Why Study Nature? - PowerPoint PPT Presentation

Slide1 l.jpg
Download
1 / 47

Why Study Nature? Power (Control over it) “When will the Nile flood?” (time/astronomy) “What will make my sick baby better?” (medicine) “How can I make my spear fly faster and farther?” (physics) Celebrity Status A-List parties Red carpet treatment

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

Download Presentation

Why Study Nature?

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Why study nature l.jpg

Why Study Nature?

  • Power (Control over it)

    • “When will the Nile flood?” (time/astronomy)

    • “What will make my sick baby better?” (medicine)

    • “How can I make my spear fly faster and farther?” (physics)

Celebrity Status

A-List parties

Red carpet treatment

MTV interviews

Because we must.

Mankind has always been driven to understand the world.

The world is inherently simple and beautiful. It can be understood.

And always: Babes…never forget the babes…


Slide3 l.jpg

As a single, unified thing there

exists in us both life and death,

waking and sleeping, youth and

old age, because the former

things having changed are now

the latter, and when those latter things change, they become the former.

- Heraclitus

(quoted in

pseudo-Plutarch,

Consolation to

Apollo )


Slide4 l.jpg

Being is ungenerated and indestructible, whole, of

one kind and unwavering, and complete. Nor was

it, nor will it be, since now it is, all together, one,

continuous...That it came from what is not I shall

not allow you to say or think — for it is not

sayable or thinkable that it is not...How might what is then perish? How might it come into being? For if it came into being it is not, nor is it if it is ever going to be. Thus generation is

quenched and perishing unheard of.

- Parmenides

circa 480 BC


Science is about simplification l.jpg

Science Is About Simplification


Slide6 l.jpg

PHILOSOPHIÆ NATURALIS PRINCIPIA MATHEMATICA AUCTORE ISAACO NEWTONO Editio tertia MDCCXXVI

Axiomata sive Leges Motus

Lex I

Corpus omne perseverare in statu suo quiscendi vel movendi uniformiter in directum,

nisi quatenus a viribus impressis cogitur statum illum mutare.

Lex II

Mutationem motus proportionalem esse vi motrici impress", et fieri secundum lineam

rectam qua vis illa imprimitur.

Lex III

Actioni contrariam semper et æqualem esse reactionem: sive corporum duorum actiones

in se mutuo semper esse æquales et in partes contrarias dirigi.


Slide7 l.jpg

PHILOSOPHIÆ NATURALIS PRINCIPIA MATHEMATICA Author Isaac Newton Third edition (1726)

Three Laws of Motion

Law I

Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.

Law II

The relationship between an object's mass m, its acceleration a, and the applied force F is

F = ma.

Law III

For every action there is an equal and opposite reaction.

Everything pertaining from

astronomical motion to

falling here on Earth can be

fully described by Newton’s

Law of Gravity plus his

laws of motion.


Science is about simplification8 l.jpg

Science Is About Simplification


Slide9 l.jpg

James Clerk Maxwell (~1864)

Modern Nomenclature

Three

Become

one

Electricity

ElectroMagnetism

Magnetism

Light


Slide10 l.jpg

Then may we not fairly plead in reply that our true lover of knowledge naturally strives for truth, and is not content with common opinion, but soars with undimmed and unwearied passion till he grasps the essential nature of things ?

  • Plato

    Republic


Slide11 l.jpg

  • Science addresses many things:

    • What is the ultimate nature of reality?

    • What is the simplest expression of nature?

    • Amongst all of the undeniable change, is there anything that is permanent and enduring?

    • How did the universe come into existence and what is its ultimate fate?

    • What is the ultimate answer to the ultimate question?


Slide12 l.jpg

42

Mensans

PUNS

DOG

للها

Dyslexic

Christians

Moslems

GOD

Christians

What is the root of it all?

From where comes meaning?


Beauty in the universe l.jpg

Beauty in the Universe


Innermost space l.jpg

Innermost Space

High Energy Particle Physics is a study of the smallest pieces of matter.

It investigates the deepest and most fundamental aspects of nature.

It investigates (among other things) the nature of the universe immediately after the Big Bang.

It also explores physics at temperatures not common for the past 15 billion years (or so).


Periodic table l.jpg

Helium

Neon

All atoms are made

of protons, neutrons

and electrons

u

u

u

d

d

d

Electron

Neutron

Proton

Gluons hold quarks together

Photons hold atoms together

Periodic Table


Slide16 l.jpg

t

u

d

b

While quarks have similar electric charge, they have vastly different masses (but zero size!)

c

s


Slide18 l.jpg

a=e2/ħc


Fermi national accelerator laboratory a k a fermilab l.jpg

Fermi National Accelerator Laboratory(a.k.a. Fermilab)

  • Begun in 1968

  • First beam 1972 (200, then 400 GeV)

  • Upgrade 1983 (900 GeV)

  • Upgrade 2001 (980 GeV)

Jargon alert: 1 Giga Electron Volt

(GeV) is 100,000 times more energy

than the particle beam in your TV.

If you made a beam the hard way,

it would take 1,000,000,000 batteries


Slide21 l.jpg

  • The Main Injector upgrade was completed in 1999.

  • The new accelerator increases the number of

  • possible collisions per second by 10-20.

  • DØ and CDF have undertaken massive

  • upgrades to utilize the increased

  • collision rate.

  • Run II began March 2001

Expected

Number

of

Events

Huge statistics

for precision physics

at low mass scales

1000

Formerly rare processes

become high statistics

processes

100

Increased reach

for discovery physics

at highest masses

10

Run II

1

Run I

Increasing ‘Violence’

of Collision


How do you detect collisions l.jpg

How Do You Detect Collisions?

  • Use one of two large multi-purpose particle detectors at Fermilab (DØ and CDF).

  • They’re designed to record collisions of protons colliding with antiprotons at nearly the speed of light.

  • They’re basically cameras.

  • They let us look back in time.


Typical detector now l.jpg

Typical Detector (Now)

  • Weighs 5,000 tons

  • Can inspect 10,000,000 collisions/second

  • Will record 50 collisions/second

  • Records approximately 10,000,000 bytes/second

  • Will record 1015(1,000,000,000,000,000) bytes in the next run (1 PetaByte).

30’

30’

50’


Slide24 l.jpg

Spooky?


Remarkable photos l.jpg

Remarkable Photos

In this collision, a top and

anti-top quark were created,

helping establish their existence

This collision is the most violent

ever recorded (and fully understood). It required that

particles hit within 10-19 m or

1/10,000 the size of a proton


Modern cosmology l.jpg

Modern Cosmology

  • Approximately 15 billion years ago, all of the matter in the universe was concentrated at a single point

  • A cataclysmic explosion (of biblical proportions perhaps?) called theBig Bangcaused the matter to fly apart.

  • In the intervening years, the universe has been expanding, cooling as it goes.


Big bang theory l.jpg

White Sox Version

Big Bang Theory


Black body radiator l.jpg

  • A black body radiator is one which absorbs all light which is incident on it.

  • Such a body can also emit light, if sufficiently hot.

  • Since the universe is the remnant of a hot explosion, it should thus have a temperature and an ‘afterglow’.

Black Body Radiator

Universe

?

?

?

?


Afterglow from the big bang l.jpg

Afterglow From the Big Bang


Afterglow from the big bang31 l.jpg

Afterglow From the Big Bang

  • In 1964, while working at Bell Labs, Penzias and Wilson discovered a radio hiss that they couldn’t make go away.

  • They had (by accident!) discovered the remnant ‘echo’ of the Big Bang

  • The universe was shown to have a temperature of 2.726K (-450 °F)


How does the afterglow work l.jpg

How Does the Afterglow Work?

+

+

+

+

+

+

+

+

+

Proton

Electron

Photon

+


Slide33 l.jpg

How Does the Afterglow Work?

H

H

H

H

H

H

H

H

H

H

H

H

H

H

Proton

Electron

Photon

+

+

=

+

H

Proton Electron Hydrogen


Mysteries of the afterglow l.jpg

Mysteries of the Afterglow

  • The temperature of the universe is uniform everywhere to parts per million.

    • Why?

  • The temperature of the universe has slight non-uniformities, at the parts per million.

    • Why?

  • Answers to both of these questions exist but are beyond the scope of this talk. Get Peter to bring in a cosmologist soon.


History of the universe readers digest version l.jpg

the universe was all concentrated at a single spot

You are here

Then God (or whoever, I’m not

getting into that tonight) said “Let there be light,”

and instead there was a vast explosion that created the universe and spread all of the matter that has ever been observed (and more) throughout the Cosmos.

Hmmmmmmmmmm…..

Large explosions  hot temperatures  very high energies

Ice melts  water evaporates  steam ionizes  atomic nuclei break apart  quarks escape the nuclei….

History of the Universe (Readers Digest Version)


Slide37 l.jpg

Fermilab

4x10-12

seconds

Stars form

(1 billion years)

Now

(13.7 billion years)

Atoms form

(380,000 years)

Nuclei form

(180 seconds)

Nucleons form

(10-10 seconds)

Quarks differentiate (10-34 seconds?)

??? (Before that)


The universe s recipe l.jpg

The Universe’s Recipe


Mysteries l.jpg

How do we know about the universe before 10-12 seconds?  

Just what is the simplest and most fundamental thing in the universe?

Does the unification/simplification stuff discussed earlier continue to hold?

Mysteries


The early universe l.jpg

Possibly the true nature of particles is that they are actually minute vibrating 11-dimensional strings.

Freebie: This theory is the only candidate way to unify gravity with the quantum forces.

The Early Universe

  • The forces have been unified. What about the particles?


Standard model summary l.jpg

Standard Model Summary

The Standard Model (quarks, leptons, three generations and four currently-distinct forces)

  • Can explain all known experimental data, from:

    • The birth of the universe (10-12 seconds) to now.

    • Motionless objects, to those traveling at the speed of light.

    • Temperatures from absolute zero to the Big Bang.

    • Lotsa stuff…..

  • Cannot explain

    • The very early universe (before 10-12 seconds).

    • Do the forces unify?

    • Are there many particles or just strings?

    • Lotsa stuff…..


Data model comparison l.jpg

Data-Model Comparison


Data model comparison44 l.jpg

Data-Model Comparison


Slide45 l.jpg

  • It is not possible to be ignorant of the end of things if we know their beginning.

    • Thomas Aquinas

    • Summa Theologica


Slide46 l.jpg

www-d0.fnal.gov/~lucifer/PowerPoint/PopTalk_Jan2005.ppt


Slide47 l.jpg

Available at Amazon, BarnesandNoble.com + local book stores


  • Login