Re: Help, help help!!! (fwd)

[Dam Son <son@fermi.phys.washington.edu>]

On Fri, 14 Mar 1997, Nong Tuan Giang wrote:

> Moi vat lon hon 0 do Kelvin deu phat ra radiation o moi buoc song, tuy nhien
> lamda max lien quan den nhiet do cua vat theo cong thuc sau
> Lamda x T=3000
> lamda: buoc song cuc dai(micron), T nhiet do cua vat (K)
> Thi du: Mat troi nong 6000K, nen phat ra lamda max la 0.5 micron hay 500 nanomet
> sau 2000 gio neu den con sang thi con phat ra UV, neu den khong hoat dong
> thi khong co UV nua, 2000 day la tuoi tho lam viec cua den (cua giay toc den)

Xin chu' thi'ch cho ddie^`u anh Giang vie^'t, vi` nhu+ anh Giang vie^'t
de^~ ga^y hie^?u nha^`m.  lambda max kho^ng pha?i bu+o+'c so'ng cu+.c
dda.i ma` va^.t no'ng co' the^? pha't ra ddu+o+.c, ma` bu+o+'c so'ng o+? 
ddo' bu+'c xa. la` cao nha^'t. Va^.t no'ng pha't ra a'nh sa'ng ta^'t ca?
ca'c bu+o+'c so'ng (pho^? lie^n tu.c), nhu+ng nhu+~ng bu+o+'c so'ng na`o
lo+'n ho+n nhie^`u hoa(.c nho? ho+n nhie^`u lambda max thi` ddu+o+.c 
pha't ra i't ho+n so vo+'i bu+o+'c so'ng loanh quanh lambda max.

Nhu+ va^.y ma(.t tro+`i pha't ra ca? tia tu+? ngoa.i, co' bu+o+'c so'ng
nho? ho+n nhie^`u 500 nm. Co' the^? dda'nh gia' bao nhie^u % na(ng
lu+o+.ng ma(.t tro+`i pha't ra la` thuo^.c UV, nhu+ng kho^ng co' tho+`i
gian, xin kha^'t ca'c ba'c (hoa(.c nho+` ba'c physicist na`o ti'nh ho^.,
chi? ca^`n du`ng co^ng thu+'c cu?a Planck).  6000K la` nhie^.t ddo^. o+? 
be^` ma(.t ma(.t tro+`i, be^n trong no'ng ho+n nhie^`u nhu+ng bu+'c xa. 
tu+` trong kho^ng thoa't ra ddu+o+.c. 

So+n.