This short story is centered around Slow Glass- a futuristic glass that slows down light passing through it, there by enabling people to save old memories and places in them, like a live painting. The story deals with human emotions, sense of loss and art of letting go; than the implications of slow glass on a global scale.
Slow Glass sounds like a realistic sci fi plot, something that might happen in future, though I am an absolute dummy on how. Maybe a futuristic metamaterial with tinkered refractive index. Light traverse differently through different medium and refractive index(the ratio of the velocity of light in a vacuum to its velocity in a specified medium) is the property of the material that determines its propagation. With a metamaterial of negative refractive index and stuff, the slowing down of light is probable. The science I postulated above is very primitive and probably a weird explanation as I mostly flunked my masters, yet keyword searches would help you pelt along.
If you strain yourself a little more, slow glass is an earthbound black domain, an escape strategy explained in Death’s End that involves slowing the speed of light below solar system’s escape velocity and thereby creating a hypothetical shrouded Dyson sphere for humanity to escape to . Though spoiled midway, this short story will leave an everlasting impact on you.
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“Light of Other Days” is the title of a 1966 Hugo– and Nebula-nominated short story by Bob Shaw. It was incorporated into a novel in 1972, Other Days, Other Eyes, which also dealt with issues of surveillance and privacy. The title for both the novel and the short story is drawn from the poem “Light of Other Days” by Thomas Moore.
It was also developed into a novel under same name by Stephen Baxter based on a synopsis by Arthur C. Clarke