Big Bang, Black Holes, No Math ASTR/PHYS 109 Dr. David Toback Lecture 4

Prep For Today (is now due) – L4 Reading: No new reading Pre-Lecture Reading Questions: PLRQ Unit 1: Was due Tuesday before class Grading in progress/will be posted soon (let us know if you were misgraded) This assignment is Pass/Revise: You must get a 10/10. If you need to do a Revision, please submit a revision before class on Monday Send mail to 109help if you need an extension eCampus Stuff: All Warm-up quizzes (including AMS): Was due Tuesday before class Extensions granted if needed. Email 109help EOC 2: Was due before class Papers Paper 0 (Reviewer Training): Will be assigned when we finish Chapter 4 You must do all the required parts of this assignment to pass it, if you didn’t/couldn’t get something in on time send email to 109help ASAP

Next Topic: Going Small Finished looking at various things in the universe going from the sizes we know to the VERY big Next we do the very small Why? If we want to understand the universe we need to know what’s in it and what its made of Then we can get to the “Why and how did it get to be the way it is?”

Starting out with small things A baseball is a size we know from everyday experience 10 centimeters, or 0.1 meters, or 10-1 meters. About 3 inches

Something smaller you can see with your eyes Getting smaller Something smaller you can see with your eyes 0.01 meters, (10-2 m) or 1 cm, or about a 1/3 of an inch

Much smaller A simple dust mite is barely visible with the naked eye Into the realm of biology 10-3 meters or 1 millimeter

A human hair Looking a the side view of a single hair 10-4 meters

Closer still… A single red blood cell 10-5 meters

Further still An HIV virus which is one of the bigger known viruses 10-6 meters

Small Virus A polio virus which is known to be one of the smaller viruses 10-7 meters

The Double Helix 10-8 meters A close up of the helical structure of DNA Starting to get into Chemistry 10-8 meters

An Atom What we’re seeing is the electron “cloud” as it goes around the atom Kinda like the blades of a fan The realm of Physics 10-9 meters or 1 nanometer 10 million in a cm

Inside an Atom Snapshot in time of 2 electrons “orbiting” the nucleus Atoms are “composite” things, not fundamental 10-10 meters

The Central Part of the Atom The electrons are outside our field of view 10-11 meters

Homing in on The Nucleus Still zooming into the center of the atom The atom is mostly empty space 10-12 meters

The Structure of the Nucleus Can just start to see the “stuff” inside the nucleus The nucleus is not fundamental 10-13 meters

Protons and Neutrons A carbon atom has 6 protons (blue) and 6 neutrons (grey) VERY tightly packed 10-14 meters

Inside the Proton Three quarks inside the proton Protons are composite Quarks are fundamental 10-15 meters

Other Fundamental Particles? Electrons and quarks (as far as we know) are fundamental Lots of other fundamental particles Recently discovered the Higgs Boson

Anti-Matter Each fundamental particle has an anti-matter version which is also fundamental

Stable and Unstable Particles Protons are stable  live forever Neutrons outside a nucleus are unstable  can decay Neutron  Proton + Electron + Neutrino Electron Decay Proton Neutron Neutrino Note that this only happens when Neutrons are by themselves (not in an atom)

Questions… How large are electrons and quarks? We don’t know… that’s what I (and others) do for a living… Are we SURE they are fundamental? Could they made of something smaller? Strings? Are there other fundamental particles we haven’t discovered?

Lecture on Chapter 3 now complete

Prep For Next Time – L4 Reading: No new reading Pre-Lecture Reading Questions: PLRQ Unit 1: Was due Tuesday before class Grading in progress/will be posted soon (let us know if you were misgraded) This assignment is Pass/Revise: You must get a 10/10. If you need to do a Revision, please submit a revision before class on Monday Send mail to 109help if you need an extension eCampus Stuff: All Warm-up quizzes (including AMS): Was due before class Extensions granted if needed. Email 109help EOC 2: Was due before class If we finished Chapter 3 then end-of-chapter quiz 3 (else just Chapter 2) Papers Paper 0 (Reviewer Training): Nothing to write! Will be assigned when we finish Chapter 4 You must do all the required parts of this assignment to pass it, if you didn’t/couldn’t get something in on time send email to 109help ASAP

Prep For Next Time – L4 Reading: No new reading Pre-Lecture Reading Questions: PLRQ Unit 1: Was due Tuesday before class Grading in progress/will be posted soon (let us know if you were misgraded) This assignment is Pass/Revise: You must get a 10/10. If you need to do a Revision, please submit a revision before class on Monday Send mail to 109help if you need an extension eCampus Stuff: All Warm-up quizzes (including AMS): Was due before class Extensions granted if needed. Email 109help EOC 2: Was due before class EOC 3: Due before class Tuesday Papers Paper 0 (Reviewer Training): Nothing to write! Will be assigned when we finish Chapter 4 You must do all the required parts of this assignment to pass it

Prep For Next Time – L5 Reading: No new reading Unit 2 reading probably assigned next time Pre-Lecture Reading Questions: Unit 1: Grades have been posted soon (let us know if you were misgraded) This assignment is Pass/Revise: You must get a 10/10. If you need to do a Revision, please submit a revision before class on Monday If you need an extension let me know End-of-Chapter Quizzes: Chapter 2: Was due already If we finished Chapter 3 then end-of-chapter quiz 3 (else just Chapter 2) Papers Paper 0 (Reviewer Training): Assigned when we do Chapter 4 You are required to do all the parts of this assignment, if you didn’t/couldn’t get something in on time send email to 109help ASAP

Prep For Next Time – L5 Reading: No new reading Unit 2 reading probably assigned next time Pre-Lecture Reading Questions: Unit 1: Grades have been posted (let us know if you were misgraded) This assignment is Pass/Revise: You must get a 10/10. If you need to do a Revision, please submit a revision before class on Monday If you need an extension let me know End-of-Chapter Quizzes: Chapter 2: Was due already Chapter 3: Due Monday before class Papers Paper 0 (Reviewer Training): Assigned when we do Chapter 4 You are required to do all the parts of this assignment

Full Set of Readings So Far Required: BBBHNM: Chap 1-4 Recommended: BHOT: Chap. 1-3 SHU: Chap. 1-2 TOE: Chap. 1

End of Lecture

Clicker Quiz A muon is observed to decay into an electron and two different neutrinos. Is a muon considered a fundamental particle? No, because it has the electrons and neutrinos inside it so it can't be fundamental. Yes, because it isn't composed of electrons and neutrinos, it just decays into them No, because fundamental particles can't decay

Clicker Quiz Q: What does it mean for an electron to be "stable?" It is balanced with exactly one proton Its orbit ring exists in one plane (no wobble) It has reached minimum size (10-19 m) Undisturbed, it can go on living forever and ever They don't appear to be made of anything smaller

Inside an Atom If an atom were the size of a large city, then the neutrons and protons would be the size of a person, and the electrons and quarks would be smaller than a small freckle http://bigbang.physics.tamu.edu/Figures/StolenAnimations/Animation_Atom.mpg

Summary: The “Small” Sciences Matter Molecule Atom Nucleus Protons & Neutrons Quarks u cm 10-9 m 10-10 m 10-14 m 10-15 m <10-19 m Chemistry top, bottom, charm, strange, up, down Atomic Physics Give scale and relationship to the domain that high energy physicists work in. Introduce the fundamental bits of matter loosely so that audience can point back to bulk matter. Domain. Nuclear Physics Electrons <10-19 m Particle Physics

Other Fundamental Particles? Electrons and quarks (as far as we know) are fundamental Lots of other fundamental particles There is also anti-matter Each fundamental particle has an anti-matter version which is fundamental