Latest on whether anything exists: off topic
I sometimes mention the, now little mentioned, Copenhagen Interpretation of quantum mechanics. It is based on the observation that a quantum property, say the direction of polarization of a photon, is not established until it is measured. There is ample experimental support for this. If you wish to delve into the mysteries a bit farther look up Bell’s Inequality. I cannot keep the whole argument in mind, but when I have looked at it it seemed sound.
By extension, it was asserted that since everything (except gravity) can be described in quantum terms, nothing existed until measured. That of course leads to a serious paradox. At the time of the Big Bang, with which the universe is generally thought to have started, everything was in some state of quantum uncertainty so no measurement could have been possible. That is not the only paradox of the Big Bang theory. There is also the question of whether the universe could have been anything but a black hole. And of course there is the question of why it happened at all. That last paradox gets some attention, but there is never discussion (by anybody but me) of the first two.
Then there was an experiment done a few years ago that challenged the notion. They found that if you made a partial measurement of something – like that photon for instance – you could get at least a probable notion of what the state was without altering the state.
It seemed like a burden was removed. “So it’s real after all, just very strange. We can go home now.”
But that later experiment has now been challenged. (Adrian Cho, Breakthrough Lost in Coin Toss SCIENCE vol. 346 no. 6205 October 3, 2014 page 22) The idea is more or less that if you toss a coin and let somebody grope it, that person can make a guess as to whether it is heads or tails. But the groping is not perfect, so the guess is only a probability. Then, and I truly do not follow the logic here, depending on the guess the coin is then flipped again. Apparently that achieves the same effect without invoking quantum mechanics, so it has nothing to say about quantum mechanics.
But wait. Didn’t we just say that it’s ALL quantum mechanics? And a guess is a probability statement. I don’t get it. Apparently at least I am not alone on that one. Some say the Copenhagen Interpretation is disproved, some say otherwise, others are unsure.
This seems to be a dark little corner of physics. It’s not the headline grabber that the Higgs Boson has been. Maybe they need to spend more money on it. It seems that all agree that the experimental results are above reproach; only the interpretation is fogged.
Maybe nothing is real until it is observed AND UNDERSTOOD. In that case I think we can rest assured that nothing exits.
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