lefra

Is "99% the same" good or catastrophic in this context?

> [if] the tests are reliable

Reading the tests is meant to check that.

I see no issue here.

Modifying a variable that is read by another thread needs special care in all multithreaded languages I know. If you don't use a synchronization primitive to tell the other thread "hey, this thing here may have changed, read it again from memory"; the other thread is free to use its old value for as long as it whishes.

> [the] spin is random and lives in a probability cloud that is probabilistic only until we observe it.

My mental model of it is kinda reversed. The maths assign a specific, deterministic state to each electron between each measurement. However, the "left" state is equal to "(up + down) / sqrt(2)". It then follows that when we measure an electron that is in the "left" state along the vertical direction, we get 50% up and 50% down: the probabilistic behavior happens when measuring, which "forces" an electron that was in the "left" state to become either "up" or "down".

I agree though that it would be less frustrating if there was some property of the electrons that would allow to predict in which state it'll collapse.

It's completely counterintuitive, but that's how it works experimentally. For example:

Measure the spin of electrons in direction X (that's done with a weirdly shaped magnet). You'll get either +1 or -1 in a conveniently chosen unit system. That's already weird, you'll never measure +0.5 for example. Keep only the +1 electrons. You can measure them again and again, you'll always get +1 in the X direction.

Now measure those electrons in the Y direction, you'll also get either +1 or -1.

But now, if you measure in the X direction again, you'll get +1 or -1 with 50% probability; although before measuring in the Y direction, these electrons always had spin +1 in the X direction.

Quantum physics is a theory, as in "as far as we can tell, this is an exact mathematical description of the world".

Models are simplifications/approximations made on purpose, as in "I know this is wrong on some level, but it's close enough for my use case", or "this makes the maths solvable".

Some countries solve that by just banning mail-in voting and moving paper ballots.

In France for example, voting happens on a specific day with transparent ballot boxes, with the counting happening in the polling station (you may stay for the whole day in your polling station if you want to oversee the whole process). Yes this is problematic for voters in foreign countries, because they need to go to the embassy to vote, but the voting protocols chose transparency over practicality.

IIRC, deployed military get a polling station in their military base. A voter may also designate someone in the same polling station as theirs to vote in their place.

I believe it's a spectrum, just like there is a whole spectrum between the Mona Lisa and a generic flyer for your local bowling alley.

Monthly revenue?

By adding up the uncertainties of all intermediate measurements they made.

As a parallel, for a regular clock, you'd measure and compute the uncertainties of:

- The distance between the axis of rotation and the center of mass of the pendulum,

- The local acceleration of gravity.

And deduce the pendulum period and its uncertainty by calculus.

In that case I'm not sure you can build (and measure) a pendulum that's more precise than a previous realization of the second (because the meter is defined from the speed of light and the second, and gravimeters probably depend on the definition of the second too).

That's why the definition of base units is carefully chosen to not depend on previous realization. IIRC time is the most fundamental of base units, because other base units depend on it.

In places where it's been living for hundreds of years, that's a legitimate concern.

In Europe though, where aedes aegypti didn't exist 20 years ago, it's probably the other way around: what did the introduction of this new species damage? (apart from making the summer unbearable outside if any of your neighbour isn't very strict with standing water elimination)

All the frequencies, in varying amounts. Next question, please.

Good idea, but it says that hiking in Spain in august is fine...

If a company wants to sell in the EU, they should comply with EU rules. The market and the regulations are closely linked, you won't get one without the other.