Dealing With the Problems First
The main problem with any attempt to create an
FTL information transfer system can be traced philosophically to relativity
theory. Before Albert Einstein, scientists had assumed that energy moved through
space instantaneously, or at least at a speed so fast that it appeared to be
instant.
Information transfer and energy
Since information can be carried using energy, such as
the energy of an electromagnetic field, information transfer could also benefit
from this high speed. It makes sense, since any information you put into a wave
will be carried at the speed of the wave.
understanding waves
To understand this better, think of a
water wave for example. You can make water waves by swishing your hand in a
swimming pool, or pond, and you can control the height of the wave by how hard
you swish. You can call this a form of amplitude modulation, and it is analogous
to how we can control the information in an electromagnetic wave.
Limitations of water waves
We can amplitude modulate a water wave as well as an electromagnetic wave. Also,
since water waves travel only a few hundred miles per hour, you would be
limiting yourself speed-wise using water. Not to mention the logistics of using
water. You need to be near it, for one, and how do you make a wave that can span an
ocean?
Well, you can drop an asteroid into the Atlantic Ocean, but seriously
folks, it's not impossible. Again, just look to nature... whales use low
frequency sound, which moves nicely through water, to hear other whales many
hundreds, and even thousands of miles away. But, it is a slow way to talk across
the big pond.... whales may not care, but we would.
AM radio and electromagnetic waves
Thankfully, your AM radio is
designed for the electromagnetic spectrum, and not the water spectrum of waves!
At first, we didn't know just how fast electromagnetic waves were, only that
they were fast.
We were shocked to realize that what we called
light was really an electromagnetic wave. Through experiments, we found these EM
(short for electromagnetic, of course) waves zipped by at 186,000 miles per
second. We were amazed. After all, 186,000 miles per second seemed
fast.
Electromagnetic waves and the birth of radio and
television
As an added bonus, it turned out electromagnetic waves were easy to manipulate,
easily used to carry information in many ways. Of course, the fact still
remained, the information they carried was bounded by the physical parameters of
the waves used. The message could not go faster than the medium used to carry
it.
Still, we managed, creating a profitable information transfer technology
based on these waves, which goes by the name of radio, television... wanna be a
movie star? Get friendly with EM waves (Star, Light, get it? OK, bad pun)....
But since electromagnetic radiation was light itself, we really lucked out by
developing it into a communications medium that allowed us to literally talk at
the speed of light, and watch re-runs of I Love Lucy. Yes, lucky indeed...
Lightspeed: the ultimate cosmic crawl
Then, Einstein did a naughty thing. He came up with a theory showing that the
speed of light (C) is, in fact, the fastest speed in the universe. Energy
itself, no matter what form it takes, is bound by this limitation - it can go no
faster. Since even solid objects like rockets and bulldozers are essentially
congealed energy, this limit applies to everything (can you even imagine a
bulldozer zooming at lightspeed?). The speed of light is also the top speed for
transmitting information because there's nothing else we can use that's faster. And
that, it seemed, is that. Ahhh, pooh.
why isn't lightspeed fast enough?
So what's the big deal, you may be asking? Isn't 186,000 miles per freakin'
second fast enough? Well, that depends.... for planetary communications, maybe
it is, but that is only because the earth is so small, compared to the rest of
creation. At the speed of light, it takes a radio wave around 2 seconds to reach
the Moon. It will take about 3 minutes for a signal
to reach Mars when it is closest to the Earth. The time lag only gets worse the
farther out you go. And don't forget to double those numbers for two way
communications.
The challenges of space exploration
The recent probes we sent out to Mars, for example, especially that cute little
robot (the mars rover) we landed there a few years back, had to have
computers built-in to make simple decisions, like to tell the robotic vehicle to
stop when it reached the edge of a cliff. When any of these Mars planetary
probes began to land, we here on Earth could
only hold our breaths and wait. Either the probe would land successfully or crash (and many did crash).
Because the distance between Earth and Mars constantly changes as they orbit the
sun, we wouldn't know the outcome for anywhere between 3 to 22 minutes - the time it took for the probe to send a signal back to Earth
announcing a successful landing.
We knew
everything had gone smoothly when, right on time, we started receiving radio
signals confirming a successful descent. If there was silence instead, we knew
there was some sort of boo-boo. Ask any planetary scientist how much better our
space program would be if we could take control of the probe from here on Earth,
and give it instructions in real-time... you could
dump the computer and use all the extra space for more experiment packages. Hey,
that sounds like a good idea, but we can't do it because, over large distances
like from Earth to Mars, the speed of light becomes a significant barrier, and
this issue only worsens as the distance increases.
Einstein's unpleasant message
Heck, even here on Earth the speed of light
can get in the way. If your telephone call is routed through a satellite 22,000
miles above your head, you can begin to hear the delay in transmission. We
perceive it as an uncomfortable pause in the conversation. So, even though the
speed of light is fast, it just isn't fast enough. But Professor Einstein gave
us the word - energy of any kind simply can't go any faster. Thank you, Albert.
Oh, it really wasn't his fault. It's not fair to get upset at the messenger,
when the message is so unpleasant, right?
In this case, it is easy to see where the bottleneck is - energy itself. Are
there alternatives to using energy as a carrier of information? Yes, there are,
but the news is both good and bad.
