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Comment Re:Distance? (Score 1) 257

We can already explain the behaviour of quantum particles, at least for all the kinds we know about.

Whatever. The only further point I think I should make at this stage is that science has assigned reasonably well-defined meanings to the words "communication" and "information", and by those definitions entanglement and quantum collapse don't qualify. Personally, I don't think the dictionary definitions are a good fit either, but that is arguably subject to interpretation.

Comment Re:Distance? (Score 1) 257

Well, what I really meant was that our best current theory is a quantized field, so individual particles don't really have an independent objective existence but are just a subjective interpretation of certain kinds of vibrations. But your way works too. (At the end of the day it all boils down to how you choose to define words like "information" and "communication" so it's a bit of a tree-falling-in-a-forest thing.)

Comment Re: Change it twice (Score 1) 257

In short, it is because the nature of spin itself is non-classical. Whenever you look at the electrons, they are always either pointing either up or down - never left or right, because there isn't any such thing.

The way in which the is-it-up-or-is-it-down property transforms as you look at the electron from different angles makes it impossible for the spin to be predetermined for more than one angle at a time. If measuring it at one angle would definitely produce a spin-up result, the result of measuring it at any different angle has to be uncertain.

Comment Re: Change it twice (Score 1) 257

It's a much more complicated theory, with no obvious advantages, so Occam's razor suggests that we shouldn't get too excited about it.

Also, you can't posit that the pilot wave propagates at the speed of light, because it doesn't propagate through space at all. As per the article: "In de Broglie–Bohm theory, the velocities of the particles are given by the wavefunction, which exists in a 3N-dimensional configuration space, where N corresponds to the number of particles in the system."

Comment Re:Change it twice (Score 1) 257

If I'm reading the paper correctly, that's because the results of each experimental run are discarded unless the measurements of Ap and Bp show that A and B are correctly lined up with one another. (Or the experiment isn't performed until the measurements show that A and B are correctly lined up with one another, it isn't entirely clear.)

The Economist article, unsurprisingly, kind of skimmed over that part. :-)

To extend the pea analogy, Alice and Bob both have a half-pea, oriented at random. They both tell Carol which way their half-pea is facing, and if they aren't lined up, Carol tells them to try again. When you're done, the alignment of the two half-peas is definitely correlated, but that doesn't mean that the two half-peas were talking to one another..

Comment Re:Distance? (Score 1) 257

Entanglement IS communication, in the proper sense of the word. You cannot use it to send a message, but entanglement without hidden variables implies that information is exchanged between particles.

Only if you assume that particles actually exist in the first place, and that wavefunction collapse is objectively real. Neither of those assumptions is particularly well-founded.

Comment Re:Considering how fast Google ditched China (Score 1) 381

It is ridiculous to ask a web site operator to have 200-odd different versions of the same web site, one for each nation, and geo-fencing shouldn't even be legal, never mind mandatory.

So *in effect* enforcing French laws on web sites located outside of France amounts to enforcing French laws outside of France. Technically, no, they're not doing that. But it amounts to the same thing in the long run.

Basically the problem is that they have jurisdiction over one part of Google's business - the parts that actually operate in France - and they're leveraging that to claim jurisdiction over other parts. Legal, no doubt, but definitely improper.

Comment Re:transistor to IC: 6 years, CPU in 9yr. Moore's (Score 1) 113

I don't think it's quite that simple. While my intuition tells me that quantum error correction can't work once the number of states becomes too large, when I tried to prove that mathematically the results showed that I was wrong. (That is, they showed that the *particular* argument I was attempting to use was wrong, not that QEC can definitely work.

I'm also doubtful that quantum mechanics is really linear at that sort of scale - historically, linear theories have always proved to be only approximations. But while a quantum computer that fails due to non-linearity would not be useful for cryptography, it would be a huge step forwards for physics - and even a negative result (yep, still looks linear!) would be interesting. So if the experts think that quantum error correction is possible in principle, I'm all in favour of the research.

Comment Re:As usual? (Score 1) 235

Yeah, I suspect still somewhat inflated - for a start, I wouldn't be surprised if they had counted every stream initiated, even the ones that only ran for 30 seconds. And if I personally had to come up with a figure I'd have wanted to look at the statistics somewhat harder - people who only stream one or two movies a week *would* probably have paid a pound per if they'd had to, but people who stream fifty movies a week probably wouldn't. (Were most of those 12 million sessions from people in the first category, or the second? I don't know, and I think it makes a difference.)

But when you're used to reading about lawsuits where the damages have obviously been inflated by several orders of magnitude, one pound per instance seems remarkably reasonable, if only by comparison. :-)

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