Delayed Telecast
When we look at the sky at night, what we’re seeing is old news.
Proxima Centauri is the closest star (besides the sun) to our planet, about 4 light-years away. Should Proxima Centauri suddenly disappear this very instant, we’ll know about it only 4 years from now. Of course, stars don’t simply vanish, they go through various phases. But the point is that the sky is not giving us visual real-time information.
Gravity, on the other hand, is real-time. Going back to our vanishing star example, the sudden disappearance of Proxima Centauri will be felt right away.
I find it quite paradoxical that the effects of gravity is instantaneous even from one end of the universe to another, whereas light takes significant time to travel vast distances.
3 Responses to “Delayed Telecast”
1 Ady 23 December 2008 @ 2:53 pm
Wow! Now you’re into astrology.
What about sound? If a supernova occurs why wouldn’t we hear anything?
2 Ady 23 December 2008 @ 4:19 pm
As Rizal has corrected me in YM, I meant astronomy not astrology.
And when Rizal mentioned the word vacuum I realized that there is no medium for sound to travel.
Silly me. See my knowledge on science?
3 Rizal 23 December 2008 @ 5:48 pm
Yeah … but for us, this kind of knowledge is good only for “filler” blog posts
… of more practical importance is your knowledge of software engineering. You have that programming instinct that can’t be taught …
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