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

1. What does Dark Matter have to do with the Big Bang Theory? Prof. David Toback Texas A&M University Mitchell Institute for Fundamental Physics and Astronomy Mock Lecture, March 2019

2. Mock Lecture for ASTR/PHYS 109 • Physics & Astronomy department offers a course entitled “Big Bang & Black Holes” (ASTR/PHYS 109) • Covers Stephen Hawking’s “Brief History of Time” • What is the Big Bang? (Cosmology, Origin and Evolution of the Universe) • What are Black Holes? • What is Dark Matter? Dark Energy? Anti-matter? • How do stars form? • More on General Relativity, Quantum Mechanics and Particle Physics • Has a lab (if you want) and can be used as a Science Distribution credit • There is an option to take it as an Honors class http://people.physics.tamu.edu/toback/109/ David Toback, Aggie Recruitment Committee

3. Prologue We live in a time of remarkable scientific understanding Scientists are arrogant/crazy enough to think that it may be possible to solve major problems in Astronomy, Cosmology and Particle Physics with a single discovery that ties all three together 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 Goal of this talk: To show you how all this might just tie together David Toback, Honors/Pasta and Prof

4. Overview David Toback, Honors/Pasta and Prof 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

5. What is Dark Matter? David Toback, Honors/Pasta and Prof

6. Dark Matter What is some of the evidence for Dark matter? David Toback, Honors/Pasta and Prof

7. 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 David Toback, Honors/Pasta and Prof

8. http://people.physics.tamu.edu/toback/Talks/Video/Lab4_SS1_video.swfhttp://people.physics.tamu.edu/toback/Talks/Video/Lab4_SS1_video.swf David Toback, Honors/Pasta and Prof

9. As the Galaxy Turns http://faculty.physics.tamu.edu/toback/Talks/Video/Lab4_GX1_video_slow.swf David Toback, Honors/Pasta and Prof

10. 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) David Toback, Honors/Pasta and Prof

11. Our Place in the Universe 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 You are here

12. What is the Big Bang Theory? David Toback, Honors/Pasta and Prof

13. Not that Big Bang Theory David Toback, Honors/Pasta and Prof

14. A Big Bang Occurred… Then What? The Story of the Universe since the Beginning David Toback, Honors/Pasta and Prof

15. 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 David Toback, Honors/Pasta and Prof

16. So What? 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 David Toback, Honors/Pasta and Prof

17. 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? David Toback, Honors/Pasta and Prof

18. A Brief History of Time • 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 • 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 David Toback, Texas A&M University Davidson Scholars

19. Artists Conception of the Big Bang David Toback, Texas A&M University

20. Before a millionth of a Second Lots of free particles banging into each other

21. Later, Quarks Combine to Form Protons and Neutrons qqq  Proton Quark Nuclear Reaction Proton Quark Quark David Toback, Texas A&M University

22. A Millionth of a Second after the Big Bang The quarks have combined to form Protons and Neutrons

23. Creating Heavier Nuclei Proton Proton + Proton  Deuterium Nuclear Reaction Deuterium David Toback, Honors/Pasta and Prof

24. A couple hundred thousand years later: Atoms Proton ElectroMagnetic Reaction HydrogenAtom Electron David Toback, Honors/Pasta and Prof

25. Wait a Billion Years 0 Our galaxy, the Milky Way After about a billion years, because of gravity atoms combine to form the first stars and galaxies David Toback, Texas A&M University

26. 0 After about 9 billion years our solar system and the Earth form David Toback, Texas A&M University

27. 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 David Toback, Texas A&M University

28. What does Dark Matter have to do with the Big Bang Theory? David Toback, Honors/Pasta and Prof

29. 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! David Toback, Honors/Pasta and Prof

30. What IS the Dark Matter?We don’t know… 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 Today:Observe 5 times more Dark Matter than Atoms in the Universe David Toback, Honors/Pasta and Prof

31. What are scientists doing today to discover Dark Matter? Just mention two of the fun experiments being done here at Texas A&M! David Toback, Honors/Pasta and Prof

32. Some Sources of Dark Matter are Cheap You are here Our Sun is Moving through our Galaxy… Lots of Dark Matter is “hitting” the Earth every second David Toback, Honors/Pasta and Prof

33. Experiment Dark Matter Particle I saw it! Eureka! Ping Atom in Detector Detector David Toback, Honors/Pasta and Prof

34. 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 David Toback, Honors/Pasta and Prof

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

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

37. How does it do it? Accelerates protons to REALLY high energies, then bashes them together http://people.physics.tamu.edu/toback/Talks/Video/particle_event_full_ns.avi David Toback, Honors/Pasta and Prof

38. Final Thoughts David Toback, Honors/Pasta and Prof

39. Conclusions • 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! David Toback, Honors/Pasta and Prof

40. End of Lecture David Toback, Honors/Pasta and Prof