Re:Milky Way’s Black Hole Just Flared, Growing 75 Times as B...
by luc4sdreyer on Tuesday August 13, 2019 @07:10PM
(#20691188)
> it would still be like blindly throwing a dart and hitting a bullseye 24,000 light years away in this case.
I liked this analogy, so I felt inspired to calculated the odds. Particularly: the percentage of the "sky" (celestial sphere) that is covered by the Earth from Sagittarius A* 's perspective. That's equal to the two dimensional projection of the Earth onto a 26000 ly sphere around Sagittarius A*.
cover% = π x (6371km)^2 / (4 x π x (26000 x 9.46 x 10^12 km)^2) x 100%
= 1.677 x 10^-26 %
I tried to put that number into "human terms", but the best I could come up with is it's the same as the width of a hair at Saturn's orbit, viewed from Earth.
Re:Milky Way’s Black Hole Just Flared, Growing 75 Times as B...
by dnadler on Tuesday August 13, 2019 @10:17PM
(#20692174)
Slightly off topic, but one of my favorite solar system facts is that the with of Saturn's rings can be measured in feet. They are much thinner than I ever expected.
Re:Milky Way’s Black Hole Just Flared, Growing 75 Times as B...
by Eriksrocks on Tuesday August 13, 2019 @10:52PM
(#20692343)
Sure, if you consider 3,200 feet as "measured in feet" [1]. Anything can technically be measured in feet. When you said that I assumed you meant they were like 20-30 feet thick, not over half a mile.
[1] http://coolcosmos.ipac.caltech.edu/ask/108-How-large-are-Sat....
Re:Milky Way’s Black Hole Just Flared, Growing 75 Times as B...
by dnadler on Thursday August 22, 2019 @11:50AM
(#20769426)
From a NASA website[0]: Saturn’s rings are incredibly thin. The main rings are generally only about 30 feet (10 meters) thick, though parts of the main and other rings can be more than a mile, or several kilometers, thick.
Re:Milky Way’s Black Hole Just Flared, Growing 75 Times as B...
by dwaltrip on Wednesday August 14, 2019 @01:48AM
(#20693001)
That's still pretty damn thin, relative to the size of the rings. An interesting quote from your link:
"If you had a model of Saturn that was a meter stick wide (3 feet), its rings would be about 10,000 times thinner than a razor blade!"
* An undetected high velocity object * Radation bursts
The thing is that since space is so big, we would have to be extremely unlikely to get hit. If a radation burst was directional it would still be like blindly throwing a dart and hitting a bullseye 24,000 light years away in this case.
I believe it's possible for our Sun to emit a solar flare large enough to kill us too (this is far more likely then radiation from a blackhole killing us because its magnitudes closer).