ok so was reading up on this one nite i was board
turns out that if you Reach the speed close to light speed time goes slower
i emailed some professor guy this ? trying to figer out why we havent done it yet this was my ? to him

> ok i dont really know much about this so hummer me please..so why is
> it that we cannot travle the speed of light or close is it because our
> ships or objects meterials cant with stand these grains of energy in
> space? or is it because we simply do not have anything to push off of..
> so hear is my real question let say you had a ship that you could breack
> into parts a space ship now will go 17,000 miles a houer or somthing
> like that. that realy doest matter to my question just wondering about
> the theroy of this.. say you have a ship or craft its going 17,000 miles
> a houer it has nothing left to push off of now if the ship could break
> apart say at the back a section would come off with a explosion kinda or
> fource would that not give us more speed you could have a craft with
> many sections that would blow off milla seconds afetr anther giveing us
> a trail to push off off if you had many couldnt you in thery reach speed
> never befor reached...????

now his answer i got emailed back to me this is so cool

The reason for not reaching light speed is not due to lack of anything to
push against. Now, I must tell you that you really do not need anything to
push against to get speed. The principle that applies here is Newton's
third law, which says that every action has an equal and opposite
reaction. Now, consider modern rockets. In these rockets, fuel is burnt,
and the combustion product gases escape through the nozzle of the rocket.
The outward momentum of the escaping gas is balanced by a thrust in the
opposite direction which results in the propulsion of the rocket itself.
This will work in vacuum too (although in vacuum there is nothing to push
against) because of Newton's third law.

Now, coming to why it is difficult to reach light speed: the reason lies
in Einstein's special theory of relativity. According to this theory, the
mass of a moving object is higher than the mass of the object at rest, and
the proportion of increase of mass increases with velocity. If an object
is moving at the speed of light, the increase in mass is infinity, which
is why no object with a finite mass at rest can travel AT the speed of
light (though it can approach it). Alternatively, that is why particles
that travel AT the speed of light have no mass at rest.

Now, the amount of force required to push a spacecraft to higher speed
depends on its mass; higher the mass, more the force required. So, as the
spacecraft gains speed, one needs more and more force to push it to higher
speed. Note that these relativistic effects become prominent only at
speeds comparable to the speed of light. But in any case, due to this, it
is very difficult to accelerate a spacecraft to a speed that is a
significant fraction of the speed of light.

Practically, the speed reached by spacecraft is extremely small compared
to the speed of light. That is because there is no current technology that
can accelerate spacecraft to high speeds given the space constraint to
carry chemical fuels. If one includes more fuel, then the weight of the
spacecraft becomes more not to mention the increased cost. Hence, one
needs some non-chemical based propulsion system to increase the speeds of
spacecraft from what they are currently. While some technologies in this
direction are being researched, it is still a field in infancy.

 

DUHH, but I dont think he even took the distance of the earth and moon for consideration. Did he? Did You think of that

 

has nothing to do with distance still the same if you just go round and round. long as you are going that fast

 

Sounds true... I guess you can think about how different cars top out at diff speeds due to drag, hp, etc.. if there was no mass buildup moving forward, they probably woulnd't stop accelerating....

 

i think its somthing like 7 years at 95% the speed of light 35 years go bye for people that are not moving that fast