LAST WEEK:

Mon (1/19) — MLK Day — No School

Tues (1/20) — NO ROCKETRY; Discuss week; Slide Show; JM, BOW, Start Conservation of Momentum

Wed (1/21) — Hand out 6.8; Con of Mom

Thur (1/22) — GUEST SPEAKER; Hand out 6.9; Con of Mom

Fri (1/23) — Con of Mom

THIS WEEK:

Mon (1/26) — Discuss week; Slide Show; JM, BOW, Work 2D Con of Mom problems, Hand out 6.10 (Final sheet on Con of Mom); Hand Out first half of Packet 6 Take Home Test

Tues (1/27) — ROCKETRY; Wrap up 2D Collisions

Wed (1/28) — Glance Ball

Thur (1/29) — GUEST SPEAKER (Pick and Hammer); Hand out 2nd half of Packet 6 Take Home Test. Begin looking at Forces

Fri (1/130) — Forces

SCREEN SHOTS FROM LAST WEEK:

I will add more captions throughout Sunday:

: French natural philosopher Rene Descarte (1596 – 1650)

: Descarte discussed the Prime Mover, but got it wrong when he said that motion is conserved.

: He got it half right.

: . . .

: We discussed the truth of this statement. Perhaps one of the greatest thoughts.

: . . .

: . . .

: Newton said that it was actually impetus (momentum) was conserved. So that the total momentum just before a collision is the same as the total momentum just after a collision.

: . . .

: Con of Mom

: Here is the general equation of 1D conservation of momentum.

: . . .

: The four types of collisions

: Three main equations in Classical Mechanical Physics

: 6.8.2 Now we need to always draw two situations: JBC (Just Before Collision) and JAC (Just After Collision)

: In this case it was JBR (Just Before Recoil) and JAR (Just After Collision)

: 6.8.4 Bullets and blocks are very common Physics problems.

: Skaters having a snow ball fight. This is a good example of a two stage physics problem. The bridge between the two stages is that the final momentum of the snowball in the first stage is the initial momentum of the snow ball in the second stage.

: . . .

: . . .

: Dr. Strauss discussed the LHC and the Higgs.

: Map showing the location of the four detectors.

: The four stages of acceleration of the proton packets

: 4 stages showing the electron volts per stage. In high-energy physics, the electron volt is often used as a unit of momentum. A potential difference of 1 volt causes an electron to gain an amount of energy (i.e., 1 eV). This gives rise to usage of eV (and keV, MeV, GeV or TeV) as units of momentum, for the energy supplied results in acceleration of the particle (from Wikipedia).

: Not to scale. The LHC is 300 meters below the surface mostly to contain the radiation that is produced.

: The Atlas sits in the largest man made cavern in the world.

: A famous picture of the Atlas as it was being built. Notice the man below center for scale.

: The debris trail after two protons collide.

: . . .

: You can get 40 minutes of Division Time by watching this show on CNN. Look for repeats. It’s only THIS Inside Man that you get Division time for. Remember, you have to write a paragraph about it on the back of your Division Time sheet.

: . . .

: . . .

: creepy uncanny valley.

: We have started looking at 2D collisions. Believe it or not, the easiest way to work these problems is using the head-to-Tail method we developed back in October.

: 6.9.1

: 6.9.2

: 6.9.2

: 6.9.2: You fist MUST do the vector algebra before attempting to draw the momentum vectors. If you start with the arrows, you will get lost pretty quickly and not know what you are looking for.

: A short recent history of this idea of mass and what makes up the mass of everything.

: JJ Thomson started the subatomic ball rolling with his discovery of the electron at the Cavendish Laboratory in England in 1897 (sorry, the screen shot is off by a couple of years).

: A cathode Ray tube

: A Crooks Tube that shows an electron beam.

: The effect of a magnet on the electron beam.

: A Cathode Ray tube very similar to one of the ones that JJ Thomson used.

: When the electromagnetic field is applied, the beam of electrons is deflected away from the negative end.

: A CRT tube is basically how a TV or Computer Screen worked. Now its mostly LED screens.

: The result of JJ Thomson’s discovery was the plum pudding model of the atom. Atoms were neutralbecause they were made up of this nebulous positive cloud with enough electrons (the plums) to keep the whole thing neutral.

: Spherical plum pudding!

: Enter a young New Zealander — Ernest Rutherford.

: Rutherford

: SOme of Rutherford’s accomplishments.

: Rutherfords 1911 Gold Foil Experiment.

: The Gold Foil experiment resulted in a NEW model of the atom where 99.99% of the atom was empty space and 99.99% of the mass was contained in the positive nucleus. Electrons were scattered about in the volume outside the nucleus. It wasn’t until Niels Bohr figured out the Balmer Series that we learned that the electrons were in energy levels, but that is a different story which has little to do with the understanding of mass.

: Plum pudding vs. nucleus

: From the Gold Foil experiment. Most of the 2+ charge alpha particles went through the gold foil, but a few were deflected by the positive nucleus.

: . . .

: . . .

: James Chadwick discovered the neutron in 1932 furthering our knowledge of where all this mass was hidden.

: . . .

: Chadwick would have liked this one.

: 1964 — Enter a young Murray Gell-Mann.

: Gell-Mann and Richard Feynman argued constantly and sometimes bitterly about subatomic and subnuclear physics. They had offices just down the hall from each other at Cal Tech.

: Some of Gell-Mann’s findings.

: Quarks have fractional charges.

: . . .

: 2 ups and a down is a proton. Two downs and an up is a neutron.

: . . .

: . . . Electrons are fundamental particles. Are quarks?

: Subatomic particles can be broken up into two basic categories: Leptons and Quarks

: Part of the Standard Model

: From Dr. Stauss’s talk.

: Murray Gell Mann is still alive! Look for his TED talk. He’s a cool guy. Has a cool ranch in New Mexico.

: So . . . most of our mass is stored in our quarks? Oops . . . not so fast!

: Enter Derek Leinweber http://www.physics.adelaide.edu.au/theory/staff/leinweber/VisualQCD/Nobel/

: Empty space is not really empty

: Flux tube between a Quark-AntiQuark pair.

: Flux tube between three quarks

: So . . . 99% of our mass comes from nothingness inside a flux tube. It is a result of the energy required to maintain that vacuum inside that flux tube. So from E = mc^2 we get m = E / c^2.

: . . .

: The correct look of one possible configuration of a proton.

: So our mass was determined 0.0001 seconds after the Big Bang when the energy was used to form the first flux tubes. That energy has been mostly contained in there for the last 13.7 by.