Stuff to Remember from PS and SAQ

Question 1

what are the 4 important things to remember from Seven Brief Lessons on Physics

Answer 1

• it explains in comprehensible language the most fundamental parts of the subject
• it introduced me to GR which I’ve looked at more in EPQ
• it infers a joy to the subject in itself
• Lev Landau - “the most beautiful of theories”

Question 2

what are the important parts of the new scientist article casino analogy

Answer 2

• first law of thermodynamics = conservation of energy, you cannot spend more in a casino than you have, money is always conserved
• second law = entropy increases, whilst you may sometimes have small wins at a casino, if you stay long enough the house will always win, this is very similar to the second law
  i. e. sometimes entropy decreases in single interactions but overall it decreases

Question 3

what are the important bits about the experiment in the new scientist article

Answer 3

• it was tested in a 2001 canberra university study, they dragged a micrometre sized bead through water using a laser
• very occasionally it would extract ambient heat from the water and convert it into work done on the kinetic energy of the bead and it would jump ahead of the laser

Question 4

what other uses were implied by the experiment in the new scientist article

Answer 4

• it could link to time going backwards at a nano scale

- it may be able to be used to help explain neurological conditions

Question 5

things to remember from Fermat’s Last Theorem

Answer 5

• legendary theorem, seems simple, is actually very complex
• shows how important mathematical links are when trying to work through a problem
• writes about the history of maths
• writes about whether maths is fundamental
• shows the importance of discussion in maths and how it may have been more beneficial had Wiles discussed more with his colleagues

Question 6

Things to remember from an Educators Guide to LIGO

Answer 6

• GW are ripples in space-time as predicted by GR
• the waves detected in 2015 were from merging black holes
• different sizes of celestial objects cause different sized black holes
• gravitational effects are not instantaneous but travel at the speed of light
• At LIGO they use ‘test masses’ fundamentally these are mirrors which will move slightly if a gravitational wave passes through
• light is sent along 2, 4km arms and reflected back, if there is no movement, they will completely destructively superpose and form a wave of 0 amplitude, if the mirrors have moved, the phase difference will be different and a wave may be detected

Question 7

things to remember about the evidence for dark matter

Answer 7

• rotation curves, the outside of galaxies rotate too quickly for the amount of mass present, given by V = sqrt(GM/d)
• gravitational lensing, the curving of light around large objects to allow us to see distant objects occurs but more than predicted by GR because there’s more matter than is visible
• structure formation, current structures are too complex for the only matter to be formed from matter at the point where the universe became transparent so there must be some matter which wasn’t interacting with EM

Question 8

what is your initial take on the purpose of physics in the opening paragraph of your personal statement

Answer 8

• “to me the ultimate success for a physicist is to develop theories and equations to beautifully and simply explain the unknowns of our universe and explain how the subject can transform our lives”
• then I mention Mathematical modelling of the pandemic and simplicity of newtons laws

Question 9

how does the second paragraph of my PS progress

Answer 9

• HE+ program, Dark matter, evidence for dark matter, lack of observed dark matter, links to GR and EPQ, gravitational wave evidence, LIGO article

Question 10

how does the third paragraph of my PS progress

Answer 10

• broader texts- rovelli, Quantum and time vs thermodynamics, A-level research project on time over time, time linked to increasing entropy, canberra uni study/new scientist article

Question 11

how does the fourth paragraph of my PS develop

Answer 11

• maths is fundamental and very important in understanding the physical world, HE+ lecture on mathematical proof, Fermat’s Last Theorem - Singh, showed links between areas of maths, Hardy’s ‘A mathematician’s apology’

Question 12

important points to remember from SAQ personal statement

Answer 12

• importance of making links between the subjects
• modern problems (climate crisis) can’t be solved using only one of the subjects, requires a knowledge of all of them
• lithium-ion batteries more efficient
• electrical recovery units

Question 13

what to remember about lithium-ion battery development mention in SAQ PS

Answer 13

• done at University of California, San Diego
• Most lithium-ion batteries use graphite anodes, they replaced with silicon (10x better energy density)
• they overcame the problem of silicon anodes shrinking and expanding with charging by replacing the liquid electrolyte with a sulphide based solid one
• charged/discharged 500 times with 80% energy retention