Archive for November 17, 2017

And then there were five….

Posted in The Universe and Stuff with tags , , , , , , on November 17, 2017 by telescoper

…black hole mergers detected via gravitational waves, that is. Here are the key measurements for Number 5, codename GW170608. More information can be found here.

Here is the abstract of the discovery paper:

On June 8, 2017 at 02:01:16.49 UTC, a gravitational-wave signal from the merger of two stellar-mass black holes was observed by the two Advanced LIGO detectors with a network signal-to-noise ratio of 13. This system is the lightest black hole binary so far observed, with component masses 12+7-2 M⊙ and 7+2-2 M⊙ (90% credible intervals). These lie in the range of measured black hole masses in low-mass X-ray binaries, thus allowing us to compare black holes detected through gravitational waves with electromagnetic observations. The source’s luminosity distance is 340 +140-140Mpc, corresponding to redshift 0.07+0.03-0.03. We verify that the signal waveform is consistent with the predictions of general relativity.

This merger seems to have been accompanied by a lower flux of press releases than previous examples…


Where The North Begins

Posted in Uncategorized with tags , , on November 17, 2017 by telescoper

I see that, once again, questions are being raised in the English media about where The North begins. I see it as symptomatic of the decline of educational standards that this issue is still being discussed, when it was settled definitively several years ago.  Let me once again put an end to the argument about what is The North and what isn’t.

For reference please consult the following map:


I think this map in itself proves beyond all reasonable doubt that`The North’  actually means Northumberland: the clue is in the name, really. It is also abundantly clear that Manchester, Leeds, Liverpool, etc, are all much further South than The North. North Yorkshire isn’t in the North either, as any objective reading proves.  All these places are actually in The Midlands.

If you’re looking for a straightforward definition of where The North begins, I would suggest the most sensible choice is the River Tyne, which formed the old Southern boundary of Northumberland. The nameless County shown on the map between Northumberland and Durham is `Tyne  & Wear’, a relatively recent invention which confuses the issue slightly, as including all of it in The North would be absurd.  Surely everyone knows that Sunderland is in the Midlands?

If this cartographical evidence fails to convince you, then I refer to a different line of argument. Should you take a journey by car up the A1 or M1 or, indeed, the A1(M) you will find signs like this at regular intervals:

This particular one demonstrates beyond any doubt that Leeds is not in The North. If you keep driving in a northerly direction you will continue to see signs of this type until you cross the River Tyne at Gateshead, at which point `The North’ disappears and is replaced by `Scotland’. It therefore stands to reason that The North begins at the River Tyne, and that the most northerly point of the Midlands is at Gateshead.

I rest my case.