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Giant Explosion Observed
KFZ Versicherung writes "Space.com is reporting on the largest explosion ever seen in space. The outburst is orchestrated by a supermassive black hole that anchors a distant galaxy sitting amid a tight cluster of galaxies. The black hole has blown two huge bubbles into the galaxy, shoving aside a colossal amount of gas equal to the mass of a trillion Suns, or more than all the stars of our own Milky Way Galaxy."
It's a bit like the usual thing about we see the sun as it was 8 seconds ago, and that what it is 'now' we will see in 8 seconds time.
While sorta true, it's just wrong enough to be annoying. Spacetime isn't quite like that. It doesn't really make sense to talk about what the sun is like 'now', since 'now' is relative.
Feynman has a wonderful example to explain it.
Imagine you keep your head fixed, and you see an object in space. You then see it having a width (angle it substends) and depth (say amount your eyes have to focus or something). Because you have now got different units, you might think the width and depth to be totally different (analogous to space (meters) and time (seconds)).
But if you move your head, you suddenly realise width and depth are an aspect of the same thing.
It's the same for space and time.
In fact the famous E = mc^2 can be thought of mass being in the 'wrong' units, in the same way we got confused when measuring width and depth as an angle and a focus amount. If we measure mass in units of c, you get E = m.
8 minutes ago