I'm no scientist, but what I would like to know is this. As far as I
know Einstein "proved" that u cannot reach the speed of light, u can
only approach it,I think its "c"  now, speed of light equels  300 x 10
to the power of 6. why can we go faster than that, why is it
IMPOSSIBLE? Is it not just technology that is keeping us back? I know
that they say we will be as flat as you can possibly get it, but if
you accelerate slowly and eventually pick up the speed, and combined
with depresurization, we will be okay? but appart from that, what is
physically keeping us from going past 299 792 458m.s? Technology? I
think so!! pls explane why not!!

This is actually a FAQ - it was answered here sevweral times

Is it not just technology that is keeping us back? 

No 

I know that they say we will be as flat as you can possibly get

No, you will not be flat, and time will not stop.

Ignore most of the comments. Here is your answer:


why
http://answers.google.com/answers/threadview?id=708752

why not
http://answers.google.com/answers/threadview?id=708752


e=mc squared wrong?
http://answers.google.com/answers/threadview?id=605720


After you read it, you may post RFC

The energy required for this would become very large. It is defined as:

E=ymc^2

Where y is: 1/[root(1-v^2/c^2)

v is the speed of the moving object.

As a mass carrying object approaches the speed of light, its energy
becomes infinite. From the value of gamma (y) you can also deduce,
that v cannot equal c. When v=y, then we have 1/0, which is not
mathematically defined.

There are other effects when approaching c. Lenght contraction. All
seen by an observer.

The problem is the notion of what the speed of light is. Everywhere in
the universe, everything is moving in respect to all else. Then, it is
difficult to determine, who/what is moving in respect to whom/what and
at what speed.

Actually, if you are interested in actually travelling very fast, it
is possible. Relativity says, that at the speed of light or very close
to it, time is less of importance, to the traveller at least. Lets say
you could venture to the next galaxy in a couple of years close to c.
For an observer, it is actually the speed he observes which counts. So
if light travels a million years to a neighbouring galaxy, roughly
that time would pass on earth. Not a nice prospect.

I don't quite understand Cadre's comment, but perhaps he is talking
about the fact that you can, in principle, travel to distant galaxies
in a short period of time if you can travel close to the speed of
light. From your point of view, it is because of the Lorentz
contraction that shrinks the distances that you must travel. From the
point of view of someone back on earth, it is because of the time
dilation that makes your clock run much slower. If you could
accelerate continuously at 1 g (10m/sec^2) (a very big if!), it would
take about a year to get close to the speed of light and you would
have traveled a reasonable fraction of a light year. With each
successive year, the distance traveled would grow exponentially, so it
would only take a matter of 10's of years to go to astoundingly great
distances. If you tried to go back home, unfortunately, you would find
all your loved ones long since dead.

Of course, the energy required to achieve these velocities is
virtually unthinkable, but it is important to understand that in spite
of relativity's unbreakable speed limit, there is no limit on how fast
we can get to distant spots in the universe and time travel is
possible, but only into the future, with no hope of return.

I did the calculation once and I seem to recall that, accelerating at
1 g, you can get anywhere in the universe within 1 year (by your
clock, of course) not 10s of years as kottekoe suggests.

Kottekoe is right as always.  At 1 g, you can get anywhere in the
observable universe in about 23 years (if we give the observable
universe a size of 10^10 light years).  I think what I was remembering
is that if a spaceman accelerates away from the earth at 1 g, and you
want to shoot them with a laser, you can't wait too long, or the laser
will never catch up to the spaceman, even though it travels at the
speed of light.  The cutoff time is a little under a year.

Racecar: Cool, I never knew that constant acceleration with a head
start could keep you ahead of a light beam. Thanks for the kind words
and for teaching me something new.

The reason the light won't catch the spaceman is counterintuitive.  As
pointed out above, as you approach the speed of light your mass would
increase exponentially.  The closer you are to a massive object the
slower time seems.  That is why while you can't travel faster than the
speed of light from your own perspective, you can travel what appears
to an observer to be more than 1 light year in 1 year.  This is
because space is also relative and affected by mass in a similar
manner to time.  You think you are 3 meters from a tree because you
are not that massive.  If you were, you would be much closer.  Very
strange. Since light has no mass it doesn't gain this advantage and is
stuck dealing with space being the size our usual non-massive selves
think it is.  So the rocket man is traveling slower, but has to cover
less distance to get there.  Space is actually smaller for him.
	One more thing to think about, chefmarius-ga , is that theoretically
if we did get any object with mass, no matter how small, to travel
very close to the speed of light then it would approach the top of the
asymptote. Then it would as massive as the entire universe and all the
mass would occur at the same point. At this point all time would stop
and everything would be one big black hole frozen in time. 
Thankfully, it would require more energy than we will ever be able to
produce (I hope) to do this.

?

The energy required for this would become infinite.  If we use the
entire energy of this universe even then we can not acquire that
speed.It is defined as:

E=ymc^2

Where y is: 1/[root(1-v^2/c^2)

v is the speed of the moving object.

As a mass carrying object approaches the speed of light, its energy
becomes infinite. From the value of gamma (y) you can also deduce,
that v cannot equal c. When v=c, then we have y=1/[root(1-1/0)], which is not
mathematically defined.

There are other effects when approaching c. Lenght contraction. All
seen by an observer.

The problem is the notion of what the speed of light is. Everywhere in
the universe, everything is moving in respect to all else. Then, it is
difficult to determine, who/what is moving in respect to whom/what and
at what speed.

kottekoe-ga

Would it interest you to comment upon Speed of Light/Relativity by
ocoeeriver-ga? Perhaps I will get a better insight into this question.
Thanks.

The energy required for this would become infinite(Very Very Large). 
The entire energy of this universe is less then the required
energy.Energy required to move an object at speed v is:
E=ymv^2
Where y is: 1/[root(1-v^2/c^2)
Where m is the mass of the object at rest.
v is the speed of the moving object.
If v=c then E=ymc^2

As a mass carrying object approaches the speed of light, its energy
becomes infinite. From the value of gamma (y) you can also deduce,
that v cannot equal c. When v=c, then we have y=1/0, which gives E=1/0=Infinite.

There are other effects when approaching c. Lenght contraction. All
seen by an observer.

The problem is the notion of what the speed of light is. Everywhere in
the universe, everything is moving in respect to all else. Then, it is
difficult to determine, who/what is moving in respect to whom/what and
at what speed.
Therefore apart from technology lack of energy is also responsible for it.

thanx for the comments, but robjewell-ga, you say that we cannot get
anything to the speed of light, but here in south africa in a town in
stellenbosch, there is a rotator with 4 blades (almost looking like a
fan) and apparently this blades move to the speed of light and they
through in this "ball" of something and then  this breaks offcourse,
giving off a huge amount of energy, then the scientist i think study
what happens inside this ball, and the atoms etc, also in the states,
there is a tunnel, where they work with a certain object that goes
through this tunnel, reaching the speed of light, bearking and then
the whole studying happens of this thing again. am I wrong with this?
o you mind explaing "This is
because space is also relative and affected by mass in a similar
manner to time." thanx

Crackhead! We are light!

Einstein "proved", not to offend relatavists but I remind you science
is 'theory' it is used to give engineers a reason to live. True
doctors may shove a needle up your but and call you a ludite if you
repeat this, but Einstein didn't 'proove' anything. He used a bunch of
math to make an elite club of people that could remark and say THE
MATH WORKS!!! Later Einstein said he made an error by establishing an
universal constant that gave quantum mechanisists breathing room from
psychotropic injection.






"that u cannot reach the speed of light"

 for us to move at light speed we have to be light.

The complex answer is not one that other physists may agree to cause
it uses my own theories.

Leptons are light (bosons)

quarks are orbiting pairs and such of bosons when they colide they create light.. 

Biological humans are made of quarks.. quarks are in 'reverse' to
light meaning they move nowhere at light speed but 'gravitate towards
the center of the universe.' light.. does not it goes the other way.
now the bosons have the capability to 'tow' if they have a greater
number of 'leptons than half the number of quarks roughly no math
here.. (there are different sized quarks)

so to go at light speed you have to be leptons.. the bigger you are
the slower you will be in one direction.. and the faster in the
other..

Note this is my theory so if you tell this to your grade 10 science
teacher they may not agree

Well, you've also got to worry about multidimensional analysis.  Any
dimension number (n) is not *determined* by it's lower dimension,
(n-1).

Then take into account the inherent finite energy nature of the
universe - there is only so much energy in existence at any given
point; this is part of the conservation of energy law.  If you can't
create it or destroy it, then you can only hope to contain it; the
larger volume you try to contain it in, the larger the entropy of that
energy.  So basically, you have an almost infinite energy in a very
finite space, which means it's tending to try to "get away" from you -
the end result is a very simplified nutshell version (this shouldn't
be used as a one-word answer, but it's an argument for it):

You can't create energy, and you can't exceed the amount of energy in
the universe.  The faster you go, the more of the universe's energy
you have - if at any point the sum of your energies changes, you've
broken the first law of thermodynamics (and physics in general), and
that's a no-no.  So there *is* a theoretical "cap" to how fast any
given mass can travel, and Einstein theorized that velocity as the
speed of light - even to this day, we can't find anything that moves
faster than "C".  If you figure out how, you can probably just buy
Google.   :-P

Do remember that scientists used to think the world was flat, today
scientists have made many discoveries about our universe.  To say that
the speed of light is unatainable just shows egotism to thinking we
know our environment.  We know tiny little aspects about our
environment and we will continue to learn and explore and prove past
theories wrong.  Laws of thermodynamics may be wrong, but for now they
work.  Relativity and many other theories work for us right now and
may no longer be applicable in 10, 20, 100 years.  Science is not to
prove what can and can't be done, science is to help us deal whith
what is happening now and in the near future.  Remember that
everything is possible, it may not be plausible..... for now!

The answer is simple. Its because science and technology is still in
its primitive stage!! What we have learnt so far is not even one -
zillionth of what nature has. We still, cannot even design an
aircraft, which moves at the speed of light, that is *always* reliable
and you are thinking about moving faster than light! We have to admit
that we are still in the process of evolving and we still have a long
way to even understand the very basics of nature.

"We still, cannot even design an
aircraft, which moves at the speed of light,"

sorry, it should be speed of sound..:)

vtmemo, can you tell me, if we cannot creat enery as you say, then how
does an atom bomb work? is that not matter wich changes into energy???

vtmemo, can you tell me, if we cannot creat enery as you say, then how
does an atom bomb work? is that not matter wich changes into
energy???The device basically works when the detonated TNT compresses
the Plutonium into a critical mass. The critical mass then produces a
nuclear chain recation similar to the domino chain reaction.  The
chain reaction then promptly produces a big thermonuclear reaction.
And there you have it, a 10 megaton explosion!

i don't claim to know what i'm talking about, but after reading all
these comments, it would all seem to come down to MATTER, it would
appear that the concept (restrictions laid down) behind matter is
what's causing the problems, i feel that we will eventuallly move on
to this problem, and perhaps work on a way that could create a field
that could encampass a object and allow the object to defy, or perhaps
help bend the rules of current physics,

i think this would also perhaps kill 2 birds in 1 stone, as elimating
the problem with matter, should also help eliviate the power
consumption requirements, however minipulating the laws of physics
won't be easy, but doing it in space should help, after all we will no
doubt see many things in space that go against our version of laws of
physics, and as with all books, the laws of physics will no doubt be
updated from time to time,

i think we could probably create enough power to create a bubble if
you will around a ship, that would eliminate if not most, all of the
matter from space and sub-space (the mass would have to have 0% energy
& gravitational Readings)

do you mind explaing "This is
because space is also relative and affected by mass in a similar
manner to time." thanx


Einstein said that both time and spacee were relative.  That is the
speed of time and the size of space.  Several decades of testing seem
to support this theory, although of course no one knows for sure. 
That is what they mean when they say if learning the theory of
relativity doesn't scare you you didn't understand it.

Example:
The spaceman discussed travels near the speed of light fot 1 year. 
According to all his instruments he never reached the speed if light
and traveled almost one light year.

Now, on Earth, 50 years have passed.  From Earth it also apears that
the spaceman almost reached the speed of light, but not qiuite.  From
here he traveled at almost the speed of light for 50 years which means
he traveled, say, 45 light years.

The problem is that if he traveled 45 light years and from his
perspective it was only 1 year then he should have traveled at 45
times the speed of light.  But he didn't.  What Einstein said is that
space is smaller around him because all his energy is transferred into
mass.  Steven Hawkings measured time being slower near a massive
object, like the Earth (atomic clocks at the top of a tall mountain
actually ran slightly faster than at the bottom - see "A Brief History
Of Time").  I don't know of any peer reviewed tests that show that
space is effected the same way, but Einstein thought it was.

If he was right, the example about the spaceman is accurate.  If not,
maybe we will find out that it works a different way in the future. 
Who knows.

The latest comment is referring to three things that have all been
verified experimentally numerous times to high accuracy: time dilation
(clock of moving observing runs slower as observed by stationary one),
length contraction (a.k.a. Fitzgerald contraction, lengths measured by
stationary observer appear smaller in moving frame in the direction of
motion), and the gravitational red shift (clocks running slower near a
massive object). All of this is perfectly consistent, without any
paradoxes, and not doubted by any mainstream physicist. In science it
is always correct to say that no one knows for sure, but special
relativity is on as firm ground as the most cherished principals of
physics, such as energy conservation. The ideas are hard to grasp and
it takes some serious thought to understand them, but once you do, the
mystery evaporates and it all makes perfect sense.

Hawking did not measure the gravitational redshift. It was first
observed by Pound and Rebka at Harvard in 1960. The slowing of time is
seen every day by the long lifetime of relativistic muons, which have
a much shorter lifetime when they are moving slowly. Both the
gravitational and velocity effects on the ticking of clocks has been
measured many times by flying atomic clocks in airplanes. These
effects are big enough to require realtivistic corrections in GPS
navigation.