and

relativity

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

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

http://www.platypusart.com/

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

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

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

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/

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 7 http://www.arthistoryarchive.com/arthistory/cubism/

Big Questions in Science, spring 2012. SdH, AUC 8 http://en.wikipedia.org/wiki/Henri_Poincar%C3%A9

http://mathworld.wolfram.com/PoincareHyperbolicDisk.html

http://nl.wikipedia.org/wiki/Flatland

Big Questions in Science, spring 2012. SdH, AUC 9

A visitor from the fourth dimension

Big Questions in Science, spring 2012. SdH, AUC 10 Erich Mendelsohn, Einstein Tower 1920-21.

Hannah Höch, Berliner Illustrierte Zeitung 1919

Naum Gabo, Kinetic Construction 1919-20

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

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

Big Questions in Science, spring 2012. SdH, AUC 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 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 15

• Psychological • Cosmological

(increase in entropy) • Operational: what a

clock measures

Big Questions in Science, spring 2012. SdH, AUC 16

Local time

http://www.sxc.hu/photo/1086908

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

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

tic

toc

Big Questions in Science, spring 2012. SdH, AUC 20

tic

toc

tic

toc toc

tic

Time

Time

Time

time for one tick of stationary clock

Time

time for one tick of moving clock

21

tic

toc

tic

toc toc

tic

Pythagoras:

postulate 2

Time

time for one tick of stationary clock

Time

time for one tick of moving clock

22

tic

toc

tic

toc toc

tic

Result:

: moving clocks run slower

Time

time for one tick of stationary clock

Time

time for one tick of moving clock

Big Questions in Science, spring 2012. SdH, AUC 23

Result:

Take:

Object traveling at 99% of the speed of light:

Stationary clock will tick seven times as fast

: moving clocks

run slower

• Time

time for one tick of stationary clock

• Time

time for one tick of moving clock

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

Big Questions in Science, spring 2012. SdH, AUC 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 26

There can be no ether in which light propagates. Light moves at the same speed in all directions.

When time and space look alike

Big Questions in Science, spring 2012. SdH, AUC 27

Einstein 1915: mass implies curvature of space-time. Curvature is perceived as gravitational attraction.

Big Questions in Science, spring 2012. SdH, AUC 28

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

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

Gravitational lensing: the earth looks like a pancake when it is behind the black hole because light rays are deflected.

If as heavy as the sun: one meter. Supermassive (one million suns): size of the solar system. Milky Way: Sagittarius A*.

Big Questions in Science, spring 2012. SdH, AUC 31

from us

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

Big Questions in Science, spring 2012. SdH, AUC 33

Near the horizon, space behaves as a timelike dimension.

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

.

Big Questions in Science, spring 2012. SdH, AUC 34

• Psychological • Cosmological

(increase in entropy) • Operational: what a

clock measures

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

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

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

Big Questions in Science, spring 2012. SdH, AUC 38

Increasing entropy (disorder)

Big Questions in Science, spring 2012. SdH, AUC 39

Increasing entropy (disorder)

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

Main source of energy Energy processed by plants

Energy is conserved: types of energy

Big Questions in Science, spring 2012. SdH, AUC 41

• Kinetic energy • Potential energy (gravitational, electric,…) • Heat (dissipated kinetic energy).

Kinetic energy

Engine

Industrial revolution

Potential energy

Altitude

Electrical attraction

Heat:

Energy loss – friction

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

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

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

Pair production of particles out of energy:

Big Questions in Science, spring 2012. SdH, AUC 45

Nuclear fusion within the Sun:

Big Questions in Science, spring 2012. SdH, AUC 46

• 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 47

The Higgs boson is the particle that gives mass to everything around us.

48

: moving clocks run slower