Peter Paul 01/27/05 PHY313-CEI544 Spring-05 1

PHY313 - CEI544The Mystery of Matter

From Quarks to the CosmosSpring 2005

Peter Paul

Office Physics D-143

www.physics.sunysb.edu PHY313

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The Mystery of Matter: The Course

• The Goal: To understand at a conceptual level…

• the current knowledge about the origin and forms of matter,

• the basic building blocks and what holds them together,

• the appearance of matter in the Universe and its evolution

• the open issues and plans to resolve them

• the spin-offs and benefits to society derived from the quest to understand “Matter”.

• The Process: The Course will..• be entirely web based: http://insti.physics.sunysb.edu/itp/lectures/05-Spring/PHY313/

• be rigorous in explaining the science without mathematical derivations or complex formulae,

• issue 5 to 6 homework problems each week, due the next week, based on material covered each week. The grade will be based on that homework with an optional final for extra credit

• http://www.physics.sunysb.edu/

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Visit to BNL on March 31

• The Goal: To visit the RHIC accelerator and its two large detectors, STAR & PHENIX

• The relativistic heavy ion collider uses heavy ion collisions to recreate the universe as it existed ~ 1 s after the Big Bang

• The tour buses(free) will start here at the beginning of the class and will return by the end of the class.

• Participation will be optional without impact on course grade.

• Registration on March 3.http://www.bnl.gov/rhic/

The STAR Detector at RHIC

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Brookhaven National Laboratory

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The View in 1898: Physics is complete

THEN CAME THE REVOLUTION

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The State of Physics at the End of 1900

• Newton “invents” mechanics

• Maxwell completes electrodynamics– Light is just an EM wave

– Incorporates Optics into EM

• Helmholtz & Boltzmann

• complete thermodynamics

• Then Planck discovers energy quantization

• Einstein “sees” the connections between these fields, before Quantum mechanics was developed.

MECHANICS

THERMO-DYNAMICS

ELECTRO-DYNAMICS

OPTICS

ENERGYQUANTIZATION

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1905: The Year of Albert Einstein

• http://www.aip.org/history/einstein/

• In 1905 Einstein produced 3 break-through papers:

1. Photoelectric effect: Light is an energy quantum that can be treated like a particle. E = h

2. Brownian motion: heat is kinetic energy of small particles moving in a medium:

3. Special Relativity: The speed of light must be the same in all inertial reference frame: E = mc2

4. His Gedanken Experiments established a whole new way to gain physical insight

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The Scales of Physics

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The Nomenclature of Dimensions

• Prefixes that define powers of ten

Fraction Prefix Symbol

10E(-18) atto a

10E(-15) femto f

10E(-12) pico p

10E(-9) nano n

10E(-6) micro

10E(-3) milli m

1

Multiple Prefix Symbol

10E(3) kilo k

10E(6) Mega M

10E(9) Giga G

10E(12) Tera T

10E(15) Peta P

10E(18) Exa E

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The Scales of Nature

• http://www.falstad.com/scale/

• http://imartinez.etsin.upm.es/ot1/Scales.html

• The Planck Scales as the ultimate for our current theory in the Universe:

• TPl = (G h/c5)1/2

Planck Length = 1.6 x 10-33 cmPlanck Time = 5.4 x 10 -44 sPlanck Energy = 1.2 x 10 19 GeV

• G = gravitational constant 6.67 x 10-11 N m2/kg2

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Red blood cells(~7-8 m)

DNA~2-1/2 nm diameter

Things NaturalThings Natural Things ManmadeThings Manmade

Fly ash~ 10-20m

Atoms of siliconspacing ~tenths of nm

Head of a pin1-2 mm

Quantum corral of 48 iron atoms on copper surfacepositioned one at a time with an STM tip

Corral diameter 14 nm

Human hair~ 60-120m wide

Ant~ 5 mm

Dust mite

200 m

ATP synthesis

~10 nm diameterNanotube electrode

Carbon nanotube~1.3 nm diameter

O O

O

OO

O OO O OO OO

O

S

O

S

O

S

O

S

O

S

O

S

O

S

O

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PO

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The Challenge

Fabricate and combine nanoscale building blocks to make useful devices, e.g., a photosynthetic reaction center with integral semiconductor storage.

Microworl

d

0.1 nm

1 nanometer (nm)

0.01 m10 nm

0.1 m100 nm

1 micrometer (m)

0.01 mm10 m

0.1 mm100 m

1 millimeter (mm)

1 cm10 mm

10-2 m

10-3 m

10-4 m

10-5 m

10-6 m

10-7 m

10-8 m

10-9 m

10-10 m

Visi

ble

Nanoworl

d

1,000 nanometers = In

frar

edU

ltrav

iole

tM

icro

wav

eSo

ft x-

ray

1,000,000 nanometers =

Zone plate x-ray “lens”Outer ring spacing ~35 nm

Office of Basic Energy SciencesOffice of Science, U.S. DOE

Version 01-18-05, pmd

The Scale of Things – Nanometers and MoreThe Scale of Things – Nanometers and More

MicroElectroMechanical (MEMS) devices10 -100 m wide

Red blood cellsPollen grain

Carbon buckyball

~1 nm diameter

Self-assembled,Nature-inspired structureMany 10s of nm

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Planck’s Constant h

• The two most important constants in Nature are:

• The speed of light c

C = 2.998 x 108 m/s

• Planck’s constant h

h = 6.626 x 10-34 J s or

4.137 x 10-15 eV s

• h is a very small amount of “action”

h c = 1240 eV nm

• Relativity becomes important when velocity ~ c

• Quantum effects become important when

energy x size ~ h c

• Example from chip design:Energy scale ~ 3 eVSize ~ 1240/3 nm = 400 nm

This is a very practical dimension!

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The Energy Scale of Matter

• http://www.jca.umbc.edu/~george/html/courses/glossary/key_energies.html

• Energy units in the standard system is the Joule, 1 W = 1 J/s

• In advanced physics the energy unit is the eV, the energy it takes to accelerate one electric charge with a potential of 1 Volt.

• This unit is very small

1 eV = 1.6 10 -19 Joules

1000 eV = 1 keV

1 Million eV = 1 MeV

1 Billion eV = 1 GeV

• A 27-in TV accelerates electrons to 30 keV

,

The Relativistic Heavy Ion Collider accelerates Au ions to 100 GeV x 197 ~ 20 TeV

about 1 Billion times your TV

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Energy scale of microscopic matter

• Atoms eV to keV

• Materials 0.1 eV

• Nuclei MeV

• Elementary particles 100 MeV to GeV

• Largest existing accelerator (LHC) 16 TeV = 1.6 x 103 GeV

• Unification scale 1016 GeV

• Planck Energy 1.2 x 1019 GeV

Thermal scales:

• Room temperature 1/40 eV

• Temperature of the sun surface6000 degrees ~ 0.5 eV

• Temperature to melt nuclei

170 MeV = 2000 x Billions of the temperature at the surface of the sun

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The Scale of the Fundamental Forces

http://csep10.phys.utk.edu/astr162/lect/cosmology/forces.html

http://hyperphysics.phy-astr.gsu.edu/hbase/forces/funfor.html

• We know four fundamental forces. (There may exist a fifth)

Interaction Relative Magnitude

Range Effect

Strong force 10E(40) Very short Binds nuclei

Electromagnetic force

10E(38) Very long Binds atoms and condensed matter

Weak nuclear force 10E(15) Very short Produces beta decay

Gravity 1 Very long Binds stellar systems

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Some questions about fundamental forces

• Why is there such a mismatch in the range of the various forces?

• Why is there such a huge difference in the strengths of the different forces?

• Why are there 4 different forces, instead of just one?

• At sufficiently high energies they all come together

• But where is gravity?

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What is Mass and where does it come from

• Mass defined by Newtons second law:

Force = Mass x AccelerationM = F / a in kg units

• But a macroscopic body of mass M consists of many small pieces that can move around inside the body.

• Where do the little pieces get their mass from?

• LHC and RHIC will provide the answer for that.

• But what about the mass of the Universe; Where does it come from?

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First Homework Set, due Feb. 3, 2005 1. Describe briefly the 3 important discoveries that Einstein published in 1905.

2. What insight made it possible for Maxwell to incorporate Optics into Electrodynamics?

3. Give the approximate dimensions of the Earth, an ant, an atom and a nucleus, with their appropriate dimensional prefixes.

4. Name the four forces that we encounter in Nature and describe briefly what action they perform.

5. If you ( weight 50 kg) run down a ski slope on a snowboard at a velocity of 10 m/s your energy of motion is ~ 2500 Joules. Explain why you don’t have to worry about the theory of relativity to describe your motion.

6. If the same snow boarder collides with another person during 1 second, explain why quantum effects are not important.

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How to submit Homework

• You have 3 possibilities:

1. Submit it ti me in class on the date it is due.

2. Put it in the TA’s (Xiao Shen) mailbox in the Physics Department main office on or before the due date

3. Submit it him by e-mail at the address: xshen@ic.sunysb.edu

• Please DO NOT submit it to me by e-mail