Pretty cool "pointless" facts and theories!
EDIT: looks like my lines didn't turn out real good
PART I: 9 CONCEPTS FOR FTL DRIVES
Since Einsteins general relativity set an ultimate speed barrier known as the
lightspeed, many physicians have tried to find out if it's possible to travel
faster than light, without violating relativity.
We know that it's impossible to keep on accelerating forever. How closer we get
to lightspeed, how heavier we become. And not to forget time dilatation: the
effect of time slowing down.
However, there are ways to break the lightspeed barrier. We will look at the
physics and possible technical realization of 9 concepts.
CONTENTS OF PART I:
1. Making space into waves, and travel through the waves
2. Bringing points in space closer together
3. Changing the speed of light around your ship
4. Reduce the ships mass to 0
5. Travelling through wormholes
6. Entering subspace
7. Star Trek warp drive
8. Emit or store tachyons
9. Compressing and expanding spacetime
------------------------------------------------------------------------------
1. Making space into waves
We want to travel from A to B:
A B
Then a special modulated gravity emitter pulls space time into waves:
/\ /\ /\
/ \ / \ / \
/ \ / \ / \
/ \ / \ / \
/ \ / \ / \
/ \ / \ / \
A-------------------------------------------------B
__/ \/ \/ \__
By travelling in a straight line, between the waves, the distance is much
shorter.
Our absolute speed is not necessarily higher than light speed, but because we
traverse A to B in much shorter time than a beam of light would do, our
effective speed is higher than light.
We traverse the waves by building wormholes.
Can this drive be realized? We need enormous amounts of energy to make spacetime
into waves, and to build wormholes. Antimatter-reactors, one of the greatest
known potential energy sources, might provide too less energy. If we can find
an energy source which provides much and much more of energy, then it might.
2. Bringing points in space closer together
This is very easy. If the distance between two points becomes smaller, then we
can travel from point A to B in a conventional sub-lightspeed drive. There is
no need for a direct FTL drive.
We bring this points together just like concept 1: we emit massive amounts of
gravity. But here do we encounter the same problem: we need an energy source
which can provide a real enormous amount of energy.
3. Changing the speed of light around your ship
We create a bubble of modified spacetime around our ship, in where te physical
laws are changed. With a higher lightspeed barrier, we can travel at a speed
just below that, but maybe higher than light in normal spacetime. To reach
a speed x times less than modified lightspeed c_m needs as much energy than
achieve a speed x times less than normal lightspeed c_n. Did you grab that?
But we don't know how we must create a bubble of modified spacetime. However,
one thing is for sure: we need lots and lots of energy.
4. Reduce the ship's mass to 0
This concept cannot achieve FTL speeds. The speed of an object with zero mass
is still restricted to lightspeed. Another problem: massless objects ALWAYS
travel at lightspeed, except in a dense medium.
If we want to achieve lightspeed, this concept is well. We only need to
eliminating gravity, and that isn't necessarily difficult. We can emit some
kind of antigravity, if we find a way how.
But we want to break the lightspeed barrier.
5. Travelling through wormholes
This is a well known concept. Wormholes can make a long travel a lot shorter,
because they make the distance shorter:
________ ________
\ A o===================o B /
\ \ \ wormhole / / /
\ \ \ / / / - bent space time
\ \ \ / / /
\ \ \ / / /
\ \ \_____/ / /
\ \ / \ / /
\ \_______/ /
\ / \ /
\/___________\/
The bent spacetime as shown here, can be considered as our galaxy; our galaxy
influents the spacetime continuum in the same way as shown above.
To travel through wormholes, we need one at a macroscopic level. Quantum
mechanics predicts wormholes, but quantumwormholes will seldomly be greater
than 10E-33 cm. We can track a quantumwormhole, and blow it up to macroscopic
size. But macroscopic wormholes are instable - they will collapse because of
their own gravitational forces. However, if we continually feed a macrowormhole
with some kind of negative energy, a macrowormhole will be stable.
Until this far, this concept is very promising. But there are still some
problems: we can't predict where a wormhole will end. And it is also possible
that travelling through a wormhole will take you back in time, causing causality
paradoxes.
And if we can predict where wormholes will end, and if we even know how to
create a wormhole to the place where we want to be, we need still very huge
amounts of energy, just like the FTL concepts above.
6. Entering subspace
Subspace is a hypothetical continuum, which encloses our entire universe. It
has different laws than ours. In Star Trek, travelling through subspace doesn't
restrict you to light speed: in subspace, you can go any speed.
But there are two problems:
1) Does subspace exists?
2) And if yes, how must we enter and leave it?
We don't know the answers.
7. Star Trek warp drive
The Star Trek warp drive is discussed a lot in the world of physics. The
designers of warp drive have made complete building schedules.
It's powered by a tuned plasma stream from an matter/antimatter reactor.
Injectors feed the plasma into coils at specific times, causing pulses to run
the length of the nacelles, front to back. This peristaltic flow should cause
the push of nested subspace fields, and moves the ship forward.
The Star Trek Technical Manual says that the fields couple and decouple from
each other at velocities near (but less than) c. It could be that the
interaction of these fields, combined with the special frame subspace provides,
causes the ship as a whole to travel at FTL speeds.
But we have again energy problems. Without a constant influx of energy, the
subspace field will decay, and the ship will drop out of warp. In other words,
you must continue to provide energy to maintain your warp velocity.
The designers of warp drive use matter/antimatter reactors to provide that
energy. If that's enough, we don't know, but we also don't know if subspace
even exists.
Maximum warp speeds in Star Trek are approx. 7000c.
8. Emit or store tachyons
Tachyons are hypothetical particles which travel billions of times faster than
light. Their mass is negative or imaginary (an imaginary number is the result
of the square of a negative number), which allows them to go travel faster
than light, with a lower limit of c. In other words, they can travel any speed,
but never slower than light (more physical information about tachyons, see my
Encyclopedia: encyc.htm).
If we emit tachyons, we need relatively low amounts of fuel for a large speed.
If we will travel faster than light, that is not known.
If we store enough tachyons, our ship's mass will decrease, and if it's lowered
to negative or imaginary proportions, we will travel faster than light with
the same mechanism as tachyons do. To slow down, we just need to dump the
tachyons, so we will drop out of super-lightspeed.
9. Compressing and expanding spacetime
This concept is proposed by physician Miguel Alcubierre. He calls it, just
like the FTL drive in Star Trek, the 'warp drive'.
At the front of the ship, spacetime is pulled towards the ship. At the back
of the ship, spacetime is expanded. The ship doesn't even needs to move.
-------> [SHIP] ------->
spacetime is pulled spacetime is expanded
In fact, spacetime moves, not the ship.
Just like all the other concepts, we need a lot of energy. Miguel Alcubierre
proposes the use of a sort of 'exotic matter', which influents spacetime.
------------------------------------------------------------------------------
PART II: ENERGY SOURCES
It is clear that we need very high amounts of energy to travel at FTL. Some
say that this point makes FTL travel impossible. But is that true? Many people
think that we'll find an suitable energy source.
In this part, we'll look at x energy sources.
CONTENTS OF PART II:
10. Matter/antimatter reaction
11. Nuclear fusion
12. Zero-point energy
13. Singularities
14. Matter-energy conversion
------------------------------------------------------------------------------
10. Matter/antimatter reaction
This energy source is based on controlled annihilation of matter and antimatter.
It is used in Star Trek as energy source for warp drive.
If you annihilate 1 gram per second, you get an energy at least equal to the
present worldwide energy production in one year. If that's enough, is not
known.
Some sub-lightspeed starship designs with matter/antimatter propulsion are
based on speeds between 30,000 and 300,000 km/s (lightspeed). However, this
engines are based on emission of the gamma radiation produced by annihilation
reactions and not as energy source for another drive.
11. Nuclear fusion
Controlled nuclear fusion of light atoms to heavier atoms. In stars is hydrogen
fused to helium, and helium to heavier elements. Nuclear fusion is just like
matter/antimatter reaction often proposed as energy source for travelling at
faster than, or just less than, lightspeed.
It's known that nuclear fusion produces less energy as matter/antimatter
reactions Thus, it's not a very serious candidate.
12. Zero-point energy
This is a new discovery and a very promising candidate. Zero-point energy is
an energy that's stored in the whole universe (in other words: it's everywhere),
and is released when the temparature is dropped to -273,16 degrees Celcius
(0 degrees Kelvin), the absolute zero-point. In experiments are little bits
of zero-point energy released, at temparatures a little bit above the absolute
zero-point.
13. Singularities
The use of artificial singularities, or miniature black holes, is often seen
in Star Trek. It is based on releasing energy from an artificial black hole
in the central energy core. In Star Trek: Voyager, we saw that an artificial
singularity produces an constant energy flux of 5 terawatt.
There's one problem: the gravity of a singularity is so strong, that the ship
should collaps by it.
14. Matter-energy conversion
Based on the E=mc^2 formula of Einstein, which says that the mass of an object
is equivalent to energy. If we find a way to convert mass to direct mass-energy,
we have found a very huge energy source. This is best shown if we say that
a black hole emits only 30% (at highest, 60%) of the mass-energy of an object
thrown in the black hole. Black holes are not very good mass-energy releasers.
A matter-energy converter is more than 3 times more efficient as a black hole.
------------------------------------------------------------------------------
PART III: CONCLUSION
I think it is possible that we can travel at FTL speeds in the future. Tachyon
emission/storage is the most promising concept. If we find a way to 'catch' or
produce tachyons artificially, tachyon drive should be invented in a matter of
a few years.
My prediction? It's hard to say when humanity will explore the galaxy in FTL
driven ships, but I think that FTL drive should be realized in two centuries.
In Star Trek: First Contact we saw that dr. Zephrem Cochrane invented warp
drive in 2063. I hope that FTL travel will come as fast as that.
------------------------------------------------------------------------------
