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Comment Anne Frank's diary too (Score 1) 420

Somewhat related: also the diary of Anne Frank is now in the public domain under the same rules, since she died about 2 months before Hitler. This is disputed by the Anne Frank Foundation, who claims that her father was co-author and that the work should thus remain under copyright for at least another 15 years. As a protest, the Dutch original text is now put online by several French politicians.

Comment Re:Let's make some assumptions... (Score 2) 163

Exactly this. What you are describing is the economic equivalent of Amdahl's law for speedup of using parallel computing: even with infinite parallelism (infinite reuse), theoretical minimal costs are dominated by non-parallelizable computation (per launch costs). Elon keeps repeating the talking point that fuel is cheap so launches can be 100x cheaper. This ignores recurring costs of launch operations, manpower, non recoverable 2nd stage, inspections and repairs. Still, lowering costs by a factor 2-3 would probably be enough to kill competition ...

Comment Re:Sort-of-worked. (Score 1) 54

They want to re-use this Dragon for an in-flight-abort test, using a Falcon 9 first stage launched from Vandenberg, so purposely introducing mechanical flaws seems risky. If it were a deliberate test, I would be simplest to just set the throttle to one of the motors to zero in software close to the end of the burn (to not ruin the overall test in case of problems), and then see if the control system can recover using the remaining 7 engines. Let's hope that Elon comments on this in the next days ...

Comment Re:Sort-of-worked. (Score 5, Insightful) 54

No, OP's remark was correct, he is not discussing the planned pitch over towards the sea after half a second, but a visible puff of smoke around the 4 second mark and some subsequent 'wobble', as if one of the 8 thrusters is switched of. See the zoomed video here. This proves the effectiveness of having 8 redundant thrusters, instead of having only 4. It is still not clear if this was a real engine failure (which might be verified via post-mortem examination of the motor), or if this was a deliberate, unannounced test of the 'engine out' capability. Credit: the discussion in the forum over at nasaspaceflight.com.

Comment Bigger issues (Score 1) 1089

I am neutral to mandatory voting. I believe they have this in Belgium, but it is not strictly enforced with sanctians, so the polical system works similar to neighboring countries. America has bigger political issues: 1) too large influence on politics of big money: by rich people via superPacs and by corporations via lobbying or outricht corruption. 2) Effective two party system, where everything is decided on a single left-right axis, so that non-issues like gun rights and being patriotic or christian enough decide all national politics. Fix these two issues first., then we can discuss mandatory voting.

Comment Re:The Secret of Nim (Score 2) 520

I completely disagree. I have worked extensively both with Matlab and Numpy, and I much prefer Python's 0-based indexing and half-open intervals over Matlab's 1-based indexing and closed intervals. Edsger Dijkstra, the famous computer scientist, explained why this is a good idea. E.g. splitting the first n items off an array in Matlab is head = x(1:n); tail = x(n+1:end) , while in Python it is head = x[:n]; tail = x[n:] . Even worse is when doing some computation over blocks within an array, in Matlab you do for i=1:n; y(i) = fun(x((i-1)*m+1:i*m)); end , while in Python it is for i in range(n): y[i] = fun(x[i*m:i*m+m]) . In Matlab, you always have to think careful about the extra +-1, which causes many off-by-one errors, while in Python you just write it down intuitively.

Comment Re:Twitter: Ran out of Hydralic fluid (Score 1) 213

The fact that he can make this claim only half a day after the fact (so I assume they had no time to piece together the debris) means that they did recover the most valuable part: the telemetry. Overall, they achieved probably 95% of the required challenges. With around 5 successful retro burns, 1 low-level flame out due to loss of roll control, 2 soft water landings, 1 bullseye impact on a boat and around ten successful low altitude tests with grasshopper, only extremely bad luck can stop them from making a good landing in the next few attempts.

Comment Make fun of them as much as possible (Score 2) 182

Some years ago, an advertisement for a Dutch insurance company made fun of some Stalinist dictator, without mentioning North Korea by name. As far as I know, this did not cause any large-scale hacking warfare against the involved company, but Korean diplomats were not amused. Watch it here while you still can. This regime cannot be ridiculed enough, Sony should just release the whole movie for free.

Comment Too expensive (Score 3, Interesting) 36

With 50 euro for a power supply, 100 for a sensor conditioning module (without the sensors!), 300 for a base station and 800 for a complete starter pack, I don't care if it is open source or not, it is way out of budget for the casual hobbyist. There are already enough different alternatives, most of which appear to be vapourware. Home automation seems easy enough that many people who follow the IoT hype start their own project. But we don't need more standards, we need less. The best would be if one of the existing protocols (not necessary that one) would win, so that people could mix and match their own components, which don't have to be more fancy than some arduinos and RPis thrown together.

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