Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.

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Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe

Transcript of Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.

Page 1: Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.

Pauline GagnonPhysicist and communicator at CERN

The dark side of the Universe

Page 2: Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.

Shrimp Nebula© VLT, European Space Observatory

• Convince you all of the existence of dark matter

• Review how one can catch dark matter

Plan

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fi

©2000, 2001 B Katzung, Andromeda galaxy

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dark matter 27%

dark energy 68%

visible matter 5%

Universe content

Page 5: Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.
Page 6: Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.
Page 7: Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.

© NASA, Orion nebula

Dark energy:

Discovered in 1998 while studying the relative speeds of galaxies

The Universe expansion is accelerating

A completely unknown type of energy must be causing this expansion

Physics Nobel Prize in 2011 went to Saul Perlmutter, Brian Schmidt and Adam Riess

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dark matter 27%

dark energy 68%

visible matter 5%

Universe content

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Page 10: Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.
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What is generating the gravitational pull needed to maintain these

galaxies together?

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Dark matter provides the gravitational force needed to maintain these galaxies together

Page 13: Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.

Mais comment mesure-t-on la composition de l’Univers?

Page 14: Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.

1 second

Protons and neutrons form

380 000 years

Atoms form

1 billion years

Stars and galaxies form

13.7 billion years

2.7 degrees

1032 degrees

The Big Bang

Page 15: Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.

Stars and Dust Across Corona Australis © Ignacio Diaz Bobillo

Rayonnement fossile

The Universe became transparent 380 000 years after the Big Bang

The photons present then are still moving around freely

But the Universe expanded and they cooled down

We still observe them today in the form of microwave background at 2.725 degrees Kelvin

Page 16: Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.

Cosmological microwave background

Page 17: Pauline Gagnon Physicist and communicator at CERN The dark side of the Universe.

Width and temperature of each lump(or angular spectrum measured by Planck)

Angular width of all structures observed in the Universe

Tem

para

ture

fluc

tuati

ons

in (μ

•K)

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Big Bang Standard Model

Λ-CDM model: a model with 6 free parameters including

Ωd : dark matter densityΩΛ : dark energy density

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Dark energy68%

Dark matter27%

Matter5%

Ωd

Ωd

ΩΛ

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How did the Universe evolve

from an immense fog of free particles…

…to an Universe filled with stars and galaxies?