FASTER THAN LIGHT 201
moves, this means that the energy motion is being converted to mass.
The precise amount of energy that turns into mass is easy to calculate,
and we arrive at the celebrated equation E = mc
2 in just a few lines.)
Since Einstein derived his famous equation, literally millions of
experiments have confirmed his revolutionary ideas. For example, the
GPS system, which can locate your position on the Earth to within a
few feet, would fail unless one added in corrections due to relativity.
(Since the military depends on the GPS system, even Pentagon generals have to be briefed by physicists concerning Einstein's theory of relativity.) The clocks on the GPS actually change as they speed above the
Earth, as Einstein predicted.
The most graphic illustration of this concept is found in atom
smashers, in which scientists accelerate particles to nearly the speed
of light. At the gigantic CERN accelerator, the Large Hadron Collider,
outside Geneva, Switzerland, protons are accelerated to trillions of
electron volts, and they move very close to the speed of light.
To a rocket scientist, the light barrier is not much of a problem yet,
since rockets can barely travel beyond a few tens of thousands of miles
per hour. But within a century or two, when rocket scientists seriously
contemplate sending probes to the nearest star (located over 4 lightyears from Earth), the light barrier could gradually become a problem.
LOOPHOLES IN EINSTEIN'S
THEORY
Over the decades, physicists have tried to find loopholes in Einstein's
famous dictum. Some loopholes have been found, but most are not
very useful. For example, if one sweeps a flashlight across the heavens,
in principle the image of the light beam can exceed the speed of light.
In a few seconds, the image of the flashlight moves from one point on
the horizon to the opposite point, over a distance that can stretch over
hundreds of light-years. But this is of no importance, since no information can be transmitted faster than light in this fashion. The image of
the light beam has exceeded the speed of light, but the image carries
no energy or information.
moves, this means that the energy motion is being converted to mass.
The precise amount of energy that turns into mass is easy to calculate,
and we arrive at the celebrated equation E = mc
2 in just a few lines.)
Since Einstein derived his famous equation, literally millions of
experiments have confirmed his revolutionary ideas. For example, the
GPS system, which can locate your position on the Earth to within a
few feet, would fail unless one added in corrections due to relativity.
(Since the military depends on the GPS system, even Pentagon generals have to be briefed by physicists concerning Einstein's theory of relativity.) The clocks on the GPS actually change as they speed above the
Earth, as Einstein predicted.
The most graphic illustration of this concept is found in atom
smashers, in which scientists accelerate particles to nearly the speed
of light. At the gigantic CERN accelerator, the Large Hadron Collider,
outside Geneva, Switzerland, protons are accelerated to trillions of
electron volts, and they move very close to the speed of light.
To a rocket scientist, the light barrier is not much of a problem yet,
since rockets can barely travel beyond a few tens of thousands of miles
per hour. But within a century or two, when rocket scientists seriously
contemplate sending probes to the nearest star (located over 4 lightyears from Earth), the light barrier could gradually become a problem.
LOOPHOLES IN EINSTEIN'S
THEORY
Over the decades, physicists have tried to find loopholes in Einstein's
famous dictum. Some loopholes have been found, but most are not
very useful. For example, if one sweeps a flashlight across the heavens,
in principle the image of the light beam can exceed the speed of light.
In a few seconds, the image of the flashlight moves from one point on
the horizon to the opposite point, over a distance that can stretch over
hundreds of light-years. But this is of no importance, since no information can be transmitted faster than light in this fashion. The image of
the light beam has exceeded the speed of light, but the image carries
no energy or information.