EPILOGUE 29i
universe? ... Do the laws of physics permit highly advanced civilizations to create and maintain wormholes for interstellar travel, and to
create time machines for backward time travel?"
The point is that in the next few decades there should be enough
data pouring in from gravity wave detectors in space to differentiate
between the various pre-big bang theories.
THE END OF THE UNIVERSE
The poet T. S. Eliot asked the question, Will the universe die with a
bang or a whimper? Robert Frost asked, Will we all perish in fire or
ice? The latest evidence points to the universe dying in a Big Freeze, in
which temperatures will reach near absolute zero and all intelligent
life will be extinguished. But can we be sure?
Some have raised another "impossible" question. How will we ever
know the ultimate fate of the universe, they ask, since this event is trillions upon trillions of years in the future? Scientists believe that "dark
energy" or the energy of the vacuum seems to be pushing the galaxies
apart at an ever increasing rate, indicating that the universe seems to
be in a runaway mode. Such an expansion would cool the temperature
of the universe and ultimately lead to the Big Freeze. But is this expansion temporary? Could it reverse itself in the future?
For example, in the Big Splat scenario, in which two membranes
collide and create the universe, it appears as if the membranes can collide periodically. If so, then the expansion that appears to lead to a Big
Freeze is only a temporary state that will reverse itself.
What is driving the current acceleration of the universes is dark
energy, which in turn is probably caused by the "cosmological constant." The key, therefore, is to understand this mysterious constant, or
the energy of the vacuum. Does the constant vary with time, or is it
really a constant? At present, no one knows for sure. We know from the
WMAP satellite currently orbiting the Earth that this cosmological
constant seems to be driving the current acceleration of the universe,
but we don't know if it is permanent or not.
universe? ... Do the laws of physics permit highly advanced civilizations to create and maintain wormholes for interstellar travel, and to
create time machines for backward time travel?"
The point is that in the next few decades there should be enough
data pouring in from gravity wave detectors in space to differentiate
between the various pre-big bang theories.
THE END OF THE UNIVERSE
The poet T. S. Eliot asked the question, Will the universe die with a
bang or a whimper? Robert Frost asked, Will we all perish in fire or
ice? The latest evidence points to the universe dying in a Big Freeze, in
which temperatures will reach near absolute zero and all intelligent
life will be extinguished. But can we be sure?
Some have raised another "impossible" question. How will we ever
know the ultimate fate of the universe, they ask, since this event is trillions upon trillions of years in the future? Scientists believe that "dark
energy" or the energy of the vacuum seems to be pushing the galaxies
apart at an ever increasing rate, indicating that the universe seems to
be in a runaway mode. Such an expansion would cool the temperature
of the universe and ultimately lead to the Big Freeze. But is this expansion temporary? Could it reverse itself in the future?
For example, in the Big Splat scenario, in which two membranes
collide and create the universe, it appears as if the membranes can collide periodically. If so, then the expansion that appears to lead to a Big
Freeze is only a temporary state that will reverse itself.
What is driving the current acceleration of the universes is dark
energy, which in turn is probably caused by the "cosmological constant." The key, therefore, is to understand this mysterious constant, or
the energy of the vacuum. Does the constant vary with time, or is it
really a constant? At present, no one knows for sure. We know from the
WMAP satellite currently orbiting the Earth that this cosmological
constant seems to be driving the current acceleration of the universe,
but we don't know if it is permanent or not.