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Aug
8
answered Is heat conduction impeded at interfaces between dissimilar materials?
Aug
8
comment If planet orbits are in the shape of an ellipse and the sun is a focus, where and what is the focus?
IIRC the mass of Jupiter means the Sun-Jupiter barycenter is just above the surface of the sun
Jul
26
comment Can we extract positrons from gamma rays?
yes, the problem is more likely to be getting a strong enough source of gamma rays
Jul
25
comment How power lines use high voltages with a low current?
@RJSmith92 the V in the question is the voltage difference along the cable = "wasted" voltage. By having a high voltage/low current cable then with a given R you have a low V difference = low wasted power.
Jul
19
comment Do all stars Turn into Black Holes?
physics.stackexchange.com/questions/99375/…
Jul
18
answered Image formation or Diffraction?
Jul
18
comment How easily can the Earth flip?
@punkerplunk the rotation kinetic energy of the Earth is around 10^29J that's a lot of energy - leaving aside the lack of a mechanism for transferring it.
Jun
21
answered Having trouble understanding spectral lines
Jun
19
awarded  Good Answer
Jun
9
answered Do transformers lose energy?
Jun
8
answered Ice/Melting Bullet
Jun
4
comment Why can't LIDAR be implemented with traditional antennae?
Yes that's true, with enough power and a poorly matched impedance you could make the antennae emit visible light - fairly briefly
Jun
4
answered Why can't LIDAR be implemented with traditional antennae?
May
22
awarded  Nice Answer
May
14
answered How do eagles fly slowly for a long time?
May
14
comment Saturn V F-1 engines and beyond
If you only care about peak power then Project Orion en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) is probably the winner
Apr
24
comment Can we find the exponential radioactive decay formula from first principles?
@dmckee it's unavoidable if the decaying nuclei are independent. If there was any field between atoms you could have a different law.
Apr
22
comment Car motor heat to drive a steam engine
en.wikipedia.org/wiki/Automotive_thermoelectric_generator
Apr
22
comment True randomness via Radioactive decay
yes, yes, and physics.stackexchange.com/q/105107
Apr
20
comment Measuring depth or height from sea level
It's a famous problem science20.com/news_articles/…