Skip The Water • Hacker News Board

Re: Skip The Water

#21

Post by AaronM » Thu, Jan 13, 2011, 5:42 PM UTC

patio11 wrote: post #5

In a similar vein: There was a Japanese TV program a few years ago testing talented youngsters. One brain teaser was "On this table you have six match sticks of equal length. Arrange them such that you create four triangles." The match sticks are presented lying flat on a table, and approximately everyone tries to solve the problem in 2D and fails hideously. The right answer, which is a peculiar kind of perverse clev…

the way I read the instructions is that you have to create exactly 4 triangles.

Re: Skip The Water

#22

Post by brlewis » Thu, Jan 13, 2011, 6:01 PM UTC

I think this advice will be counterproductive for most web entrepreneurs, as I detail here:

http://ourdoings.com/ourdoings-startup/2011-01-13

Summary: In the 2.70 contest, everyone was watching and agreed what the goal was. On the web, the people you want to reach might not be watching, and might rely on authorities who have a different idea of what the goal is. Thinking outside the box may make it harder for people to see that you've solved their problem better.

Re: Skip The Water

#23

Post by knieveltech » Thu, Jan 13, 2011, 6:35 PM UTC

noahlt wrote: post #20

A tangentially related story: Talented secondary school kids all across America end up doing egg drop competitions all the time. But the rules of each competition are each slightly different. A friend of mine was in a competition which was scored like this: Score = (intactness of egg, as 1 or 0)/(distance to target)/(mass of egg-protecting device) While everybody else designed careful egg encasements, but my friend p…

Awesome, but was he awarded the prize?

I was in a similarly poorly specified contest in the 6th grade. The goal was to take a single large sheet of construction paper and build a paper airplane. The only metric was distance covered and weighting your plane was allowed.

Day of the competition everyone else in class has their planes out, while I'm standing around with a sheet of paper. When it was my turn I promptly balled up the paper as tight as I could around a handfull of 1" steel washers and proceeded to throw the thing across the gym, out the doors and into the hallway outside, roughly 2x the distance covered by the closest competitor.

I was promptly disqualified for unspecified reasons.

Re: Skip The Water

#24

Post by Dove » Thu, Jan 13, 2011, 7:21 PM UTC

noahlt wrote: post #20

A tangentially related story: Talented secondary school kids all across America end up doing egg drop competitions all the time. But the rules of each competition are each slightly different. A friend of mine was in a competition which was scored like this: Score = (intactness of egg, as 1 or 0)/(distance to target)/(mass of egg-protecting device) While everybody else designed careful egg encasements, but my friend p…

I was in a similar egg drop contest in which devices were scored by weight.

The winning entry was helium balloons attached to a basket. It had a decidedly negative weight.

Re: Skip The Water

#25

Post by jwn » Thu, Jan 13, 2011, 7:27 PM UTC

Dove wrote: post #24

noahlt wrote: post #20

A tangentially related story: Talented secondary school kids all across America end up doing egg drop competitions all the time. But the rules of each competition are each slightly different. A friend of mine was in a competition which was scored like this: Score = (intactness of egg, as 1 or 0)/(distance to target)/(mass of egg-protecting device) While everybody else designed careful egg encasements, but my friend p…

I was in a similar egg drop contest in which devices were scored by weight. The winning entry was helium balloons attached to a basket. It had a decidedly negative weight.

Very poorly designed indeed. They should have been checking for mass!

Re: Skip The Water

#26

Post by Timothee » Thu, Jan 13, 2011, 7:57 PM UTC

knieveltech wrote: post #23

noahlt wrote: post #20

A tangentially related story: Talented secondary school kids all across America end up doing egg drop competitions all the time. But the rules of each competition are each slightly different. A friend of mine was in a competition which was scored like this: Score = (intactness of egg, as 1 or 0)/(distance to target)/(mass of egg-protecting device) While everybody else designed careful egg encasements, but my friend p…

Awesome, but was he awarded the prize? I was in a similarly poorly specified contest in the 6th grade. The goal was to take a single large sheet of construction paper and build a paper airplane. The only metric was distance covered and weighting your plane was allowed. Day of the competition everyone else in class has their planes out, while I'm standing around with a sheet of paper. When it was my turn I promptly ba…

I was promptly disqualified for unspecified reasons.

In my experience, most teachers really don't like smart-asses. Devil's advocate will say that the accelerations you submitted your imaginary passengers were way too strong.

My story in that vein was in PE: we were to run 20 minutes at the most constant pace to practice our endurance. The grade was taking into account the regularity of your pace (13 points out of 20 if you hit the exact same time for all but the fastest and slowest laps) as well as your average speed (the remaining 7 points).

Not being the most athletic guys, a friend and I went on our way to run 4 laps of exactly 5 minutes to insure a decent 13 out of 20, where a lap should have been in the 30-45s range. Obviously, our little stunt was not really appreciated. :)

Re: Skip The Water

#27

Post by nooneelse » Thu, Jan 13, 2011, 8:01 PM UTC

zck wrote: post #16

shard wrote: post #12

Earlier quoted context omitted.

Do you mean a box with an x through it? I guess the rules never said the ends of the matchsticks had to match up either. I'm definitely enjoying all these different answers which explore (exploit?) the imprecisely specified problem.

That's still more than four triangles -- two right triangles next to each other that way make a larger triangle. One way to make only four triangles is: \ / \ / -------\----/------ \1 / \/ /\ \ / \ / \ / 2 \ / ---\---/------\----/- \3/ \4 / \ \/ / \ /\ / \ / \

Ok, so make a box with an incomplete x in the middle, a "y", by only sticking that one match partway into the square.

    \ 
     \----
     |\  /|
     | \/ |
     | /  |
     |/   |
      ----

Re: Skip The Water

#28

Post by CountHackulus » Thu, Jan 13, 2011, 9:01 PM UTC

dmlorenzetti wrote: post #9

In a similar class, we were given the problem of designing a large yo-yo. The judgement criterion was the diameter multiplied by the return ratio (how far back up it rebounded). There was no hard-and-fast definition of a yo-yo. Experimenting with various designs, my buddy and I saw that the biggest challenge was preventing precession, which caused the string to rub against the disks, wasting energy and killing the re…

That's a very interesting solution to the problem. Though as an avid yoyoer, I have to make the point that modern yoyos have solved this problem in an entirely different manner as seen here, in one of the more extreme examples: http://spyy.ca/index.php/pro

Re: Skip The Water

#29

Post by dagobart » Thu, Jan 13, 2011, 9:54 PM UTC

knieveltech wrote: post #23

noahlt wrote: post #20

A tangentially related story: Talented secondary school kids all across America end up doing egg drop competitions all the time. But the rules of each competition are each slightly different. A friend of mine was in a competition which was scored like this: Score = (intactness of egg, as 1 or 0)/(distance to target)/(mass of egg-protecting device) While everybody else designed careful egg encasements, but my friend p…

Awesome, but was he awarded the prize? I was in a similarly poorly specified contest in the 6th grade. The goal was to take a single large sheet of construction paper and build a paper airplane. The only metric was distance covered and weighting your plane was allowed. Day of the competition everyone else in class has their planes out, while I'm standing around with a sheet of paper. When it was my turn I promptly ba…

I guess contests like these intend to foster out of the box thinking. But once that very out of the box thinking surfaces every competitor cries foul, including (some) teachers. So, do they perform such competitions because they have to? Or do they just fail to see what they engage them to?

Re: Skip The Water

#30

Post by beagle3 » Thu, Jan 13, 2011, 11:34 PM UTC

noahlt wrote: post #20

A tangentially related story: Talented secondary school kids all across America end up doing egg drop competitions all the time. But the rules of each competition are each slightly different. A friend of mine was in a competition which was scored like this: Score = (intactness of egg, as 1 or 0)/(distance to target)/(mass of egg-protecting device) While everybody else designed careful egg encasements, but my friend p…

My university had this competition with a different twist: - The egg was dropped from a 10-story building - The winner is whoever gets the egg safely to the concrete below in the minimal time. Nothing else matters. (But the judges must be able to see that the egg does indeed touch the concrete).

Most contestants tried to get the egg to drop slowly, e.g. using helium or parachutes.

The winner used a rocket to speed the egg down, and placed the egg within a honey jar. The jar hit the floor and cracked in ~1.5 seconds, the honey absorbed all the shock, and it took 2 more seconds for the egg to roll out of the honey and touch the concrete.