# Talk:Physics

## Contents |

## [edit] Hawking quote

Either I don't get it or it's a reference to God. So what is it doing here? **Tetronian** ^{you're clueless} 03:40, 4 December 2009 (UTC)

- I think it's more of a question than an assertion, and gods aren't the only "answers".
**ħuman**04:42, 4 December 2009 (UTC)- Yeah I guess that makes sense. I found it a bit odd though.
**Tetronian**^{you're clueless}13:09, 4 December 2009 (UTC)

- Yeah I guess that makes sense. I found it a bit odd though.
- I could find a better quote. Nerd (talk) 01:09, 22 June 2016 (UTC)

## [edit] Theory of Everything.

The article says that "One of the more popular of today's physics topics is the attempt to unify the theory of general relativity with quantum mechanics. This would be called a 'theory of everything' because it would mean that all four of the known fundamental forces (gravity, weak-nuclear, strong-nuclear and electromagnetic) are explained by one theory governing their interaction with the world as we know it." This isn't true. Loop Quantum Gravity, for example, is a quantum theory of gravity but it says nothing about unification of gravity with the other forces. Andy Frankinson (talk) 13:46, 28 June 2012 (UTC)

- Just go ahead and change that to something more suitable.
^{theist}13:48, 28 June 2012 (UTC)- Thanks! Does it look good now? Andy Frankinson (talk) 14:12, 28 June 2012 (UTC)

## [edit] Four principal breakthroughs

I don't see why "planetary motion, fluid flow, wave propagation and the classical kinetic theory of gases" is all bundled into one. Sure, newton worked on most of them (not sure about the last one), but they are separate fields.

## [edit] Four principal breakthroughs

I don't see why "planetary motion, fluid flow, wave propagation and the classical kinetic theory of gases" is all bundled into one. Sure, Newton worked on most of them (not sure about the last one), but they are separate fields. Super^{ Dude,Where's my car?} 13:57, 11 March 2015 (UTC)

- Newton did manage to derive Boyle's law, which states that the pressure and volume of a gas (in thermodynamic equilibrium) are inversely proportional to one another. However, he did so by assuming that a gas may be modeled by a static lattice of atoms (yes, he did believe in the reality of atoms) that repelled one another by a force that weakens with distance, rather than a collection of randomly moving particles colliding with each other and with the walls of the container. It was Daniel Bernoulli who first derived Boyle's law in the latter manner. Finally, "planetary motion, fluid flow, wave propagation" are not separate fields; rather they are all parts of what we now call classical mechanics. Euler's equations of fluid flow and the Navier-Stokes equations are really just applications of Newton's second law, as is d'Alembert's (partial differential) wave equation. In fact, it was Newton who first showed that the speed of wave propagating on a string with two fixed ends depends on the tension along the string and the mass density of the string. I hope that is clear. Please do not hesitate to ask further questions. Nerd

## [edit] Just for fun about matrices

Heisenberg came up with a formulation which he was uncertain what to do about. Matrix analysis was then an arcane branch of mathematics, but Max Born happened to have taken a course in that field and immediately realized the connection. Thus Heisenberg's matrix approach was born. Everyone was relieved when it turned out that the Heisenberg-Born formulation was equivalent to Schrödinger's wave function analysis. Cheerio Sorte Slyngel (talk) 22:51, 5 September 2015 (UTC)

- A very good point. In fact, physicists unfamiliar with matrices, which is to say most of those working in the 1920s, referred to these objects as 'Heisenberg arrays' which obey 'Heisenberg's law of multiplication'. Nerd.

- Just for added fun, when I took numerical analysis many a moon ago, it was estimated that at least 75% of all calculations in physics would entail the solution of massive systems of linear equations. To satisfy my ritræpa (that's the scientific name, it is commonly known as writing compulsion) I'll add that I don't think any discussion about these matters should omit mentioning Courant-Hilbert - mostly Courant. He gathered what he could about what was expressed in the name of the books,
*Methods of Mathematical Physics*, that is all he could imagine what**could**be of use. This was before the quantum revolution and the physicists discovered to their delight, that someone had been considerate enough to give them what they needed - in advance. :-) Cheers Sorte Slyngel (talk) 00:31, 6 September 2015 (UTC)

- Just for added fun, when I took numerical analysis many a moon ago, it was estimated that at least 75% of all calculations in physics would entail the solution of massive systems of linear equations. To satisfy my ritræpa (that's the scientific name, it is commonly known as writing compulsion) I'll add that I don't think any discussion about these matters should omit mentioning Courant-Hilbert - mostly Courant. He gathered what he could about what was expressed in the name of the books,