FASTER THAN LIGHT 215
engineers at the Stanford Linear Accelerator Center, UCLA, and USC
demonstrated that you can double the energy of a huge particle accelerator in just 1 meter. They started with a beam of electrons that are
fired down a 2-mile-long tube in Stanford, reaching an energy of 42
billion electron volts. Then these high-energy electrons were sent
through an "afterburner," which consisted of a plasma chamber only
88 centimeters long, where the electrons pick up an additional 42 billion electron volts, doubling their energy. (The plasma chamber is
filled with lithium gas. As the electrons pass through the gas, they create a plasma wave that creates a wake. This wake in turn flows to the
back of the electron beam and then shoves it forward, giving it an extra boost.) In this stunning achievement, the physicists improved by a
factor of three thousand the previous record for the amount of energy
per meter they could accelerate an electron beam. By adding such "afterburners" to existing accelerators, one might in principle double
their energy, almost for free.
Today the world record for a Wakefield tabletop accelerator is 200
billion electron volts per meter. There are numerous problems scaling
this result to longer distances (such as maintaining the stability of the
beam as laser power is pumped into it). But assuming that we could
maintain a power level of 200 billion electron volts per meter, this
means that an accelerator capable of reaching the Planck energy
would have to be 10 light-years long. This is well within the capability
of a Type III civilization.
Wormholes and stretched space may give us the most realistic way of
breaking the light barrier. But it is not known if these technologies are
stable; if they are, it would still take a fabulous amount of energy, positive or negative, to make them work.
Perhaps an advanced Type III civilization might already have this
technology. It might be millennia before we can even think about harnessing power on this scale. Because there is still controversy over the
fundamental laws governing the fabric of space-time at the quantum
level, I would classify this as a Class II impossibility.
engineers at the Stanford Linear Accelerator Center, UCLA, and USC
demonstrated that you can double the energy of a huge particle accelerator in just 1 meter. They started with a beam of electrons that are
fired down a 2-mile-long tube in Stanford, reaching an energy of 42
billion electron volts. Then these high-energy electrons were sent
through an "afterburner," which consisted of a plasma chamber only
88 centimeters long, where the electrons pick up an additional 42 billion electron volts, doubling their energy. (The plasma chamber is
filled with lithium gas. As the electrons pass through the gas, they create a plasma wave that creates a wake. This wake in turn flows to the
back of the electron beam and then shoves it forward, giving it an extra boost.) In this stunning achievement, the physicists improved by a
factor of three thousand the previous record for the amount of energy
per meter they could accelerate an electron beam. By adding such "afterburners" to existing accelerators, one might in principle double
their energy, almost for free.
Today the world record for a Wakefield tabletop accelerator is 200
billion electron volts per meter. There are numerous problems scaling
this result to longer distances (such as maintaining the stability of the
beam as laser power is pumped into it). But assuming that we could
maintain a power level of 200 billion electron volts per meter, this
means that an accelerator capable of reaching the Planck energy
would have to be 10 light-years long. This is well within the capability
of a Type III civilization.
Wormholes and stretched space may give us the most realistic way of
breaking the light barrier. But it is not known if these technologies are
stable; if they are, it would still take a fabulous amount of energy, positive or negative, to make them work.
Perhaps an advanced Type III civilization might already have this
technology. It might be millennia before we can even think about harnessing power on this scale. Because there is still controversy over the
fundamental laws governing the fabric of space-time at the quantum
level, I would classify this as a Class II impossibility.