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why_can_t_we_go_faster_than_the_speed_of_light_can_we_ever_colonize_other_planets 2009/02/02 13:17 current
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+**1. Is the the speed of light the maximum speed and why/why not?**
+----
+
+For a particle which is created travelling slower than the speed of light,
+the speed of light is the fastest possible speed. The reason is that,
+in order to accelerate an object, you need to use energy. The more massive
+(or "heavier") an object is, then the more energy it takes to accelerate
+it. You understand this well, as it is easier to throw a ball at 50
+kilometers per hour than it is to throw an automobile at 50 kilometers an
+hour.
+As an object moves faster, it appears to gain mass (or become
+heavier). We don't notice this in everyday life, because this effect
+really only becomes noticeable when you get very close to the speed of
+light, but scientists have measured and verified this theory in laboratory
+experiments. In fact, if an object gets very very close to the speed of
+light, it's mass goes up so fast that it can seem to be infinitely heavy!
+At this point, it is impossible to gain enough energy to accelerate the
+object any further.
+
+**2. E.g. if you travel in a ship that are well protected from paticle hits
+or are flying far from all material, would it be possible to gain
+lightspeed (theoretically) ? and could you increase speed from there ?**
+----
+
+No, for the reasons I describe above. It would require infinite energy
+just to reach the speed of light, let alone accelerate beyond it!
+
+**3. If 2 photons emitts from the same source, are not their speed, compared
+to each other, twice the light speed ?**
+----
+
+No. This is a very strange thing about special relativity. Einstein's
+theory states that, no matter whether you are moving or standing still,
+light always moves at the speed of light. So, if you were on one photon
+and looking at the other photon, it would appear to be moving at the speed
+of light. This is very complicated, and I really cannot explain it via
+email, but good books on special relativity should be able to help you
+somewhat.
+Mathematically, the ideas behind special relativity are very
+simple, and can be understood with basic algebra. However, a physical
+understanding of what special relativity means is very difficult to
+achieve. I'm still not certain that I truly understand it; I just accept
+it as true (since repeated experiments show these theories are true).
+
+** 4. In your oppinion, how far are we from common use of spacetravel,
+collonization and space mining etc.? 50, 250 ...?**
+----
+
+For colonization and mining of objects in the solar system, we have the
+technology now to be able to accomplish these things. The major hurdles
+are economics (space travel is very expensive, and it is hard to justify
+sending people to an asteroid to mine iron when it is cheaper and safer to
+mine iron on the Earth) and physiological (we don't know what will happen
+to astronauts who are in space for years at a time, both physically and
+mentally). In the next several decades we will probably begin to reach
+out within our solar system, but it will take economic pressure to
+establish permanent residences.
+
+As for colonizing other stars, I personally believe that it may take
+thousands to millions of years, if ever, for us to reach out. The nearest
+star is four light-years away, but at the speeds of modern rockets, it
+would take us tens of thousands of years to get there. There are dreamy
+designs for nuclear powered rockets that may be able to go as fast as 1/10
+the speed of light, but even then it would take 40 years to get to the
+nearest stars. And we have no clue if these stars have planets capable of
+supporting life! Outer space is much larger than most people imagine, and
+so I think it will be much longer than most people imagine before we are
+able to bridge the gaps between stars.
+
+Thanks for writing!
+
+Sincerely,
+Kurtis Williams