Unclaimed science and engineering bounties


“Successfully launch, land, and operate a rover on the lunar surface.”

Lunokhod did all that.

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Billion-digit prime, huh? Okay, I’ll put my marker down on 1,000,… [999,999,993 zeroes omitted]… ,001.

Let me know if I win!

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I will flat-out pay five bucks to the person who successfully figures out how to program the clock in the stereo of my wife’s car. Seriously, it’s been driving me nuts for two goddamn years.


okay wise guy, we all know the Prime has to be in hex and must translate to Optimus at some point when converted to ASCII.

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Is this the new version of “I can’t fix the blinking 12:00 on my vcr”?

The atomic attack version: find the RTC chip on board (hopefully the vendor was not too cheap to actually put in one, in that case it could be a SO08 chip near a little 32.768 kHz crystal), tap the I2C bus, set registers via e.g. Bus Pirate or similar adapter.

For bonus points, replace the RTC chip with a microcontroller that emulates its registers and keeps precision time via e.g. tapping the GPS NMEA messages.

What’s the density of primes a billion digits out? I wonder if anybody knows. At any rate, I’ll just put my markers on the next million odd numbers after yours. One of them is sure to be prime,and therefore the prize is mine.

My old calc II professor once tried to win that prime-number contest. You need a lot of computing power, and most people have multiple participants pool computing resources to share the prize. He had a nifty idea that involved thinking outside the box a little. I don’t remember his strategy as well as I remember the strategy commonly used, which involves looking for Mersenne primes since they tend to get really big, really fast…

The prime counting function (gives the # of primes less than n) is asymptotic to n/ln(n). So the density of primes below 10^(10^9) should be about 4.34*10^-10. So you might want to go another 3 billion or so further.

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That seems fair, I’ve got enough budget for five billion.


“You must be an engineer,” said the balloonist.
“I am,” replied the woman, “How did you know?”

“Well,” answered the balloonist, “everything you told me is technically
correct, but I’ve no idea what to make of your information, and the fact
is I’m still lost. Frankly, you’ve not been much help at all. If anything,
you’ve delayed my trip.”

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