Dark holes.

[AdonisLoved]

So light takes time to travel. But think about the absence of light or a black hole taking in the light and space around them, how long could it take to notice the gap it would leave, Could it be instant? Or would it take longer. It should be longer because the light is being pulled in. The fact, however, that the absence of light should be instantly perceptible due to the idea that the light isn't traveling anymore but being sucked back in the direction of the black hole against time, and space. The "dark hole" we see is happening there and now?; while the light we see happened years, to billions of years, ago. Would the hole be a 3dimensional(|+/-|?) object only imperceptible due to the fact of its gravity? Or is it a lack of dimension that causes such gravity. Also our pupils, oddly resemble them. The take in light, and project it to your brain. Any pros out there?

-adonai

[ajb]

Maybe a little easier to think about, but what if the Sun stopped shining? How long would it take us to notice?

[MigL]

Black Holes don't suck.

Light, and anything else for that matter, outside the event horizon goes on its merry way along the geodesic paths in spacetime defined by the BH's mass-energy.

[AdonisLoved]

Wouldnt it take about 7 minutes? But light is affected by the holes gravity correct?

Edited March 20, 2016 by AdonisLoved

[ajb]

Wouldnt it take about 7 minutes?

Yes. So if the Sun stopped shining now, we would only detect this something like 7 mins later.

 

 

But light is affected by the holes gravity correct?

Yes, but in exactly the same way as it is by a star. Let us suppose that our Sun suddenly becomes a black hole. Let us forget about any possible mechanism here. We would not notice this change for something like 7 mins as you say. And then we would only notice that the Sun is not shinning, gravitationally we would continue on our standard orbit round the Sun.

[DanTrentfield]

The funny thing about light taking time to travel is that there is the distinct possibility that half the stars shining in the night sky could have become black holes or other non main sequence stars, or even may have gone supernova, and we still wouldn't know about it because they're so far away. It's going to be hilarious when an astronomer says that a star just blinked out, and then notices an expanding gas cloud and goes "oh......"

[Sensei]

Wouldnt it take about 7 minutes? But light is affected by the holes gravity correct?

 

150 mln km / 300k km/s = 8 min 20 sec

Slightly less, but not much, because light is emitted from surface of Sun, not its center.

[aliceinwonderland]

So it would take us around 8 minutes until we would start to notice, that makes sense to me. But how long would it take for us to die? I'm really wondering what the first consequences of the sun turning dark would be. I assume the problem would be the darkness and the drop in temperature, so how soon would the earth start to freeze and become a completely hostile environment? How long would humans be able to survive this? Would anything survive this?

[Strange]

My guess was a few weeks, and it seems to be about right: http://www.popsci.com/node/204957

It seems to be a very common question: https://www.google.co.uk/search?q=how+long+survive+after+sun+goes+out