Search found 6 matches

by DiEvAl
Thu Apr 28, 2016 5:36 pm UTC
Forum: Science
Topic: How large a disc would it take to block a star from view for all of earth?
Replies: 26
Views: 6117

Re: How large a disc would it take to block a star from view for all of earth?

Maybe if we put the distant star into a specific orbit around our sun, then..... nah. Assuming that the purpose is to prevent the star from distracting humans, it's enough to block the star at night, when it isn't outshone by our sun. Depending on the location of the star, that can reduce the size ...
by DiEvAl
Thu Apr 28, 2016 5:53 am UTC
Forum: Mathematics
Topic: Volume of the convex hull of parallel (convex) shapes?
Replies: 5
Views: 2646

Re: Volume of the convex hull of parallel (convex) shapes?

It's (almost) a Prismatoid, so it's volume is h(A1+4A2+A3)/6.
by DiEvAl
Wed Nov 12, 2014 8:08 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1446: "Landing"
Replies: 1143
Views: 224172

Re: 1446: "???"

taixzo wrote:
ker wrote:probably the time changed to the time when we can know about separation having completed successfully (or not)


Oh, right. So the ESA is counting down to the actual event, and Randall is counting down to the event + 30 minutes of light-speed delay.


Actually it's 28:20 minutes.
by DiEvAl
Tue Dec 31, 2013 4:21 pm UTC
Forum: What If?
Topic: What-if: chat thread
Replies: 123
Views: 147325

Re: What-If # 0076.5 Merry Xmas

bachaddict wrote:What if every leopard became a leopard?

Your post looks pretty funny with s/leopard/leopard/g browser extension ;-)

What-if there was no what-if today?
by DiEvAl
Fri Dec 13, 2013 3:47 pm UTC
Forum: Mathematics
Topic: Putnam 2013
Replies: 4
Views: 2966

Re: Putnam 2013

My strategy for B6:
Spoiler:
If before your turn there were less than n-1 stones, after your turn sum of indexes of cells with stones must be (n+1)/2 mod n+1 (indexes are from 1 to n). If before your turn there were n-1 or n stones, make any valid move.
by DiEvAl
Tue Dec 10, 2013 4:54 pm UTC
Forum: Logic Puzzles
Topic: Find a set of numbers containing mine
Replies: 32
Views: 10605

Re: Find a set of numbers containing mine

This problem was problem 3 on IMO 2012 (C6 in the shortlist). Here is the original wording: The liar’s guessing game is a game played between two players A and B. The rules of the game depend on two positive integers k and n which are known to both players. At the start of the game A chooses integer...

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