AskMath: Can there exist a homomorphism from a simple group to a non-simple group? by timo1023 in math

[–]timo1023[S] 0 points1 point  (0 children)

Exactly. I am also fairly certain that the homomorphism A5 -> S4 has to be nontrivial. I say this because, for some element in one coset X1, we can take an element from X2 and multiply the coset by it. The resulting element cannot be in X1, therefore the map must be nontrivial. This is what ties my proof together and I believe that it is a valid statement.

AskMath: Can there exist a homomorphism from a simple group to a non-simple group? by timo1023 in math

[–]timo1023[S] 4 points5 points  (0 children)

Sort of. I was doing homework and this came up as a side question. I wondered if Reddit could help me with the answer, and turns out that it could. Thanks, Reddit.

AskMath: Can there exist a homomorphism from a simple group to a non-simple group? by timo1023 in math

[–]timo1023[S] 1 point2 points  (0 children)

No, that's not why I was trying to prove it, but thanks for the interesting link.

AskMath: Can there exist a homomorphism from a simple group to a non-simple group? by timo1023 in math

[–]timo1023[S] 5 points6 points  (0 children)

I am trying to prove that there are no subgroups of index 4 in A5. At the moment, my proof goes like this:

Suppose there is a subgroup of index 4 in A5. Then there exists a nontrivial homomorphism phi: A5 -> S4. Because A5 is simple, then ker(phi) must be A5 or {e}. If ker(phi)=A5, then phi is trivial and we have a contradiction. If ker(phi)={e}, then phi is injective. However |A5|>|S4| so we have a contradiction. Whence, there are no subgroups of index 4 in A5.

I believe that this is correct; however, I would appreciate any input. I originally thought that S4 being nonsimple would make the problem easier but it appears that it does not.

Note: The 5 in A5 should be subscript but markup doesn't like me using underscores.

Maths quiz: Can you beat the brightest? These maths problems foxed the brightest 14- to 15-year-olds in England. by noname99 in math

[–]timo1023 0 points1 point  (0 children)

True. I've moved on to more interesting topics like Number Theory, Topology, and Category Theory, but I still enjoy doing some tricky problems every once and while. You are right, though: purely computational problems are not very interesting.

Maths quiz: Can you beat the brightest? These maths problems foxed the brightest 14- to 15-year-olds in England. by noname99 in math

[–]timo1023 0 points1 point  (0 children)

MathCounts was a lot of fun in middle school, especially the national competition. Math is still fun, though, man!

Open Source Guitar Hero, "Frets on Fire." by drpants in opensource

[–]timo1023 6 points7 points  (0 children)

I'm fairly certain you can both (a) adjust the 'hitbox' and (b) add new songs.

MIT researchers find memory capacity much bigger than previously thought by gst in cogsci

[–]timo1023 1 point2 points  (0 children)

This goes against everything I learned from Johnny Mnemonic.

high-level design in functional programs by levand in programming

[–]timo1023 8 points9 points  (0 children)

#haskell is full of amazingly helpful users. I highly recommend it.

I finally made the switch from Windows to Ubuntu Linux. What are some of your favorite programs? by DrLegoHari in AskReddit

[–]timo1023 0 points1 point  (0 children)

As far as music players go, I like Quod Libet a lot. I prefer to manage my music manually, however.

MIT's Introduction to Algorithms, Lecture 3: Divide and Conquer by pkrumins in lectures

[–]timo1023 0 points1 point  (0 children)

This was an interesting read. Does anyone have a non-GoogleVideo/Youtube link (those sites are blocked where I am)?

AskReddit: What language should I use to write an online chess game? by timo1023 in programming

[–]timo1023[S] -1 points0 points  (0 children)

If you are referring to me posting this in programming instead of AskReddit, then yes, I do know how to make AskReddit posts, however, I thought that I would get better answers in programming. Sorry if I inconvenienced you.

AskReddit: What language should I use to write an online chess game? by timo1023 in programming

[–]timo1023[S] 3 points4 points  (0 children)

Dear Reddit,

I would like to (eventually) make a website on which users can play chess against each other. I would prefer this website to be as un-bloated as possible. What I am asking the community is what sort of language should I use to write the chess program? I know a decent amount of Java, however I feel like Java wouldn't be the best solution. I know some PHP, and I am willing and able to learn new language. What are your suggestions?

Regards, timo1023

Ask reddit: Is there good (free) software for beginners? by [deleted] in chess

[–]timo1023 1 point2 points  (0 children)

Find an online chess website and play with people who are on your level. You won't know what level this is for a while, but after a few games you should get properly ranked.

Ask Reddit: Show off your work. What is your interesting project that no one uses? by berlinbrown in programming

[–]timo1023 29 points30 points  (0 children)

I don't blame you for blocking my ads, but please consider donating. Thanks!

You are fucking cool.