A flashlight Answer chemical, in a sealed environment.
Fruits and Vegetables rich in vitamin A are the best and safest source of photochemicals, of course if you payed attention in my class, then you would no need to ask this question.
i have no idea sorry but maybe if you go on a different website. and oh ily mi husbands Emma and skye and peeps that c this skye is a water monkey ? ily chookalicious ? mwh ?
It is the only source of light!
Wind [APEX]
solar
I think that a screwdriver with a light source would be a marketable product. It would appeal to a wide range of professions. E.g. Joiners/carpenters.
Yes
photometer or light meter
Generically, a power source (usually batteries), a light source (usually a light bulb), a switch to turn it on and off, and wiring of some sort to connect the energy source to the light source. Theoretically this is the minimum you would need to build a "flashlight".
You would either position the object creating the shadow perpendicular to the light source or move it closer to the light source.
No, the Sun is not the only light source in the univrse. Every star is it's own light source, just as the sun is, but due to there distance they are not very effective. The Moon also creates a light source, because it reflects the light from the Sun back to earth. In the same way, if we where on the Moon, the Earth would be a light source, reflecting the light from the Sun at the moon.
solar