## Search found 36 matches

Thu Jun 09, 2011 4:45 pm UTC
Forum: Science
Topic: An interesting question: Perfect Mirror Ball
Replies: 56
Views: 13033

### Re: An interesting question: Perfect Mirror Ball

Somewhat related question: Say you had a "mirror" that reflected hawking radiation. It is indestructible and lines an indestructible sphere around a black hole. What would happen? I have constantly wondered this since I learned about hawking radiation. Wouldn't you just end up with Hawkin...
Thu May 12, 2011 4:14 pm UTC
Forum: School
Topic: Which of these values are exact (have no uncertainty)?
Replies: 9
Views: 2592

### Re: Which of these values are exact (have no uncertainty)?

It seems to me that the correct answer should be "Number of liters in a gallon," because a gallon is precisely defined in terms of metric units. There is an exact, precise answer to that question, because in the US, "gallon" unambiguously refers to the US liquid gallon. The US li...
Tue May 10, 2011 3:59 pm UTC
Forum: Mathematics
Topic: Four Color Theorem
Replies: 15
Views: 6043

### Re: Four Color Theorem

well, yes, all this is clear to me now, but when I was 12, I thought I was pretty clever
Mon May 09, 2011 5:16 pm UTC
Forum: Mathematics
Topic: Four Color Theorem
Replies: 15
Views: 6043

### Re: Four Color Theorem

But what if I make a map that has five regions that each touch the other four? Surely that would require five colors. Where did I go wrong? Is there a proof that I can't construct such a map? Yes, such a map would require 5 colors. Go right ahead and draw one*. I will be impressed. * without pullin...
Mon May 09, 2011 4:48 pm UTC
Forum: Language/Linguistics
Topic: Every male/female word
Replies: 44
Views: 24849

### Re: Every male/female word

tempter/temptress
Tue Mar 29, 2011 7:19 pm UTC
Forum: Language/Linguistics
Topic: Here you go!
Replies: 1
Views: 890

### Here you go!

I was struck recently by the strange constructions we use in English to indicate the presentation of an object (or at least, that's how I classified it): "Here you are!" "Here you go!" Why do we use the verbs "to be" and "to go" in these limited cases? Are the...
Fri Mar 25, 2011 6:37 pm UTC
Forum: Language/Linguistics
Topic: Media that mixes two or more languages?
Replies: 40
Views: 12566

### Re: Media that mixes two or more languages?

Does A Clockwork Orange count?
Tue Mar 08, 2011 5:51 pm UTC
Forum: Logic Puzzles
Topic: Ordering of Vases [solution]
Replies: 25
Views: 4990

### Re: Ordering of Vases [solution]

How about a pattern of odd, odd, even, even? Eg: 1,3,2,4,5,7,6,8,9,11,10,12,13 etc. ad infinitum? Or, if your number sequence "ends badly", for example the last one is a 10 and thus you can't stick the 11 before it, just move the odd man out to the front, eg: 10,1,3,2,4,5,7,6,8,9. If you ...
Wed Feb 23, 2011 7:26 pm UTC
Forum: Computer Science
Topic: Rootkits
Replies: 5
Views: 1693

### Rootkits

I was reading this article today, and it brought up quite a few questions: http://arstechnica.com/tech-policy/news/2011/02/black-ops-how-hbgary-wrote-backdoors-and-rootkits-for-the-government.ars/ ⋅ could you reliably take a snapshot of the contents of RAM and use the snapshot for analysis...
Tue Feb 22, 2011 5:03 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0863: "Major in the Universe"
Replies: 108
Views: 25353

### Re: 0863: "Major in the Universe"

Did anyone else find the initial requirements for that major acceptable?

Or is it just me?
Sat Feb 12, 2011 1:13 am UTC
Forum: Logic Puzzles
Topic: Spelling Cards
Replies: 3
Views: 1586

### Re: Spelling Cards

(obviously this doesn't fit the problem description, but it's the normal way the trick is performed) there are exactly 52 letters in acetwothreefourfivesixseveneightninetenjackqueenking, with an offset (from 4) no greater than 0 and no less than -2. That means that if you order the cards AAA...
Sat Feb 05, 2011 12:08 am UTC
Forum: School
Topic: Hair (Long)
Replies: 28
Views: 5289

### Re: Hair (Long)

Or a turban... I doubt any school official is going to want the kind of attention that would come from punishing a student for wearing a turban.
Tue Jan 18, 2011 5:51 pm UTC
Forum: Computer Science
Replies: 13
Views: 3773

### Re: OF Loading Bars and Things...

"But, sir! I have to be playing Space Invaders or my update won't go through!"
Tue Jan 18, 2011 5:37 pm UTC
Forum: School
Topic: In what ways do schools fail kids?
Replies: 19
Views: 4156

### Re: In what ways do schools fail kids?

Gah! Look, this isn't the point of this thread. I genuinely want to know about ways in which schools are not equipped or not set up to deal properly with some aspect of students' educational experience. The discussion of my personal experiences with homework is inflammatory and completely misses the...
Mon Jan 17, 2011 8:41 pm UTC
Forum: School
Topic: In what ways do schools fail kids?
Replies: 19
Views: 4156

### Re: In what ways do schools fail kids?

Because the purpose of the grade is not only "how much does the student know the subject". The purpose of the grade is to provide incentives and feedback to the student. Its use by third parties is secondary. No, that's not the only purpose of the grade, but "how much does the studen...
Mon Jan 17, 2011 4:46 pm UTC
Forum: School
Topic: In what ways do schools fail kids?
Replies: 19
Views: 4156

### Re: In what ways do schools fail kids?

To clarify/reiterate: I have no problem with doing homework, or even having it be required. Where I think it constitutes a systemic failure is the way it is applied to subject grades. Having it affect your grades is just one among many ways to encourage people to do it. And it probably helps to mak...
Sat Jan 15, 2011 5:38 pm UTC
Forum: Logic Puzzles
Topic: An easy tournament puzzle
Replies: 10
Views: 2782

### Re: An easy tournament puzzle

Doesn't a quarterfinal round necessitate 8 teams, which would include the entire field?

Assuming elimination rounds are seeded the same as the first 3, and that you need two wins to avoid elimination, we end up with this:

Spoiler:
A LLL
B WWW
C WLL
D LWL
E LWW
F WLW
G LLW
H WWL
Fri Jan 14, 2011 11:25 pm UTC
Forum: School
Topic: In what ways do schools fail kids?
Replies: 19
Views: 4156

### Re: In what ways do schools fail kids?

Homework has lots of purposes. 1: It gives the teacher the ability to evaluate how the students are doing in a low-stakes and early manner. This is a huge benefit to the teacher -- without homework, the effort required for the teacher to know if the student is understanding the material is much lar...
Fri Jan 14, 2011 4:57 pm UTC
Forum: School
Topic: In what ways do schools fail kids?
Replies: 19
Views: 4156

Suppose you spent half an hour a night doing your homework. This boosted your grades by 10 to 20 percent. This caused your grades to raise enough that you got a scholarship at a better college, or got into a better college. The net effect was maybe a 10k$a year change in your income at this point ... Wed Jan 12, 2011 4:20 pm UTC Forum: Mathematics Topic: Truely massive numbers Replies: 7 Views: 1521 ### Re: Truely massive numbers I think he was annoyed by the fact that you can't nest the subscript and superscript BBCode tags. It's not broken, it just doesn't work in quite the way the OP was expecting it to. Tue Jan 11, 2011 8:26 pm UTC Forum: School Topic: In what ways do schools fail kids? Replies: 19 Views: 4156 ### Re: In what ways do schools fail kids? One issue with that is that it takes time to set up justifications. And sometimes the justifications are more remote than others. And meanwhile, there is a real mountain of knowledge you need to get through, and you are spending the time you have on justifications rather than getting through it. . ... Tue Jan 11, 2011 5:20 pm UTC Forum: School Topic: In what ways do schools fail kids? Replies: 19 Views: 4156 ### In what ways do schools fail kids? About 5 years ago, I overheard someone complaining, "when am I going to use this?" For some reason, even though I'd heard the same complaint many times before, this time the question got me thinking about the ways in which schools fail students, and how those failures could be rectified. S... Mon Jan 10, 2011 4:50 pm UTC Forum: Language/Linguistics Topic: "Since then, and up to date" Replies: 12 Views: 5301 ### Re: "Since then, and up to date" Yeah, it sounds funny to me, now, too. Scratch that. Tue Jan 04, 2011 5:32 pm UTC Forum: Language/Linguistics Topic: "Since then, and up to date" Replies: 12 Views: 5301 ### Re: "Since then, and up to date" The most natural way to construct that phrase for most English speakers at any point since 1970 would probably be something like: "The first X was discovered in 1970; as of [date], about twenty X have been discovered." or "The first X was discovered in 1970; through [date], about twen... Thu Dec 30, 2010 5:54 pm UTC Forum: Language/Linguistics Topic: Phonemic Inventory Replies: 2 Views: 2660 ### Re: Phonemic Inventory Some things to consider: How distinct do we want to be? Does English /u/ suffice for high back vowels, or do we need to teach the kid the Japanese /u/ which isn't exactly rounded? Do we want to gloss over really rare distinctions, like dental vs. alveolar stops, or do we want to totally maximize th... Thu Dec 30, 2010 4:32 am UTC Forum: Language/Linguistics Topic: Phonemic Inventory Replies: 2 Views: 2660 ### Phonemic Inventory If I wanted to expose a child to as large a phonemic inventory as possible, what would be the most efficient combination of languages to expose them to? Obviously I would want to make sure that as many sounds as possible are represented, but I also want to make sure that phones are distinct from eac... Wed Dec 29, 2010 2:17 am UTC Forum: Science Topic: am I just a few cells or a whole brain? Replies: 63 Views: 6020 ### Re: am I just a few cells or a whole brain? Speaking strictly from memory, I believe that the patient in question had severe damage to an entire hemisphere of his brain, and then had the entire damaged hemisphere removed (or possibly separated) surgically afterwards (probably to control seizures brought on by the damage). I could be mistaken,... Mon Dec 27, 2010 7:21 pm UTC Forum: Logic Puzzles Topic: Black to play and kill Replies: 6 Views: 2119 ### Re: Black to play and kill I'm fairly new to Go, but this is my hunch: Spoiler: E2? My initial hunch was F4, but E2 effectively eliminates the chances for white to get two eyes in there. But then again, I'm new to this. Wed Dec 22, 2010 4:59 pm UTC Forum: Logic Puzzles Topic: My write-up of the "Blue Eyes" solution (SPOILER A Replies: 1368 Views: 424607 ### Re: My write-up of the "Blue Eyes" solution (SPOILER A Diagnosis: "Misunderstanding of 'Common Knowledge' " Subject remains indignant, and keeps muttering "But it's still a stupid answer" under his breath. Thanks, guys. Tue Dec 21, 2010 8:46 pm UTC Forum: Logic Puzzles Topic: My write-up of the "Blue Eyes" solution (SPOILER A Replies: 1368 Views: 424607 ### Re: My write-up of the "Blue Eyes" solution (SPOILER A This is that thread, and it is correct. The standard inference from n=3 to n=4 is invalid, because in the n=4 case, the existence of blue-eyed individuals is already common knowledge. At what point do you think my argument fails? EDIT: I wasn't trying to be curt... but I've read my way through the t... Tue Dec 21, 2010 7:31 pm UTC Forum: Logic Puzzles Topic: My write-up of the "Blue Eyes" solution (SPOILER A Replies: 1368 Views: 424607 ### Re: My write-up of the "Blue Eyes" solution (SPOILER A Perhaps they know, but can they say with certainty that the people around them also know? Or that the person to their left can also say with certainty that everyone else knows? This is where common knowledge comes in to play - "What we know" is not the same as "What we know that we a... Tue Dec 21, 2010 6:42 pm UTC Forum: Logic Puzzles Topic: My write-up of the "Blue Eyes" solution (SPOILER A Replies: 1368 Views: 424607 ### Re: My write-up of the "Blue Eyes" solution (SPOILER A I've been familiar with this puzzle for quite some time, but it occurred to me recently that the important piece of information is the implicit enumeration of the different eye-colors that are actually in occurrence on the island. In other words, the induction fails, and nobody dies. Here is why: In... Tue Dec 21, 2010 6:05 pm UTC Forum: Logic Puzzles Topic: An interesting encryption scheme Replies: 1 Views: 1165 ### Re: An interesting encryption scheme Here's another encoding of the same sentence, with a different encryption scheme: a-!@#$%^&*(),./?;':"A1a F0#$0#1W0:;Ifs9Vf2@5"T((ZE_fs9MRUR62!!N%(;"_Wu$JX#_:Sr!St Hints: Regarding the "encryption scheme" string: "A", "1", and ...
Sat Dec 18, 2010 12:09 am UTC
Forum: Logic Puzzles
Topic: An interesting encryption scheme
Replies: 1
Views: 1165

### An interesting encryption scheme

The following string represents an English sentence: xScdScTOSqoA7,1N7UbXrLiiRw_7,1EJMJYUaaFeior_O/dBPc_qK)aK. (I've replaced spaces with underscores for clarity) The encryption scheme can be represented like this: a-aA1!@#\$%^&*(),./?;':" It is not a cipher. That much informatio...
Wed Dec 15, 2010 10:22 pm UTC
Forum: Logic Puzzles
Topic: A coin as likely to land on it's edge.
Replies: 9
Views: 3613

### Re: A coin as likely to land on it's edge.

Alright, since no one else seems to want to, I'm going to finish what I've started: If we assume the coin is unfair, the equations defining the profile of the energy well are: \frac{E}{gm}=\sqrt{h_R^2+h_T^2}\cdot\sin\left(\theta+\arctan\left(\frac{h_T}{h_R}\right)\right) and \frac{E}...
Fri Dec 10, 2010 8:35 pm UTC
Forum: Logic Puzzles
Topic: A coin as likely to land on it's edge.
Replies: 9
Views: 3613

### Re: A coin as likely to land on it's edge.

I find the explanations given on that site rather unsatisfactory. The probability of the coin (or any object) ending up in some configuration depends on a number of things: ⋅ The potential energy of the object in each configuration ⋅ The minimum potential energy achieved transiti...

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