Half-hour mock class on the "ultraviolet catastrophe" and Planck's model of black-body radiation, delivered for an accepted students event at Union.

2. US Library of Congress,
LC-DIG-ggbain-35303
Anyone who is not
shocked by quantum
theory has not
understood it.
-- Niels Bohr

5. https://commons.wikimedia.org/wiki/File:Wiens_law.svg

6. http://commons.wikimedia.org/wiki/File:Max_Planck_1901.GIF

7. “Black-Body Radiation”
Absorbs all colors
Model: Box with hole
Tiny leak of light
from inside

8. Pipe Organ, Bath Abbey (UK)

9. 𝜆1 = 2𝐿
𝜆2 = 𝐿
𝜆3 =
2𝐿
3
𝜆4 =
𝐿
2
𝜆 𝑛 =
2𝐿
𝑛
Standing Waves

10. Wavelength (arb. units)
0.0 0.2 0.4 0.6 0.8 1.0
Numberofmodes
0
2
4
6
8
10

11. Wavelength (arb. units)
0.0 0.2 0.4 0.6 0.8 1.0
Numberofmodes
0
10
20
30
40
50
𝜆 𝑛 =
2𝐿
𝑛

12. https://commons.wikimedia.org/wiki/File:Black_body.svg
“Ultraviolet Catastrophe”
(Rayleigh and Jeans)

13. “Black-Body Radiation”
Absorbs all colors
Model: Box with hole
Tiny leak of light
from inside
𝜆 𝑛 =
2𝐿
𝑛

14. “Black-Body Radiation”
Absorbs all colors
Model: Box with hole
“Oscillators” in
walls produce light
Oscillators have
characteristic
energy 𝐸𝑓 = ℎ𝑓
ℎ = 6.626 × 10−34J-s  “Planck’s Constant”

15. “Black-Body Radiation”
Absorbs all colors
Model: Box with hole
Oscillators have
characteristic
energy 𝐸𝑓 = ℎ𝑓
 ONLY INTEGER MULTIPLES OF 𝑬 𝒇 ALLOWED
Quantum Hypothesis:

16. 6 quanta
3 quanta
2 quanta
1 quantum
0 quanta
http://commons.wikimedia.org/wiki/File:Max_Planck_1901.GIF
Energy:

17. https://xkcd.com/54/
http://hyperphysics.phy-astr.gsu.edu/hbase/bkg3k.html#c6

18. https://commons.wikimedia.org/wiki/File:Max_Planck_1933.jpg
Planck in 1933

19. http://commons.wikimedia.org/wiki/File:Einstein_patentoffice_full.jpg

20. 𝐵 𝜈, 𝑇 =
2ℎ𝜈3
𝑐2
1
𝑒−ℎ𝜈/𝑘 𝐵 𝑇 − 1