I don't understand exactly how these tires work, but having wheels with integrated rollers so that you can move sideways is a pretty old idea, see for example this forklift (video from 2006!).

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.

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 ...

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 ...

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.

Indeed, they would need some mechanism like this, which is implemented using several heterogeneous processes. Triple hardware redundancy is useless if they all have a common mode software bug. Same thing happened to the first flight of Ariane 5, where all 3 controllers crashed within milliseconds.

[Mod parent informative] Indeed, this seems exactly the same issue. For Boeing, it might either be a signed integer being incremented at 100 Hz, or an unsigned one at 200 Hz.

I guess this might be due to a 32-bit signed integer being incremented at 100 Hz: 2^31 / 24 / 3600 / 100 = 248.5 days.

Easy workaround: dual-booted laptop, one partition with WindowsXP and weak password, full with celebrity porn, 9/11 conspiracy documents and spyware to keep them busy for a while. Fully encrypted Linux partition for everything else.

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.

Hmm, seems it will still take a while ...

I am not sure if we will get some personal answers out of this guy, I guess he will just forware every single question into one of these websites that claim to know everything. Serioudly, though, what do you think of Elon Musk's fear of A.I., and when do you think that Wolfram Alpha will become self aware?

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.

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.

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.