Math and science jokes -- GO!

[evolved yet?]

This amused me.

I don't get it.

 

[Gunfingers]

I don't get it.

The square root of eight is an irrational number and a pain in the *** to calculate so this equation proposes getting the square root of eight by pretending it's nine. Since the square root of nine is three the equation claims that the square root of eight is three.

I'm oversimplifying, and honestly if you've never taken calculus you won't get it enough for it to be funny.

 

[evolved yet?]

Thanks.

 

[DarkSun]

I don't get it.

Eight is a numerical value, not a variable. You can't apply limit theory to it. Eight will never approach nine, because it's a set number, whereas a variable could approach nine, because its value is not preordained. You can only find the limit of f(x) as x approaches a certain value, given that a variable x exists to begin with. If there is only a set number, then there is no limit, the number is set. There are infinite degrees of freedom with a single variable, with a number there are zero, so you can't say find the limit of 8 as it approaches 9, since it will never approach 9.

Maybe that over-complicates it.

 

[9-10ths_Penguin]

Eight is a numerical value, not a variable. You can't apply limit theory to it. Eight will never approach nine, because it's a set number, whereas a variable could approach nine, because its value is not preordained. You can only find the limit of f(x) as x approaches a certain value, given that a variable x exists to begin with. If there is only a set number, then there is no limit, the number is set. There are infinite degrees of freedom with a single variable, with a number there are zero, so you can't say find the limit of 8 as it approaches 9, since it will never approach 9.

Maybe that over-complicates it.

It reminds me of that joke about engineers: an engineer is someone who will assume that a horse is a sphere to make the math easier.

 

[Gunfingers]

 

[DarkSun]

I read this the other day and laughed. Btw, I didn't come up with it, the source is down the bottom. But whoever did this is a freaking genius. XD

Urinal protocol vulnerability

When a guy goes into the bathroom, which urinal does he pick? Most guys are familiar with the International Choice of Urinal Protocol. It’s discussed at length elsewhere, but the basic premise is that the first guy picks an end urinal, and every subsequent guy chooses the urinal which puts him furthest from anyone else peeing. At least one buffer urinal is required between any two guys or Awkwardness ensues.
Let’s take a look at the efficiency of this protocol at slotting everyone into acceptable urinals. For some numbers of urinals, this protocol leads to efficient placement. If there are five urinals, they fill up like this:

The first two guys take the end and the third guy takes the middle one. At this point, the urinals are jammed — no further guys can pee without Awkwardness. But it’s pretty efficient; over 50% of the urinals are used.
On the other hand, if there are seven urinals, they don’t fill up so efficiently:

There should be room for four guys to pee without Awkwardness, but because the third guy followed the protocol and chose the middle urinal, there are no options left for the fourth guy (he presumably pees in a stall or the sink).
For eight urinals, the protocol works better:

So a row of eight urinals has a better packing efficiency than a row of seven, and a row of five is better than either.
This leads us to a question: what is the general formula for the number of guys who will fill in N urinals if they all come in one at a time and follow the urinal protocol? One could write a simple recursive program to solve it, placing one guy at a time, but there’s also a closed-form expression. If f(n) is the number of guys who can use n urinals, f(n) for n>2 is given by:

The protocol is vulnerable to producing inefficient results for some urinal counts. Some numbers of urinals encourage efficient packing, and others encourage sparse packing. If you graph the packing efficiency (f(n)/n), you get this:

This means that some large numbers of urinals will pack efficiently (50%) and some inefficiently (33%). The ‘best’ number of urinals, corresponding to the peaks of the graph, are of the form:

The worst, on the other hand, are given by:

So, if you want people to pack efficiently into your urinals, there should be 3, 5, 9, 17, or 33 of them, and if you want to take advantage of the protocol to maximize awkwardness, there should be 4, 7, 13, or 25 of them.
These calculations suggest a few other hacks. Guys: if you enter a bathroom with an awkward number of vacant urinals in a row, rather than taking one of the end ones, you can take one a third of the way down the line. This will break the awkward row into two optimal rows, turning a worst-case scenario into a best-case one. On the other hand, say you want to create awkwardness. If the bathroom has an unawkward number of urinals, you can pick one a third of the way in, transforming an optimal row into two awkward rows.
And, of course, if you want to make things really awkward, I suggest printing out this article and trying to explain it to the guy peeing next to you.
Discussion question: This is obviously a male-specific issue. Can you think of any female-specific experiences that could benefit from some mathematical analysis, experiences which — being a dude — I might be unfamiliar with? Alignments of periods with sequences of holidays? The patterns to those playground clapping rhymes? Whatever it is that goes on at slumber parties? Post your suggestions in the comments!
Edit: The protocol may not be international, but I’m calling it that anyway for acronym reasons.

(Source: Urinal protocol vulnerability « xkcd)

 

[Engyo]

Discussion question: This is obviously a male-specific issue. Can you think of any female-specific experiences that could benefit from some mathematical analysis, experiences which — being a dude — I might be unfamiliar with? Alignments of periods with sequences of holidays? The patterns to those playground clapping rhymes? Whatever it is that goes on at slumber parties? Post your suggestions in the comments!
Edit: The protocol may not be international, but I’m calling it that anyway for acronym reasons.

(Source: Urinal protocol vulnerability « xkcd)

Absolute genius, I agree - but one particular has been left un-dealt-with: Urinal height.

I want to see the math that explains that, when faced with a selection of urinals some of which are mounted lower (a "shorter" model) and some higher on the wall (a "taller" model), shorter men will inevitably choose a taller model urinal if one is available. I know this is true because as a tall person I often get stuck with a short model while someone who is 6"-8" shorter than I am is using a tall model next to me.

 

[9-10ths_Penguin]

Absolute genius, I agree - but one particular has been left un-dealt-with: Urinal height.

He's left more than that undealt-with, but rather than take this thread off-topic, I've given my objections here.

 

[9-10ths_Penguin]

I just found another joke that I find really funny for some reason:

A farmer is having problems with his chickens. They are all suddenly getting very sick and he doesn't know what is wrong with them. After trying all conventional means, he calls a biologist, a chemist, and a physicist to see if they can figure out what is wrong. The biologist looks at the chickens, examines them a bit, and says he has no clue what could be wrong with them. Then the chemist takes some tests and makes some measurements, but he can't come to any conclusions either. So the physicist tries. He stands there and looks at the chickens for a long time without touching them or anything. All of the sudden, he starts scribbling away in a notebook. After several gruesome calculations, he exclaims, "I've got it! But it only works for spherical chickens in a vacuum."

 

[Engyo]

Well, that's better than my Aggie chicken farmer joke.............

{snip}

"Send soil samples."

 

[painted wolf]

wa:do

 

[painted wolf]

OH.. one more... for now...muahahahah...

wa:do

 

[9-10ths_Penguin]

Since we're going that way, here's another: