PERPETUAL NOTION MACHINES 207
(What was shocking to me was not that a person was trying to swindle
the unwary-this has been true since the dawn of time. What was surprising was that it was so easy for this inventor to fool wealthy investors because of their lack of understanding of elementary physics.) I repeated to
the Journal the proverb "A fool and his money are easily parted" and P. T.
Barnum's famous dictum "There's a sucker born every minute." Perhaps
not surprisingly, the Financial Times, the Economist, and the Wall Street
Journal have all run large feature articles on various inventors touting
their perpetual motion machines.
THE THREE LAWS AND SYMMETRIES
But all this raises a deeper question: Why do the iron laws of thermodynamics hold in the first place? It is a mystery that has intrigued scientists since the laws were first proposed. If we could answer that
question, perhaps we might find loopholes in the laws, and the implications would be earth-shattering.
In graduate school I was left speechless one day when I finally
learned the true origin of the conservation of energy. One of the fundamental principles of physics (discovered by mathematician Emmy
Noether in 1918) is that whenever a system possesses symmetry, the
result is a conservation law. If the laws of the universe remain the
same over time, then the astonishing result is that the system conserves energy. (Furthermore, if the laws of physics remain the same if
you move in any direction, then momentum is conserved in any direction as well. And if the laws of physics remain the same under a rotation, then angular momentum is conserved.)
This was staggering to me. I realized that when we analyze starlight from distant galaxies that are billions of light-years away, at the
very edge of the visible universe, we find that the spectrum of light is
identical to spectra that we can find on Earth. In the relic light that was
emitted billions of years before Earth or the sun was born, we see
the same unmistakable "fingerprints" of the spectrum of hydrogen, helium, carbon, neon, and so forth, that we find on the Earth today. In
(What was shocking to me was not that a person was trying to swindle
the unwary-this has been true since the dawn of time. What was surprising was that it was so easy for this inventor to fool wealthy investors because of their lack of understanding of elementary physics.) I repeated to
the Journal the proverb "A fool and his money are easily parted" and P. T.
Barnum's famous dictum "There's a sucker born every minute." Perhaps
not surprisingly, the Financial Times, the Economist, and the Wall Street
Journal have all run large feature articles on various inventors touting
their perpetual motion machines.
THE THREE LAWS AND SYMMETRIES
But all this raises a deeper question: Why do the iron laws of thermodynamics hold in the first place? It is a mystery that has intrigued scientists since the laws were first proposed. If we could answer that
question, perhaps we might find loopholes in the laws, and the implications would be earth-shattering.
In graduate school I was left speechless one day when I finally
learned the true origin of the conservation of energy. One of the fundamental principles of physics (discovered by mathematician Emmy
Noether in 1918) is that whenever a system possesses symmetry, the
result is a conservation law. If the laws of the universe remain the
same over time, then the astonishing result is that the system conserves energy. (Furthermore, if the laws of physics remain the same if
you move in any direction, then momentum is conserved in any direction as well. And if the laws of physics remain the same under a rotation, then angular momentum is conserved.)
This was staggering to me. I realized that when we analyze starlight from distant galaxies that are billions of light-years away, at the
very edge of the visible universe, we find that the spectrum of light is
identical to spectra that we can find on Earth. In the relic light that was
emitted billions of years before Earth or the sun was born, we see
the same unmistakable "fingerprints" of the spectrum of hydrogen, helium, carbon, neon, and so forth, that we find on the Earth today. In