Transcript Inquiring minds want to know

Much ado about nothing: the 30 minute
guide to the universe
NYSS-AAPT meeting
SUNY - Brockport
October 1, 2005
[email protected]
http://www.pas.rochester.edu/~manly/
The intimate relationship
between the very big and the
very small
Inquiring minds want to know ...
Yo! What holds it together?
Fermi National Accelerator
Laboratory (near Chicago)
CDF
Minos
Stanford Linear
Accelerator Center
Event display from the SLD
experiment at SLAC
What forces exist in nature?
What is a force?
How do they interact?
How do forces change with energy or temperature?
How has the universe evolved?
Force
Gravitation
Source
mass
Range
infinite
Strength
-39
10
Electromagnetism Electric
charge
Strong nuclear
Color
charge
Weak nuclear
Weak
charge
infinite
10-2
10
-15
10
-18
m
m
1
10
-5
qqq
Baryons - proton,neutron
Mesons - pion, kaon
qq
Mini-Ph.D. – Quantum Mechanics 101
Lesson 1:
Size actually does matter.
Determine the postion and velocity
of a car … no problem
Determine the postion and velocity
of a small particle … no problem
Problem!
Heisenberg
uncertainty
principle
Cannot have
perfect
knowledge of
both the position
and velocity
Heisenberg
The fundamental nature of forces: virtual particles
Et  h
e-
Heisenberg
E = mc2
Einstein
qq
e+e+e+
e
ee
e+ee+eqq
e+eqq Much ado about NOTHING:
qq
qq
qqqq qq e+eNothing is something qq
qq
+eqqNothing
has
energy
+
e
+ee
e
+
e
ee
+ee
+
e ee+einteracts
Nothing
with something
qq
+ee
qq
qq
qq
qq
qq
-R. Kolb
The essence of inertial mass at the quantum level
(quantum field theory)
qqq
qq
qqq
qqq
qqq
qq
On to the very big …
Telescopes are
time machines
1 Mpc= 1 Megaparsec = 3x1022 m
1 light year = 9x1015 m
Light travels from NYC to San Francisco in 1/100 second
…. and it travels 1 Mpc in 3 million years
Edwin Hubble (1889-1953)
discovers a surprise in 1929
Galaxies that are further away
appear redder
Apparent Doppler shift
-From webphysics.davidson.edu
Light travels from NYC to San Francisco in 1/100 second
…. and it travels 1 Mpc in 3 million years
Welcome to the
“expanding universe”!!
extrapolate back in
time find the age of the
universe  13 billion
years.
Type Ia SNe from Riess, Press and Kirshner (1996)
-MSSL astrophysics group
Cosmic Microwave Background
Penzias and Wilson - 1964
Uniform and isotropic
– in as far as they could measure
BANG!
TIME
Very hot, dense primordial
soup of fundamental particles
At 0.000001 second after bang,
protons and neutrons form
At 3 minutes, light nuclei form
At ~300,000 years, t = 3000 degrees, atoms
form and light streams freely
t=~13 billion years, Ben Affleck and Jennifer
Lopez break up
Modern accelerators study processes at
energies that existed VERY early in the
universe
Another form of time travel !
What were forces like at those temperatures?
What types of particles existed?
Many, many missing pieces …
How can the universe be so isotropic?
How did the structure (galaxies, clusters of galaxies) arise??
Do we know about all of the fundamental particles that exist?
Why 3 families?
Why is the mass spectrum of fundamental particles as it is?
Why is the universe matter instead of antimatter?
Recent progress! But new puzzles…
-R. Kolb
We seem to be missing most of the
mass in the universe!
-P. Cushman
Very exciting development in last decade
Observed fluctuations in the CMB temp
WMap data on the temperature
fluctuations in the CMB
why structure matters
Einstein’s field equations: the modern laws of Genesis
-R. Kolb
One possible future of the universe
End of universe
Buffalo wins the Superbowl
Hell freezes over
Sun burns out
Today
Million- billion
years
1000 billion years
100 billion years
17 billion years
12 billion years
time
-R. Kolb
“Power spectrum” (size) of temperature fluctuations
sensitive to different matter/energy components of the
universe
WMAP composition of the universe
~1/20
W = WM + WL = WB + WDM + WL
-P. Cushman
The elusive neutrino
mass
Mass eigenstates
(3 or more)
1
2
3
4
e + target  e- + X
Flavor eigenstates – relevant for
weak interaction with other particles
 + target  - + X
 + target  - + X
The elusive neutrino
Quantum mechanical mixing of states:
|> = ΣiU*i|i>
Weak flavor eigenstate
Mass eigenstate
Unitary leptonic mixing matrix
Analogous to CKM matrix for quarks
Neutrino with momentum p evolves with time:
|(t)> = ΣiU*i|i>e-iEi(p)t/h
Neutrino of definite flavor is a superposition of several mass eigenstates
whose different masses cause them to propagate differently changing
the mixture of the mass eigenstates, i.e. neutrino oscillations in vacuum
Solar neutrino puzzle
Solar neutrinos (only e produced in core of sun)
Homestake Mine, Davis et al.
100,000 Gal tetrachloroethylene
37Cl
 37Ar
e(Homestake)/e(theory) ~ 0.34+-0.06
Homestake only sensitive to high E tail
of e flux
Fisher, Kayser, McFarland, Ann. Rev. Nucl. Part. Sci. 49, (1999) 481.
Neutrinos physics in the last decade
Sudbury Neutrino Observatory (SNO)
1000 metric tons of D2O in 12 m acrylic vessel
 sund  e  
 sune  e  0.15
 sund  e
SNO: e+=5.44+-0.99x106 cm-2s-1
Bahcall: total ~ 5.05x106 cm-2s-1
SNO: e/(total ) ~ 0.34
Neutrinos oscillate and have mass
… solar puzzle solved!
Neutrinos physics in the last decade
SuperKamiodande
50,000 tons of pure H2O
Atmospheric neutrinos
Cosmic rays interact in atmosphere
and produce e and  neutrinos
Accelerator neutrinos
K2K experiment
M.H. Ahn et al., PRL 90 (2003) 041801
Reactor neutrinos
KamLAND experiment
D. Eguchi et al., PRL 90 (2003) 021802
Evidence for a sterile neutrino?
MiniBooNE results in late summer or
early fall …
The  future
Long baseline
Two detectors – one near, one far
High statistics – challenge for accelerator and detector
On and off axis
Need to minimize systematic errors
Videos from ATLAS
Collaboration website
Large Hadron
Collider (LHC)
SuperNova
Acceleration Probe
We live in exciting times!
Thanks to:
Priscilla Cushman, CDMS, G-2, Univ. of Minnesota
Rocky Kolb, Fermilab and University of Chicago
Stanford Linear Accelerator Center
CERN, European Center for Particle Physics
Fermi National Accelerator Laboratory
Brookhaven National Laboratory
Davidson University webphysics project
WMAP project
Hubble Space Telescope project
Ned Wright, UCLA
MSSL astrophysics group
Newton, Einstein, Heisenberg, Plank, etc.
And whoever else I forgot to mention … 