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

2. 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

3. Prologue Continued: Dark Matter September 2014 David Toback, AESS Seminar 3 We 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 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

4. Overview of the Talk 4 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

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

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

7. How Stars Move in Galaxies January 20147 David Toback, AESS Seminar 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

8. 8 http://people.phy sics.tamu.edu/to back/Talks/Video /Lab4_SS1_video.swf September 2014 David Toback, AESS Seminar

9. As the Galaxy Turns http://faculty.physics.tamu.edu/toback /Talks/Video/Lab4_GX1_video_slow.sw f 9September 2014 David Toback, AESS Seminar

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) 10September 2014 David Toback, AESS Seminar Lots of other evidence for dark matter like gravitational lensing, but that’s for another day…

11. 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

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

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

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

15. 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 September 2014 David Toback, AESS Seminar

16. So What? 16 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 September 2014 David Toback, AESS Seminar

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? 17September 2014 David Toback, AESS Seminar

18. 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 September 2014 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

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

20. 20 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

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

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

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

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

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

26. 26 After about 9 billion years our solar system and the Earth form September 2014

27. 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 September 2014 David Toback, AESS Seminar

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

29. The Known Particles 29 –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

30. 30 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… September 2014 Today: Observe 5 times more Dark Matter than Atoms (by mass) in the Universe

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

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

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

34. Can we Make and Discover Dark Matter? 34September 2014 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

35. David Toback, AESS Seminar 35 More Expensive Dark Matter? High Energy Collisions  Dark Matter Particles LHC  ≈1 ps after the Big Bang Dark Matter Particle Detector Proton September 2014 Dark Matter Particle Ok… Its more complicated than this since Dark Matter Particles don’t easily interact with detectors… Nor do we usually produce them directly

36. David Toback, AESS Seminar September 201436 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

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

38. Final Thoughts 38September 2014 David Toback, AESS Seminar

39. 39 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 September 2014 http://faculty.physics.tamu.edu/toback/109/ http://people.physics.tamu.edu/toback/TalkScience /

40. Conclusions 40 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

41. 41September 2014 David Toback, AESS Seminar

42. 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 42September 2014 David Toback, AESS Seminar