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The quantum physics of large things: Macro quantum effect. Why don’t tennis balls behave like quantum particles? What happens to a baseball in a double slit experiment? This experiment shows that atoms behave like waves of probability when not measured, and particles when measured. We also see that two quantum particles can be entangled, meaning that are connected through a sharing of one probability wave.
Why don’t we see these kinds of behavior in our everyday macro lives? At what point does the quantum behavior stop and classical behavior of everyday objects begin?
Scientists have shown quantum behavior through a double slit in particles as large as molecules containing thousands of atoms, but what about really large things like balls? Will we see the same kind of behavior that electrons or atoms have? No we will just see two patterns on the back wall. Why doesn’t the whole behave like the individual atoms it is made up of?
To answer this, we have to understand some of the basics of quantum mechanics. When we shine a Monochromatic light through a double, we see an interference pattern on the other side because as the waves spreads out, This should be no big mystery. This is not quantum mechanics, this is just a property of waves. It will happen with water waves too.
In the Copenhagen interpretation, these particles are not particles - they are like wave of probabilities. The waves become distinct like particles only when they are measured. At the point at which the probability wave becomes a distinct particle is called a collapse of the probability wave. What scientists have found is that when the which-path information of any particle is measured, its probability wave collapses. For the particles to remain probability waves, their path information must remain in absolute secrecy. If at any point any kind of measurement is made, whether it seen by anyone or not, the particles become distinct and do not display wave-like behavior.
A measurement always collapses the wave. A measurement is a formation of any physical record of which path the particle takes. It is such that a quantum forensic exam could establish which path the particle took. The particle has to be informationally isolated. The interference can only occur if it is impossible, even in principle, to find out which path the particle took.
Now what if throw really large particles that are composed of quintillions of atoms, like tennis balls at a double slit? Will be see an interference pattern? No, The reason is that large objects are nearly impossible to isolate informationally from the outside world. Let’s look and see what it would take to isolate a tennis ball informationally.
First we have to remove all the air and photons in the experiment - Because if a photon or air molecule bounces off the tennis ball, then it has potentially recorded the path of the tennis ball. The photon will do the same thing, if a photon reflects off of the ball, then that could be a measurement because the path of the photon would be changed and the bounced path of the photon has recorded the path information of the ball. Potentially, someone or the universe could examine the paths of all the photon in the room, find out how they were affected by the path of the tennis ball, and find out from that information, the path of the tennis ball.
We will also need to cool the baseball to near absolute zero, because the baseball that has a temperature will emit photons due to something called black body radiation. These emitted photons will have recorded information about the tennis ball, such that someone examining the photons could determine the path of the tennis ball.
We even have to worry about the small amount of gravitation that the tennis ball will have, because this gravitation will effect nearby atoms. This in principle can allow someone to determine the path the tennis ball took. So this ball will also somehow have to be isolated from that.
We have to completely isolate the tennis ball because any information that is leaked to the universe about its path will create a record. Even if this information is recorded in one atom, it is still information which has been captured in the universe, and the tennis ball will not be in superposition.
#macroquantumeffects
Macroscopic objects like this are very difficult if not impossible to isolate informationally. So in our everyday experience, we will not see quantum superposition or wave like behavior of macro objects. This is the reason, you and I and the cat in Schrodinger’s experiment are NOT in superposition. The cat is not dead and alive at the same time. That is a myth.