PHYSICS

Yesterday evening, I virtually attended a lecture given by Alain Goriely from Gresham college, Oxford. In this lecture I learned:

plants obey the golden ratio (phi)

I'd seen addition fractions once on integral, yet I'd not understood where they came from, or really what they were. despite being a niche topic, this lecture taught me a lot about some key concepts within the greater field of mathematics

the addition fraction of phi simplifies to

learned the key concept of 1 + 1/r = r, r^2 - r - 1 = 0 is the golden ratio, which can be most famously seen when cutting a rectangle into a square and smaller rectangle

plants exhibit this in the angle of divergence between leaves, where this angle takes the golden angle (137.5)

Greene utilises beautiful analogies to describe abstract concepts in a digestible way, from special relativity and the photon clock, to the reappearances of George and Gracie and Slim and Jim—he makes learning these concepts fun, continuously linking back to previous chapters, or providing links to the chapters ahead, so you can view the larger picture. 

First, Greene sets up the age-old clash of QM & GR, but before long (roughly chapter 6), he begins to dive into the core ideas of string theory. Despite the abstract ideas, I found Greene’s descriptions extremely helpful, as well as having  a string that I could model with. Yet, this made me consider whether we’re held back conceptually. What if the real model of the universe was locked behind the limits of what we can perceive and understand?

Often I find the complex maths of higher-level physics overwhelming, and hearing of the use of computers and programming to do the calculations helped. In school, we tend to see the calculations of physics as the easy part and the explanations as the harder part—that’s why it’s so important to learn and understand the concepts fully —ripping away the maths and solely showing the concepts is a really good approach to open science to more people, and to set good foundations.

Personally, one of the most intriguing things were the Calabi Yau spaces.

Not only the story of combining maths and physics [some regard them as the same field but they’re not!], but the sheer complexity of them. Further, the idea of just cutting below the Planck length was such a shock! Strings just bouncing back and growing had never occurred to me—how are simple ideas chained back due to shame or doubt; is it better to outwardly say your ideas to not mislead, or to help science develop by outing them?

As well as this, 1/R and R radii strings having the same properties link to all black holes having “no hair”, with the same mass force charge and area they’re identical!

Specifically, I found the description of Einstein’s reluctance to accept Bohr’s probabilistic quantum mechanics intriguing. His loyalty to determinism (shown also in his insistence in the cosmological constant), shows that physics is affected by biases, and that even revered physicists sometimes cannot look past their own preferences.

This book is dated in aspects since it's ~30 years old, but it reflects the philosophical, neat view that the 90s held towards unifying theories, & physics in general. An idea being beautiful (like string theory) doesn’t mean it’s true—could this bias influence how it’s seen as evidence & the prevalence of that idea going forwards? Greene highlights how science is a creative process. For example, how string theory has the theory first, and the equations are so complex, they just have approximations. It really makes you think if it blurs the line between mathematical theory and description, and whether it’s more driven by logic, or imagination. It made me think of Karl Popper’s idea of falsifiability — can a theory that can’t be tested count as scientific?

This book being dated did, to an extent, help, as I had to further research topics to see if they were still relevant. For example, the idea of string-driven cosmic inflation hasn’t had much further evidence, and the LHC didn’t find any evidence of strings either. 

I believe that, rather than using string theory as a legitimate answer, we should evaluate its strengths and weaknesses–and Greene’s book perfectly demonstrates the hopes of the time. The idea of supersymmetry being used yet again made me think of bias—how much of this is a good idea, and how much of it is a bias towards beauty? 

[ACTUAL CONCEPTS]

“Black holes have no hair” as they’re only defined by charge, spin, mass.

Strings/branes could explain black-hole structure: wrapped branes resemble gravitational fields of extremal black holes.

Number of possible string vibrations = black-hole entropy; hints at a quantum description of gravity.

Hawking radiation explained by virtual particle pairs at the event horizon; temperature far too small to detect.

Raises the “information paradox”: if wavefunctions fall in, can information ever be restored?= later evidence was discovered to support this 

Extremal branes might store information, suggesting a holographic link between surface area and internal data.

Laplacian determinism fails because of the uncertainty principle.

“Quantum determinism”; probabilities fixed by the wavefunction, not exact outcomes.

Black holes challenge both: they seem to destroy the wavefunction altogether.

Inflation solves the horizon problem by rapid early expansion; keeps temperature uniform.

Symmetry breaking: strong, weak and EM forces were unified at high temperature.

String theory offers an explanation for why only 3 spatial dimensions expanded—strings in 3D collide and annihilate most efficiently, freeing those dimensions.

Calabi–Yau shapes (extra curled dimensions) could rip, merge and reform during the Big Bang.

Strings might be “shards” of spacetime; their vibrations generate geometry rather than move through it.

Holographic principle; reality in 3D could be encoded on a 2D surface (like black-hole entropy).

Zero-branes & non-commutative geometry; space itself may not exist at the smallest scales; distances become meaningless.

M-theory unites different string theories through quantum connections.

Anthropic principle: our universe’s parameters suit life because we exist in one that allows it.

Smolin’s “cosmic natural selection”; universes reproduce through black holes; those optimized for black-hole production “survive.”

I just attended a virtual webinar from the University of Sheffield discussing CERN- specifically the Higgs Boson- and I'm excited to discuss what I've learned!

THE HIGGS BOSON

the Higgs Boson (HB) is a particle that gives other particles mass.

this is by having a field which spans the entire universe, so therefore particles must interact with it. How fast/slow they move through the field determines their mass.

A GOOD ANALOGY I SAW USED WAS THAT AT A PARTY, THE MORE FAMOUS YOU ARE (THE MORE MASS), THE HARDER IT IS TO MOVE THROUGH THE ROOM, SEEN AS THOUGH YOU MUST TALK TO MORE PEOPLE

the HB's mass was originally a free parameter, so it was perturbative

HB= was created by colliding 2 protons at extremely high energy is the centre of the collider. This immediately decayed into 2 Z Bosons, and then into a pair of electrons and a pair of muons, as predicted by the standard model

This event was then reconstructed with a hypothesis test , where the prediction of a ratio of 2:2 (2 in a pair) was proven correct

Technically the HB can decay into any (eg. a tau and an anti-tau) but a massless particle (at least directly)

125 GEV peak = HB proven!!

The Higgs coupling constant is the strength with which the HB interacts with other particles, and it grows with the particles' mass.

The HB interacts indirectly with light, as when it interacts with the heavy top quarks, they 'fold back on themselves' and decay into photons

CERN ITSELF

in the LHC, protons turn anti-clockwise and clockwise, and 4 experiments take place. This includes with symmetry and antisymmetry in matter, and quarks in a dense environment

The LHC has 2 beam pipes, where the protons are housed

There's superconductor magnets, which, using the Lorentz force, force the protons onto a circular path

**THE LORENTZ FORCE IS THE FORCE ON A CHARGED PARTICLE DUE TO ELECTRIC AND MAGNETIC FIELDS- electric is regardless of motion, and magnetic is due to motion--perpendicular to velocity and the magnetic field

in the ATLAS, there's a layered structure, which measures the path of particles inside to outside, as well as a calorimeter, which measures energy by absorbing them.

there's also the measuring of charged particles, electromagnetic particles, particles which contain quarks, particles with core energy and invisible particles

**INVISIBLE PARTICLES ARE PARTICLES WHICH ARE DIFFICULT TO DETECT AS THEY RARELY INTERACT WITH MATTER, LIGHT OR EM RADIATION (EG, NEUTRINOS, DARK MATTER)

collisions and decays within the LHC; traces are left--"footprints"

the count of events is used to indicate a probability of the strength of an interaction

calorimeters are made of lead

at cern, there's still lots of research going on about the identities of dark matter, and why there's more matter than antimatter

**SUBSTANCES COMPRISED OF ANTIPARTICLES--SAME MASS AS THEIR COUNTERPART, BUT THE OPPOSITE CHARGE, SO THEY CANCEL EACH OTHER OUT.

antimatter could have gravitational properties

This interview really made me consider how the average person views physics; something appearing non-sensical and 'difficult'. I also realised just how many different approaches are being taken by physicists around the world, and how slight variations in logical viewpoints can lead to a whole new field! It really exposes the diversity of the field itself.

I also appreciated the lengthy discussion of time. The idea of time being an emergent property has always intrigued me, and hearing Al-Khalili discuss its' place made me think about what I believed. O'Connor made a point about how at the quantum scale, time could have not emerged yet--an idea that I have always leaned towards.

I know I am late to this, yet seeing the recent development has engaged me with this topic.

What are dark matter & dark energy?

Dark matter is matter said to not interact with the EM spectrum, therefore we cannot see it. It's thought to play a role in the BB model of the universe, where it plays a large role in expansion. When put in combination with string theoretical (and other dimensional theories), it proposes a habitat for supersymmetric particles (those in complement with our current SM particles), and perhaps a valley towards parallel universes. Extendedly, it's supported by gravitational lensing, as it provides a medium through which light would be slowed.

Dark energy, on the other hand, is energy said to have an overall effect on the universe, and so, would be repulsive, pushing the galaxies apart (resulting in expansion).

What is Gupta proposing instead?

Instead, Gupta proposes that over space-time natural forces weaken, leading to the redshift that is observed from distant galaxies, and the expansion to which we are already aware.

To explain this, Gupta proposes that photons 'shed' energy over their travel, therefore increasing their WL to the red side of the spectrum (TL). And that, if the universal constants differ over space-time (CCCs), by an immeasurable amount (thus far), it could provide evidence towards Gupta's theory.

Main learning points:

may be too heavy to be currently created with particle colliders

were thought to be in iron initially

solves Dirac's symmetry

Maxwell: if the motion of electrically charged particles makes a magnetic field, would a magnetic monopole make the same?

charge x pole strength = 1/2

conservation of pole strength--cannot disappear unless a n equally, and oppositely charged monopole cancels it out

pole strength of a monopole must be quantised = 1/root(137)

heavier than any elementary particle discovered

3x more heavy than a proton [experimentally]

different kinds--spin, nuclear charge etc.

Eiichi Goto; cosmic

could be ideal projectiles for accelerators; high energy & mass, extracted from target for use again. Would be sustainable

could be trapped from space when entering the earth's atmosphere, in iron (and other magnetic materials)

EXTRACTION= pull out using magnetic field, or destroy the magnetism of the material

identification would be easy-rapid loss of energy=nuclear photographic emulsion track is HEAVY

maybe a molecule is formed due to oxygen molecules surrounding it? maybe its attracted to the nuclear magnetic force in an atom?

A similar situation to the the suspicion and doubt with the "law of strangeness" and conservation of number --one cannot vanish without another appearing (muons, neutrinos etc.) [the Two Neutrinos Experiment by Leon M. Lederman]

Due to quantum mechanics introducing probability, there are lots of ways a MM could break down, so there's not a surefire way that they could be detected--could be by chance, we could've already seen the aftermath [eg broken down into muons, neutrinos etc.] and not been aware of it.

theory about symmetry is seen in the verified theory of relativity, giving some hope to the MMs.

overall, it's worrisome as it brings some doubt to Dirac's laws and Maxwell's equations; the whole field of EM.

ATTEMPTS TO CREATE in BNL, LI & CERN, GENEVA.

1) bombard target (thin plate of metal) with accelerator high energy proton beam

monopole hits 8 inch-thick oil container and is pulled up to the surface by a magnetic field & fly through the detector

2 DETECTORS=

scintillation chamber-liquid filled xenon tube emitting tiny flashes of light when particles pass through

nuclear emulsion-heavy tracks

neither worked

2) monopole trap; pulsed EM exposed 5cm^2 of ore to 60000 Gauss

pulse of 1/10000th of a second, once per minute

accelerate monopoles through a nuclear-emmissions plate and re-trapped at the top of a vacuum chamber

none detected in 1000m^2 of the surface :(

therefore, monopoles must be more massive--in space perhaps?

Ford, Kolm, Goto

60000 Gauss magnet & portable generating equipment in Adirondack Mountains, NY.

accelerate monopoles to >1 billion eV, nuclear emissions detector & retrap

It got me thinking; perhaps there's a slight point (like a billionth of a second), when cutting a magnet, that it becomes 2 monopoles in it's static state (since the movement of magnetic particles would give rise to to an electrical field). But then, when the 2 monopoles meet, they annihilate each other.