astronomy, cosmology, particle physics and the...

Aerospace Engineering Special Seminar Series (AESS)Seminar Series (AESS)

Astronomy, Cosmology, Particle Physics and The

UniverseProf. David Toback

&M Texas A&M UniversityMitchell Institute for

David Toback, AESS Seminar 1September 2014

Fundamental Physics and AstronomySeptember 2014

Prologueg(Apologies for the simplistic definitions)• Astronomy is the study of things we can see through telescopes Stuff in can see through telescopes… Stuff in Universe (space)C l i b i • Cosmology is about trying to understand the origin and evolution gof the Universe

• Particle Physics is about trying to • Particle Physics is about trying to understand the smallest things that

k th t ff i th U imake up the stuff in the UniverseSeptember 2014 David Toback, AESS Seminar 2

Prologue Continued: Dark MattergWe live in a remarkable time where

scientists have a good understanding of each

We are arrogant enough to think that it is possible to solve major problems in p j pAstronomy, Cosmology and Particle Physics with a single discoveryg y

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

September 2014 David Toback, AESS Seminar 3

the Universe and the stuff in it

Overview of the TalkWill talk about this exciting possibility by

i ti b answering some questions 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 h4

Final ThoughtsSeptember 2014 David Toback, AESS Seminar

What is Dark DMatter? Matter?

5September 2014 David Toback, AESS Seminar

Dark Matter

What is What is some of some of

the the evidence evidence for Dark for Dark matter?

6matter?September 2014 David Toback, AESS Seminar

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

January 2014 7David Toback, AESS Seminar

p

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

.swf


As the Galaxy Turnsy

http://faculty.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


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, AESS Seminar 18

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

Artists Conception of the Big Bangp g g


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

25

galaxiesSeptember 2014 David Toback, AESS Seminar

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

solar solar system and y mthe Earth

formDavid Toback, AESS Seminar 26September 2014

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

27

years agoSeptember 2014 David Toback, AESS Seminar

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


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


ysecond

September 2014

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, AESS Seminar 34September 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…


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, AESS SeminarSeptember 2014 36

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

i energies, then bashes them together


togetherSeptember 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 department now offers a

course entitled “Big Bang & Black Holes” Black Holes

(ASTR/PHYS 109)– Covers Stephen Hawking’s p g

“Brief History of Time”– Origin and Evolution of the

UniverseUniverse– How do stars form?– What is Dark Matter? Dark W D M D

Energy?– What are Black Holes?– General Relativity & Quantum

Mechanics– Particle Physics


– Particle Physics

September 2014http://faculty.physics.tamu.edu/toback/109/

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

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

• Astronomy Cosmology and Particle Astronomy, Cosmology and Particle Physics are all comingP 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 !

40

the corner!September 2014 David Toback, AESS Seminar

AbstractScientists have entered a golden age of discovery. We are

starting to be able to answer some of the most exciting starting to be able to answer some of the most exciting questions ever asked, including questions that touch on the Big Bang, the fundamental building blocks of nature, and the Dark Matter that fills the Universe. In this talk I will talk about Astronomy, Cosmology, Particle Physics and The Universe and the reasons to think that Physics and The Universe and the reasons to think that the biggest things in the Universe (like the Universe itself) and the smallest things (like quarks and electrons) are inextricably linked Indeed many of us electrons) are inextricably linked. Indeed, many of us believe there is a new, fundamental particle just around the corner waiting to be discovered that could all these things together


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