Fermi's contribution the neutrino (1 Viewer)

mrpotatoed · Oct 18, 2015

in the 2005 hsc theres this question about how pauli and Fermi contributed to the neutrino and in the markers notes it says many didn't mention what Fermi did. Fermi simply stated that the so called neutral particle that Pauli suggested should be called a neutrino, so that it wasn't confused with the neutron, right? or was there something else he also did.

mrpotatoed · Oct 22, 2015

Also when talking about what Heisenberg contributed, the success one textbook talks about some matrix mechanics stuff that he did, what the hell is that? Only ever learnt about him developing the uncertainty principle

InteGrand · Oct 22, 2015

mrpotatoed said:
Also when talking about what Heisenberg contributed, the success one textbook talks about some matrix mechanics stuff that he did, what the hell is that? Only ever learnt about him developing the uncertainty principle

$Matrix mechanics is one of the mathematical formulations of quantum mechanics, developed by Heisenberg (and some others). See here:$ https://en.wikipedia.org/wiki/Matrix_mechanics

$A bit later, Schr$\ddot{\text{o}}$dinger's wave formulation of quantum mechanics was created (by Schr$\ddot{\text{o}}$dinger). It is mathematically equivalent to Heisenberg's matrix mechanics, and is famous for Schr$\ddot{\text{o}}$dinger's equation (a partial differential equation):$

$i \hbar \frac{\partial }{\partial t}\Psi (\bold{r},t)=\hat{H}\Psi (\bold{r},t)$

$where $i=\sqrt{-1}$, $t$ is time, $\hbar = \frac{h}{2\pi}$ ($h$ is Planck's constant), $\Psi$ is the wave function for the quantum system, and $\hat{H}$ is the Hamiltonian operator.$

https://en.wikipedia.org/wiki/Schrödinger_equation

$Heisenberg's contribution of matrix mechanics was thus to be the first to develop a rigorous mathematical formulation of quantum mechanics; according to Wikipedia, ``Matrix mechanics was the first conceptually autonomous and logically consistent formulation of quantum mechanics. It extended the Bohr Model by describing how the quantum jumps occur. It did so by interpreting the physical properties of particles as matrices that evolve in time. It is equivalent to the Schr$\ddot{\text{o}}$dinger wave formulation of quantum mechanics, and is the basis of Dirac's bra-ket notation for the wave function.''$

InteGrand · Oct 22, 2015

$Another website says:$

$\textsl{``From 1924 to 1927, Heisenberg lectured at the University of G$\ddot{o}$ttingen, and conducted research with Niels Bohr at the University of Copenhagen. It was during this time that the young Heisenberg developed the ``matrix mechanics'' formulation of quantum mechanics (in collaboration with Max Born and Pascual Jordan). Matrix mechanics was the first complete and correct definition of quantum mechanics, and it extended the Bohr model of atoms by describing how the quantum jumps occur and by interpreting the physical properties of particles as matrices that evolve over time.''}$

(Source: http://www.physicsoftheuniverse.com/scientists_heisenberg.html)

$So basically, you don't need to know about the mathematical details of matrix mechanics (this is too advanced for high school maths or physics), but you need to know Heisenberg's contributions to the development quantum theory; so two points you can talk about are the uncertainty principle (describe it and explain its significance, i.e. it shows that we can never be sure of where anything is (if we know anything about its momentum), which changed our views of the world around us and led scientists to develop quantum mechanical models of atoms' electrons, which are based on probability clouds which describe probabilities of finding electrons in certain regions of an atom, rather than deterministic models, etc.); and matrix mechanics (first mathematical formulation of quantum mechanics, and talk about the stuff from the links above).$

mrpotatoed · Oct 22, 2015

What are we expected to know for the hsc? Are we even supposed to know that for the hsc? Is simply saying, "Heisenberg developed matrix mechanics to explain quantum phenomena, that is similar to Schrodinger's wave equations, to further our understanding of the atom" in a typical HSC question good enough?

InteGrand · Oct 22, 2015

mrpotatoed said:
What are we expected to know for the hsc? Are we even supposed to know that for the hsc? Is simply saying, "Heisenberg developed matrix mechanics to explain quantum phenomena, that is similar to Schrodinger's wave equations, to further our understanding of the atom" in a typical HSC question good enough?

Don't know, depends on how many marks it's worth. But it's best to know as much as possible so you can add in as much info as you think necessary. Just memorise the info above.

kawaiipotato · Oct 22, 2015

mrpotatoed said:
in the 2005 hsc theres this question about how pauli and Fermi contributed to the neutrino and in the markers notes it says many didn't mention what Fermi did. Fermi simply stated that the so called neutral particle that Pauli suggested should be called a neutrino, so that it wasn't confused with the neutron, right? or was there something else he also did.

Iirc, Fermi noticed that when a neutron underwent radioactive decay to form a proton and an electron, the initial momentum was not equal to the addition of momentums of proton and electron, which would violate the conservation of momentum. Thus, there must've been another particle that was undetected, which carried away the remaining momentum, which was the neutrino as suggested.

InteGrand · Oct 22, 2015

Iirc the textbooks are good for this section. Add together the sample answers from the Odlum book and you should have enough stuff to memorise to be able to answer Q's on this topic (at least the typical questions, even if they're long markers).

mrpotatoed · Oct 22, 2015

Isn't that what Pauli did

kawaiipotato · Oct 22, 2015

mrpotatoed said:
Isn't that what Pauli did

Yep lol, my bad.

Fermi's contribution the neutrino (1 Viewer)

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