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Telescopes gather light from space. ...and tell us the Universe is full of matter. The discovery of antimatter. Paul Dirac (1928) Carl Anderson (1932). The science of antimatter is born. 1951: positronium (predicted by Mohorovičić in 1934!) 1955: antiproton 1965: antideuteron atom
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The discovery of antimatter • Paul Dirac (1928) • Carl Anderson (1932)
The science of antimatter is born • 1951: positronium (predicted by Mohorovičić in 1934!) • 1955: antiproton • 1965: antideuteron atom • 1995: antihydrogen atom • 2003: antihelium atom • 2007: di-positronium molecule There are no anti-objects to date except in the movies
How to understand antimatter? • The Big Bang created a set of particles: p, n, e, γ, ν... • The Big Banks give out a set of coins: 5¢, 10¢, 20¢, 50¢, $1, $2... • The Big Bang created a set of antiparticles: p, n, e, γ, ν... • The Big Banks do not use anticoins: 5¢, 10¢, 20¢, 50¢, $1, $2...
A fundamental difference $100 + $100 = 0
100% pure – the ultimate green energy 1 gram of antimatter can power Sydney for a day... 1000 times more efficient than nuclear energy... But at current market prices, it costs $25B to make 1 gram
Can we use antimatter on Earth? PET scanners
Cosmic antimatter mystery The universe began with a balance of matter and antimatter Today, matter dominates... Where did all the antimatter go?
γ γ γ γ e- e- e+ e+
Solution: Large Hadron Collider? There may exist a fundamental imbalance between matter and antimatter that favours matter in the first second of the Universe The LHC creates conditions that existed immediately after the Big Bang
The Universe today is mostly dark ! The nature of the dark stuff is the most fundamental question in astrophysics. Dark antimatter may exist, but it cannot dominate over dark matter.
The Metal-Poor Halo of the Andromeda Spiral Galaxy K.Gilbert M31 Image from GALEX Feb. 7th, 2006 Local Group Cosmology, Aspen CO
The Metal-Poor Halo of the Andromeda Spiral Galaxy M31 Image from GALEX Feb. 7th, 2006 Local Group Cosmology, Aspen CO
But cosmic antimatter does exist ! Possible explanations • Antimatter objects (antistars ??) • Something to do with black holes ?? • Decaying dark matter ?? • Something new ?? PAMELA satellite
γ γ γ γ γ e- e- e+ e+ How do we know antimatter exists there ? Anti-Parallel Spin Annihilation • 2 photons emitted with same energy • (E=511 keV) • 3 photons emitted with different energies • (E<511 keV) Parallel Spin Annihilation
The mystery at the Centre of our Galaxy INTEGRAL 2010
NEMESIS – an Australian project "to detect antimatter before it annihilates" Dr. Simon Ellis Special thanks to staff and students at USyd and the AAO. We are using recent advances in astrophotonics to make the infrared sky go dark. Starting in 2011, we will target the Galactic Centre.
e+ The signature of positronium gas e- e- Positronium
How does it work? Fibre Bragg Gratings • Redfern Optical Components makes the best and • the most complex FBGs in the world
What might we find? decaying dark matter? rips in the fabric of space-time?
What will we find? What will we find? If the history of science teaches us anything, it is to prepare for the unexpected. The Supermassive Black Hole – 4 million times more massive than the Sun – was far more violent in the past
Matter Giant Magellan Telescope (2018)