I saw an episode of ST:VOY and in one of the vessel-flies-by scenes, there was a large cloud in the background (similar to the Orion cloud) and it blinked at some 1Hz.

I guess the FX people thought it would be neat to have some variable star in the center of a cloud and make it blinking...

Now, if an object is large and lighted from some central light source, it can't be blinking uniformly. Some parts of the cloud are closer to the center, reached earlier by the light than farther parts (this is how optical illusions of rings appear around some exploding stars - the expanding light sphere hits some dust layer.

Even our Sun would look strange if it would blink with 1Hz on/off. The edge of the Sun
is some two light seconds farther away from the eye then the Sun's center. So, what we would actually see would be concentric circles of light starting in the center of the disc going outwards.

Or am I completely mislead by something?

Harald

Your analysis makes sense to me. The only way it would work is if the central light source (a pulsar perhaps?) was surrounded by a thin, spherical shell of dust which was centered at the source. This is not very likely, to say the least.

The only thing that is misleading you is the thought that Voyager would portray science correctly! [img]/phpBB/images/smiles/icon_wink.gif[/img]

Maybe it is something we don't know about yet. [img]/phpBB/images/smiles/icon_smile.gif[/img] Or a cosmic bug-zapper zapping the dust in the cloud. -Colt

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