Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Comment The reason why Schneier is a target (Score 1) 217

It's common knowledge that if you knock out Chuck Norris with a roundhouse kick you become the new Chuck Norris.

Similarly, if you manage to steal Bruce Schneier's identity, you become the new Bruce Schneier.

No wonder he's a target. Everybody wants to be him.

My personal favorite Bruce Schneier Fact: "Most people use passwords. Some people use passphrases. Bruce Schneier uses an epic passpoem, detailing the life and works of seven mythical Norse heroes."

Comment When will there be Pi2/Pi3 images? (Score 1) 134

The archaic ARMv6 architecture CPU in the original Pi is radically different from the ARMv7+NEON of the Pi2 or the ARMv8 of the Pi3. When the Pi2 was released you said the performance advantage of ARMv7 builds optimized for the Pi2 wasn't big enough to justify the complication of having a separate OS image. But after the introduction of the Pi3, as people migrate to newer Pis and the rest of the open source ARM world takes v7 and NEON for granted, don't the scales start to tip in favor of builds for modern processors?

Mathematica devs in particular have said that having to target such disparate architectures in a single binary prevents them from using a high-performance BLAS, which slows many kinds of algorithms down dramatically. And many multimedia codecs have had extensive NEON optimizations but these don't always get enabled at runtime on Pi2/3.

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.

Slashdot Top Deals

egrep patterns are full regular expressions; it uses a fast deterministic algorithm that sometimes needs exponential space. -- unix manuals