LESSWRONG
LW

Personal Blog

3

Snape's knowledge of valence shells

by Bound_up
13th Apr 2015
1 min read
13

3

Personal Blog

3

Snape's knowledge of valence shells
21TrE
2Bound_up
1Algon
0Bound_up
0Algon
0Algon
0Normal_Anomaly
0Gunnar_Zarncke
0[anonymous]
12Jan_Rzymkowski
17Luke_A_Somers
7falenas108
0gattsuru
New Comment
13 comments, sorted by
top scoring
Click to highlight new comments since: Today at 11:57 PM
[-]TrE10y210

You might want to post this on the hpmor subredit page instead - or in the latest open thread. I don't, however, think that a top-level discussion post is necessary for this.

In any case, Snape saying that the number of valence electrons of carbon is a meaningless fact is weak evidence that he didn't read it in Harry's mind.

Reply
[-]Bound_up10y20

Thank you. So, I posted this as a top-level discussion post? What I did is more the kind of thing I should reserve for more substantial posts?

I understand the hpmor subredit, but what do you mean by the latest open thread? Just comment on a recent post in LessWrong discussion? Or forego so doing in favor of finding one specifically about HPMOR?

Thanks again

Reply
[-]Algon10y10

Open threads are ones wherein they say something like 'ask any question'.

Reply
[-]Bound_up10y00

Gotcha.

So I should have checked for one of those (are they very common?) or created my own.

Reply
[-]Algon10y00

I just checked, there's one open for this week.

Reply
[-]Algon10y00

I believe there is an 'ask stupid questions' thread for each month, and some other open threads. I'm not sure if you can make open threads yourself, but they're fairly common.

Reply
[-]Normal_Anomaly10y00

I think there's an open thread once or twice a month. Also, IMO this post would go better in an open thread than a stupid questions thread; the stupid questions thread is for sharing advice.

Reply
[-]Gunnar_Zarncke10y00

Actually the convention is to have a weekly Open Thread. It is usually created by the first person wanting to post an open question when the old thread has expired. That can be you, but please make it run exactly 7 days otherwise you will called to order.

Reply
[-][anonymous]10y00

Seems like it would be weak evidence in the other direction... if he thinks it's a useless fact, why does he have it memorized?

Reply
[-]Jan_Rzymkowski10y120

Overscrupulous chemistry major here. Both Harry and Snape are wrong. By the Pauli exclusion principle an orbital can only host two electrons. But at the same time, there is no outermost orbital - valence shells are only oversimplified description of atom. Actually, so oversimplified that no one should bother writing it down. Speaking of HOMOs of carbon atom (highest [in energy] occupied molecular orbitals), each has only one electron.

Reply
[-]Luke_A_Somers10y170

The notion that (neutral) Carbon has 4 electrons to share and prefers to have 4 electrons shared with it is so oversimplified that no one should bother writing it down?

That is, umm, a surprising viewpoint to me.

Reply
[-]falenas10810y70

It's at least plausible that Snape, as a potions expert who grew up with muggles, thought there might be some connection between potions and chemistry and learned the basics of chemistry.

Reply
[-]gattsuru10y00

It's possible that he read it from Harry's mind. Snape is a powerful legilimens, does not believe that anything is cheating when he has to win, Harry had no protection or even deep knowledge of the technique, had to have been thinking of the answer, and hadn't thought to avert his gaze until later.

That said, Severus is more in tune with the Muggle world than most others in the setting, and in Chapter 61 we see Dumbledore treat him as an expert source on muggle technology :

"Severus?" the old wizard said. "What was it actually?" "A rocket," said the half-blood Potions Master, who had grown up in the Muggle town of Spinner's End. "One of the most impressive Muggle technologies."

Later in Chapter 18, we also see the phrase "Common sense is often mistaken for legilimency." Especially as a potions master and someone who retained an interest in muggle chemistry into adulthood, Snape does have more reason than most wizards to know this information. Harry also tends to overestimate both his knowledge, and both he and Quirrel tend to assume the victories of others come from innate differences rather than simple changes in planning or knowledge.

On the other hand, had Snape known that information, it would also mean he could have ended the world accidentally. Dunno what to make of that.

Reply
Moderation Log
Curated and popular this week
13Comments

Just a quick question.

Harry James Potter Evans-Verres and the Methods of Rationality: Chapter 18

HJPEV: So, Professor, can you tell me how many electrons are in the outermost orbital of a carbon atom?"

 

Severus's smile widened. "Four," he said. "It is a useless fact which no one should bother writing down, however."

 

Did Snape really know that, or did he read Harry's mind?

 

As to the possibility, this passage,  "Harry stared into Severus's cold gaze and remembered that the Sorting Hat had warned him not to meet anyone's eyes while thinking about - Harry dropped his gaze to Severus's desk." occurs after that already quoted.

 

(If I do something wrong here, which merits a downvote, would you mind specifying the error in question?)