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Ah, ok, it's back.
Carry on, taty-girl-zor-cantremember.
Carry on, taty-girl-zor-cantremember.
Hey Stefka...I made you and Samote a pikshure
- Thread starter jack sparrow
- Start date
b0und said:
See the chapter titled "Found Out in Paris" in his book "Surely You're Joking, Mr. Feynman!", available online here: http://www.gorgorat.com/
nimbus
New member
samoth said:See the chapter titled "Found Out in Paris" in his book "Surely You're Joking, Mr. Feynman!", available online here: http://www.gorgorat.com/
my high school algebra teacher got me that book as a present
nimbus said:my high school algebra teacher got me that book as a present
The most recent hardcover edition with that and "What do YOU care...?" has an audio CD from his old Cal-Tech lectures (same as the book). I bought it just for the CD, lol.
They recently re-released his PhD thesis on the least action principle in quantum mechanics, too!
nimbus
New member
samoth said:The most recent hardcover edition with that and "What do YOU care...?" has an audio CD from his old Cal-Tech lectures (same as the book). I bought it just for the CD, lol.
They recently re-released his PhD thesis on the least action principle in quantum mechanics, too!
lol i can't remember anything at all from that book except for the chapters on picking locks and getting 'tang
nimbus said:
Ok, now we're talking.
Let's stay on topic, shall we?
nimbus said:
It was the first place I heard the squares-of-numbers-near-50 trick.
When I was at Los Alamos I found out that Hans Bethe was absolutely
topnotch at calculating. For example, one time we were putting some numbers
into a formula, and got to 48 squared. I reach for the Marchant calculator,
and he says, "That's 2300." I begin to push the buttons, and he says, "If
you want it exactly, it's 2304."
The machine says 2304. "Gee! That's pretty remarkable!" I say.
"Don't you know how to square numbers near 50?" he says. "You square 50
-- that's 2500 -- and subtract 100 times the difference of your number from
50 (in this case it's 2), so you have 2300. If you want the correction,
square the difference and add it on. That makes 2304."
A few minutes later we need to take the cube root of 2 1/2. Now to take
cube roots on the Marchant you had to use a table for the first
approximation. I open the drawer to get the table -- it takes a little
longer this time -- and he says, "It's about 1.35."
I try it out on the Marchant and it's right. "How did you do that one?"
I ask. "Do you have a secret for taking cube roots of numbers?"
"Oh," he says, "the log of 2 1/2 is so-and-so. Now one-third of that
log is between the logs of 1.3, which is this, and 1.4, which is that, so I
interpolated."
So I found out something: first, he knows the log tables; second, the
amount of arithmetic he did to make the interpolation alone would have taken
me longer to do than reach for the table and punch the buttons on the
calculator. I was very impressed.
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