So my friend Blake Walker started his segment "Walker's Wisdom" earlier this week, and his first topic was on Perspectives. That is, in a philosophical and perhaps psychological sense, how our perspective can change not only the way we approach things, but our experience of them too. It was funny he chose this as his first topic because I had been reading a book on Quantum Physics, In Search of Schrödinger's Cat, and the last chapter was essentially about perspectives in quantum physics.
Specifically, the difference between the Copenhagen Interpretation and the Many Worlds Interpretation of Quantum Mechanics. Both of these are different perspectives on how things on a quantum level play out.
So, to explain what each interpretation is, let me use the ever so popular Schrödinger's cat thought experiment as an example.
So basically there is a radioactive isotope of some kind, that has a 50/50 chance to decay. If it does decay, it will give of some radiation, which the Geiger counter will detect. If the Geiger counter detects the decay, it will trigger a hammer which in turn will smash a bottle of cyanide poison. Now you can probably guess what happens if you smash cyanide bottles around a cat.
The Copenhagen Interpretation basically says that the cat exists in a state of superposition until it is observed. So the cat is both alive and dead until the box is opened. By looking inside the box, you are forcing the universe to make a choice. Of course the weird thing is that there is no way to know exactly what it's going to choose!
The Many Worlds Interpretation however, says that the universe doesn't choose one or the other, instead it chooses both possibilities. But how can it choose both? Well, in terms of this experiment, instead of the universe having a cat that is either dead or alive, there are two universes, one in which the cat is dead, and another in which it is alive.
Both of these perspectives are pretty crazy, but both surprisingly have solid mathematical evidence behind them. Regardless of which one is true, its obvious that simple cause and effect does not suffice in explaining the natural world. These perspectives on quantum physics also bring up some curious philosophical problems. If on the most basic level, we cannot predict what is going to happen, what does this mean for free will? Is everything inherently random? Does "God play dice" with the universe? Albert Einstein didn't think so. He regarded the whole idea of quantum mechanics to be madness.
He even wrote a paper on it, Can Quantum-Mechanical Description of Physical Reality be Considered Complete?
Einstein may have been a genius, but he isn't the final say in physics. That's not how science works. In fact, a more modern day genius; Stephen Hawking, completely disagrees with Einstein on this.
"...Einstein was wrong when he said God does not play dice. Consideration of black holes suggests, not only does God play dice, but that sometimes he confuses us by throwing them where they can't be seen." -Stephen Hawking
It might be an uncomfortable idea, but experimentally and mathematically, it is the truth. Randomness is inherit on a quantum scale.
Perhaps more disturbingly, if one prescribes to the Many Worlds Interpretation, we are all just along for the ride, with quantum probability choosing which track we go on, with a duplicate of ourselves living out almost the exact same life in a parallel universe. And by the way, there are infinite many parallel universes.
But perhaps, even more interestingly, there is the possibility that we are the one's choosing. Maybe our free will is in fact, collapsing the wave function and is thus manipulating our reality on a quantum level. This is quite possible, seeing as the very act of observing a particle can make it behave differently.
Some spiritualists and New Age followers believe that this inherit quantum uncertainty is the explanation for all sorts of wacky pseudo-science. Some believe that quantum physics can explain telepathy or the afterlife. Big names in the spiritual playing field like Deepak Chopra believe and write books about "mind over matter" and the idea that our consciousness creates reality.
I'm not one to immediately dismiss these claims, as they are interesting to consider regardless of their source. However it can be problematic when people misuse the term "quantum physics" to hand-wavedly explain some mystical phenomena, in order to make it appear more believable. But science has always taken very strange turns throughout history. If it turned out that something like the Schrödinger wave equation and quantum electrodynamics can at least partially explain some 'supernatural phenomena' then that would certainly be interesting indeed. Perhaps just like how we used to worship the sun as a deity, until it was revealed it's just a big ball of flaming gas, then science will similarly cast away the mysticism surrounding such supposed phenomena.
Those are a lot of big "If's" though, and quantum physics is already starting to make a physical impact on our world today. With regard to how scientists and researchers think about interpretations of quantum mechanics, the de facto response is to "shut up, and calculate". Perhaps it doesn't matter which interpretation is correct, as long as the maths checks out, quantum mechanics can be used for all sorts of really cool things. Quantum supercomputers, long range instantaneous communication and quantum cryptography.
There is no doubt however, that quantum physics will be the source of a wealth of powerful new technologies in the decades to come. I reckon that's pretty exciting, even if the physics and maths flies over my head anyway.