48,173 reputation
589149
bio website
location New England (USA)
age 53
visits member for 2 years, 1 month
seen 38 mins ago

I have formal training in physics, but tend to approach it very intuitively; I prefer estimation over exact calculation, principles over details. I believe many problems can be solved by making a careful sketch. Label your axes, and don't use insignificant digits.

I visit this site in the hope of sharing my enthusiasm and occasional insights with others.


1h
answered Density and Wave Speed
2h
revised Would the hot windows break?
made typography of 50C look more pleasant
4h
comment Is Wikipedia's definition of angular velocity incorrect?
Key point in this answer: "for a single particle". And worth pointing out that the Wikipedia equation is also "for a particle", not an object of finite size.
4h
answered Would the hot windows break?
5h
answered Find the separation distance for a line of oil being squashed between two flat plates
15h
awarded  drag
21h
revised Explanation for the spectrum of the sun?
added code
21h
comment Explanation for the spectrum of the sun?
@Mareck That is just a result of the math... which in turn is because the QM solution does not allow a high occupancy of the oscillators with the highest energy (avoiding the "UV catastrophe" was one of the early triumphs of quantum mechanics).
21h
comment is it possible to use capacitors to quickly charge batteries?
@WhatRoughBeast - you are right about the main point, but the "exception" in my last paragraph is talking about the possibility of using a small but leaky supercap that sacrificed leakage for size.
21h
answered Explanation for the spectrum of the sun?
22h
comment Temperature increase during friction
It might be helpful to state the pin material - thermal conductivity is an important factor. Also it matters exactly where / how you measure the pin temperature (and what the heat sinking arrangement is).
22h
comment Temperature increase during friction
Related question: physics.stackexchange.com/q/203401/26969
22h
answered The different in wear test when using Aluminum and Steel disc in pin on disc apparatus
22h
comment The different in wear test when using Aluminum and Steel disc in pin on disc apparatus
Are you sure the disc was "aluminum" and not "alumina"? There is a massive difference in composition / hardness... What was the material of the pin you were testing?
22h
revised Books on waves with Fourier Transforms
added 590 characters in body
22h
comment Is it possible to jump by using only my arms?
@OussamaBoussif - thanks. For birds, the movement of the wings has far more complex aerodynamic reasons; I don't think that the inertial effect I describe would be important for them.
22h
answered is it possible to use capacitors to quickly charge batteries?
22h
comment Is it possible to jump by using only my arms?
@OussamaBoussif - that is not true. You can lift off without applying force to the ground. See my answer for an explanation.
23h
answered Is it possible to jump by using only my arms?
23h
comment Interference conditions problem
@CarlWitthoft - no apology needed.