Transcript The Big Bang

Faster than the speed of light
Was Einstein wrong?
The Big Bang, the LHC and the God
Particle
Cormac O’Raifeartaigh (WIT)
Cormac O’Raifeartaigh (WIT)
Overview
I The experiment
What, why, how
II Skepticism from theory
Special relativity
General relativity
III Skepticism from experiment
Particle experiments
Astronomy
Supernova observations
Coda: what if..?
IV Skepticism in science
The OPERA experiment
Beam of neutrinos at CERN
Detector under Gran Sasso
Distance of 732 km
Time of flight 2.43 ms
Highly respected group
Result early by 60 nanoseconds
0.003% faster than light!
Neutrinos
• Suggested by Pauli (1930)
• Conservation of energy
• Zero charge, ‘zero’ mass
• Weak interaction
• Skepticism (non-physicists)
Detected in 1956
Standard Model
Higgs boson outstanding
Neutrinos today
• Three different types
• Tiny mass
• Dark matter?
• The solar neutrino paradox
Neutrino oscillation
• Gran Sasso experiment
Missing neutrinos
• Unexpected result
The OPERA experiment
OPERA: the numbers
Time of flight: +/- 10ns
2.43006 +/- 0.00001 ms
Velocity = distance/time
Δv/v = 2.5 x 10-5 or .003%
Measurement of distance (GPS)
732 km +/- 20 cm (18 m?)
Note: neutrinos in pulses
.01 ms long (10,000 ns)
Snags
Not direct comparison
Light does not travel through mountain
Accurate measurement of distance
Relies on GPS
Accurate measurement of time-of-flight
Relies on GPS and statistics (pulses)
Relatively short distance
Need to direct beam at the moon
Expect: systematic error
II Skepticism from theory (SR)
The special theory of relativity (1905)
• Laws of physics identical for observers in uniform motion
• Speed of light in vacuum a universal constant
Distance not absolute
L(v)  L0 1  v 2 / c 2
Time not absolute
t (v )  t 0 / 1  v 2 / c 2
Mass increases with velocity
m(v)  m0 / 1  v 2 / c 2
Reception: skepticism
E = mc2
Evidence for relativity
Early experiments
Kaufmann, Bucherer
Modern particle accelerators
Length contraction
Time dilation
Mass increase
Particle accelerators
Speed limit
Antimatter E = mc2
• 9 accelerators
• velocity increase?
K.E = 1/2mv2
m
m0
1 v
2
c2
Relativity ‘skepticism’
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Extraordinary concept
Counter-intuitive
Only observable at tremendous speeds
Only observable for subatomic particles
Speed of light plays role of ∞
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Simple maths
Time and distance calculations
Personalization
Confusion of discovery and justification
Compare: quantum physics
Dr Al Kelly
‘Einstein wrong’
The Irish Times
Skepticism from theory (GR)
General Relativity (1915)
• Laws of physics identical for all observers
• Speed of light in vacuum a universal constant
• Principle of equivalence
Gravity = curvature of space and time
• New view of gravity
• Revolution
• Cosmological implications
Matter warps space and time
General relativity
Predictions
• Bending of starlight by sun
• Black holes
• Expanding universe
• Time dilation by gravity
• Geodesic effect
Evidence
• Eddington experiment
• Astronomy
• GPS
• Everett experiment
Breakdown at quantum scales
III Skepticism from supernovas
Supernova
• Huge implosion of massive star
• Neutrinos released
• Light delayed by debris
Supernova 1987a
• Neutrinos detected
• Ahead of light by 5 min
Not by 5 years !
IV Skepticism in science
Many years for new result to be accepted
Must be reproducible
Must fit known experiments
If so
• Paradigm shift
• Slow, gradual process (DJ)
• Consensus process
Compare: accelerating universe
Thomas Kuhn
The OPERA viewpoint
‘Despite the large significance of the measurement reported here
and the stability of the analysis, the potentially great impact of the
result motivates the continuation of our studies in order to
investigate possible still unknown systematic effects that could
explain the observed anomaly. We deliberately do not attempt any
theoretical or phenomenological interpretation of the results’
‘Up to half of the members of the OPERA project are opposed to
immediately publishing the result in a peer-reviewed journal. They
do not believe any known mistakes are being hidden by other
members of the group, but are worried about the significant impact
to physics of the results.’ Physics World
‘Skepticism’ in the media
Scientific skepticism misunderstood
Attributed to conservatism
Role of evidence misunderstood
‘Balanced’ debate unweighted
Science journalism: news driven
Climate ‘skepticism’ is not scientific
Bjorn Lomborg
contrarian
Summary
Extraordinary result
Indirect measurement
Contradicts theory
Special and general relativity
Contradicts experiment
Particle experiments
Astronomy experiments
What if.... ?
Extraordinary evidence? X
Further reading: ANTIMATTER
What if result stands?
Extra dimensions
Shortcut?
Doesn’t violate relativity
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Unification theory
7 dimensions curled up?
High energy
Lightest particles
Doesn’t contradict previous results
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First evidence of string theory ?