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- TL;DR Summary
- Trying to make sense of a vague comment by Susskind
So I was watching one of Susskind's lecture on Youtube* and about the 37:00 mark he has this equation relating the frequency of a matter wave to its wavelength:
$$\nu = \frac{h}{2m\lambda^2}.$$
This is arrived at by assuming that matter has a wavelike nature and that the energy and momentum formula for the photon ([itex]E=h\nu[/itex] and [itex]p=h/\lambda[/itex]) still hold true for the matter wave. Then Susskind said that this is essentially just Shr¨ödinger's equation, or at least that Schrödinger was looking for an equation which would result in this relation between [itex]\nu[/itex] and [itex]\lambda[/itex]. But if I set [itex]\psi(x,t) = e^{i(x-vt)}[/itex] and use [itex]v=\lambda\nu[/itex], then feeding [itex]\psi[/itex] into Shrödinger's equation
$$\frac{1}{2m}\frac{\partial^2}{\partial x^2}\psi = -\frac{i}{h}\frac{\partial}{\partial t}\psi,$$
I find instead
$$\nu = \frac{h}{2m\lambda}.$$
What am I missing??
*
$$\nu = \frac{h}{2m\lambda^2}.$$
This is arrived at by assuming that matter has a wavelike nature and that the energy and momentum formula for the photon ([itex]E=h\nu[/itex] and [itex]p=h/\lambda[/itex]) still hold true for the matter wave. Then Susskind said that this is essentially just Shr¨ödinger's equation, or at least that Schrödinger was looking for an equation which would result in this relation between [itex]\nu[/itex] and [itex]\lambda[/itex]. But if I set [itex]\psi(x,t) = e^{i(x-vt)}[/itex] and use [itex]v=\lambda\nu[/itex], then feeding [itex]\psi[/itex] into Shrödinger's equation
$$\frac{1}{2m}\frac{\partial^2}{\partial x^2}\psi = -\frac{i}{h}\frac{\partial}{\partial t}\psi,$$
I find instead
$$\nu = \frac{h}{2m\lambda}.$$
What am I missing??
*