Astronomy, Cosmology, Particle Physics and The Universe

1. 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 Seminar

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 Physicsis about trying to understand the smallest things that make up the stuff in the Universe David Toback, AESS Seminar

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

4. 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 David Toback, AESS Seminar

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

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

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, AESS Seminar

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, AESS Seminar

9. As the Galaxy Turns http://faculty.physics.tamu.edu/toback/Talks/Video/Lab4_GX1_video_slow.swf 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) Lots of other evidence for dark matter like gravitational lensing, but that’s for another day… David Toback, AESS Seminar

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? David Toback, AESS Seminar

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

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

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, AESS Seminar

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, 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? David Toback, AESS Seminar

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, AESS Seminar

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

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 David Toback, AESS Seminar

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

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

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

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

25. Wait a Billion Years 0 Our galaxy, the Milky Way After about half a billion years, because of gravity, atoms combine to form the first stars and galaxies David Toback, AESS Seminar

26. 0 After about 9 billion years our solar system and the Earth form David Toback, AESS Seminar

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, AESS Seminar

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

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, AESS Seminar

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 (by mass) in the Universe David Toback, AESS Seminar

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, AESS Seminar

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, AESS Seminar

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

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, AESS Seminar

35. More Expensive Dark Matter? High Energy Collisions  Dark Matter ParticlesLHC  ≈1 ps 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, AESS 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, AESS Seminar

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, AESS Seminar

38. Final Thoughts David Toback, AESS Seminar

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 http://faculty.physics.tamu.edu/toback/109/ http://people.physics.tamu.edu/toback/TalkScience/ David Toback, AESS Seminar

40. 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! David Toback, AESS Seminar

41. End of Lecture 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 David Toback, AESS Seminar