PV Gap

Naomi Said:

How to make an object that can work on a solar cell?

We Answered:

Hi - Sorry, I am unable to give you details (lack of time) but what I can do is direct you to these web pages.
With the first link: Scroll down until you find a suitable Grade level and experiment that fills your needs.
The second one: Lists projects under different Topic headlines.
I hope you can find a good fit for you.
Have fun and good luck.

Bill Said:

How to make an object that can work on a solar cell?

We Answered:

make a simple motor. easy to make, cheap, and impressive to watch.

http://www.simplemotor.com/

Rachel Said:

Please, need a real scientist's answer to this long & complex question (not for school)?

We Answered:

UPDATE 2:
mr.c, one can imagine & speculate about all sorts of sources of energy and power. My specific point here is that, whatever the source might be, how do you handle it without being destroyed? How does your skull channel/handle/manage 6000 MW of power without being destroyed?

=======================================…

UPDATE:
- To mr.c's answer: I think the principles of conservation of momentum and energy don't give much scope for the ideas you are suggesting: There is nothing in modern quantum theories that gives any particular hope for these problems; and putting the solution in subsidiary universes with different rules is just saying, "Break the known rules."

- To lordmyst's comment: Building up an electric charge fast won't help, because you have to get it from somewhere: If you take it from surrounding matter, you will expend enormous amounts of energy and generate huge electric fields. If you take it from somewhere else, you will be violating conservation of electric charge, a big no-no.

Antennas don't get blasted apart because they are NOT transmitting significant amounts of energy. The radiative reaction force is real: It is what keeps the stars from collapsing immediately. If you are going to channel a macroscopic amount of force through your head, using electromagnetic fields, you have to channel the associated amount of energy. It's going to have to be an awful lot: Notice that the Sun's radiative power is blasting away at the Earth, but it doesn't make much impact on the gravitational pull between them. You will need an enormous amount of radiative power to make a macroscopic effect on a spoon: For example, if you beamed light upwards against an object to hold up 1 kg against gravity, to generate a force of 1 * g = 9.8 (N) from photons of energy E and momentum E/c at a rate of n photons per second, because of the bouncing photons:
2*(E/c)*n = 9.8
Power = E*n = (9.8 * c)/2 = 19.6 * 3 *10^8 = 5.88*10^9 (W)
This is the output of a 6000-MW power plant. Where is this supposed to come from, and how are your cells supposed to handle it?


=======================================…

You seem to be slightly confusing two separate concepts:
- "Solar sails" which catch light energy (and thus momentum) to ride outward from the Sun
- "cells" that are designed from step one to somehow facilitate transfer of electromagnetic energy against gravitational pull

There are two major problems with your concept:
- Conservation of momentum: If something in a skull is doing something to transmit force to an external object, there has to be something that receives the equal-and-opposite reaction force, according to Newton's 3rd law. You don't want to have this something be in your brain: The sensible way to move a spoon is to pick it up, not to dent your brain!
- Using electromagnetic energy: If the something that receives the reaction force is not your brain but an external source (in the solar-sail case, the outgoing radiation field of the Sun), you have to catch enough energy and momentum to do the job. In the solar-sail case, this comes from the large area of the sail, that can capture a large-enough amount of solar energy. If this energy is to be captured in the neighborhood of your head, you can't capture very much momentum in that relatively small area, without needing an enormous amount of electromagnetic power near your head. Blowing up your head to move a spoon also seems like a cost-ineffective way to do the job.

Of course, I am not even addressing the question of the mechanism to be used: My point is that, even without addressing the specific mechanism, that general conservation principles of momentum and energy impose very difficult conditions to meet.

Everett Said:

How to make an object that can work on a solar cell?

We Answered:

Try operating a LED light from Solar Cells