January 2009 David Toback, Saturday Morning Physics 1 Prof. David Toback Texas A&M University January 2014 Dark Matter and the Big Bang Theory

Overview January 2014 David Toback, Saturday Morning Physics 2 Two of the most exciting topics in all of science are Dark Matter and the Big Bang Start with questions: What IS Dark matter and what is the evidence for it? What IS the Big Bang Theory? What does Dark Matter have to do with the Big Bang? What are scientists doing today to discover Dark Matter? Final Thoughts

What is Dark Matter? January 2014 David Toback, Saturday Morning Physics 3

Dark Matter January 2014 David Toback, Saturday Morning Physics 4 What is some of the evidence for Dark matter?

How stars move in galaxies January 2014 David Toback, Saturday Morning Physics 5 Start by considering the case that there IS no Dark Matter in galaxies Can use laws of gravity to predict the orbits of planets and stars as they move around the solar system and galaxy For the solar system, the data agree perfectly, but for the outer part of galaxies it should look like stars in orbit around a massive center Problem: This isn’t what the data shows

January 2014 David Toback, Saturday Morning Physics 6 sics.tamu.edu/to back/Talks/Video /Lab4_SS1_video.swf

As the Galaxy Turns /Talks/Video/Lab4_GX1_video_slow.sw f January 2014 David Toback, Saturday Morning Physics 7

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) January 2014 David Toback, Saturday Morning Physics 8

Our Place in the Universe You are here In some ways, 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? January 2014 David Toback, Saturday Morning Physics 10

Not that Big Bang Theory January 2014 David Toback, Saturday Morning Physics 11

January 2014 David Toback, Saturday Morning Physics 12 A Big Bang Occurred… Then What? The Story of the Universe since the Beginning

January 2014 David Toback, Saturday Morning Physics 13 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

So What? January 2014 David Toback, Saturday Morning Physics 14 All the stuff in the galaxies appears to have come from a single point in space ~13.7 billion years ago Name this time The Big Bang  A moment of Creation What happened in the past? Run the clock backward in time

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? January 2014 David Toback, Saturday Morning Physics 15

March 2011 David Toback, Texas A&M University Davidson Scholars 16 A Brief History of Time Zero One millionth of one second after the Bang A few minutes A few hundred thousand years 100 million to 1 billion years 9 billion years ~13.7 billion years The Big Bang  produces lots of particles Quarks combine to form protons and neutrons Protons and Neutrons combine to form the nucleus of an atom Nuclei and electrons combine to form atoms Atoms combine to form Stars and Galaxies The Earth and our solar system forms You listen to me talk

May 2009 David Toback, Texas A&M University 17 Artists Conception of the Big Bang

May 2009 David Toback, Texas A&M University 18 The very early Universe Lots of free particles just hanging around… Universe is so hot that quarks can’t combine to make protons/neutrons

May 2009 David Toback, Texas A&M University 19 Later, Quarks Combine to Form Nucleons Quark  Proton Nuclear Reaction Quark qqq  Proton

May 2009 David Toback, Texas A&M University 20 A Millionth of a Second after the Big Bang The quarks have combined to form Protons and Neutrons

Creating Heavier Nuclei January 2014 David Toback, Saturday Morning Physics 21 Proton  Deuterium Nuclear Reaction Proton + Proton  Deuterium

January 2014 David Toback, Saturday Morning Physics 22 A couple hundred thousand years later: Atoms Proton Electron  Hydrogen Atom ElectroMagnetic Reaction

May 2009 David Toback, Texas A&M University 23 Wait a Billion Years After about a billion years, because of gravity atoms combine to form the first stars and galaxies Our galaxy, the Milky Way

May 2009 David Toback, Texas A&M University 24 After about 9 billion years our solar system and the Earth form

May 2009 David Toback, Texas A&M University 25 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

What does Dark Matter have to do with the Big Bang Theory? January 2014 David Toback, Saturday Morning Physics 26

The Known Particles January 2014 David Toback, Saturday Morning Physics 27 –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 !

January 2009 David Toback, Saturday Morning Physics 28 Hypothesis: The Dark Matter in the Universe is made up of LOTS of particles that we haven’t discovered yet! Best Guess: Huge numbers got created in the Early Universe like everything else and are still here today! Big Bang! Then Universe gets bigger What IS the Dark Matter? We don’t know… Today: Observe 5 times more Dark Matter than Atoms in the Universe

What are scientists doing today to discover Dark Matter? Just mention two of the fun experiments being done here at Texas A&M! January 2014 David Toback, Saturday Morning Physics 29

Some Sources of Dark Matter are Cheap January 2014 David Toback, Saturday Morning Physics 30 You are here Our Sun is Moving through our Galaxy… Lots of Dark Matter is hitting the Earth every second

Experiment January 2014 David Toback, Saturday Morning Physics 31 Dark Matter Particle Atom in Detector Detector Ping I saw it! Eureka!

Can we Make and Discover Dark Matter? January 2014 David Toback, Saturday Morning Physics 32 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

October 2011 David Toback, Texas A&M University Research Topics Seminar 33 More Expensive Dark Matter? High Energy Collisions  Dark Matter Particles LHC  ≈1 ps after the Big Bang Dark Matter Particle Detector Proton Ok… Its more complicated than this since Dark Matter Particles don’t easily interact with detectors… Nor do we usually produce them directly

May 2009 David Toback, Texas A&M University 34 Aerial View of the LHC CMS ATLAS 27 km in Circumference! One of the largest and the most complex scientific instrument ever conceived & built by humankind p p Collides high energy protons Two huge detectors Lake Leman Geneva Airport

January 2009 David Toback, Saturday Morning Physics 35 How does it do it? Accelerates protons to REALLY high energies, then bashes them together ks/Video/particle_event_full_ns.avi

Final Thoughts January 2014 David Toback, Saturday Morning Physics 36

January 2009 David Toback, Saturday Morning Physics 37 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 –High School Students: Get your school to get involved with the Talk Science Program /

Conclusions January 2014 David Toback, Saturday Morning Physics 38 It’s an incredibly exciting time to be a scientist! Astronomy, Cosmology and Particle Physics are all coming together! Starting to 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! Wanna join us? We need your help!

January 2009 David Toback, Saturday Morning Physics 39