They run on the magical power of fiction. Don't think too much about it. This was created in a book for kids in the 1940s.

Light you can physically touch is a ridiculous concept on its own, but a fun one. I love the GL mythos, even the SA weakness to yellow despite all the things that don’t make sense logically, but all comics are like that. Even the most grounded ones have regular people doing improbable feats. It’s just like watching an ‘80s action movie, turn your brain down and the volume up.

The SA has a lot of things the ring can do that I don’t like, however. Mind reading and time travel and such. There are times when the ring can do such incredible things it makes other stories ridiculous when it’s used in such mundane ways.

Nothing I have read implies that the constructs can accurately emulate the properties of things beyond visual appearance, mass and texture, IIRC. for example, food constructs have never been explore to my knowledge. Can they simulate taste? Even so, the food would not nourish as the light dissipates when concentration is broken. I don’t know if the constructs can also emit other wave properties, such as radiation. Could a GL create a kryptonite construct that would affect Superman? A fire construct that emits heat? A battery that emits electricity?

It all comes down to the particular writer as to what the rings are capable of in the end.

Shortening silver age to SA is probably not the best idea, as usually that acronym is short for sexual assault

I think most people here are intelligent enough to know what I’m talking about within the context of the post.

Haha ok that's a blow to the ol ego. I thought it was sinestro something, was trying to figure out the A. Gaddang nerds :D

The constructs are only limited by the lantern’s imagination and as strong as the lantern’s willpower as they draw on that emotion. They usually take the form of barriers, forcefields, supports, weapons, vehicles, aircraft, and sometimes people. Never seen uses for food or drink but that’s interesting. As others have said, I wouldn’t put much thought into it.