Periodic
Reference
Questions

101365
Gallery

o o
+ o + o + + + o
+ o + + + o + o
+ o + + + + + o o o + + + + + + o o
+ o + + + + + + + + + + + + + + o o
+ o + + + + + + + + + + + + + + + +
+ + + + + + + + + + + + + + +
La + + + + + + + + + + + + + +
Ac + + + + + + + + + + + + + +

December 2002
Sun Mon Tue Wed Thu Fri Sat
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31        
Nov   Jan
Last update:
9/30/03; 2:49:38 AM

p e r i o d i c
a table of the elements


 Tuesday, December 17, 2002


Aiming the spectroscope at a piece of sunlit paper revealed the spectral features known as Fraunhofer lines (the faint vertical dark lines in the spectrum) caused by absorbing elements in the atmosphere of the sun.

When they were discovered in 1814 by Joseph von Fraunhofer, the lines caused quite a stir because they marred the 'perfect' light of the sun. At the time, even many scientists believed in Aristotelian ideals and the light coming from the sun was supposed to be one of those ideals, but now it was covered with marks. Within the next 100 years, quantum theory, spurred by atomic spectroscopy, ravaged the clockwork universe constructed by Newton.

Observed Fraunhofer lines:
BO2687nm    dFe467
CH656    eFe438
aO2629    fH434
DNa589    GFe+Ca431
EFe527    gCa423
bMg517    hH410
cFe496    HCa397
FH486    KCa393

  10:55:51 AM   comments