re: Off-Topic Topic
Posted: Fri Oct 21, 2011 6:57 pm
you are seeing light that is millions of years old. (this is were math comes in)StarWolf wrote:I noticed that. In Elementary/Middle school, Pluto was the 9th planet. But in 9th grade there is no 9th planet.
Isn't weird to look out at the night sky and think, 'I'm actually seeing the stars how they looked many years ago'? Or is it just my mind that is always saying WHY?
Proxima Centauri, the closest star to our own, is still 39,900,000,000,000 km away. (Or 271,000 AU.) When we talk about the distances to the stars, we no longer use the AU, or Astronomical Unit; commonly, the light year is used. A light year is the distance light travels in one year - it is equal to 9.46 x 1012 km. Alpha Centauri A & B are roughly 4.35 light years away from us. Proxima Centauri is slightly closer at 4.22 light years.
The Voyager 1 spacecraft is on an interstellar mission. It is traveling away from the Sun at a rate of 17.3 km/s. If Voyager were to travel to Proxima Centauri, at this rate, it would take over 73,000 years to arrive. If we could travel at the speed of light, an impossibility due to Special Relativity, it would still take 4.22 years to arrive!
Why Can't We Travel Faster Than the Speed Of Light?
According to Special Relativity the mass of an object increases as its speed increases, and approaches infinity as the object's speed approaches the speed of light. This means that it would take an infinite amount of energy to accelerate an object to the speed of light.
There's no fundamental reason why we can't get as close to the speed of light as we like, provided we have enough energy. But this is probably far in the future.
If the space between stars is that large i think its going to take a while to reach our sky.