12 Issues for the Future
259
some extremely small number, just as any charge is a multiple of the electronic
charge.
Of course the above argument is by necessity oversimplified. Before
proceeding one should “explain” quantitatively how the process of storing
information works and how the stored information can be retrieved in order
to influence the physics of the system. But for our purposes here it is sufficient to conclude that the truncation of numbers with an infinite number of
digits can in principle destroy the determinism of most physical theories, and
thus eliminate the main cause of incompatibility between QM and relativity.
Einstein’s theory of General relativity, like the classical laws of Newton, is
symmetric with respect to time. Both theories work equally well with time
advancing from the present to the future, or retreating from the present to
the past. One cannot tell by looking at a video of two balls colliding on
a billiard table whether the movie has been run forwards or backwards. A
few months before he himself died, Einstein wrote a letter to the family of
a recently deceased, dear friend, Michele Besso, concerning his death: “That
signifies nothing. For us believing physicists, the distinction between past, present
and future is only a stubbornly persistent illusion.” This symmetry between past
and future does not exist in Quantum Mechanics where, as we have seen
in the last Section, the act of observation plays such an important role in
defining the present, and separating the past from what lies in the future.
So in these few paragraphs we have a brief glimpse into the fundamental
contradictions between the two iconic theories of Twentieth Century physics.
These issues are still very much under discussion, and as yet far from resolution. The search for a quantum theory of gravity, perhaps one that requires
the discretisation of space and time, looks likely to continue apace for a
considerable time yet.
12.10 Conclusion
In much ancient Greek and Roman theatre, the underlying structure of the
play is basically the same: (a) introduce the situation; (b) make it as intricate
as possible, and (c) find some unexpected and timely trick, capable of solving
all the problems neatly, and tying up the loose ends. In a comedy, the good
guys live happily ever after, and in a tragedy they usually die.
Sometimes it was the playwright’s plot that got tied in knots, so that the
only way he could extricate the protagonist from impending disaster was to
bring a god on stage suspended from a crane. The deity promptly dispensed
justice: the villains were punished and the good rewarded. Such a theatrical
259
some extremely small number, just as any charge is a multiple of the electronic
charge.
Of course the above argument is by necessity oversimplified. Before
proceeding one should “explain” quantitatively how the process of storing
information works and how the stored information can be retrieved in order
to influence the physics of the system. But for our purposes here it is sufficient to conclude that the truncation of numbers with an infinite number of
digits can in principle destroy the determinism of most physical theories, and
thus eliminate the main cause of incompatibility between QM and relativity.
Einstein’s theory of General relativity, like the classical laws of Newton, is
symmetric with respect to time. Both theories work equally well with time
advancing from the present to the future, or retreating from the present to
the past. One cannot tell by looking at a video of two balls colliding on
a billiard table whether the movie has been run forwards or backwards. A
few months before he himself died, Einstein wrote a letter to the family of
a recently deceased, dear friend, Michele Besso, concerning his death: “That
signifies nothing. For us believing physicists, the distinction between past, present
and future is only a stubbornly persistent illusion.” This symmetry between past
and future does not exist in Quantum Mechanics where, as we have seen
in the last Section, the act of observation plays such an important role in
defining the present, and separating the past from what lies in the future.
So in these few paragraphs we have a brief glimpse into the fundamental
contradictions between the two iconic theories of Twentieth Century physics.
These issues are still very much under discussion, and as yet far from resolution. The search for a quantum theory of gravity, perhaps one that requires
the discretisation of space and time, looks likely to continue apace for a
considerable time yet.
12.10 Conclusion
In much ancient Greek and Roman theatre, the underlying structure of the
play is basically the same: (a) introduce the situation; (b) make it as intricate
as possible, and (c) find some unexpected and timely trick, capable of solving
all the problems neatly, and tying up the loose ends. In a comedy, the good
guys live happily ever after, and in a tragedy they usually die.
Sometimes it was the playwright’s plot that got tied in knots, so that the
only way he could extricate the protagonist from impending disaster was to
bring a god on stage suspended from a crane. The deity promptly dispensed
justice: the villains were punished and the good rewarded. Such a theatrical