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

2. 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. 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 to 109help ASAP

3. 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?”

4. 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

5. 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

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

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

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

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

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

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

12. 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

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

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

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

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

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

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

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

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

21. 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)

22. 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?

23. Lecture on Chapter 3 now complete

24. 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. 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 to 109help ASAP

25. 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. 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

26. 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 to 109help ASAP

27. 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

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

29. End of Lecture

30. 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

31. 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

32. 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

33. 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

36. 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