SI
SI
discoversearch

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor.  We ask that you disable ad blocking while on Silicon Investor in the best interests of our community.  If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.
Technology Stocks : Advanced Micro Devices - Moderated (AMD)
AMD 221.02+6.4%Jan 13 3:59 PM EST

 Public ReplyPrvt ReplyMark as Last ReadFilePrevious 10Next 10PreviousNext  
To: Neil Booth who wrote (32649)3/22/2001 5:52:51 AM
From: fyodor_Read Replies (1) of 275872
 
Neil: Do you have an example from physics of delta meaning the difference between two different things? I don't think so.

Sure I do!!!

RANDOM BOOK from my bookshelf: Introduction to the structure of Matter, John J. Brehm & William J. Mullin.

RANDOM PAGE (I'll admit a bit of luck on this bit): (144)

(I'm going to write an uppercase delta as DELTA in the following)

DELTA N / N0 = INTEGRAL (n/A0 * dsigma / dSIGMA) dSIGMA = ...

blah blah blah

We then find

DN = 4*pi* .... = 0.179 alpha particles per second

(this particular calculation was on simple Rutherford scattering)


NEXT RANDOM BOOK: Physics of Atoms and Molecules, B.H. Bransden and C.J. Joachain
RANDOM PAGE (yes, it really was... I'll admit to a lot of luck again): (458)

The chapter is on molecular spectra, specifically doublets (specifically the inversion spectrum of ammonia).

PSI(z,t) = c1 * phi1(z) * exp(-(i/hbar)E1*t) + c2 * phi2(z) * exp(-(i/hbar)E2*t)

where

E2 = E1 + DELTA E

(DELTA E being the energy splitting of the doublet)


Would you care to see any more examples?

Or do you think I'm making all this crap up? If so, I'd be happy to scan the pages and upload them e.g. at a geocities page.


P.S. Ok, I found a good online example: Theoretical Neuroscience by Peter Dayan and LF Abbott.

Look at, e.g., chapter 1 page 21:

play.ccs.brandeis.edu

Middle of page.

---

1/M SIGMA ( S(m)S(m+p)) = sigma(s) * sigma(s) / DELTA t if p=0, otherwise 0.

The factor of 1/DELTA t on the right side of this equation reproduces the delta function of equation 1.24 in the limit of DELTA t --> 0. blah blah blah

---

More examples? No? Are you sure? Ok, then. I'll keep f'n using DELTA as meaning difference. ;p

-fyo
Report TOU ViolationShare This Post
 Public ReplyPrvt ReplyMark as Last ReadFilePrevious 10Next 10PreviousNext