Posts by Olin Lathrop
As the pendulum swings, it experiences a changing magnetic field from the externally fixed magnets. Any changing magnetic field causes eddy currents in a conductor. Since these conductors aren't ...
You are somewhat misquoting what I said. It would help if you provide a link to the comments you are asking about, but the issue was most likely about lack of units on numeric values, not variable...
The light shines on everything in an unblocked direct line from the light source. This light is quite bright, so can be seen by human eyes all the way out to the horizon (until the curvature of th...
After 4 edits, it seems you are asking whether there are places in the universe where galaxies can form, but planets in those galaxies can't support life. It seems you want life to be impossible d...
No, this site is about physics, not chemistry. Whether something is on topic anywhere else has no bearing on it being on topic here. That said, there are some gray areas between physics and chemi...
This depends, of course, on what you are trying to achieve with the model. Remember that a model is a simplification for purpose of analysis, because the full physics is either too complicated or ...
No, going deeper into the moon would reduce gravity. This is covered by the shell theorem of gravity, proved by Newton centuries ago. If you have an evenly-distributed mass shaped as a hollow sph...
There seems to be some confusion about decibels here. "Decibel" stands for deci⋅Bel, meaning 10x of a Bel. A Bel is the log10 ratio of two powers, named for Alexander Graham Bell. Since a Bel is...
Back when what light is and how it propagates was poorly understood, people naturally related it to sound. Sound propagates thru a medium, like air. Light was therefore assumed to propagate thru ...
The center of thrust is effectively the weighted average of all the thrust locations. The weighting for each location is proportional to how much the thrust from that location contributes to the o...
The spring constant specifies force per compression distance. When you put multiple spring in series, the force on each spring is the same, which is also the overall force on the combined spring. ...
How do I deduce which setting suffices for mixing table salt + COLD tap water? Measure it. That really should have been obvious. My gut feel is that any reasonable agitation will work about equa...
Basic answer It depends on what you care about. If you're primary concern is to minimize injury to the people in your car, then hold the brake firmly in ordinary low speed cases. This minimizes ...
It depends on what the failure was. Working the hinge could possibly make the little screw come loose quicker. This is the screw that acts as the shaft of the hinge. If the hinge actually broke,...
All refractive lenses are approximations of the ideal. This is particularly the case of single-element lenses such as in eyeglasses. It so happens that the centers of such lenses are closer appro...
This looks like something the soldiers are being trained to do, or were trained to do. This means procedures were likely worked out that mitigate most bad effects most of the time. The top pictur...
If you are already heating the space to maintain a constant temperature, and if both humidification methods result in the same eventual humidity, then the net energy used ends up the same. Any ene...
To be optically equivalent, the lens made from lower index of refraction material needs to be thicker. My guess is that your optician thinks the metal grooved frames you want won't work well with ...
Think about how that is supposed to work. It seems you want two photons to somehow combine into a single photon and nothing else. That means the output photon must have the combined energy of the...
Why can these Single Vision lenses slow myopia for kids, but not adults? Kids' eyeballs are still growing, so there is opportunity to steer them into growing to a less myopic final result.
It counters intuition that although a light fails to illumine the area between the source and the target, the light can still illumine SOLELY the target! The light is illuminating everything. The...
The electrons by themselves don't absorb or release this energy. They do that within the context of the atom they are within. The discrete energy levels available to electrons are only there due ...
I'd say it's not the best design. Maybe that's why they discontinued it. However, there are also advantages. Cooling will be a little easier without a cover. But the real advantage is price. U...
The third law says we will never find a particle accelerating unless there’s some other particle accelerating somewhere else. The other particle might be far away, as with the earth–sun system, but...
Planet 9 would certainly be "dim", but whether it would be dark according you your definition is impossible to say. Planet 9 needs to be smaller or further away than Pluto, otherwise its gravitati...
