What I've been thinking about...
To memeengine: When you say that we humans can “propagate quantum effects at the human level on purpose” what do you mean exactly?
The gist of the photo above is that Schrodinger’s Cat turns out to be a good example of what I’m talking about. And just to soothe those who are already objecting, no, I’m not about to claim that quantum superposition exists at the macro level.
Schrodinger’s Cat is a famous (and cruel) thought experiment in which a cat is shut into a box along with a complicated device that may or may not release poisonous gas, thus killing the cat. Inside the device is some radioactive substance which (over some given length of time) may or may not emit an alpha particle. If a particle is emitted, a Geiger counter in the device will detect it and cause a hammer to smash a glass vial containing the poison gas.
Erwin Schrodinger suggested that before we open the box, we don’t know whether or not the cat is alive, and we could thus consider it to be in a superposition of living and dead states. This is not reality of course, and Schrodinger certainly knew that - he merely wanted to explain the idea of quantum superposition (which happens at tiny scales) using everyday scale objects. At quantum scales superposition is indeed real, and is not just a matter of “not knowing yet”.
Though it’s not required, his thought experiment contains a quantum element… decay of a radioactive substance is due to quantum tunnelling, and the timing of such radiation is one of the truly random things in our universe. Falling dice seem random, but are actually under the sway of air resistance, gravity, etc, so their randomness is an illusion. The same can be said of random number generators in computers, which often use math combined with the current exact time to generate numbers that seem random.
Quantum randomness is the real deal, meaning that even if we know every physical detail of the geiger counter and the radioactive substance, we will still be unsure if the cat will be killed or not while it is in the box.
This true randomness is what is relevant to my comment earlier. Though we do not see quantum superposition in the cat, we do see a causal chain that starts at a truly random quantum event, and ends in a tragically macroscopic effect (the death, or not of the cat). In this thought experiment, it can truly be said that the cat is neither determined to live or to die. Its fate is truly random.
I say that this quantum randomness can be propagated to our level on purpose, because this example (and the one I used earlier) required humans to use our technology to observe a random event, and decide in advance to react to different options in different ways. In the Schrodinger’s Cat experiment, the different reactions are built into the geiger counter, the hammer and the poison.
There is some doubt as to whether quantum randomness can “naturally” have effects on higher levels of complexity. Though I don’t know the detail of why, I know that quantum superpositions are “delicate”, and tend to collapse into plain “this way or that way” facts in more (physically) complicated systems. This is why I had to seek out an example to be sure that human level events could hinge on quantum-level randomness.