Thanks to NASA ...

[fivemack]

You will observe that getting a Mac has neither endowed me with a steadier mouse hand, nor greater graphic design skills. Do not tempt me with Wacom tablets of inordinate cost.

mobbsy: looking at this map of city lights, the Pennines are much more an obstacle to the growth of the Liverpool conglomeration towards the Nottingham-Sheffield and Birmingham conglomerations than anything much in the Frankfurt region manages.

meirion: I don't have any very useful citation information for the database I'm using, but I suspect Manchester is counted as tiny (400k) because the city itself insisted on not being counted as part of the Mersey-and-parts-east blob; Liverpool (city) is marked as 450k, Liverpool (area) as 3.6 million

Comments

[akirlu.livejournal.com]

Sometimes Wacom tablets of not-so-inordinate cost may be had through eBay. FWIW.

[beamjockey.livejournal.com]

Don't tempt him!

Bet light pollution is cutting into enjoyment of the sky in all those areas.

When my astronomy club was seeking a new dark-sky observing site, the leaders got a bright (sorry) idea: they went out on cloudy nights, and drove around mapping out the places with the least reflected glow. This gave them a good idea where to concentrate in further surveys, seeking out astronomy-friendly farmers in reasonable driving distance from here...

[akirlu.livejournal.com]

Clever astronomy club you have there. Hate to have anything happen to it...

[fanf]

How are they defining conurbations? Surely the London area is bigger than Paris (judging by the lights).

One of the odd things about Paris (qua Paris) is that its population has been rougly constant at 2M for about 250 years, since they decided to fix the boundary at what is now the Peripherique. It wasn't until the creation of Greater London in this century, reinforced by the M25, that London has acquired a strong boundary. If Paris is allowed to include its sprawling non-Parisian suburbs, I think London should too. After all, the Underground goes all the way to Amersham.

[fivemack.livejournal.com]

The DMSP data that I have access to is entirely binary - has light been detected here or not. So I can't distinguish between a small core of really bright lights, and a more spread-out region of dimmer lights totalling more light. I'm not competent to say whether the Parisian or the London sprawl is the denser.

The figure I have for London counts suburbs, I think; I have 'london-city' as 7.4M, 'london-urbanarea' as 11.2M. Paris-city is 2.1M, Paris-urbanarea 11.3M.

It might be possible to get better figures by looking for census data broken down by local-government divisions; at really tiny subdivisions, governments consider that more a revenue source, but it may be available at more reasonable aggregations. Is there an obvious French administrative subdivision smaller than a département?

Possibly election maps are the place to look; electoral districts are generally of roughly equal population, so if you colour them with a brightness proportional to 1/area you'll end up with a population-density map.

[fanf]

Is there an obvious French administrative subdivision smaller than a département?

Yes, the commune.

[fivemack.livejournal.com]

I read the last word initially as 'Amsterdam'.

The trains go there (0613 from Waterloo, change Brussels, you're in Amsterdam Centraal in time for a late lunch), and the impression I got from the Heroic Engineering supplement of the Guardian a few weeks back was that, when the Channel Tunnel Rail Link is finished, the route will be underground most of the way to Calais ...