[snowwrestler]

The 3-polarizer experiment is a very cool way to demonstrate the weirdness of light.

And the idea of using sequential rotation to keep track of cumulative bias in coin flips is an interesting concept.

But ultimately I think neither one of those concepts really depends on the other in this experiment. Checking for light through polarizers is neat, but keeping track of any other rotating macro-scale object would work just as well. You can do the same thing by rotating a stick on a piece of graph paper. If it goes beyond your pre-determined test angle, you declare a bias.

As I understand it, the crazy thing about quantum computing is that you don't need to go sequentially; you can simultaneously compute every test flip in one step with qubits. That's why quantum computing could speed up certain calculations. (Note: please don't ask me to explain how.)

[dhruvp]

Hey, you're right you could use a stick on a piece of paper etc. Totally fair. That being said this is in fact a real application where a qubit can model things a standard bit can't. Professor Aaronson describes it in this paper: https://www.scottaaronson.com/papers/qcoin13.pdf. Additionally, it's described in his lecture notes here: https://www.scottaaronson.com/qclec/5.pdf

[snowwrestler]

Thanks for the links. It doesn't seem like your experiment captures the interesting part, which is that you don't need more qubits to measure a more subtle bias.

As I understand the experiment now, it seems like the more subtle the bias in the coin, the more times you would need to rotate the polarizer to detect the bias.

If there is something about using the polarizing filters to keep track of tries that is more efficient than using something like a stick, then I would emphasize that in your write-up.

[htfu]

Yup. As greek to me as the paper is at least it makes very clear what it sets out to achieve and why (and when) it differs. I suppose it's implicit but I feel article really ought to explain that in the demonstrated case of heavy bias, few attempts and fixed, coarse steps there is of course no advantage - apart from the stick in ground one could also best its resolution off 0b1000000 and ++/--.

It's a nice explainer on polarization but tries to be more than that and doesn't achieve it - but with further work (not in form of added caveats but rather a new approach to tying the two concepts together) I'm sure it could.