Sounds logical to me. Trying to think what this would mean for one-dimensional motion in the x direction, it first seems to me that a pretty good candidate trajectory would consist of waiting until the acceleration reaches its positive maximum and then letting the mass quickly move from x min to...
In some cases, yes. But if you have to stop your industrial production line to change batteries, you may think differently. Also, if you have hundreds of sensor units in your production plant or in your vehicles, your maintenance team may not be able to cope with the additional workload without...
Makes sense to me. To calculate the energy, I then obviously need to multiply the acceleration with the mass and with the distance available for movement, and to do the same for the angular quantities. To maximize power output, the movement should perhaps take place when the acceleration is at...
What you say is obviously true, but does not yet answer my problem. Let me try to make myself more clear: In my problem setting the engine power is not known. What are known are the trajectory and the speed of the movement. I then assume that both of these can be maintained by adjusting the...
The idea is not that the contraption purported to harvest power from a vehicle should absorb all of its kinetic energy. The idea is that the vehicle has an engine or a motor that keeps it performing a pre-known movement no matter what the contraption is or does.
My question was and still is: " Is there a general expression for the mechanical power that can be extracted from a moving vehicle by means of an inertial device?". In my subsequent postings I only try to keep the discussion from diverging by describing what a practical application could look like.
I want to attach to a push rod of an engine a sensor box that uses the movement of the rod to power its circuitry. For this purpose, I plan to use a solenoid, a magnet and whatever mechanical parts that are needed to allow inertial forces to cause the magnet to move inside the solenoid. The...
Take, for example, the rotation of the earth. One would think that it cannot be converted to useful work (excluding tides from the consideration), but how do we know for sure? On the other hand, we know that the movement of a cocktail shaker performs work on the ingredients because we can see...
Assume that a contraption with loosely suspended internal weights is fixed to the body of a vehicle that is moving in free 3D space without gravitational sources nearby. Given the position and orientation of the vehicle as functions of time, how can one tell whether it is possible for the...
Now I see. The recession speed of the event horizon is always positive, even in the case of accelerated expansion, which makes my scenario impossible. The misconception I had was that the recession speed would be negative in this case. Thanks for your patience!
Assuming that the accelerated expansion prevails, it seems to me that my original question is still relevant. To recapitulate: I am standing one mile behind another observer who sees a flash of light coming from a source located, let us say, half a mile beyond my horizon. I am looking past his...
Many thanks for your answer! It was of great help for a novice who has just fumbled through the basic math but has trouble interpreting the results. Also, the Davis paper looks way more clear and precise than the material I have been reading so far.
Thank you for your answer, and for bringing up the intriguing idea of using relay stations to overcome the physical limit. What still puzzles me is the following. There is a remote light signal coming towards me past the point where the the front observer is standing. If he would light a torch...
My question was about light sources that are outside my event horizon but within the event horizon of the other person. According to how the event horizon is defined, light from such sources should never reach me.
Hello!
I am a retired EE interested in advances in cosmology and particle physics. A spent a large part of my professional life developing satellite navigation technology. I am glad to have found this forum and look forward to participating interesting discussions and deepening my understanding...