h2g2bob @h2g2bob@mastodon.dbatley.com

TCP keep alive works by re-sending the previous ack, even though no more data has been received. There is normally no response for ack packets with no data, but for keep-alives servers respond by also re-sending the previous ack. https://github.com/wireshark/wireshark/blob/178e7ce9a533ba9e5e152c9f7bc08f5ba8f25f0b/docbook/wsug_src/WSUG_chapter_advanced.adoc #networking

Europe's Galileo global positioning system had 5 days downtime earlier this month. The satellites were fine, the issue was with the support on the ground. https://www.gsc-europa.eu/news/galileo-initial-services-have-now-been-restored Current status: https://www.gsc-europa.eu/system-status/Constellation-Information #space

Scientists do autopsies on whales and dolphins if they get stranded on a beach.
https://naturalhistorymuseum.blog/2018/05/23/strange-strandings-the-case-of-a-rissos-dolphin-in-the-southern-north-sea-cetacean-strandings-investigation-programme/ #biology

The Minister's cake
https://www.roads.org.uk/blog/ministers-cake

It's a great time to read Sustainable Energy Without The Hot Air, an easy to read book asking if/how we can stop using fossil fuels. There are great ballpark estimates, which make the huge numbers instantly understandable. Free pdf. https://withouthotair.com/

How many disks can you add to a virtual machine?
https://rwmj.wordpress.com/2017/04/25/how-many-disks-can-you-add-to-a-virtual-linux-machine/ #computing

LightSail 2 will be unfurling its solar sail on Tuesday. The crowdfunded spacecraft plans to accelerate by reflecting sunlight off the solar sail. http://www.planetary.org/blogs/jason-davis/ls2-sail-deployment-live.html #space

Music recommendation: Ecuador by Sash! The song is just so ridiculous and awesome. https://youtu.be/9cQlVww0zKo

Drama as two conflicting proposals both want to use the same TCP's congestion notification flags. https://lwn.net/Articles/783673/ #networking

Liquid chromatography in beer glass. Draw line in felt-tip 2cm from the bottom of kitchen towel. Place in 1cm deep water. Water carries felt-tip mark upwards. Chemicals have different friction from paper, so colours separate. #chemistry

A new process to make ammonia
https://blogs.sciencemag.org/pipeline/archives/2019/04/25/who-cares-about-making-ammonia-you-do #chemistry

What's wrong with signals in Unix and Linux? https://lwn.net/Articles/414618/ #linux

Did you hear about the town in Ireland whose population went up by a factor of two? It was Dublin!

Does the news reflect what we die from?
https://ourworldindata.org/does-the-news-reflect-what-we-die-from #world

Up close with NeNe Geese at #london wetland centre

New #debian version is released this Saturday. AppArmour and Wayland by default, upstart removed, Python 3.7 (which supports type annotations) https://wiki.debian.org/DebianBuster

Game recommendation: FTL: Faster Than Light. Send the crew to frantically patch up the spaceship, while being chased across the galaxy by an overpowering foe. Which is basically the plot of star wars, firefly, etc. Great soundtrack. https://www.gog.com/game/faster_than_light

Political party destruction
https://timrollpickering.blogspot.com/2018/02/can-established-party-truly-vanish.html #ukpol

QR https://dbatley.com/blog/2019/06/qr-squared.html