[Joyce Rops (OP)]

I am currently reading a book called ''I am Pilgrim''. In the book they try and succeed in developing mirrors just like you would develop a photo. The story is that there was a really bright flash from exploding magnesium and that the silver nitrate in the mirror captured a picture of the room it was facing. Is that actually possible? Especially since the mirrors were really old I wonder if daylight wouldn't have made the silver nitrate inactive?

[chiralSPO]

Interesting idea, but I think a mirror would qualify as 'fully developed' as the silver nitrate has already been decomposed to silver metal to make the mirror in the first place...

[RD]

Even with you run with that chemical conceit, optically it wouldn't work : you'd need a small aperture to focus the image , [ and you'd have to shield the mirror from the direct flash ].

In that scenario holography is less implausible than photography.

[puppypower]

Say the light source is very strong and this alters the reflective characteristics of the mirror relative to weaker light. In other words, the energy signal of the image is such that what is normally reflected, becomes part of the absorption. This may give a fizzy positive on the negative.

[alancalverd]

You might capture a hologram by evaporating the silver, or even melting the glass, but you'd probably fry the subject in the process.

[RD]

... you'd probably fry the subject in the process.

If frying is acceptable, silhouettes are possible ...

http://nowiknow.com/nuclear-shadows/

[syhprum]

I Victorian times it was believed that it should be possible to obtain a picture of the killer by dissecting the eyes of the vivtim