Big Bang, Black
Holes, No Math
ASTR/PHYS 109
Dr. David Toback
Lecture 4
Big Bang, Black
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Introduction
Topic 3: Going Small
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Prep For Today (is now due) – L4
• Reading (should already have been completed)
– Required: BBBHNM: Chapter 1-4
• Pre-Lecture Reading Questions (PLRQ)
– All Boot Camp quizzes in eCampus (already due)
– Unit 1 in CPR: Stage 1
• End-of-Chapter Quizzes
– Chapter 2
• Papers
– None assigned
– First one will be assigned when we do Chapter 6
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Topic 3: Going Small
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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
• Why and how did it get to be the
way it is?
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Topic 3: Going Small
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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
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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
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Topic 3: Going Small
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Much smaller
A simple dust
mite is barely
visible with the
naked eye
Into the realm
of biology
10-3 meters
or 1 millimeter
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A human hair
Looking a the
side view of
a single
hair
10-4 meters
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Closer still…
A single red
blood cell
10-5 meters
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Further still
An HIV virus
which is one
of the
bigger known
viruses
10-6 meters
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Topic 3: Going Small
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Small Virus
A polio virus
which is
known to be
one of the
smaller
viruses
10-7 meters
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The Double Helix
A close up of
the helical
structure of
DNA
Starting to get
into Chemistry
10-8 meters
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Topic 3: Going Small
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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
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10-9 meters or
1 nanometer
10 million in a cm
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Introduction
Topic 3: Going Small
Inside an Atom
• Snapshot in time of
2 electrons
“orbiting” the
nucleus
• Atoms are
“composite” things,
not fundamental
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-10 meters
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Introduction
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Topic 3: Going Small
The Central Part of the Atom
• The electrons
are outside our
field of view
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Topic 3: Going Small
10-11 meters
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Homing in on The Nucleus
• Still zooming
into the center
of the atom
• The atom is
mostly empty
space
10-12 meters
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The Structure of the Nucleus
Can just start to
see the “stuff”
inside the
nucleus
The nucleus is not
fundamental
10-13 meters
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Topic 3: Going Small
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Protons and Neutrons
• A carbon atom
has 6 protons
(blue) and 6
neutrons (grey)
• VERY tightly
packed
10-14 meters
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Inside the Proton
Three quarks inside
the proton
– Protons are
composite
– Quarks are
fundamental
10-15 meters
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Other Fundamental Particles?
• Electrons and
quarks (as far as
we know) are
fundamental
• Lots of other
fundamental
particles
• Recently discovered
the Higgs Boson
Introduction
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Anti-Matter
Each fundamental particle has an anti-matter
version which is also fundamental
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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
Note that this only
happens when Neutrons
are by themselves (not in
an atom)
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Neutrino
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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
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Summary: The “Small” Sciences
Matter
Molecule
Atom
Nucleus
Protons &
Neutrons
Quarks
u
cm
10-14 m
10-9 m
10-10 m
Chemistry
Atomic Physics
Nuclear
Physics
10-15 m
<10-19 m
top, bottom,
charm, strange,
up, down
Electrons
<10-19 m
Particle Physics
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Questions…
• How large are electrons and
quarks?
– We don’t know… that’s what I
(and others) do for a living…
• What are they “made of”? Are
they made of anything? Strings?
• Are there other fundamental
particles we haven’t discovered?
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Prep For Next Time – L4
• Reading:
– No new reading
– Unit 2 reading assigned next time, but likely
due Sept 16th
• Pre-Lecture Reading Questions
– PLRQ Boot Camp quizzes (due already)
– Unit 1: Stage 2 in CPR, due before class
Monday
• End of Chapter Quizzes
– If we finished Chapter 3 then EOC quiz 3
(else just Chapter 2)
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Full Set of Readings So Far
•Required: BBBHNM: Chap 1-4
•Recommended:
– BHOT: Chap. 1-3
– SHU: Chap. 1-2
– TOE: Chap. 1
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Clicker Quiz
A muon is observed to decay into an electron
and two different neutrinos. Is a muon
considered a fundamental particle?
a) No, because it has the electrons and
neutrinos inside it so it can't be
fundamental.
b) Yes, because it isn't composed of electrons
and neutrinos, it just decays into them
c) No, because fundamental particles can't
decay
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Clicker Quiz
Q: What does it mean for an electron to be
"stable?"
a) It is balanced with exactly one proton
b) Its orbit ring exists in one plane (no
wobble)
c) It has reached minimum size (10-19 m)
d) Undisturbed, it can go on living forever and
ever
e) They don't appear to be made of anything
smaller
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Prep For Next Time – L4
• Reading:
– No new reading
– Unit 2 reading assigned next time, but likely due
Feb 9th
• Pre-Lecture Reading Questions
– Stage 2 in CPR for Unit 1 due Wednesday before
class
– Stage 1 in CPR for Unit 1 Revision will be
assigned after grades are posted (will happen
after next class)
– Stage 1 for Unit 2 will be assigned Next class,
probably due Feb 9th
• End-of-Chapter Quizzes
– If we finished Chapter 3 then End-of-Chapter
Quiz 3 (else just Chapter
2)
Introduction
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Prep For Next Time – L5
• Reading:
– Unit 2
• Pre-Lecture Reading Questions
– Stage 1 for Unit 2 due before Class
– Stage 1 in CPR for Unit 1 Revision
will be assigned after grades are
posted
• End-of-Chapter Quizzes
– If we finished Chapter 3 then Endof-Chapter Quiz 3 (else just
Chapter 2) Introduction
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Topic 3: Going Small
Prep For Next Time – L3
• Reading:
–BBBHNM: Chap 3 and 4
• Reading Questions:
– Two questions from Chapter 3 or the
recommended reading
– Two questions from Chapter 4 or the
recommended reading
• eLearning Quizzes
– If we finished Chapter 3 then endof-chapter quiz
3 (else just 2)
Introduction
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Topic 3: Going Small
Prep For Next Time – L4
• Reading:
–BBBHNM: Chap 4
• Reading Questions:
– Two questions from Chapters 4
if you didn’t complete already
• eLearning End-of-Chapter Quizzes
– If we finished Chapter 3 then
end-of-chapter quiz 3 (else just
2)
Introduction
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Holes, No Math
Topic 3: Going Small
Prep for Today (Is now due) – L4
• Reading:
– Required: BBBHNM: Chapter 4
• eLearning End-of-Chapter Quizzes:
– End-of-Chapter Quizzes for
Chapter 2
• Reading questions:
– Two questions for Chapter 3 and
two questions for Chapter 4
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Introduction
Topic 3: Going Small
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Prep For Today (is now due) – L4
• Reading:
– Required: BBBHNM: Chapter 1-4
– Recommended Reading:
• BHOT: Chap. 1-3
• SHU: Chap. 1-2
• TOE: Chap. 1
• Pre-Lecture Reading Questions
– Three questions from Unit 1
• End-of-Chapter Quizzes
– Chapter 2
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Topic 3: Going Small
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Big Bang, Black
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Introduction
Topic 3: Going Small
Other Fundamental Particles?
• Electrons and quarks
(as far as we know)
are fundamental
• Lots of other
fundamental particles
• There is also antimatter
– Each fundamental
particle has an antimatter version which
is fundamental
Big Bang, Black
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Introduction
Topic 3: Going Small
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Prep For Next Time – L4
•Reading:
–BBBHNM: Chap 5
•Pre-Lecture Reading Questions:
–Two questions from Chapter 5
•End-of-Chapter Quizzes
–If we finished Chapter 3,
then do 3 (if not, just 2)
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Introduction
Topic 3: Going Small
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Prep For Next Time – L4
• Reading:
– Required: BBBHNM Unit 2 (Chapters 5-9), will
be due Monday
– Recommended Reading:
• See P3 of
http://people.physics.tamu.edu/toback/109/Syllabus.pdf
• Pre-Lecture Reading Questions
– Unit 1: Stage 1 Revision (if needed), due
Monday. Pass/Revise grades posted on CPR later
this week
• Will post the assignment after class
– Unit 2: Stage 1 due Monday
• End-of-Chapter Quizzes
– If we finished Chapter 3 then End-of-Chapter
2)
Introduction
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Black3 (else just Chapter
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Topic 3: Going Small