I vaguely remember something along those lines, but the equipment was something academic. You wouldn't actually be able to see anything.

On the other hand, you can se thngs happen at light speed in space, as long as the light is bright enough and the distance great enough.

Notice however, that you cannot observe light from the side. You have to deflect part of the beam from its path so that it strikes your eye. To get the idea, look at a laser pointer in the dark from beside the beam of course! In very clear air you cannot see it passing. In practice one usually can see it, but that is because there always is some dust or aerosol in the air. Out in space you would see nothing before the beam hits something to scatter it. The same would apply if you slowed light down through really clear glass or crystal.

Now, suppose you put a satellite in the L5 point of the Earth - moon system, and scattered a very diffuse puff of fine white powder in space between the moon and the satellite. Now you send a series of intense laser pulses from satellite to moon. Each pulse would take something over 1 second to pass through the mistiness, so you could see the light leaping from source to target. Do the same thing with the Earth - sun system, and you could watch the progress for something like 8 minutes.

At cosmological distances flashes for supernovae have been observed passing through nebulae, if I remember correctly.

Slow enough for you? By modulating your laser beam, you could even use the light path as a delay-line data memory!

Cheers,

Jon