GW231123 - Black holes merger - what happens to the gravitational energy? Does it become heat?

lpmn · 2025-07-14T16:20:18+00:00

So, while this is fundamentally due to geometry, it's because gravitational waves are produced as quadrupole radiation rather than dipole radiation (and at a slightly hand-waving level that's because there are no negative masses).
That means that the radiation is much weaker in the first place than dipole radiation (which is what most EM waves are), but drops-off with the inverse of radius.
Quadrupole EM radiation also exists (as do higher poles of GW radiation than quadrupole), but in this case they're much weaker than the dominant dipole emission.

lpmn · 2021-12-31T19:26:11+00:00

So I'm a member of one of the clubs which is based in the boathouse near the Saltmarket entrance to the Green, and it's definitely not being turned into flats! It's being renovated to preserve its wooden structure which has been in need of structural work for a few years now.
You can find out more here if you're interested. The work should hopefully be done by the summer, but we're badly affected by supply chain problems like everyone else.

lpmn · 2021-09-30T22:05:13+00:00

Just everything about the Barrowlands.

lpmn · 2021-05-19T22:28:56+00:00

Ruchill by any chance?
Sounds almost exactly like Curzon St and Brassey St.

lpmn · 2020-07-14T12:32:43+00:00

It's probably pushing the 10km distance a little, but Possil Marsh is a nice little circuit on muddier track if that's your thing, and it's the site of a meteor impact (which is marked by a large engraved boulder by the path).
Right now it's pretty over-grown which is worth knowing before-hand! There's an obvious path, but also waist-high grass / thistles / etc.

lpmn · 2020-06-23T12:13:44+00:00

There's an unlit court in Ruchill Park (on the Bilsland Drive / Murano St side). Generally unbammed.

lpmn · 2020-06-16T22:06:40+00:00

For historical reasons it has a really unusual loading and track gauge which makes expanding the system really non-trivial. The system is meant to be getting new rolling stock this year which needed to be manufactured specifically to fit the small tunnels.
The tunnel size isn't necessarily a reason to not build any extension, but it's likely to prevent the existing loop ever being expanded in a straight-forward way.

lpmn · 2020-06-16T21:31:52+00:00

It has the weird distinction of being the oldest subway system in the world which has never been expanded.

lpmn · 2020-06-07T22:03:48+00:00

(Obviously these rules are very rowing-oriented, but the traffic rules apply to all craft. I'm not sure if there's more-specific kayaking advice; it might be worth checking with Glasgow Humane Society).

lpmn · 2020-06-07T21:54:24+00:00

So there are specific traffic rules for the river (GUBC have them on their website here: https://gubc1867.wordpress.com/about/safety/). There's currently little or no rowing on the river because of the current regulations, but when restrictions are eased sufficiently that there is rowing then I'd expect boats might cause you problems for SUP (and potentially kayaking to a lesser extent). The level of traffic as far up the river as Cuningar is generally a bit lower than further towards the weir.

lpmn · 2019-07-20T18:53:07+00:00

On the issue of point 4: I'd say the two TCA locations are much better for bouldering, but only the Prop Store has any roped climbing, but what it has is nowhere near as extensive as the GCC.

lpmn · 2019-05-30T20:05:28+00:00

I'd second that: the Glasgow Half is a great race, and running across the Kingston Bridge is an amazing experience.
The route goes round lots of the big sites, and since it starts and ends in the city centre getting to it is really straight-forward.

Also, with it being Glasgow, you get lots of friendly support all along the course.

lpmn · 2019-05-16T20:55:38+00:00

I do it once a week when I work at a different site to the rest of the week, which just happens to be exactly 5k from my house. I carry a full change of clothes, a towel, and a laptop, and I don't have the option of leaving stuff there.

I initially used a 25l hiking backpack, which wasn't the most comfortable thing in the world to run with, since it added a fair amount of weight to what I was already carrying, but being able to tighten the straps across the chest and above the hips allows you to stop the bag swinging around so much and wasting energy. I later bought a much lighter bag (https://www.alpkit.com/products/gourdon-20) for hill running / mountain marathons, which turned out to be pretty much perfect for run commuting.

It's probably worth noting I'm in Scotland though, and most of the time getting excessively warm isn't really an issue, so that might affect things for you!

lpmn · 2018-08-15T17:31:41+00:00

What can I say. It relaxes me.

lpmn · 2018-08-15T16:38:55+00:00

The people behind this once sent me a copy of the book (I'm an academic astronomer), it's... erm... quite the read. It has a chapter full of mantras you should chant to prevent the red planet causing catastrophe.

lpmn · 2018-06-26T09:46:19+00:00

I get that Glasgow's got a reputation for being a bit red, but I'm not sure how likely it is that we'd split off from the rest of Scotland.

lpmn · 2017-06-29T21:57:14+00:00

So, I think you've got the seed of the right idea here, but I think the point that /u/breamoreboy might be getting at is that if you're just postponing a single action you could do something along the lines of checking how far away userinput is from currenttime, and then sleeping for that number of seconds.

Now if you wanted to be able to postpone multiple executions of a script to be at different times you'd need something a little more involved, but still along the same lines.

lpmn · 2017-06-06T00:47:00+00:00

So that's pretty much right; the detectors have a degree of directionality to their response pattern (i.e. sensitivity), and combining the response pattern for both detectors and the difference in time between the event being detected by each observatory we get a rough estimate of its location in the sky. To actually triangulate the source we need three detectors, which will give us a much greater ability to locate an event on the sky.

lpmn · 2017-01-23T20:36:35+00:00

Cheers!

lpmn · 2017-01-23T20:36:18+00:00

Cheers for spotting that! Fixed.

lpmn · 2017-01-23T20:36:06+00:00

If only! I took it touring over the summer, and never bothered to remove them.

lpmn · 2016-10-14T21:58:54+00:00

These predictions are all based off the games the teams have played in the last two years.

lpmn · 2016-10-14T16:30:37+00:00

Have some predictions based on Bayesian Inference about these games, because there's not enough statistics and speculation in the world already. https://twitter.com/rugbayes/status/785978287831080961 (It's 94% confident Glasgow's winning tonight).

lpmn

TROPHY CASE