Big Questions in Science series, (4 of 9). Class taught at AUC (University of Amsterdam) during the 2012-2013 fall semester.

1. and
relativity
Big Questions in Science, spring 2012. SdH, AUC 1

2. http://www.platypusart.com/
 Clockwork universe
 Ptolemy geocentrism
 Copernicus: heliocentrism
 Gelileo: moons of Venus, Jupiter's satellites,
Saturn's rings, sunspots
 Kepler's laws
 Newton unifies heavens and earth: law of
gravity
 Scientific revolutions
Big Questions in Science, fall 2012. SdH, AUC 2

3. Big Questions in Science, spring 2012. SdH, AUC 3

4.  1880-1900: optimism. Telegraph, telephone, radio,
automobile, airplane, economic growth.
 Later on: new cultural movements (van Gogh,
Cézanne, de Toulouse Lautrec).
 “There is nothing new to be discovered in physics
now. All that remains is more and more precise
measurement” (attributed to Lord Kelvin).
 Somewhat of a myth.
 Modern physics developed in a context of crisis and
decadence.
Big Questions in Science, spring 2012. SdH, AUC 4

5.  Questions on the internal structure of matter.
 Questioning properties of aether.
 Matter vs. radiation.
 Clash of world views:
materialism vs. energeticism,
mechanicism vs. electromagnetic
world view.
Big Questions in Science, spring 2012. SdH, AUC 5

6. http://en.wikipedia.org/wiki/File:Jean_Metzinger,_Le_go%C3%BBter,_Tea_Time,_1911,_75.9_x_70.2_cm,_Philadelphia_Museum_of_Art.jpg
Big Questions in Science, spring 2012. SdH, AUC 6
http://www.theartworlddaily.com/2013/01/08/usps-turns-to-modern-art-for-its-2013-stamps-2/

7. Big Questions in Science, spring 2012. SdH, AUC 7
http://www.arthistoryarchive.com/arthistory/cubism/

8. http://mathworld.wolfram.com/PoincareHyperbolicDisk.html
http://nl.wikipedia.org/wiki/Flatland
http://en.wikipedia.org/wiki/Henri_Poincar%C3%A9
Big Questions in Science, spring 2012. SdH, AUC 8

9. A visitor from the fourth dimension
Big Questions in Science, spring 2012. SdH, AUC 9

10. Hannah Höch, Berliner Illustrierte Zeitung 1919
Naum Gabo, Kinetic
Construction 1919-20
Big Questions in Science, spring 2012. SdH, AUC 10
Erich Mendelsohn, Einstein Tower 1920-21.

11.  Ideas about higher (spatial) dimensions were very
much part of culture in the end 19th, beginning 20th
centuries (Flatland).
 Poincaré suggested to represent higher-dimensional
objects combining multiple perspectives.
 Picasso and Georges Braque responded to physics
redefining matter and space: X-rays, radioactivity,
electron, waves; not relativity.
 Picasso’s Vollard: space as suffused with ether, matter
as transparent and continually dematerializing into
ether on model of radioactivity.
Big Questions in Science, spring 2012. SdH, AUC 11

12.  After Einstein’s publication of general
relativity in 1916, artists engaged with motion
and dynamical space-times:
 Gabo’s Kinetic Construction: sculpture in which
space and time are active components.
 Mendelsohn’s Einstein Tower: awareness of
energies in mass, dynamic condition. Contractions
of form. Science, technology organic as
distortions of muscles human body (L. Dalrymple).
Big Questions in Science, spring 2012. SdH, AUC 12

13. The Persisentece of Memory,
1931.
Dalí engaged with time slowing
down. He humorously compares
paranoic “psychic dilation of
ideas” to Einstein’s “physical
dilation of measures”.
“The soft, extravagant, and
solitary paranoic-critical
Camembert of time and space.”
http://arthistory.about.com/od/from_exhibitions/ig/dali_painting_and_film/dali_moma_0708_11.htm
Big Questions in Science, spring 2012. SdH, AUC 13

14. … and this is what The Simpsons made of it…
http://www.gearfuse.com/simpson-meets-dali-the-simpsons-and-the-persistance-of-memory/
Big Questions in Science, spring 2012. SdH, AUC 14

15. • Psychological
• Cosmological
(increase in entropy)
• Operational: what a
clock measures
Big Questions in Science, spring 2012. SdH, AUC 15

16. Local time
http://www.sxc.hu/photo/1086908
Big Questions in Science, spring 2012. SdH, AUC 16

17. Postulates:
1. Laws of physics are the same in all
frames of reference
2. Speed of light is the same for all
observers
http://www.newsbiscuit.com/2012/09/10/ministers-to-consider-raising-the-speed-of-light/
Big Questions in Science, spring 2012. SdH, AUC 17

18. Big Questions in Science, spring 2012. SdH, AUC 18

19. tic
toc
Big Questions in Science, spring 2012. SdH, AUC 19

20. Time time for Time time for one
one tick of tick of moving clock
stationary clock
tic tic tic
Time
Time
toc
toc toc
Big Questions in Science, spring 2012. SdH, AUC 20

21. Time time for Time time for one
one tick of tick of moving clock
stationary clock
tic tic tic
toc
toc toc
Pythagoras:
postulate 2 21

22. Time time for Time time for one
one tick of tick of moving clock
stationary clock
tic tic tic
toc
toc toc
Result: : moving clocks run slower
22

23. • Time time for one tick of
Result: : moving clocks stationary clock
run slower • Time time for one tick
of moving clock
Take:
Object traveling at 99% of the speed of light:
Stationary clock will tick seven times as fast
Big Questions in Science, spring 2012. SdH, AUC 23

24.  Observers moving with constant velocity with
respect to each other:
1. The laws of physics are the same.
2. Velocity of light in vacuum is the same.
Big Questions in Science, spring 2012. SdH, AUC 24

25. Even though the observer on the ground and the observer in
the airplane see different things, the laws of physics that apply
must be the same for both.
Big Questions in Science, spring 2012. SdH, AUC 25

26. There can be no ether in which light propagates. Light moves at the same speed in all
directions.
Big Questions in Science, spring 2012. SdH, AUC 26

27. When time and space look alike
Big Questions in Science, spring 2012. SdH, AUC 27

28.  Einstein 1915: mass implies curvature of space-time.
 Curvature is perceived as gravitational attraction.
Big Questions in Science, spring 2012. SdH, AUC 28

29.  Black hole itself cannot be seen.
 Indirect evidence: matter swallowed up by supermassive black
object.
 Predictions: time delay, gravitational lensing.
Big Questions in Science, spring 2012. SdH, AUC 29

30. Gravitational lensing: the earth looks like a pancake when it is
behind the black hole because light rays are deflected.
 Black hole itself cannot be seen.
 Indirect evidence: matter swallowed up by supermassive black
object.
 Predictions: time delay, gravitational lensing.
Big Questions in Science, spring 2012. SdH, AUC 30

31.  If as heavy as the sun: one meter.
 Supermassive (one million suns): size of the solar system.
 Milky Way: Sagittarius A*.
from us
Big Questions in Science, spring 2012. SdH, AUC 31

32. Big Questions in Science, spring 2012. SdH, AUC 32

33. If the water travels at downward speed (increasing down the waterfall) and the fish swims
at upward speed , the fish cannot escape beyond the point where .
Near the horizon, space behaves as a timelike dimension.
Big Questions in Science, spring 2012. SdH, AUC 33

34. • Psychological
• Cosmological
(increase in entropy)
• Operational: what a
clock measures
Big Questions in Science, spring 2012. SdH, AUC 34

35.  Compare the two figures (on earth/in space).
 What is the equivalence principle?
 What does this say about gravity?
Big Questions in Science, spring 2012. SdH, AUC 35

36.  1959 lecture The Two Cultures and the
Scientific Revolution: C.P. Snow famously
argued that asking whether someone is able
to describe the Second Law of
Thermodynamics is scientific equivalent of:
Have you read a work of Shakespeare’s? His
conclusion: every academic should know it.
 State the law (see e.g. p. 19, 64-65).
 How does it relate to time?
 Provide arguments for Snow’s statement.
Big Questions in Science, spring 2012. SdH, AUC 36

37.  Measure of a system’s thermal energy per
unit temperature that is unavailable for doing
mechanical work.
 Number of ways in which a system may be
arranged (logarithmic grow times
Boltzmann’s constant).
 The latter definition gives a measure of
"disorder" (the higher the entropy, the higher
the disorder).
Big Questions in Science, spring 2012. SdH, AUC 37

38. Increasing entropy (disorder)
Big Questions in Science, spring 2012. SdH, AUC 38

39. Increasing entropy (disorder)
Big Questions in Science, spring 2012. SdH, AUC 39

40. Big Questions in Science, spring 2012. SdH, AUC 40

41.  Main source of energy
 Energy processed by plants
• Kinetic energy
• Potential energy (gravitational, electric,…)
• Heat (dissipated kinetic energy).
 Energy is conserved: types of energy
Big Questions in Science, spring 2012. SdH, AUC 41

42.  Kinetic energy
 Engine
 Industrial revolution
 Potential energy
 Altitude
 Electrical attraction
 Heat:
 Energy loss – friction
Big Questions in Science, spring 2012. SdH, AUC 42

43. Big Questions in Science, spring 2012. SdH, AUC 43

44.  Energy quadratic in speed
first written down by
Émilie du Châtelet.
 Willem Jacob ‘s Gravesande
 The heavier the object, the
more energy it contains.
Big Questions in Science, spring 2012. SdH, AUC 44

45.  Pair production of particles out of energy:
Big Questions in Science, spring 2012. SdH, AUC 45

46.  Nuclear fusion within the Sun:
• Proton: positively charged, found in nucleus
of the atom
• Neutron: neutral, found in nucleus of atom
• Positron: positive charge, antiparticle of
electron
• Neutrino: neutral, interacts only weakly,
small mass
• Gamma ray: highly-energetic photon
Big Questions in Science, spring 2012. SdH, AUC 46

47. The Higgs boson is the particle that gives mass to everything around us.
Big Questions in Science, spring 2012. SdH, AUC 47

48. : moving clocks run slower
48