Aerospace Engineering Special Seminar Series AESS Astronomy Cosmology

Aerospace Engineering Special Seminar Series (AESS) Astronomy, Cosmology, Particle Physics and The Universe Prof. David Toback Texas A&M University Mitchell Institute for Fundamental Physics and Astronomy September 2014 David Toback, AESS 2014 Seminar September 1

Prologue (Apologies for the simplistic definitions) • Astronomy is the study of things we can see through telescopes… Stuff in Universe (space) • Cosmology is about trying to understand the origin and evolution of the Universe • Particle Physics is about trying to understand the smallest things that make up the stuff in the Universe September 2014 David Toback, AESS Seminar 2

Prologue Continued: Dark Matter We live in a remarkable time where scientists have a good understanding of each We arrogant enough to think that it is possible to solve major problems in Astronomy, Cosmology and Particle Physics with a single discovery 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 stuff in it September 2014 David Toback, AESS Seminar 3

Overview of the Talk Will talk about this exciting possibility by 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 does Dark Matter have to do with the Big Bang and the evolution of the Universe? • What are scientists doing today to discover Dark Matter? Final Thoughts September 2014 David Toback, AESS Seminar 4

What is Dark Matter? September 2014 David Toback, AESS Seminar 5

Dark Matter What is some of the evidence for Dark matter? September 2014 David Toback, AESS Seminar 6

How Stars Move in Galaxies • Start by considering the case that there IS no Dark Matter in galaxies • Can use laws of gravity to predict two things: – 1) The orbits of planets as they move around the 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 that • Data: – For the solar system, the data agree perfectly – For the stars in the outer part of galaxies, the prediction doesn’t work at all January 2014 David Toback, AESS Seminar 7

http: //people. phy sics. tamu. edu/to back/Talks/Video /Lab 4_SS 1_video. swf September 2014 David Toback, AESS Seminar 8

As the Galaxy Turns http: //faculty. physics. tamu. edu/toback /Talks/Video/Lab 4_GX 1_video_slow. swf September 2014 David Toback, AESS Seminar 9

Data well explained by lots of “Dark Matter” we can’t see This is where it gets its name In some sense, the name is a statement of almost all we know about it (it doesn’t interact with light, and it has mass) Lots of other evidence for dark matter like gravitational lensing, but that’s for another day… September 2014 David Toback, AESS Seminar 10

Our Place in the Universe You are here The Dark Matter surrounds the galaxy like the water in a fishbowl surrounds a fish in the middle of the bowl Not exactly the same… denser in the middle because of the pull of gravity

What is the Big Bang Theory? September 2014 David Toback, AESS Seminar 12

Not that Big Bang Theory September 2014 David Toback, AESS Seminar 13

A Big Bang Occurred… Then What? The Story of the Universe since the Beginning September 2014 David Toback, AESS Seminar 14

Observe lots of galaxies with the world’s best telescope We notice that All the far away ones are moving away from us VERY quickly September 2014 David Toback, AESS Seminar 15

So What? All the stuff in the galaxies appears to have come from a singlehappened point in space What in the~13. 7 past? billion years ago Run the clock backward in time Name this time The Big Bang A moment of Creation September 2014 David Toback, AESS Seminar 16

Slightly more complicated than that… • As best as we understand the Universe began with a Big Bang – A REALLY Big Bang • Then what? • How did we get from the bang to the Universe we have today? September 2014 David Toback, AESS Seminar 17

A Brief History of Time • Zero • • The Big Bang produces lots of particles • Quarks combine to form One millionth of one protons and neutrons second after the Bang • Protons and Neutrons A few minutes combine to form the nucleus of an atom • Nuclei and electrons A few hundred combine to form atoms thousand years • Atoms combine to form 100 million to 1 billion Stars and Galaxies years • The Earth and our solar 9 billion years system forms • You listen to me talk ~13. 7 years September billion 2014 18 David Toback, AESS Seminar

Artists Conception of the Big Bang September 2014 David Toback, AESS Seminar 19

The very early Universe Lots of free particles just hanging around… Universe is so hot that quarks can’t combine to make protons/neutrons September 2014 David Toback, AESS Seminar 20

Later, Quarks Combine to Form Nucleons qqq Proton Quark Nuclear Reaction Quark September 2014 Proton Quark David Toback, AESS Seminar 21

A Millionth of a Second after the Big Bang The quarks have combined to form Protons and Neutrons September 2014 David Toback, AESS Seminar 22

Creating Heavier Nuclei Proton + Proton Deuterium Nuclear Reaction September 2014 Deuterium David Toback, AESS Seminar 23

A couple hundred thousand years later: Atoms Proton Electro. Magnetic Reaction Hydrogen Atom Electron September 2014 David Toback, AESS Seminar 24

Wait a Billion Years After about half a billion years, because of gravity, atoms combine to form the first stars and galaxies September 2014 Our galaxy, the Milky Way David Toback, AESS Seminar 25

After about 9 billion years our solar system and the Earth form September 2014 David Toback, AESS Seminar 26

Recent History: Life on Earth • Earth is about 4 or 5 billion years old • Evidence that microbial tracings existed on Earth about 3. 5 billion years ago • Humanoids, like “Lucy” existed a mere 3 million years ago • Homo-sapiens at around 100, 000 years ago September 2014 David Toback, AESS Seminar 27

What does Dark Matter have to do with the Big Bang Theory? September 2014 David Toback, AESS Seminar 28

The Known Particles – No known particles have the properties of Dark Matter – Other reasons to believe there are new fundamental particles to be discovered – For example, we just discovered the Higgs Boson – Maybe Dark Matter is a New Particle! September 2014 David Toback, AESS Seminar 29

What IS the Dark Matter? We don’t know… Hypothesis: The Dark Matter in the Universe is made up of LOTS of particles r ! that we haven’t discovered yet! e g g n g a i B b Best Guess: Hugeignumbers got s created in t B e geverything else the Early Universe like e s r e v and are ni still here today! U n The Today: Observe 5 times more Dark Matter than Atoms (by September 2014 David Toback, AESS Seminar mass) in the Universe 30

What are scientists doing today to discover Dark Matter? Just mention two of the fun experiments being done here at Texas A&M! September 2014 David Toback, AESS Seminar 31

Some Sources of Dark Matter are Cheap You are here September 2014 Our Sun is Moving through our Galaxy… Lots of Dark Matter is hitting the Earth every second David Toback, AESS Seminar 32

Experiment Dark Matter Particle Ping I saw it! Eureka! Atom in Detector Low Temperature Detector September 2014 David Toback, AESS Seminar 33

Can we Make and Discover Dark Matter? • High energy collisions between particles in the Early Universe • Recreate the conditions like they were RIGHT AFTER the Big Bang • If we can produce Dark Matter in a collision then we can STUDY it September 2014 David Toback, AESS Seminar 34

More Expensive Dark Matter? High Energy Collisions Dark Matter Particles LHC ≈1 ps after the Big Bang Detector k r a ti cl e Proton r a P Proton Ok… Its more complicated than this since Dark Matter Particles don’t easily interact with detectors… Nor do we usually produce them directly 35 David Toback, AESS Seminar Pa r er at t M k ar September 2014 D a M r e tt e l tic

Aerial View of the LHC 27 km in Circumference! Lake Leman One of the largest and the most complex scientific CMS instrument ever conceived & Geneva Airport Two huge detectors built by humankind Collides high energy protons p p ATLAS September 2014 David Toback, AESS Seminar 36

How does it do it? Accelerates protons to REALLY high energies, then bashes them together http: //people. physics. tamu. edu/toback/Tal September 2014 David Toback, AESS Seminar ks/Video/particle_event_full_ns. avi 37

Final Thoughts September 2014 David Toback, AESS Seminar 38

Interested in learning more? • Physics department now offers a course entitled “Big Bang & Black Holes” (ASTR/PHYS 109) – Covers Stephen Hawking’s “Brief History of Time” – Origin and Evolution of the Universe – How do stars form? – What is Dark Matter? Dark Energy? – What are Black Holes? – General Relativity & Quantum Mechanics – Particle Physics http: //faculty. physics. tamu. edu/toback/109/ September 2014 David Toback, AESS Seminar/ http: //people. physics. tamu. edu/toback/Talk. Science 39

Conclusions • It’s an incredibly exciting time to be a scientist! • Astronomy, Cosmology and Particle Physics are all coming • Perhaps we understand the role of Dark Matter in the Universe since the Big Bang! • If our understanding is correct, a major discovery may be just around the corner! September 2014 David Toback, AESS Seminar 40

September 2014 David Toback, AESS Seminar 41

Abstract Scientists have entered a golden age of discovery. We are 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 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 believe there is a new, fundamental particle just around the corner waiting to be discovered that could all these things together September 2014 David Toback, AESS Seminar 42