what does dark matter have to do with the big bang th...

Lunar S i tSociety

What does Dark Matter have to do with the Big Bang

Th ?Theory?Prof. David Toback

&M Texas A&M UniversityMitchell Institute for

Fundamental Physics and AstronomyMay 2016

ProloguegWe live in a time of remarkable scientific

d diunderstandingScientists are arrogant/crazy enough to think

th t it b ibl t l j bl that it may be possible to solve major problems in Astronomy, Cosmology and Particle Physicswith a single discovery that ties all three with a single discovery that ties all three together

Idea: Dark Matter is a particle that was created Idea: Dark Matter is a particle that was created right after the Big Bang and has had a major impact on the evolution of the Universe and the pstuff in it

Goal of this talk: To show you how all this might

2

y gjust tie together

May 2016 David Toback, Lunar Society

Overview of the TalkWill talk about some of the most exciting

ti i ll f i bquestions in all of science one-by-one:• What IS Dark matter and what is some

of the evidence for it? • What is the Big Bang Theory?What s the B g Bang heory?• What does Dark Matter have to do with

the Big Bang and the evolution of the the Big Bang and the evolution of the Universe?What are scientists doing today to • What are scientists doing today to discover Dark Matter?

Fi l Th h3

Final ThoughtsMay 2016 David Toback, Lunar Society

What is Dark DMatter? Matter?

4May 2016 David Toback, Lunar Society

Dark Matter

What is What is some of some of

the the evidence evidence for Dark for Dark matter?

5matter?May 2016 David Toback, Lunar Society

How Stars Move in Galaxies• Start by considering the case that there IS no Dark Matter in galaxiesDark Matter in galaxies

• Can use laws of gravity to predict two things: – 1) The orbits of planets as they move around ) f p ythe solar system and

– 2) Stars as they move around a galaxy • Prediction: both have very massive centers so we expect the data to look consistent with thatD t• Data:– For the solar system, the data agree perfectlyperfectly

– For the stars in the outer part of galaxies, the prediction doesn’t work at all

6

p


http://people phyhttp://people.physics.tamu.edu/toback/Talks/Video/Lab4 SS1 video/Lab4_SS1_video

.swf


As the Galaxy Turnsy

http://people.physics.tamu.edu/toback/Talks/Video/Lab4 GX1 video slow sw/Talks/Video/Lab4_GX1_video_slow.sw

f


Data well explained by lots of Data well explained by lots of “Dark Matter” we can’t see

This is where it gets its nameI th i In some sense, the name is a

statement of almost all we know statement of almost all we know about it (it doesn’t interact

h l h d h )with light, and it has mass)Lots of other evidence for dark matter like gravitational

9

Lots of other evidence for dark matter like gravitational lensing, but that’s for another day…


Our Place in the UniverseYou are here The Dark Matter The Dark Matter

surrounds the galaxy like the

water in a fishbowl surrounds a fish in the middle of the the middle of the

bowlNot exactly the Not exactly the same… denser in

the middle because of the pull of

gravity


What is the Big gBang Theory? Bang Theory?


Not that Big Bang Not that Big Bang TheoryTheory


A Big Bang A Big Bang Occurred… Then

What?The Story of The Story of the Universe the Universe

since the Beginning


Observe lots of galaxies ith th ld’ b t with the world’s best

telescopetelescopeWe notice that All the far away ones are moving away

from us VERY quicklyfrom us VERY quickly


So What?

All the stuff in the galaxies t h f appears to have come from a

single point in space ~13 7 What happened in the past? single point in space 13.7 billion years ago

What happened in the past? Run the clock backward in timeName this time The Big Bang A f C i A moment of Creation


Slightly more complicated than that…

• As best as we understand the As best as we understand the Universe began with a Big BBang–A REALLY Big Bang–A REALLY Big Bang

• Then what?• How did we get from the bang to the Universe we have today?today?


A Brief History of Timey• The Big Bang

produces lots of • Zero

p fparticles

• Quarks combine to form • One millionth of one protons and neutrons

• Protons and Neutrons combine to form the

second after the Bang• A few minutes

combine to form the nucleus of an atom

• Nuclei and electrons • A few hundred Nuclei and electrons combine to form atoms

• Atoms combine to form

A few hundred thousand years

• 100 million to 1 billion Stars and Galaxies

• The Earth and our solar f

years• 9 billion years

David Toback, MSC Bethancourt Lecture 17

system forms• You listen to me talkOctober 2014• ~13.7 billion years

Artists Conception of the Big Bangp g g

It all started with a Big BangIt all started with a Big Bang

BBang


The very early Universey yLots of free particles just hanging around…Universe is so hot that quarks can’t combine Universe is so hot that quarks can t combine

to make protons/neutrons


Later, Quarks Combine to Form NucleonsNucleons

Q kqqq Proton

Quark

ProtonNuclear Reaction

Quark Quark


A Millionth of a Second after the Big BangBang

The quarks have combined to form Protons and Neutrons


Creating Heavier NucleigProton Proton + Proton DeuteriumProton roton roton D ut r um

DeuteriumNuclear Reaction


A couple hundred thousand years later: Atomslater: Atoms

P tProton

HydrogenAtom

ElectroMagnetic Reaction Atom

Electron


Wait a Billion Years

After about Our galaxy, the Milky Way

After about half a billion

years, because of gravity of gravity,

atoms combine to form the

fi t t d first stars and galaxies

24

galaxiesMay 2016 David Toback, Lunar Society

Aft b ut After about 9 billion 9 billion years our years our

solar solar system and y mthe Earth

form25May 2016 David Toback, Lunar Society

Recent History: Life on Earthy• Earth is about 4 or 5 billion years oldE id th t i bi l t i • Evidence that microbial tracings existed on Earth about 3.5 billion years agoH id lik “L ” i t d • Humanoids, like “Lucy” existed a mere 3 million years ago m m y g

• Homo-sapiens at around 100,000

26

years agoMay 2016 David Toback, Lunar Society

What does Dark Matter have to do with the Big Bang Theory?g g y


The Known Particles– No known particles have

the properties of Dark the properties of Dark Matter

– Other reasons to believe – Other reasons to believe there are new fundamental particles to be discoveredparticles to be discovered– For example, we just di d th Hi discovered the Higgs Boson

– Maybe Dark Matter is a New Particle!


What IS the Dark Matter?We don’t know

Hypothesis: The Dark Matter in the Universe is made up of LOTS of particles

We don t know…p f f p

that we haven’t discovered yet!Best Guess: Huge numbers got created in the Early Universe like everything else y y g

and are still here today!

Today: Observe 5 times more

David Toback, MSC Bethancourt Lecture 29October 2014

Today: Observe 5 times more Dark Matter than Atoms (by

mass) in the Universe

What are scientists doing today to di D k M tt ?discover Dark Matter?

Just mention two of the fun experiments being done here at

Texas A&M! Texas A&M!


Some Sources of Dark Matter Chare Cheap

You are here O You are here Our Sun is Moving Moving

through our Galax Galaxy…

Lots of Dark Lots of Dark Matter is hittin th hitting the Earth every

31

ysecond


ExperimentpDark Matter

Particle

PingI saw it! Eureka!

Atom in Detector

Ping

Low TemperaturepDetector


Can we Make and Discover Dark Matter?

Hi h lli i b t • High energy collisions between particles in the Early Universeparticles in the Early Universe

• Recreate the conditions like they were RIGHT AFTER the Big Bang Big Bang

• If we can produce Dark If we can produce Dark Matter in a collision then we

David Toback, MSC Bethancourt Lecture 33October 2014can STUDY it

More Expensive Dark Matter? High Energy Collisions Dark Matter ParticlesHigh Energy Collisions Dark Matter Particles

LHC ≈1 ps after the Big BangDetectorDetector

Proton ProtonProton Proton

Ok… Its more complicated than this since Dark Matter than this since Dark Matter

Particles don’t easily interact with detectors…

David Toback, MSC Bethancourt Lecture 34October 2014

Nor do we usually produce them directly

Aerial View of the LHC27 km in Circumference!

One of the largest and th t l i tifi

Collides high energy protons

Lake LemanCMS

the most complex scientific instrument ever conceived &

built by humankind

gy p

Two huge detectorsGeneva Airport

pp

p

ATLAS

David Toback, MSC Bethancourt LectureOctober 2014 35

How does it do it? Accelerates Accelerates protons to REALLY REALLY high

i energies, then bashes them together

David Toback, MSC Bethancourt Lecture 36

togetherOctober 2014

http://people.physics.tamu.edu/toback/Talks/Video/particle_event_full_ns.avi

Fi l Th htFinal Thoughts


Interested in learning more?g• Physics & Astronomy department

now offers a course entitled “Big Bang & Black Holes” Bang & Black Holes

(ASTR/PHYS 109)– Covers Stephen Hawking’s “Brief

Hi t f Ti ”History of Time”– Origin and Evolution of the Universe– How do stars form?– What is Dark Matter? Dark Energy?– What are Black Holes?– More on General Relativity Quantum More on General Relativity, Quantum

Mechanics and Particle Physics– Has a lab (if you want) and can be

used as a Science Distribution creditused as a Science Distribution credit– There is an option to take is an

Honors class

38

http://people.physics.tamu.edu/toback/109/


Conclusions• It’s an incredibly exciting time to be a scientist!

• Astronomy Cosmology and Particle Astronomy, Cosmology and Particle Physics are all coming togetherP h d t d th l f • Perhaps we understand the role of Dark Matter in the Universe since the Big Bang!

• If our understanding is correct a If our understanding is correct, a major discovery may be just around th !

39

the corner!May 2016 David Toback, Lunar Society

what does dark matter have to do with the big bang th...

Documents