Explosion in Ophiuchus galaxy cluster

I've just read an article by Hannah Devlin, Science Correspondent on The Guardian in which she reports that there's been a bit of a bang, originating from the black hole in Ophiuchus cluster, which has made a 'void' about 15 Milky Way's (the galaxy, not the confectionery bar) diameter in the gas cloud. An unimaginable amount of energy involved.

The cluster is about 390 million light years away so if my calculation is right the edge of the hole is (or was about 390 million years ago?) over 380 million light years away, so no need to head for the hills just yet.

As if all this wasn't all mind-boggling enough, Devlin ends her article with:

"The event is thought to have taken place several hundred million years ago, with the black hole showing no signs of dramatic activity at present."

Unless I have misunderstood things (it wouldn't be the first time!) this is nonsense. How would we know what's happening out there 'at present'?

Robin.

Edited By Robin Graham on 28/02/2020 01:17:28

We wouldn't, but she didn't say "happening" at present. She said "showing no signs ...at present".

Something happens out there, then some millions of years later we see the signs (of whatever that is) here.

Edited By Bandersnatch on 28/02/2020 01:34:01

Unless I have misunderstood things (it wouldn't be the first time!) this is nonsense. How would we know what's happening out there 'at present'?

Too true. This event took place long before the dinosaurs started to roam the planet - probably twice as long as that.

Some journalists just don’t have a clue!

Your reading was more precise than mine Bandersnatch - I yield! Hannah is acquitted!

Robin.

Yep - early fish developing as the first vertebrates, and the Devonian red sandstone being laid down on earth.

I thought I heard a bang.

Mike

'At present' is utterly meaningless on that sort of scale, it only make sense in the context of what we can see here and now.

What is time?

I submit there is no such thing as 'at present', because it's the boundary between us and the past, constantly in motion, not a detectable instant. We are propelled into the future like flotsam on the tide, aware of the movement without understanding it.

As human perception lags reality by about 0.5 seconds, everyone is always out-of-date. Getting a signal from Ophiuchus 700 million years after the event is just a measure of how distant from reality we are on a bad day...

Dave

PS What Astrology believes about Ophiuchus is completely trustworthy!

This is the answer.

It's the property of the universe that stops everyhing happening at once.

Lately it doesn't seem to be working too well.

George B.

Hi Dave, "at present" can mean a moment of time, or a period of time, depending upon its context, i.e. a period of time can be defined as being at present when it is in a status que. Many threads on here are "at present" in a status que and have been for quite a while, because no one has added a post, and so "at present" remain unchanged.

Regards Nick.

Well. At least we now know the reason for climate change!

A little further confusion - I thought that once black holes went bang they stopped being black holes and just went back to being space. Very odd.