# Unclaimed science and engineering bounties

**beschizza**#1

**MarjaE**#2

â€śSuccessfully launch, land, and operate a rover on the lunar surface.â€ť

Lunokhod did all that.

**semiotix**#3

Billion-digit prime, huh? Okay, Iâ€™ll put my marker down on 1,000,â€¦ [999,999,993 zeroes omitted]â€¦ ,001.

Let me know if I win!

**Brainspore**#4

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

**anon33466019**#5

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.

**shaddack**#7

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.

**Boundegar**#8

Whatâ€™s the density of primes a billion digits out? I wonder if anybody knows. At any rate, Iâ€™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.

**anon26940528**#9

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 donâ€™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 fastâ€¦

**knappa**#10

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.

**L_Mariachi**#12

â€śYou must be an engineer,â€ť said the balloonist.

â€śI am,â€ť replied the woman, â€śHow did you know?â€ť

â€śWell,â€ť answered the balloonist, â€śeverything you told me is technically

correct, but Iâ€™ve no idea what to make of your information, and the fact

is Iâ€™m still lost. Frankly, youâ€™ve not been much help at all. If anything,

youâ€™ve delayed my trip.â€ť