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Comment Re: What is this I don't even (Score 1) 268

Those points in the phase space where there exist objects like brains that have records of other parts of the universe, necessarily have records of the universe as it was (is) in less-entropic states, because the processes involved in forming those records happen along paths from less entropic to more entropic states.

No. If you treat all parts of phase space equally, the most likely paths to "brains with memory records" are paths from higher entropy states. Even though memory-filled brains or any other kind of "record" spontaneously appearing from disorder is very unlikely, it is more likely than their emerging from an even lower entropy and thus even less likely state.

Without other reasons to believe an arrow of time exists - a privileged region of phase space or asymmetric physical laws- the likeliest explanation of whatever "record" that appears to indicate a lower-entropy past is that the records are random fluctuations from higher-entropy states. And there are no reasons why "records" should not equally well actually record "previous" higher-entropy states. The region of phase space where I sit here with a neuron arrangement "remembering" my cold chocolate this morning spontaneously getting hot is just as large as the region where I sit here with neurons that "remember" my hot chocolate getting cold.

Comment Re: What is this I don't even (Score 1) 268

But without any other asymmetries in physical laws, we have every reason to think entropy should increase going backwards in time just as well as forwards.

Decreases in entropy aren't impossible, they're just vanishingly unlikely. If you have a state with less than maximal entropy, of course you expect its entropy to increase. But because the physical laws are symmetric, if you're treating all volumes of state space equally, you also expect the same thing if you replace t with -t. The most likely way for a low entropy state to arise is as an unlikely random fluctuation from a higher entropy state. A past with lower entropy than the present is just as unlikely as a future with lower entropy than the present.

So if you define past and future via entropy, any state with less than maximal entropy has no past and both -t and t count as future.

This doesn't match our way of understanding the macroscopic world. We're much more inclined to believe we had an astoundingly unlikely astoundingly low-entropy initial condition. But from a stat mech point of view, without more of an idea why we should treat volumes of phase space this unequally, this amounts to a deus ex machina. So the arrow of time is still a puzzle and this is part of why people are still looking for hints of time asymmetry.

Comment Good parody (Score 5, Funny) 147

I first saw this news on the BBC yesterday. The account is really funny, and the tweet they quote at the start of the article is nicely representative; I'll reproduce it here for those who haven't RTFA yet:

Vladimir Putin (@DarthPutinKGB) May 27, 2016
        Arriving at Athens today:
        Customs: Name?
        Me: Vladimir Vladimirovich Putin
        Customs: Occupation?
        Me: No, this time i'm just here for 2 days

Comment Re:It depends (Score 1) 240

The followup article in the German paper says:

Zudem habe sich nach dem Unfall auch einer der vier Mitfahrer geäußert. Er hat wohl eine Geschwindigkeit von 150 bis 160 Stundenkilometern vom Tacho abgelesen.

which I'd translate as "In addition, after the accident one of the four passengers also weighed in. He read a speed of probably 150-160 kph from the speedometer."

Comment Re:Simple question (Score 1) 150

Though your second question may be unpopular I don't think that's the problem with it.

Asking the "shouldn't we put our resources to better use" question certainly makes sense when talking about human spaceflight. The claim some others here are making that the reason this is important is future space colonization is not really credible. And maybe you could make a case for questioning the value of some NASA probe missions.

It simply doesn't make any sense when talking about satellite launches. We all, directly or indirectly, rely on satellites every day; we will need to have some number of launches every year for the forseeable future. To do this in a way that is less expensive, more rapid, and more environmentally friendly really is a big deal. This IS putting our resources - resources we're already using - to better use.

There really isn't a way to make your first question reasonable. Though will be some benefit to everyone from this, you may well not call it significant. But it's possible to live your life in a way such that practically nothing in the news impacts you very significantly. So if you're only interested in what directly and significantly impacts you, quit wasting your time reading news on the internet.

At its best, Slashdot has been a site where impressive feats of engineering have been publicized and celebrated. (e.g. the Top 10 Hacks long ago.) If "news for nerds" isn't the "stuff that matters" to you, don't spend your time here.

Comment Plurality voting got us here, Condorcet would fix (Score 4, Insightful) 605

We've known since at least the 1700s that first-past-the-post plurality voting is a totally broken system. It's irresponsible to conduct any election with more than two alternatives in this fashion.

In many places, especially early in the election cycle, Trump would have lost any single head-to-head matchup. But his opponents were always split, and plurality voting is tremendously vulnerable to this kind of problem.

Process matters. If our elections were conducted using a Condorcet method like Ranked Pairs, Maximum Majority, or Schulze, we would have had less irrationality and extremism from both parties throughout the years, and the existing parties would not have become so entrenched.

Here's a popular-audience explanation by a couple of Nobel winners.

Comment Re:How can I give you money for this? (Score 3, Insightful) 546

I've been on slashdot since quite close to the beginning. (I had another user name before this one, too bad I abandoned it before low UID was something worth bragging rights). I had never really considered subscribing before.

After the changes you've been making, and knowing a bit about your plans, I'd be happy to subscribe just to vote with my wallet in favor of what's going on, even if a subscription doesn't have any benefits whatsoever beyond knowing that I'm supporting a good thing.

My wallet is not very thick but I think there are thousands of others who feel similarly.

Keep up the good work!

Comment It's many orders of magnitude worse than that!!!1 (Score 3, Funny) 170

According to some physicists, one material commonly found not only in nuclear waste but also in the byproducts of many industrial chemical processes is radioactive and has a lifetime of 10^32 years!!! Just think what kind of lasting problems that creates!

Not only should we shut down those nuclear and chemical processes, we should obviously jettison all these troublesome 'protons' into space so future generations don't have to deal with them!!!!1111

Comment Re:Why not EXI instead of XML and IR instead of JS (Score 1) 169

For binary XML, as well as for the various fledgling binary json or binary yaml formats, the binary representation can be quickly converted to a plaintext one that has basically only minor formatting differences from the original. (I was about to say "to a human-readable one that..." but that's a stretch for a lot of XML.)

An AST / IR / bytecode is decompilable; e.g. from what I understand LLVM can do a good job of translating its IR back to C. Obviously a lot more information that could help with human comprehensibility is lost in that process than in the cases above. But decompiled IR can be as readable as minified JS source code is.

Of course, even without using any of these, what's sent over the wire is usually not human readable anyways, it's just that the tools to translate these other formats back to plaintext are higher-level than gzip is.

Comment Why not EXI instead of XML and IR instead of JS? (Score 1) 169

I guess the browser-side performance isn't so much what they're talking about (rather, reducing network round-trips), but still, I have always wondered why we're still sending xml and js, plain or gzipped, rather than sending compact binary formats.

EXI is a W3C standard; it's more compact than gzipped xml and it's more than a dozen times faster to parse.

Rather than coding in JS all the time, lots of people are using javascript as an intermediate representation or bytecode. This is tremendously inefficient.

Though the WebAssembly effort sounds like people are finally realizing they need to address the problem, it sure seems like they're approaching it from a rather odd angle. asm.js and pnacl don't necessarily seem like where one should start if one has the freedom to design a new IR.

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