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Comments

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Forests Around Chernobyl Aren't Decaying Properly

maxwell demon Re:Fire = Good (167 comments)

Chernobyl was a fission plant, but nature does have fusion reactors reacting all over the universe all the time,

And quite a lot of them actually exploded. ;-)

about a month ago
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Snowden A Hero? Gates Says No, Woz Says Yes

maxwell demon Re:The full sentence (335 comments)

The people hiding Jews in Nazi Germany also broke the law. I guess that would also exclude them from being heroes in Bill Gates' opinion?

about a month ago
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Snowden A Hero? Gates Says No, Woz Says Yes

maxwell demon Re:Obvious response from Gates (335 comments)

Not a fan of the NSA part, but anything that reduces the worldwide birth rate is good in my opinion.

So you are in favour of a global thermonuclear war? Because that certainly would reduce the birth rate worldwide.

about a month ago
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Hungarian Law Says Photogs Must Ask Permission To Take Pictures

maxwell demon Re:Out of step with reality (149 comments)

Just don't take pictures of people who obviously don't want to be in your photo and you're fine

Must be a great place if you're a thief.

No, because in Germany, while you're forbidden to publish the picture without consent of the person, you're not forbidden to take it, nor to show it to the police.

about a month ago
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Hungarian Law Says Photogs Must Ask Permission To Take Pictures

maxwell demon Re:Out of step with reality (149 comments)

for example just about any photograph depicting the demolishing of the Berlin Wall would have been illegal.

Given that the German law contains an explicit exemption for pictures of contemporary history, that statement is not true.

about a month ago
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Hungarian Law Says Photogs Must Ask Permission To Take Pictures

maxwell demon Re:Out of step with reality (149 comments)

No, there are usually exceptions for that type of photography. Also there are typically exceptions for people of special interest (that is, if you photograph a politician, he cannot forbid you you to publish it, at least not on the ground of that law) and for certain other common cases.

about a month ago
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Type Ia Supernovae As Not-Quite-So-Standard Cosmological Candles

maxwell demon Re:God created the heavens. (33 comments)

That's why astrophysicists concentrate on the sky instead.

about a month and a half ago
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Ask Slashdot: Does Your Employer Perform HTTPS MITM Attacks On Employees?

maxwell demon Re:Yes they did. (572 comments)

For example, I have to pay travel expenses from my own money, and then get them reimbursed afterwards. That is, I may have a legitimate reason to access my bank account in order to e.g. pay my flight. But that doesn't give my employer the right to access my banking password (and possibly look what's going on in my bank account).

Also, if I'm not allowed to access my bank account from the company network, the right thing is not to decrypt it, but to block it.

about a month and a half ago
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Internet Shutdown Adds To Venezuela's Woes

maxwell demon Re:Hi, jack (194 comments)

soylentnews.org
pipedot.org

about 2 months ago
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Internet Shutdown Adds To Venezuela's Woes

maxwell demon Re:He's s shill probably (194 comments)

No under capitalism no one is exploited.

What colour is the sky on your planet?

Values exchanges for value and nobody does anything forcibly against their will.

Sure. And people can just decide not to eat for prolonged time whenever no acceptable way to generate income is available. </sarcasm>

It's only when you add government activity beyond the protection of private property that you get exportation.

You mean, government activity like protection of lives? Protection of freedom? Or protection of any other human rights?

about 2 months ago
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Chrome 33 Nixes Option To Fall Back To Old 'New Tab' Page

maxwell demon Re:Burning Chrome (125 comments)

Alienating your users seems to be all the rage lately.

about 2 months ago
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Stack Overflow Could Explain Toyota Vehicles' Unintended Acceleration

maxwell demon Re:Perfect Software (664 comments)

Anyone who thinks all software has bugs has never written "Hello World" in assembly.

Or he has, and the resulting program crashed. ;-)

about 2 months ago
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Stack Overflow Could Explain Toyota Vehicles' Unintended Acceleration

maxwell demon Re:Wow (664 comments)

No, you misunderstood. After not finding the solution themselves, Toyota asked on Stack Overflow, and they could explain the problem to Toyota.

about 2 months ago
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Making Sure Our Lab Equipment Isn't Tricking Us

maxwell demon Re:again with the assumptions. (108 comments)

It's independent of whether you describe it graviton based or geometry-based. Indeed, the very same apparent problem also occurs in electrodynamics:

Assume you've got a charged particle orbiting a much heavier particle of opposite charge, and let's assume we can neglect the back-action of the radiation that orbiting particle inevitably emits. The orbiting particle feels an electrostatic force towards the central particle it orbits (which, due to its much larger mass, essentially is at rest).

Now look at the very same system in a frame of reference where the whole thing is moving perpendicular to the orbital plane. Now you would naively say that the electron should orbit a point slightly behind the central charge (because — and that has been experimentally verified — the electromagnetic field also propagates just with the speed of light, and until the field has reached the orbiting particle, the central particle has already moved on). However if you actually calculate the electric field, you'll find it points exactly to the point where the charge actually is — or more exactly, at the place at which the charge would have been predicted to be at the time when the current position of the orbiting particle could be reached with light speed if one assumed that the central particle continued to go with its current speed unchanged. That is, if the speed of the central charge changed afterwards (that is, the central charge was accelerated in the mean time), the orbiting particle will still orbit the point where the central charge would have been until the information of the change (the radiation from the accelerated central charge) arrives.

about 2 months ago
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Making Sure Our Lab Equipment Isn't Tricking Us

maxwell demon Re:again with the assumptions. (108 comments)

One could argue that the propagation of gravity reveals information about the mass in question.

Yes. And gravity propagates with the speed of light. If some alien would manage to kick the sun out of the solar system, the earth would continue to follow its orbit for another 8 minutes. Only then would it feel the changed movement of the sun (at the same time you'd also see that the sun suddenly starts to move) and change its orbit accordingly.

about 2 months ago
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Making Sure Our Lab Equipment Isn't Tricking Us

maxwell demon Re:again with the assumptions. (108 comments)

Entanglement is the same thing.

Not quite. I think it is best seen by the Mermin paradox:

Three particles are brought into a special shared quantum state (termed GHZ state) and then distributed to three parties, who each can then make, on their own choice, one of two measurements on the particles, X or Y. Either measurement can result either in the value 1, or the value -1.

Now it turns out that while the individual results are completely random, whenever any two of them choose the measurement Y and the third one chooses X, the product of all three measures values are 1, every time.

Now, so far there's no problem: This could easily be explained by the original procedure producing not really the same state, but randomly different states which determine all measurement results, and which all fulfil the condition. This would be the analogue to your coin: Every actual state (heads up or tails up in the case of the coin, the set of six potential measurement results in the case of the Mermin paradox) fixes every measurement result, and all states fulfil a certain condition (the opposite sides of the coin having different symbols, the products of XYY-type measurements being 1 for the Mermin paradox), but the states are otherwise chosen by random. Due to the restriction on the states, you can predict one measurement result if you know the other(s) (for the coin, the down-facing symbol if you know the up-facing, for the Mermin paradox the third measured value of an XYY-type measurement if you know the other two).

Assuming this explanation, let's figure out what the product of measurement results should be if all three people measure X. To this end, let's label as x1 the measurement result the first person got from measuring X, y1 the result the first person would have gotten if measuring Y (which, in the above scenario, would be well-defined, just as in the case of the coin the symbol facing up is well defined even if you don't look at it), x2 the second person's result from measuring X, and so on.

Now we already know that y1*y2*x3=1, y1*x2*y3=1 and x1*y2*y3=1. If we multiply those three values together, we get x1*y1^2*x2*y2^2*x3*y3^2=1. But since the measurement results are all either 1 or -1, their squares are always 1, and thus we end up with x1*x2*x3=1. So according the above explanation, when all three people measure X, the product of their measurement results should be 1, every single time.

Now for the specific quantum state quantum mechanics predicts something different (and experiments confirm it, of course only within measurement error): When all three people measure X, the product of their measurement results is -1, every single time.

about 2 months ago
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Making Sure Our Lab Equipment Isn't Tricking Us

maxwell demon Re:again with the assumptions. (108 comments)

Whether all light cones lead to the big bang is independent of whether you believe it.

about 2 months ago
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Making Sure Our Lab Equipment Isn't Tricking Us

maxwell demon Re:again with the assumptions. (108 comments)

Even if the universe is infinite, the observable part of it is finite, and there's evidence (the homogeneity of the cosmic microwave background) that all of it was once causally connected. A quasar that is outside the observable part of the universe won't help you because you can't use anything it emits — it doesn't reach you.

about 2 months ago
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Making Sure Our Lab Equipment Isn't Tricking Us

maxwell demon Re:How about not-quite-random numbers? (108 comments)

What if they seed the PRNG with cosmic ray data? And/or XOR the PRNG with cosmic ray data?
I think if that also shows Bell correlations, it would only leave two possibilities:
* Either there's a god-like entity determining the results and actively misleading us. In which case, no amount of experimenting would help.
* Or quantum mechanics is right.

OK, there's third one:
* Actually the correlations don't really exist, but due to an extremely unlikely sequence of events the data still looks like we have one (similar to how a fair coin can land on the same side a million times in a row; it's just that it is so unlikely that we'd not believe that the coin is really unbiased if it happened; obligatory link).

Well, there's also a fourth one:
* Quantum mechanics as such is wrong, but we have parallel universes with an analogue of quantum suicide, and some extraterrestrial race wants to prevent us from discovering the true laws (because those would lead us to powerful weapons and thus make us a threat to them), and immediately vaporizes the earth as soon as a measurement violates quantum mechanics. Therefore in all surviving copies of the earth, the laws of quantum mechanics seem to hold.

OK, I guess I should stop before my possibilities get even more silly. ;-)

about 2 months ago

Submissions

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Scientists create functional Maxwell's Demon

maxwell demon maxwell demon writes  |  more than 3 years ago

maxwell demon (590494) writes "For the first time, scientists have converted information into pure energy, experimentally verifying a thought experiment first proposed 150 years ago.

The idea was originally formulated by physicist James Clerk Maxwell, but it gained controversy because it appeared to violate the second law of thermodynamics. Put in experimental terms, this law states that when hot and cold water are mixed, they will eventually reach an equilibrium middling temperature.

Maxwell proposed that a hypothetical being (later dubbed Maxwell's demon) could separate the water into two compartments and reverse the process, isolating hot molecules from cold by letting only the hotter-than-average through a trap-door between the compartments.

(Link to original paper)"

Link to Original Source
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Green laser pointers may be dangerous

maxwell demon maxwell demon writes  |  more than 3 years ago

maxwell demon (590494) writes "Researchers at NIST have found out that cheap green laser pointers can emit dangerously intense infrared light. Since you cannot see infrared light, you'll normally not notice it, however it's dangerous for your eye. The article also describes how to test laser pointers with consumer equipment. Of course, while doing that, do not look into laser with remaining eye."
Link to Original Source

Journals

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maxwell demon maxwell demon writes  |  more than 11 years ago

Yes, it's the First Post in this journal.

All those Anonymous Cowards trying to make a First Post again after every story obviously have not yet found out about this foolproof way to get a First Post: As soon as you create an account on slashdot, you get a journal, and in your journal you always will have the first post.

So don't be an Anonymous Coward, get an account, and you get your guaranteed First Post for free!

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