Quantum Theory Cannot Hurt You_ A Guide to the Universe - Marcus Chown [23]
Such stars are thought to form violently in supernova explosions. While the outer regions of a star are blown into space, the inner core shrinks to form a neutron star. Neutron stars, being tiny and cold, ought to be difficult to spot. However, they are born spinning very fast and produce lighthouse beams of radio waves that flash around the sky. Such pulsating neutron stars, or simply pulsars, semaphore their existence to astronomers.
UNCERTAINTY AND THE VACUUM
White dwarfs and neutron stars apart, perhaps the most remarkable consequence of the Heisenberg uncertainty principle is the modern picture of empty space. It simply cannot be empty!
The Heisenberg uncertainty principle can be reformulated to say that it is impossible to simultaneously measure the energy of a particle and the interval of time for which it has been in existence. Consequently, if we consider what happens in a region of empty space in a very tiny interval of time, there will be a large uncertainty in the energy content of that region. In other words, energy can appear out of nothing!
Now, mass is a form of energy.
3
This means that mass too can appear out of nothing. The proviso is that it can appear only for a mere split second before disappearing again. The laws of nature, which usually prevent things from appearing out of nothing, appear to turn a blind eye to events that happen too quickly. It’s rather like a teenager’s dad not noticing his son has borrowed the car for the night as long as it gets put back in the garage before daybreak.
In practice, mass is conjured out of empty space in the form of microscopic particles of matter. The quantum vacuum is actually a seething morass of microscopic particles such as electrons popping into existence and then vanishing again.
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And this is no mere theory. It actually has observable consequences. The roiling sea of the quantum vacuum actually buffets the outer electrons in atoms, very slightly changing the energy of the light they give out.
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The fact that the laws of nature permit something to come out of nothing has not escaped cosmologists, people who think about the origin of the Universe. Could it be, they wonder, that the entire Universe is nothing more than a quantum fluctuation of the vacuum? It’s an extraordinary thought.
1 See Chapter 8, “E = mc2 and the Weight of Sunshine.”
2 See Chapter 7, “The Death of Space and Time.”
3 See Chapter 8, “E = mc2 and the Weight of Sunlight.”
4 Actually, every particle created is created alongside its antiparticle, a particle with opposite properties. So a negatively charged electron is always created with a positively charged positron.
5 This effect is called the Lamb shift.
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THE TELEPATHIC UNIVERSE
HOW ATOMS CAN INFLUENCE EACH OTHER INSTANTLY EVEN WHEN ON OPPOSITE SIDES OF THE UNIVERSE
Beam me up, Mr. Scott.
Captain James T. Kirk
A coin is spinning. The coin is in a strong box sitting in the mud at the bottom of the deepest ocean trench. Don’t ask what has set the coin spinning or what is keeping it spinning. This isn’t a well-thought-out story! The point is that there is an identical spinning coin in an identical box sitting on a cold moon in a distant galaxy on the far side of the Universe.
The first coin comes down heads. Instantaneously, without the merest split-second of delay, its cousin 10 billion light-years from Earth comes down tails.
The coin on Earth could equally well have come down tails and its distant cousin heads. This is not important. The significant thing is that the coin on the far side of the Universe knows instantly the state of its distant terrestrial cousin—and does the opposite.
But how can it