Read Knocking on Heaven's Door Online
Authors: Lisa Randall
Knocking on Heaven's Door
Knocking
on Heaven’s
Door
HOW PHYSICS AND SCIENTIFIC
THINKING ILLUMINATE THE UNIVERSE
AND THE MODERN WORLD
Lisa Randall
Chapter 1
What’s So Small to You Is So Large to Me
Chapter 3
Living in a Material World
Chapter 5
The Magical Mystery Tour
Chapter 6
“Seeing” Is Believing
Chapter 7
The Edge of the Universe
MACHINERY, MEASUREMENTS, AND PROBABILITY
Chapter 8
One Ring to Rule Them All
Chapter 9
The Return of the Ring
Chapter 10
Black Holes That Will Devour the World
Chapter 12
Measurement and Uncertainty
Chapter 13
The CMS and ATLAS Experiments
Chapter 14
Identifying Particles
MODELING, PREDICTING, AND ANTICIPATING RESULTS
Chapter 15
Truth, Beauty, and Other Scientific Misconceptions
Chapter 17
The World’s Next Top Model
Chapter 18
Bottom-Up Versus Top-Down
Chapter 20
What’s So Large to You Is So Small to Me
Chapter 21
Visitors from the Dark Side
Chapter 22
Think Globally and Act Locally
1.
XKCD comic.
2.
Line segments.
3.
Eiffel Tower as seen from different scales.
4.
Temperature and pressure.
5.
Three interpretations of light.
6.
Scrovegni Chapel image.
7.
Galileo experiment with an inclined plane.
8.
Optical illusion.
9.
Phases of Venus.
10.
Cosmological systems.
11.
Painting of the sublime
12.
“Physics souffié.”
13.
Tour of small scales.
14.
Atom size versus wavelength of visible light.
15.
An atom.
16.
Valence quarks in a proton.
17.
Production of matter and antimatter.
18.
More complete picture of a proton.
19.
Unification of forces.
20.
Rutherford experiment.
21.
Fixed-target versus collider experiment.
22.
Differences among colliders.
23.
The particle physics Standard Model.
24.
The LHC in its setting.
25.
Schematic of LHC rings.
26.
A cryodipole magnet cross section.
27.
The faulty busbar connection.
28.
LHC time line.
29.
Looking into the ATLAS cavern.
30.
Visiting CMS.
31.
Looking down the beam pipe.
32.
The ATLAS and CMS detectors.
33.
Graphic of the CMS detector.
34.
Simulation of a particle event in the ATLAS detector.
35.
Visiting CMS.
36.
Lead tungstate crystal.
37.
Part of the ATLAS ECAL.
38.
The CMS muon detector under construction.
39.
Graphic of the ATLAS detector.
40.
The Standard Model in more detail.
41.
Particle jets.
42.
Standard Model particle identification at the LHC.
43.
Bottom quark signature.
44.
W
boson decay.
45.
Measuring the
W
mass.
46.
Pictorial summary of the Standard Model.
47.
Richard Serra sculptures.
48.
Religious symbols.
49.
Chartres Cathedral and the ceiling of the Sistine Chapel.
50.
Asymmetry in Japanese art.
51.
Higgs boson production modes.
52.
Heavy Higgs boson decay to W bosons.
53.
Light Higgs boson decay to a bottom quark and its antiparticle.
54.
The hierarchy problem of particle physics.
55.
Contribution to the Higgs boson mass from virtual particles.
56.
Conference slide with different models.
57.
Table of the supersymmetric Standard Model.
58.
Supersymmetric contributions to the Higgs mass.
59.
Squark decay.
60.
Squark production and decay at the LHC.
61.
“Tightrope universe.”
62.
“Showerbrane.”
63.
An open and a closed string.
64.
Braneworld.
65.
“Gravity sprinkler.”
66.
Kaluza-Klein particle from large extra dimensions.
67.
The graviton and warped geometry.
68.
Rescaling in warped geometry.
69.
KK particle production and decay in warped geometry.
70.
Tour of large scales.
71.
Red and blue shifts.
72.
“Ballooniverse.”
73.
Curved spaces.
74.
Pie chart of energy densities in the universe.
75.
Gravitational lensing.
76.
The Bullet cluster.
77.
Expansion of the universe over time.
78.
Detecting dark matter three ways.
79.
DAMA results.
80.
PAMELA results.
81.
Nine-dots problem.
82.INTRODUCTION
Thinking outside the box.
We are poised on the edge of discovery. The biggest and most exciting experiments in particle physics and cosmology are under way and many of the world’s most talented physicists and astronomers are focused on their implications. What scientists find within the next decade could provide clues that will ultimately change our view of the fundamental makeup of matter or even of space itself—and just might provide a more comprehensive picture of the nature of reality. Those of us who are focused on these developments don’t anticipate that they will be mere post-modern additions. We look forward to discoveries that might introduce a dramatically different twenty-first-century paradigm for the universe’s underlying construction—altering our picture of its basic architecture based on the insights that lie in store.
September 10, 2008, marked the historic first trial run of the Large Hadron Collider (LHC). Although the name—Large Hadron Collider—is literal but uninspired, the same is not true for the science we expect it to achieve, which should prove spectacular. The “large” refers to the collider—not to hadrons. The LHC contains an enormous 26.6 kilometer
1
circular tunnel deep underground that stretches between the Jura Mountains and Lake Geneva and crosses the French-Swiss border. Electric fields inside this tunnel accelerate two beams, each consisting of billions of protons (which belong to a class of particles called hadrons—hence the collider’s name), as they go around—about 11,000 times each second.