Recent content by alikim

I'm just curious, if such device could find an application, I don't have any particular case in mind. For example, modules returning from space, first use heat shield to slow down and then parachutes to land. Could such drag system be used at some point of descend to alleviate requirements/need...

Theoretically, if a person falls from outer space to earth, and they hold 10000 rolls of toilet paper by their loose end, will that slow their fall down? Can you do that with a rocket booster returning to earth, keeping its speed subsonic all the way? On more serious note, what happens if you...

If I solve a problem of a box sliding down a slope or standing still on the slope, the force of friction is directed up along the slope. What happens if there is a force F pulling the box up along the slope, but it's unknown if it overcomes gravity and box is moving up or it only slows the box...

I found this equation as a solution to the original problem of a point-like ball rolling without friction in a parabolic cavity from Lagrangian mechanics: Is it possible to add an extra force to this equation? I want to add a "magnet" at a certain position that will affect the ball. The...

If I stand by a flying with constant speed charged particle, at my location the electric field will change as the particle get closer and further from me. So this change in electric field should create magnetic field and so on, producing an EM wave?

It needs to support its own weight with w/e tech it uses. Doesn't matter, consider it's above an area that doesn't have any air traffic. Yes, so the tech the platform uses need to function at this temperature. No, let assume there is no wind, also no meteor showers, solar flares, falling...

How would I approach this task: I have a platform 10x10 meters footprint, 15 meters height, I need it to permanently float at about 10km, doesn't need to navigate/steer. That volume can contain some tech inside like balloons, batteries, propellers, solar panels etc. What is the power requirement...

I understand that there are forces at play there. I'm asking about energy, see my OP.

Let's say I have a bullet flying by a magnet, the magnet will attract the bullet and change its trajectory so it will turn slightly. Does that trajectory change take energy? If it does, where does it come from? The kinetic energy of the bullet?

So if I have interference and I get a flight time as an average between two paths it is explained by a large error in the flight time measurement, in particular the uncertainty in the start time?

More like this. If I understand it right, here they measured travel time of a photon between the slit and points on the screen where interference maximums are and proved that up to their camera resolution the flight time is consistent with the speed of light. I understand that there is always...

As far as I understand, in case of light traveling through a layer of glass, for example, the speed of light in the glass (calculated through integration along all infinite possible paths between the point of entry and point of exit) is a definite value that doesn't have statistical nature, i.e...

Let's say here are two ways for a photon to go between point A and B and a detector at B detects photons with some probability based on interference. Mathematically, it's calculated by carrying phases along each path and then adding them up regardless of how much time it takes to travel along...

What is detected on the second screen if after a photon went through the slits but before it hits the second screen, the screen with slits is removed (or both slits are closed)?

I heard about the following experiment and I'd like to know if it really works this way: Double slit experiment with a detector that gathers information about which slit every particle goes through and stores it in an unobserved black box. The screen is an unobserved photo film that needs to be...