While we haven’t observed a quantum object as both particle and wave at the same time, new research being hyped as such is very real and very useful.
Snap To
The Stern-Gerlach effect is strangely counterintuitive, but we can use it to study the magnetic fields of stars.
And Then There’s Maude
In modern physics, matter in the universe is made up of quanta or “particles” such as electrons, protons and neutrons. These particles can be said to interact through various forces or fields (strong, weak, electromagnetic, gravitational) for which there are corresponding “field quanta” such as photons and gluons. These quanta can are often seen as the particles that make up these fields, and while things are a bit more complicated it is the right basic idea. We have a lot of experimental evidence for these quanta, but there is one that’s often mentioned for which we have no experimental evidence. That’s the graviton.
But No Simpler
Recently there’s been a flurry of news articles claiming that “Quantum physics just got simpler!” as if new research has finally solved a big mystery of physics. Not so, when you look at the actual research. The work looks at a connection between particle-wave duality, and something known as entropic uncertainty.
Twist of Fate
The next time someone tries to describe quantum theory as mysterious or magical, imagine how silly it would seem if the same arguments were applied to polarized light.
Calvinball
In Bill Watterson’s comic strip Calvin and Hobbes, there is a game known as Calvinball. The basic idea of Calvinball is that rules are added by players as the game progresses. Players can add to the rules as you go along, but once a rule is in place it can’t be undone. The result is a hodge-podge game where the action is incomprehensible by anyone but the participants. Often in popular science quantum theory is portrayed as the physics version of Calvinball, even though that isn’t how quantum theory works. Quantum objects may be strange, but they aren’t making up rules as the universe plays on.
Black Hole Thermodynamics
In the 1800s scientists studying things like heat and the behavior of low density gases developed a theory known as thermodynamics. As the name suggests, this theory describes the dynamic behavior of heat (or more generally energy). The core of thermodynamics is embodied by its four basic laws.
The Great Escape
Earlier this week I talked a bit about black holes. In particular, one of the properties of a black hole known as the event horizon. The event horizon is the point of no return for matter entering a black hole. Once you cross the event horizon, you can never escape. Not even light can escape a black hole because of the warping of space at the event horizon. Of course this means that the mass of a black hole can only increase. Over time material crosses the event horizon, and in so doing forever adds its mass to that of the black hole.
The Great Unknown
Last time I talked about how things like photons and electrons have a strange wave-particle duality. Related to this is the fact that there are limits to what you can know about quantum particles. To see how this works, let’s return to our baseball analogy. Suppose you were watching a game, and just after the ball was hit you wanted to determine where the ball will land. In principle you could measure the ball’s position and speed. Knowing its position and speed at a particular time you could then use Newton’s laws to predict where the ball will land. That’s because Newtonian mechanics is deterministic. If you know an object’s position and momentum (velocity and mass) and the forces acting on the object, then you know where it will be at any point in the future.