Practical Statistics – part I ‘Basics Concepts’ W. Verkerke (NIKHEF) Wouter Verkerke, NIKHEF 1.
Frank Linde Nikhef & UvA +31-205925001 [email protected]
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Transcript of Frank Linde Nikhef & UvA +31-205925001 [email protected]
Frank LindeNikhef & UvA
MicrocosmosI. The Wild World of Subatomic ParticlesII. The Story of the HiggsIII. The Mystery of Dark MatterIV. Particle Physics and You!
Elementary Particle Physics
Dark
ag
es
Long ago …Empedocles Plato
Aristoteles
Leucippus
Democritus
AirWaterFireEarth
Atoms
Lead
Gold
Alchemy
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03
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Wate
r ele
ctro
lysi
s
Atoms NA = 6.0221420 1023/Mol
Number of atoms per volume independent of atom type!(Avogadro)
22.4 liters NA atoms
=1 Mole
How large? 30-3001012 meters
How heavy? 2-4501025 kilograms
How many? 31023/gram hydrogen
gas
nummering: kernlading
Het Periodiek Systeem
Periodic Table of Elements
Nobel gasses
Not part of the original Mendeleev
periodic table
Th
e a
tom
Thomson1897
Thomson1897
e/m = 1.761011 C/kg
Millikan1900
qe = 1.60217646 1019 Cme = 9.1093819 1031 kg
electron
Atoms: Rutherford’s view
Elementary particles (1932):Electron, Proton & Neutron
1897electronThomson
1911nucleusRutherford
1911protonRutherford
1932neutronChadwick
Physics just before 1900
??????? all ok ???????No: few “minor” problems:
· “black body” radiation· no eather?· natural radioactivity (Curie et al.)
· stability of the Rutherford atom
Don
e?
I.Special relativity
1905
Intermezzo: Einstein & relativity
Time travel becomes a reality!
L
t = 2Lc
observer at rest
‘hence-and-forward’light flash period t:
‘click’ of the light clock at rest: t
c=299792458 m/s (exact)
Moving clock ‘clicks’ slower!
‘click’ of the moving light clock: t’
v [m/s]
½vt’
L
vt’
t’ = 2L2+(½vt’)2
c (ct’)2 = 4L2+(vt’)2
t’ = = 2Lc2v2
t1v2/c2
observer moving with velocity v
‘hence-and-forward’light flash period: t’
c=299792458 m/s (exact)
t
II.Quantum world
1900-19
Imag
inati
on
Planck (1858-1947)
Planck1900
Einstein (1879-1955)
Einstein1905
Compton (1892-1962)
Compton1922
Light: quantum effects
I. Black body radiation
Planck 1900
L
Easier to fit short wavelengths!
=½L=1L=2L
Stacking waves!
Fit ½, 1, 1½, 2, etc. wavelengths in box such that amplitude=0 on
walls
Light wave's energy: classical
|amplitude|2
energ
y
E continuous!
Radiated energy spectrum: classical
wavelength ()0 m 0,5 m
en
erg
y d
en
sity
kT1λ
8πλρ4E
ult
ra-v
iole
t ca
tast
roph
Light wave's energy: quantum
E = hf
E = 2hf
E = 4hf
E = 3hf
E = 5hf
energ
y
# quanta N
E discrete!
E = Nhf Planck’s constant h = 6.62606881034 J/s
wavelength ()0 m 0,5 m
en
erg
y d
en
sity
λhc
1e
1
λ
8πλρ λkThc4E
Radiated energy spectrum: quantum
ult
ra-v
iole
t ca
tast
roph
Color
T=15,000 oC
T=12,500 oC
T=10,000 oC
T=7,500 oC
T=2,500 oC
T=5,000 oCthe sun
Universe as black body radiator
T 2.725 K 270.5 oC
Big Bang’s afterglow on your TV
incident lightwavelength (frequency f)
slab of materialEinstein 1905
II. Photo electric effect
knocked outelectrons
Compton 1922
III. Compton effect
incident lightwavelength scattered
electron
scattered lightwavelength ’
Duality: wave & particle characteristics
It is safe to say that nobody understands quantum mechanics. R.P. Feynman
Quantum mechanics is magic.Daniel Greenberger.
Everything we call real is made of things that cannot be regarded as real. Niels Bohr. Those who are not shocked when they first come across quantum theory cannot possibly have understood it. Niels Bohr.
If you are not confused by quantum mechanics, you do not understand it. John Wheeler.
If quantum theory is correct, it signifies the end of physics as a science. Albert Einstein.
I do not like quantum mechanics; I am sorry I ever had anything to do with it. Erwin Schrödinger.
morequotes
Atom: quantum effects
Bohr1910
Bohr (1885-1962)
Schrödinger1927
Schrödinger (1887-1961)
Heisenberg1925
Heisenberg (1901-1976)
Bohr’s atom model
1234n = 5
n=3
n=2n=1
Balmer serie
eVn
13.6E 2n
μm10.97n
1
2
1 122
μm10.97n
1
3
1 122
μm10.97n
1
1
1 122
1
2
3
13.6
3.4
1.5
0.0
Balmer
bin
din
g e
nerg
y (
eV
)
quan
tum
num
ber
(n)
Paschen
LymaneV
n
13.6E 2n
eV
f [1/s]
f large
t small
t [s]
f [1/s]
f small
t large
t [s]
Heisenberg’s uncertainty principle
electron
light
micr
osco
pe
electron
light
micr
osco
pe
4/2
Schrödinger’s wave equation
n=1
1H ground state
n=1
n=2
n=3
“s” states
“p” & “d” states
Electron: quantum details
Uhlenbeck & Goudsmit1925
(1887-1961) (1901-1976)
Lorentz & Zeeman1896
(1885-1962) (1887-1961)
Leiden Leiden LeidenAmsterdam
(1900-1958)
Pauli1925
N
Z
N
Z
Zeeman
SternGerlach
Electron spin!
UhlenbeckGoudsmit
Democracy: all electrons are equal
Pauli:
Each electron in a different state! electron =
asocial
The electronMass:0.000000000000000000000000000910938188 gram
Mean lifetime: (infinite) seconds
Electric charge:0.00000000000000000016021765 Coulomb
”Spin”: ½
Perfect description of atoms!
‘Physics 2000’website(Colorado)
Relativistic quantum theory
Dirac1928
Dirac (1902-1984)
Feynman1947
Feynman (1918-1988)
Anderson1932
Anderson (1905-1991)
Dirac’s anti-matter hypothesis
e+
e
e+e
e
e+
neg
ati
ve e
nerg
yp
osi
tive e
nerg
y
Anderson’s anti-electron discovery
e+e
Positron EmissionTomograph
Angels & Demons: the movie
creation & annihilition
time
the only interaction
Bhabha scattering:
Pair creation:
Pair annihilation:
Compton scattering:e e
Möller scattering:ee ee
e+e e+e
e+e
e+e
Real fun:
Part
icle
colli
sion
s
boringcollisions
excitingcollisions
E=mc2funcollisions
highenergy
largemass
E=mc2
Frank LindeNikhef & UvA
MicrocosmosI. The Wild World of Subatomic ParticlesII. The Story of the HiggsIII. The Mystery of Dark MatterIV. Particle Physics and You!
Elementary Particle Physics