Eli5: Shouldn’t light from distant stars and galaxies appear to be continuously blinking by tons of space debri constantly moving between it and us through the Billions or year?

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Hopefully the question makes sense. But it seems like we are always getting such great photos of these objects. You would think that one day you may be able to see a galaxy; while the next it may be completely obstructed by another object that is closer to earth but still thousands to millions of light years away.

In: Planetary Science

8 Answers

Anonymous 0 Comments

As others have said, space is just way bigger and emptier than you’re thinking. As example to make it more intuitive, consider this question:

“Shouldn’t the light from the ceiling light in your room right now be blinking due to the thousands of dust particles between you and the bulb?” or “should the illumination under a streetlight on the roadside be blinking due to all the debris in the air outside?”

Hopefully you can “feel” that the answer is “no of course not, because the debris is too small and too few compared to how big the light source is and its brightness.”

Well your question has the same answer, and for the same reasons. Even for far away stars, the debris between us and the star is too small and to few to obstruct the light by any meaningful amount. It’s like the dust between you and the lamp across the room.

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