physics we need topic 4: nuclear physics & chemistry big bang, black holes, no math 1 big bang,...

Physics We NeedTopic 4: Nuclear Physics &

Chemistry

Big Bang, Black Holes, No Math

1


ASTR/PHYS 109

Dr. David TobackLecture 12 & 13


Chemistry


2

Was due Today – L13• Reading:

– (BBBHNM Unit 2)• Pre-Lecture Reading Questions:

– Let us know if you were misgraded– Unit 1 in CPR

• You MUST pass this portion to pass the class• Grades on eCampus, Contact me if you haven’t

passed yet (additional quizzes needed)• End-of-Chapter Quizzes:

– Chapter 7a & 7b quizzes• Paper 1:

– (Stage 2 is due Monday before class)– (Text needs to be in turnitin on eCampus)

• Honors Paper:– Stage 1 due March 11th


Chemistry


Heads Up: Paper 2

•What is the evidence that Stars are made of Atoms?

•This will be the topic of Paper 2

• In order to understand the evidence, we next talk about Atoms and how they work

•Will be assigned after we finish Chapter 8

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Chemistry


4

Outline for Unit 2: Physics We Need

1. Light and Doppler Shifts Done

2. Gravity, General Relativity and Dark MatterDone

3. Atomic Physics and Quantum Mechanics Done

4. Nuclear Physics and Chemistry This time

5. Temperature and Thermal Equilibrium


Chemistry


5

Looking at the Lights in the Sky

What we know about the universe comes from multiple places

So far:•Learned about the light coming from the sky

•Learned that atoms can produce this light


Chemistry


6

Questions We’re Trying to Answer

• What are stars made of?

• What can we learn from looking at them?

• How do we know?Today: More about

different types of atoms that produce the light

A “smoking gun” piece of evidence that the light from the sky is from atoms out there


Chemistry


7

Outline

•Overview•What protons and neutrons

are made of: Quarks•How protons and neutrons

interact & combine to form a nucleus

•Chemistry•Spectral lines

–Light from stars!•Learning about the stars


Chemistry


8

Overview of the story• Big things are made from LOTS of small things • Small things: The Fundamental Building Blocks of Nature

– What is the “stuff” in atoms• ElectroMagnetism (electric charge)

– What holds electrons and protons together• Quantum Mechanics

– Why atoms form the way they do– Electron in orbits– Atoms absorbing and emitting photons (light)

• Different TYPES of Atoms– The Strong Force– Keeping protons and neutrons together (atomic nuclei)– Nuclear Physics and Chemistry– Different atoms Different light…

• Studying the Stars using their light– Spectral lines of the atoms – Atomic “fingerprints”– The light we see from the stars

LastLecture

ThisLecture


Chemistry


9

Smaller Building Blocks of Nature

•Atoms are made of a nucleus surrounded by electrons–Many types of nuclei–Only one kind of electron

•Nuclei is composed of neutrons and protons–Neutrons and protons are two different types of nucleons

•Nucleons are made of quarks


Chemistry


10

Chemistry

•We can put nucleons together in lots of different ways…

•Each different way corresponds to a different type of atom

Knew about the periodic table in the 19th century,

understood it was just combinations of protons and

neutrons in the 1920’s


Chemistry


11

Observation: Different Kinds of Atoms

•The kind of atom depends on the number of protons in the nucleus

Helium 4

Different numbers of

neutrons ↔ different isotopes• Helium (He),

with 2 protons, 2 neutrons and 2 electrons


Chemistry


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Why do nucleons stick together?

•If what holds the atom together is the opposite charge of the protons and the electrons… Why don’t the same sign charges of the protons “blow the nucleus apart?”


Chemistry


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What Nucleons are Made Of

•Each nucleon is made of 3 quarks

•Two different types of quark

•Called “up” quarks and “down” quarks

•Each quark has fractional charge

More to say about this

later


Chemistry


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What holds the quarks together?

• The strong force holds the quarks together inside the nucleon

• The force mediator is the “gluon”– Quarks talk

to each other via gluons


Chemistry


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The Answer

The same strong force keeps the nucleons together

Essentially the gluons “leak” out of the nucleons and provide the attractive force


Chemistry


So what?

•Why do we care about all the different kinds of atoms?

•What does this have to do with Stars and the Big Bang?

•The different mass and charge of each nucleus means that each as a different set of energy levels–Each one has unique fingerprints!

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Chemistry


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Different energy levels for each different type of atom

Can use light of different energies to identify atoms: Different Colors

Hydrogen Helium Boron

Fingerprinting the

different atoms


Chemistry


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Atomic Fingerprints•Each atom produces a large number of different wavelengths with VERY SPECIFIC values

•Quantum Mechanics predicts ALL of them

•If you see all the ones you expect and none you don’t, that gives you confidence


Chemistry


More on Fingerprinting

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• Look at light from a light bulb with Hydrogen gas in the way

• Different lines will be absorbed by Helium

• Can now identify a mystery gas!


Chemistry


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Overview of the story• Big things are made from LOTS of small things • Small things: The Fundamental Building Blocks of Nature

– What is the “stuff” in atoms• ElectroMagnetism (electric charge)

– What holds electrons and protons together• Quantum Mechanics

– Why atoms form the way they do– Electron in orbits– Atoms absorbing and emitting photons (light)

• Different TYPES of Atoms– The Strong Force– Keeping protons and neutrons together (atomic nuclei)– Nuclear Physics and Chemistry– Different atoms Different light…

• Studying the Stars using their light– Spectral lines of the atoms – Atomic “fingerprints”– The light we see from the stars

LastLecture

ThisLecture


Chemistry


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Using Light From Stars

•Can look at the light from the stars to “see” if they are made of atoms

•Figure out what TYPE of atoms…

•How stars are formed…

•What makes them shine…


Chemistry


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What is a Star?

• Our best understanding is that stars are great big balls of (mostly) hydrogen gas

• The hydrogen interacts and produces the light we see– Makes them shine…

• What is the evidence for this?


Chemistry


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Stars

•What would happen inside a giant ball of hydrogen?–Interactions

•What would it look like to us?–Light from the interactions

–Next look at interactions


Chemistry


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Proton + Proton Deuterium + Anti-Electron + Neutrino

Hydrogen Interactions

Proton

Proton

DeuteriumNuclear Reaction

Anti-Electron

Neutrino

The Deuterium, neutrino and the Anti-Electron get energy in the

reaction


Chemistry


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Proton + Deuterium Helium3 + Photon

More interactions

Deuterium

Proton

Helium3

Nuclear Reaction

Photon

Photon can have almost any energy


Chemistry


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Helium3 + Helium3 Helium4 + 2 Protons

Creating Stable Helium

Helium3

Helium3

Helium4

Nuclear Reaction

Proton

Proton


Chemistry


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Stars

•Nuclear interactions in the center of the star create lots of energy which is eventually emitted as light from the surface of the star– Shine white (or yellow)

•This light passes through other atoms of the star– Light is “absorbed” by the outer atoms Spectral lines

•Tells us what the stars are made of


Chemistry


Looking at the Stars

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Chemistry


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Analyzing Absorption Spectra

•Each element produces a specific set of absorption (and emission) lines

•Using this information, we can study the composition of stars

See only spectral lines for known atoms


Chemistry


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Remarkable…

•The Sun and stars are mostly made of Helium and Hydrogen

•Our Sun is made of the same stuff as all the other stars!

•The stuff out in the universe is made of the same stuff that is found here on Earth!


Chemistry


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Even More Remarkable

If all the stuff “out there” looks the same as the stuff here on Earth then:

–The particles out there (electrons, protons, photons etc.) are the same as they are here–The laws of physics that govern putting together protons, nuclei and atoms are likely to be the same everywhere! –Provides evidence that it’s been this way for billions of years!


Chemistry


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Now that we know what stars are made of and

what they are SUPPOSED to look like, can we learn anything

else?


Chemistry


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•What if the stars were MOVING?

•Can we tell? Yes! Doppler effect

How?


Chemistry


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Atoms with Different Speeds

•If an atom emits a photon it will correspond to an energy that reflects the change of two energy levels

•However if the atom is MOVING the light will be shifted to a different color


Chemistry


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Observing an Atom

Atom Emitting Light

Not MovingMoving to the right

Can use this to study the motions of the stars


Chemistry


Looking at the Stars

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Provides additional evidence stars are

made of atoms


Chemistry


Paper 2

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• Abbreviated description: What is the evidence that Stars are made of Atoms? – More detail on CPR, you REALLY need to read

ALL the instructions• Explain it to someone who isn’t taking the

class (no jargon)• Format:

– Introduction paragraph– ~1 paragraph per piece of evidence– Conclusion paragraph that ties it together– http://faculty.physics.tamu.edu/toback/109/

WritingAssignments/samplepaper.shtml


Chemistry


Phase I and Phase II in CPRPhase I: (Due 1 week after we finish

Chapter 8)• Submit online two ways: CPR and

turnitin.comPhase II: (Due one week after Phase I)• Three-Part Calibrations/Reviewing

1. Calibrations, learning to use the Rubrics

2. Grade three other papers3. Grade your own paper

Want feedback before you submit? Get it to the TA on eCampus by Friday for guaranteed feedback.

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Chemistry


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Outline for Unit 2: Physics We Need

1. Light and Doppler Shifts Done

2. Gravity, General Relativity and Dark Matter Done

3. Atomic Physics and Quantum Mechanics Done

4. Nuclear Physics and Chemistry Done

5. Temperature and Thermal Equilibrium Next time


Chemistry


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Prep for Next Time – L12• Reading:


– Let us know if you were misgraded– Unit 1 Grades Posted in eCampus, contact if needed

• End-of-Chapter Quizzes:– If we finished Chapter 8 then end-of-chapter quiz 8 (else just up

to Chapter 7a & b)• Papers:

– Paper 1: • Stage 2 is due before class on Monday• (Text needs to be in turnitin on eCampus)

– Paper 2: • If we finished Chapter 8, Stage 1 is due Monday before class• Also due in turnitin

• Honors Paper:– Stage 1 due Wed March 11th


Chemistry


41

Prep for Next Time – L13• Reading:


– Let us know if you were misgraded– Unit 1 Grades Posted in eCampus, contact if needed (more

quizzes to take)• End-of-Chapter Quizzes:

– If we finished Chapter 8 then end-of-chapter quiz 8 (else just up to Chapter 7a & b)

• Papers: – Paper 1:

• Stage 2 is due before class on Monday• (Text needs to be in turnitin on eCampus)

– Paper 2: • If we finished Chapter 8, Stage 1 is due Monday before class• Also due in turnitin

• Honors Paper:– Stage 1 due Wed March 11th


Chemistry


Full set of Readings So Far

•Required:–BBBHNM: Chap 1-9

•Recommended:–BHOT: Chap. 1-6, 9 and 11 (117-122)

–SHU: Chap. 1-3, 6 and 7 (up-to page 153)

–TOE: Chap. 1

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Chemistry


43


Chemistry


Clicker QuestionA hydrogen atom is hit by a photon and the

electron absorbs the photon and moves to an excited state. Later, a photon with the exact same energy is emitted from the atom, and the electron moves back to its original state.

Is this the same photon as before? a)Yes, it was inside the electronb)Yes, it was bouncing around inside the atomc)No, the electron “destroyed” the original

photon and created the new photond)No, the nucleus “destroyed” the original

photon and created the new photon

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Chemistry


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Clicker Question

A star is observed with the following light pattern. Which way is it moving? a)Towards us, slow speedb)Away from us, slow speedc)Towards us, high speedd)Away from us, high speede)Stationary


Chemistry


Clicker Question

As far as we know, Dark Matter exists:

a)Everywhere in the universe

b)Only near black holesc)Mostly in or around galaxies

d)It doesn't existe)We don't know where it exists

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Chemistry


Clicker Question

A man shoots a red photon straight up into the air next to a very tall building. The photon rises in the air. Which statements are true:

a)The photon slows down as it rises, the same way a rock would

b)The photon loses energy, the same way a rock would

c)The photon gets blue-shifted

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Chemistry


Clicker QuestionInstead of throwing a rock into the air, a man shoots a red photon

straight up into the air next to a very tall building. The following question are about the photon when it reaches the top of the building. Which of the following statements are true

Question 1: Speeda) The speed of the photon stays the sameb) The speed of the photon slows down like a rock would

Question 2: Energya) The energy of the photon stays the same b) The energy of the photon gets lower (like the kinetic energy would

for a rock)c) The energy of the photon gets larger (since it is getting closer to

outer space)

Question 3: Colora) The color of the photon stays the sameb) The color of the photon is red-shifted (gets a longer wavelength)c) The color of the photon is blue-shifted (gets a shorter wavelength)

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Chemistry


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Clicker QuestionTwo mystery galaxies (on the right) only have a single spectral line in the visible spectrum as shown below.

If the above galaxy is stationary, which way is the below galaxy moving?a)Towards usb)Away from usc)It is also stationaryd)Not enough information


Chemistry


Extra Credit

• Still offering extra credit for people who find typos in the Textbook

• Extra credit for people who find mistakes for any/all eCampus quizzes or CPR assignments

• Now offering extra credit for students who send good clicker questions. If it becomes the basis for one used in class I will give you extra credit 50


Chemistry


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Prep For Next Time – L6•Final•Reading:

–BBBHNM: All reading through Chapter 10

•Reading Questions:–All reading questions through 10

•eLearning Quizzes:–Chapter 7

•Paper 2:–Calibrations and grading if you didn’t pass Paper 1, due before class on Monday


Chemistry


Tentative Due Dates• Monday March 4th (Today)

– Paper 1 revisions due– Paper 2 assigned

• Monday March 11th – No class, Spring Break. – Want feedback on a Paper 2 draft? Due today in eLearning

• Monday March 18th – Paper 3 Assigned– Reading for Chap 11 and 12, EOC quizzes for 9 due

• Tuesday March 19th – Paper 2 Text due in CPR and eLearning (1-day extension)

• Friday March 22nd

• Want feedback on a Paper 2 draft? Due today in eLearning• Monday March 25th

– Paper 2 Reviews due in CPR• Wednesday March 27th

– Paper 3 text due in CPR and eLearning (2-day extension)• Monday April 1st

– Paper 3 Reviews due in CPR

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Chemistry


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Prep for Next Time – P11•Reading:

–BBBHNM 9•Reading questions:

–Chapter 9 or the recommended reading

•End-of-Chapter Quizzes:– If we finished Chapter 8, end-of-chapter quiz due before next class (else just 7)

•Papers:–Paper 1 Resubmissions:

•CPR Calibrations due Monday–Start working on Paper 2

•Paper 2 due Monday in CPR/Turnitin.com


Chemistry


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Prep For Next Time – L13• Note: May change depending on how far we get in

lecture• Reading:

– BBBHNM: All reading through Chapter 9• Pre-Lecture Reading Questions:

– Through Chapter 9• End of Chapter Quizzes:

– If we finished Chapter 8 then end-of-chapter quiz 8 (else just up to Chapter 7)

• Papers:– Paper 0: Was due Friday. Pass/Revise grades will be

posted by the end of the night or after all regrades – Paper 0 Revision (if necessary – See eCampus score,

not CPR Score): Open now, Text due Monday before class. All Calibrations/Reviews following Monday

– Paper 1: Text was due before class. All Calibrations/Reviews due this coming Monday

– Paper 2 (if we finished Chapter 8): Due Monday before class.


Chemistry


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Prep for Next Time – P11

•Reading: –BBBHNM 9

•Reading questions: –Chapter 9 or the recommended reading

•End-of-Chapter Quizzes:–If we finished Chapter 8, end-of-chapter quiz due before next class (else just 7)

•Paper:–If you see problems with the grading of your Paper 1 send us email

–Work on revision if needed


Chemistry


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Prep for Next Time – P12•Reading:

– BBBHNM 9•Reading questions:

–Chapter 9 or the recommended reading

•End-of-Chapter Quizzes:– If we finished Chapter 8, end-of-chapter quiz due before next class (else just 7)

•Paper:– If you see problems with the grading of your Paper 1 send us email

–Work on revision if needed–Start working on paper 2


Chemistry


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Prep for Today (Is now due) – L11


•End-of-Chapter Quizzes:–Chapters 2-6

•Reading questions:–Two questions from Chapter 8 or recommended reading

•Paper 1:–CPR work was due today


Chemistry


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Prep for Today (Is now due) – L12


•End-of-Chapter Quizzes:–Chapter 7

•Reading questions:–Two questions from Chapter 9

•Paper 1:–Working on Revisions if necessary


Chemistry


Paper 0 Notes

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• If you believe you were misgraded on Paper 0 let us know ASAP

• If you did not pass all the pieces of Paper 0 you need to do a full revision in CPR including calibrations and grading– If you did well on the text, you don’t

need to change much• Pass/Revise Grading will be posted on

eCampus after we have responded to all the requests for regrades

• You need a passing grade on paper 0 to pass the course


Chemistry


Sad Truth

•Every semester we have people who don’t listen to what is said in class and just look at their score on CPR and decide they have passed.

•Your score will be on eCampus.

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Chemistry


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Protons and Neutrons

•A carbon atom has 6 protons (blue) and 6 neutrons (grey)

•VERY tightly packed


Chemistry


62

Review of a Helium Atom

Again look at the stuff as we zoom in

http://bigbang.physics.tamu.edu/Figures/StolenAnimations/Animation_Atom.mpg


Chemistry


63

Exciting Atoms

Atom in Ground State

Proton

Atom in Excited State


Chemistry


64

Excited Atoms Emit Light

Photon with a

specific energy

Atom in Excited State

Atom in Ground State


Chemistry


65

Analyzing Absorption Spectra

•Each element produces a specific set of absorption (and emission) lines

•Comparing the relative strengths of these sets of lines, we can study the composition of stars

See only spectral lines for known atoms


Chemistry


Paper Notes

•~600 words (This is the equivalent of both side of a sheet of paper, double spaced)

•No citations! Use your own words

•Text should be professional. You are “trusted guide” not a “buddy” or “comedian”

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Chemistry


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Chemistry


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A “moving” Spectral Line…

More Blue

More Red


Chemistry


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Light from the Stars

A light bulb (or a star) will emit light at all wavelengths and thus produce a continuous spectrum


Chemistry


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What about the Gas Outside a Star?

•What will we see if we look at the Gas outside the star?

•Light from the star will hit the gas, and we see the light from the gas itself


Chemistry


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The light from excited atoms

If the light hits a bunch of low speed atoms (typically call this a gas) at specific wavelengths it can create an emission spectrum Light excites electrons in

atoms to higher energy states

Transition back to lower states emits light at specific energies

(wavelengths)


Chemistry


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When atoms “get in the way”

If a continuous spectrum of light passes through atoms, it can create an absorption spectrum

Light excites electrons in atoms to higher energy

states

Wavelengths corresponding to the transition energies are absorbed from the continuous

spectrum


Chemistry


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The Spectra of StarsInner parts of a star

produces a continuous spectrum

Outer parts absorb light at specific wavelengthsThe light spectrum shows spectral lines!


Chemistry


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Papers for the Course

• There will be three papers for the course– http://

faculty.physics.tamu.edu/toback/109/WritingAssignments/

• Due dates are posted there• Paper 1 will be assigned after we

start Chapter 9, due one week after we finish Chapter 9

• You should start thinking about your research paper topic


Chemistry


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Helium3 + Helium3 Helium4 + 2 Protons

Creating Stable Helium

Helium3

Helium3

Helium4

Nuclear Reaction

Proton

Proton


Chemistry


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Writing Assignments

1. Short Assignment 1 is Due Wednesday March 4th before the beginning of Class• Instructions on how to turn it in are

on the web2. Short Assignment 2 is posted

• Currently Due Wed March 253. Research Paper is posted

• Stage 0 due March 30th

• Stage 1 due April 13th • Final paper due the last day of

class, May 4thNeed to be finishing Unit 2 WebCT stuff


Chemistry


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Chemistry


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In Class Quiz

Answer the following question:

Why do we believe that stars are made of atoms?


Chemistry


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Looking Forward

With an understanding of how to build up nucleons, nuclei, atoms, molecules and matter here on earth we begin to have confidence that we can understand how to build up planets and moons, stars and galaxies in the sky

If we can understand how the objects in the universe were formed we have a chance to understand where it all came from


Chemistry


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Yet more remarkable

•Want to explain WHY most of the universe is Hydrogen

• Its not crazy to think that the reason its mostly hydrogen is because it started out as mostly quarks and just turned into Hydrogen, and not much else because its HARD to form the other stuff


Chemistry


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Chemistry


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Why Do Stars Shine?

•Stars are Hydrogen balls

•During the reactions of the Hydrogen (protons) creating heavier elements some of the light escapes

•This is why stars shine


Chemistry


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Different Types of Nuclei

•How do we CREATE different types of nuclei in nature?

•Collisions between nuclei allow them to combine

•Decay of nuclei allow them to change


Chemistry


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Summary

•Given enough nucleons and time you can eventually make helium

•Lots of energy released in the creation process

•From Helium and more protons you can make even heavier things…


Chemistry


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Forming Protons

Quark

Quark

ProtonNuclear Reaction

Quark

qqq Proton


Chemistry


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Now Nucleons Typically Combine in Nature

•Note about this video: They change the colors for the last slide!!!

•And the colors are screwed up for Helium on the last slide also!


Chemistry


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Electron Orbits

• Electron orbits in the electron cloud are restricted to very specific radii and energies.

r1, E1

r2, E2

r3, E3

• These characteristic electron energies are different for each individual element


Chemistry


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Spectral Lines

•Shine white light on a bunch of atoms:

•Prism shows the colors in white light going in

•After going through the atoms we are left with spectral lines–The excited states absorb and then re-emit in some different direction


Chemistry


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•Video here of photon coming in and exciting an atom then de-exciting… This explains excitations and then spectral lines.

•Prism of light coming from Page 54 of BHOT

• Jonathan!•Feynman diagram on page 71

of BHOT.


Chemistry


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History

•1816: Spectral lines: von Fraunhofer

•Different lines from different atoms

•1880 Huggins: Spectral lines indicate what the chemical elements are


Chemistry


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Chemistry

•How do we make up the different kinds of atoms

•Different number of protons and neutrons in the nucleus and electrons

•Energy states•Quantum mechanics•Spectral lines.


Chemistry


92

Fundamental continued• It turns out there are lots of different

types of nuclei– This is the domain of nuclear physics

• It turns out that a nucleus is actually just a collection of protons and neutrons– Hydrogen: a single proton– Helium: 2 protons and 2 neutrons– Sodium: XX protons and XX neutrons– More on what holds all this together

later…– More on what protons and neutrons

are made of later (answer for now… quarks)


Chemistry


93

Moving towards the fundamental building blocks

• What is gas made of?– It turns out its made of

molecules of different types– CN, others?

• What are molecules made of?– It turns out molecules are made

of different types of atoms put together in different ways

– Hydrogen, Helium, Sodium, Carbon, Nitrogen etc…


Chemistry


94

Spectral lines and Stars

•Atoms have excited states… these photons from the surface of the star excites the atom and is absorbed.

•Ok… they’re re-emitted later when the atom de-excites, but that goes in a random direction so we don’t see it.


Chemistry


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Chemistry


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Chemistry


97

•The same force holds the nucleons together


Chemistry


98

How Atoms Combine

•Need this?


Chemistry


99

Making Molecules

•H20 picture from Giancoli


Chemistry


100

•How atoms combine to form molecules?


Chemistry


101

Chemistry

•How do we make up the different kinds of atoms

•Different number of protons and neutrons in the nucleus and electrons

•Energy states•Quantum mechanics•Spectral lines.


Chemistry


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Chemistry


103

BHOT 11 cont…• Gravity continued… We think of gravity being

caused by the exchange of virtual gravitons (not yet confirmed).

• Gravity is the weakest of the forces by a lot• Two important things to know:

– It acts even at long distances– It is (as far as we know) always attractive

• So what, if objects are really far away we might never notice gravity, but if they are really HEAVY then the attraction can be big.

• Earth going around the Sun.• Others tend to cancel out.


Chemistry


104


Chemistry


105


Chemistry


106

Uncertainty Principle

•Uncertainty Principle determines the size of an atom and a nucleus

•DPDX > h


Chemistry


107

More so what…• One more particle that we need to talk about, and

that’s a photon (“gamma ray”).• A photon is actually light (a gamma ray hits our eyes

and that’s how we “see”)• It also turns out that photons also play an important

role in atoms• Why do the electrons “orbit” the nucleus? • The protons have positive charge, the neutrons are

neutral, and the electrons are negatively charge.• Since positive and negative charges attract each

other, the electrons are attracted to the nucleus and that’s what keeps them “in orbit”– Again, the truth is MUCH more complicated than

this, but its actually a good understanding…


Chemistry


108


Chemistry


109


Chemistry


110

How do the particles talk to each other? Feynman

Diagrams

e

e

W

d

u


Chemistry


111


Chemistry


112

Chemistry

•We can put nucleons together in lots of different ways…

•Each different way corresponds to a different type of atom


Chemistry


113


Chemistry


114

Quantum Mechanics

• Some quick discussions of quantum mechanics (particles and waves, probability, small sizes and big energies) and

• What do we do for Quantum mechanics – QM and Gribbins' book?– The great experiments? Two slit? Bohr

model? Heated metal? – Also mention to special relativity, general

relativity, thermodynamics as applied to stars and blackbody radiation, quantum mechanics, and any other general scientific ideas? Later perhaps?

– Need QM for now?


Chemistry


115

SHU 6• Anti-matter here? Page 149• When matter and anti-matter meet they

annihilate and disappear in a burst of energy• How could all the matter in the universe exist

and be easily detectible if theoretically there should be just as much antimatter around? Either the matter and antimatter should have annihilated each other, or we ought to be able to detect as much antimatter in the universe, which we clearly do not.

• Evidence for anti-electrons (positrons) in 1932.

• Ends on page 153


Chemistry


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Chemistry


117

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?


Chemistry


118

Fundamental Building Blocks

•This is a lecture on the fundamental building blocks of nature…

•Need a textbook for this…•Charm of Strange Quarks???

•Where is my lecture from Physics 101?


Chemistry


119

BHOT 11 cont…

• Force 2: Electromagnetic force• Most people know about this also,

it is what causes the interactions between electrically charge particles that we know and love

• Electrons and protons• Electrons and quarks• Ignores electrically neutral

particles such as neutrons and neutrinos.


Chemistry


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Chemistry


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physics we need topic 4: nuclear physics & chemistry big bang, black holes, no math 1 big bang,...

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