The Big Bang, the LHC and the God Particle

Cormac O’Raifeartaigh (WIT)

Faster than the speed of light

Was Einstein wrong?

Cormac O’Raifeartaigh (WIT)

Overview

I The OPERA experiment

What, why, how

II Relativity (special)

Theory and experiment

III Relativity (general)

Theory and experiment

IV Skepticism in science Coda: a mundane explanation

The OPERA experiment

Result: early by 60 nanoseconds

Beam of neutrinos at CERN

Detector under Gran Sasso

Distance of 732 km

Time of flight 2.43 ms

0.003% faster than light !

Neutrinos

• Suggested by Pauli (1930)

• Conservation of energy

• Particle of zero charge, low mass

• Weak interaction

Skepticism Detected in 1956

Neutrino puzzles

• Tiny mass (non-zero?)

• Created in nuclear reactions • The solar neutrino paradox

Three different types Neutrino oscillation

OPERA experiment

Standard Model

neutrino = lighter cousin of electron

The OPERA experiment

OPERA: The numbers

Measurement of distance (GPS)

732 km +/- 20 cm

• Time of flight (GPS)

2.43006 ms +/- 10 ns

Velocity = distance/time Δv/v = 2.5 x 10-5 (25 ppm)

Note: proton pulse 10 μs long (10,000 ns) 60 ns early (18 m??)

OPERA: The 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/timeNeed to direct beam at the moon

Systematic error ?

II The theory of relativity (special)

• Laws of physics identical for observers in uniform motion• Speed of light in vacuum a fundamental constant

Length contraction

Time dilation

Mass increase

220 /1)( cvLvL

220 /1/)( cvtvt

220 /1/)( cvmvm

E = mc2

Implications for bodies at high speed

Early experiments Kaufmann, Bucherer

Particle accelerators Length contraction

Time dilation Mass increase

Modern particle accelerators Speed limit

Particle creation E = mc2

Evidence for relativity

CERN (Geneva)

• energy increase

• velocity increase?

K.E = 1/2mv2

mass increases

220 /1/)( cvmvm

Relativity ‘skepticism’

• Extraordinary concept• Counter-intuitive • Only observable at tremendous speeds• Only observable for subatomic particles

• Simple maths• Time and distance calculations • Personalization• Confusion of discovery and justification

Speed of light plays role of infinity

Dr Al Kelly ‘Einstein wrong’

III The general theory of relativity

Gravity = curvature of space and time

• Laws of physics identical for all observers• Speed of light in vacuum a universal constant• Principle of equivalence

• New view of gravity• Cosmological implications

Matter warps space and time

General Relativity (1915)

General relativity (evidence)

• Bending of starlight by sun Eddington experiment

• Time dilation by gravity Pound experiment

• Expanding universe Hubble’s law

• Geodesic effect Everett experiment

Breakdown at quantum scales

Skepticism from astronomy

Supernova• Huge implosion of massive star• Light released• Neutrinos released

Supernova 1987a• Neutrinos detected• Light detected• Time difference of 5 min

Not 5 years !

IV Skepticism in science

Many years for new result to be accepted

Must be reproducible

Must fit known data

• Paradigm shift• Slow, gradual process (DJ)• Consensus process

If so

Compare: accelerating universe

Thomas Kuhn

Skepticism in the media

Scientific skepticism misunderstood

Attributed to conservatism

Role of evidence misunderstood

‘Balanced’ debate unweighted

Science journalism: news driven

Bjorn Lomborg

SummaryExtraordinary result Indirect measurement

Contradicts theorySpecial and general relativity

Contradicts experimentParticle experimentsAstronomy experiments

Extraordinary evidence? X

Explanation ?

The verdict

Unreliable resultRe-runs possible but not beneficial

• Reproducible?Many checks carried out

• Technical flaw discoveredCable to external GPS clock Accounts for time discrepancy

• A second flawInternal clock

We told you so

Lessons to be learnt

1. Unexpected result? Check, check, check Emphasis on simple errors

2. Do not publish If in conflict with theory and experiment 

3. Do not underestimate the media ‘Einstein wrong’ is a huge story

Further reading: ANTIMATTER

Relativity and GPS

• Signal from satellite

compare time received to transmitted

synchronized clocks

• Convert time to distance

x speed of radiowaves

Assumes constancy of speed of light

• Triangulation using 4 sources accurate to within 5 metres

GPS: a relativistic correction

• Motion of satellite (SR)

Clocks slow by 7 μs/day

• Reduced gravity field (GR)

Clocks fast by 45 μs/day

Satellite clocks fast by 38 μs/ day

Well-known correction to GPS OPERA - new correction? (18m?)

Synchronization of satellite/earth clocks

What if result stands?

First evidence of string theory ?

• Extra dimensionsShortcut?

Doesn’t violate relativity

• Unified field theory 7 dimensions curled up?

• High energy Lightest particlesDoesn’t contradict previous results

Further reading: ANTIMATTER

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