David Penfold 

@davep@infosec.exchange
1.9K Followers
258 Following
22.1K Posts

Does IT stuff. Vegan and anarchism curious.

Likes permaculture, infosec, Tranmere Rovers. But mainly bad jokes stolen from https://www.justthetalk.co.uk/thehaven/17468/urgent-i-need-a-good-joke-right-now

Also unreasonably fond of BPMN.

Officially not right in the noggin #ʘ‿ʘ

likewhatever
SignalDave.14
CO2 ppm at birth321.37
David Penfold 34m ago
Am I being totally dozy? Could someone explain how to remove old clients' accounts from the PC MS Teams program? I've had a root around and nothing seems to give the option to get rid of the accounts. Yes Teams, I know there's a bloody problem with them, they've deleted the sodding accounts, numbnuts.
David Penfold 38m ago
Dr. Amy, Psy.D.1h ago

Hi friends, I need quotes for another article! This one is about how hormone fluctuations from the mensural cycle impact ADHD symptoms. Personal stories are welcome, and also I need to chat with a couple of medical professionals.

#ADHD

resiliencymentalhealth.com/contact/

David Penfold 56m ago
Lukito6h ago
You’re all VERY welcome  
David Penfold 57m ago
CatSalad🐈🥗 (D.Burch) 1h ago
You can only pick one, choose wisely!
one
wisely
Poll ends at .
David Penfold 59m ago
Chronic Illness Humor Funny3h ago

Don't forget to stay hydrated and to stay inside between 10AM and September 01.

#heatwave #funny #haha #humor #summerhumor #summer #toohot #itstoohot #chornicillnesshumor #chronicillnessmemes #autoimmunehumor #autoimmunefunny

David Penfold 1h ago
Dave B 5h ago
David Penfold 1h ago
James Gleick10h ago

We can argue about what’s the absolute worst part of what Congress is about to do. The enormous transfer of the nation’s wealth to the richest one percent from everyone else?

But for me it’s this: https://toad.social/@KimPerales/114762327100958328

Kim Perales (@KimPerales@toad.social)

Attached: 1 image 🚨"If the bill passes, it could make #ICE the US' largest jailer, with more funding for #detention than the entire fed Bureau of Prisons. It'd give ICE enough💰to have more officers on board than the entire FBI. This alone could transform American society forever." -A Reichlin-Melnick #BBB "Trump is committed to keeping his promises, & failure to pass this bill would be the ultimate betrayal." -C Pergam In effect: funds terrorism agst undoc #immigrants +others who oppose the #TrumpRegime. #USPol

toad.social
David Penfold 1h ago
John Carlos Baez10h ago

If you're the kind of person who follows me, you may know about the Kessler Syndrome.

That's when collisions between satellites and space junk create enough debris to cause *more* collisions, leading to a runaway chain reaction. This could render certain regions of near-Earth space unusable!

It's one of nature's ways of containing stupid civilizations, sort of like how inflammation contains infections. So don't be surprised:

A new study by Lewis and Kessler argues that we've hit the "runaway threshold" - the point where a chain reaction is expected - at nearly all altitudes between 520 and 1000 kilometers.

Below that, or above that, space could remain usable. So we could still get out and ruin other layers of space - or go to other planets and mess up those. Luckily, planned deployments of large satellite constellations like Starlink, Amazon's Project Kuiper, etc. will reduce the risk of such a breakout.

Yes, I'm joking - we can differ on whether the expansion of stupidity into the cosmos would be a good or bad thing compared to a mostly dead cosmos, and I don't really have an opinion on that. But the study is for real, and worth checking out:

• Hugh G. Lewis and Donald J. Kessler, Critical number of spacecraft in low Earth orbit: a new assessment of the stability of the orbital debris environment, https://conference.sdo.esoc.esa.int/proceedings/sdc9/paper/305/SDC9-paper305.pdf

Thanks to @michael_w_busch for pointing this out.

(1/2)

David Penfold 1h ago
Show threadmekka okereke 1h ago

If you understood this thread, then you will understand why due to ICE's recent actions:

*Arrests of violent criminals who are undocumented will go down🤡

*Violent crime by undocumented people will go up

*Unlicensed gun ownership among undocumented people will go up

So ICE is *creating* crime.

You can prioritize deporting the 100 most dangerous undocumented people, who commit the vast majority of the violent crimes.

Or you can prioritize deporting the 12 million other undocumented people.

But you can't prioritize both.

Again, to put the numbers in perspective:

Of ~12 million undocumented people, 50,000 are in ICE detention. That's bad.

Of ~20 million Black men, 4 million will be imprisoned at some point in their life. Not a typo. 1 in 5.

Those are horrific numbers.

3/3

David Penfold 2h ago
Mr and Mrs Trellis2h ago

Why are UK cities often the hottest spots in the country? Compare this to Singapore, which is now half green space, and where more than half a million trees have been planted since 2020....

https://www.bbc.co.uk/weather/articles/cednp88vpxqo

UK heatwave: Why do our cities get so hot?

Temperatures in city centres can be 10C higher than surrounding areas but why does that happen and can anything be done about it?

BBC Weather
×
Show threadPhilipp Birken14h ago

First ride is an electric accordion bus. This is a standard one, but the town has even bought so called superbusses, which have two "accordions", not just one. This is part of an ongoing transformation of traffic: Electric busses, Bikes, less cars, more trees. I love it.

A week ago, the town has introduced a new line network. This is the first time we ride with the completely new line 9, which will take us to the central station.

2/n

Show threadPhilipp Birken14h ago

Now on to the Öresundstrain, which will take us in 34 minutes to Copenhagen central station. These go every 15 minutes, making Malmö sort of a suburb of Copenhagen. They are not 100% reliable, unfortunately, so on such trips, we go early and then have breakfast in Copenhagen.

3/n

Show threadPhilipp Birken13h ago

This train goes over the Öresund bridge, which just filled 25 years! It's a smashing success and has completely transformed the region, causing Scania to now be a part of the Greater Copenhagen Area.

The cars go on the top lane, whereas the train is on the lower lane. That means unfortunately that the view is not so great, but let's not complain.

After the bridge, the train goes into a tunnel starting on the artificial island Pepparholm, where we pass Copenhagen airport (and don't get out!).

Now on to breakfast at Copenhagen Central station!

4/n

Show threadPhilipp Birken12h ago

On to the train from Copenhagen to Hamburg. This connects Scandinavia to the rest of Europe and it is run jointly by DB and DSB. It is also notoriously unreliable and it is rare that one arrives in Hamburg on time. Indeed, already wagon 8 is locked and travelers on that one are relegated to a replacement bus.

The 4.5 hours trip is slow. Also, the wagons being used are old and not very comfortable. Today, we have old german InterCity wagons, I guess from the 90s. Often, the wifi is turned off once on enters Germany.

But better times are ahead: Denmark is building a tunnel that will shorten the trip by two hours, a game changer for Scandinavia! The construction is currently on time, and due to finish 2029. So yay Denmark!

Both the german and the swedish government behave quite ignorant of this, and the followup construction in both countries is at best in a planning stage.

Nevertheless, good times ahead for train travel in northern Europe!

5/n

Show threadPhilipp Birken9h ago

After lots of fields and meadows, there's a real highlight on the trip, namely the Rendsburg High Bridge over the Kiel canal, both built during imperial times more than a 100 years ago. The track follows a circular pattern with modest slope up and down.

6/n

Show threadPhilipp Birken7h ago

We did arrive in Hamburg on time, yay!

Hamburg has a DB Lounge, which is nice since it's a crowded station. Access has become more restrictive, but after a short discussion, they accepted our 1st class Interrail tickets with a Bahn Bonus Silver card.

It's unfortunate that you can't buy a day pass for these using Bahn Bonus points anymore.

Anyhow, off on the last leg for today, 4 hours to Cologne in a nice quiet and comfortable ICE.

7/n

Show threadPhilipp Birken3h ago

And we made it to Cologne with 5 minutes delay. All in all, a nice, stress-free trip with fully electric modes of transport.

I slept, read, ate, chatted, and read lots of interesting information about international rail from you fedihomeys. Love it.

8/n

Show threadpair1212h ago
@philippbirken Wir fahr'n, fahr'n fahr'n, auf dem Eisenbahn.
Show threadSøren Have10h ago

@philippbirken Also DSB will put the new Talgo carriages into service later this year, so the connection to Hamburg should hopefully become more reliable 🤞

https://www.dsb.dk/om-dsb/baredygtighed/strategiske-projekter/talgo/

Nye vognstammer | Bæredygtige, el-vognstammer fra Talgo

Vi har købt 8 nye vognstammer, som hver har plads til 492 passagerer, hos spanske Talgo. De indsættes på ruterne til Hamborg. Læs mere her →

Show threadPhilipp Birken10h ago
@sorenhave Ah, nice, very much looking forward to that. It should also improve the sanitary situation...
Show threadHolger Seelefand10h ago
@sorenhave @philippbirken will they also allow bicycles on board of the new carriages? The last time I had to take the flix bus to Hamburg 😩
Show threadSøren Have8h ago

@seelefand Unfortunately I don’t know, but yes they should.

@philippbirken

Show threadJens Christian Skov44m ago
@sorenhave @seelefand @philippbirken
According to this press release (in Danish): https://www.dsb.dk/om-dsb/baredygtighed/strategiske-projekter/talgo/
There will be room for bicycles and even an option to charge your e-bike.
Nye vognstammer | Bæredygtige, el-vognstammer fra Talgo

Vi har købt 8 nye vognstammer, som hver har plads til 492 passagerer, hos spanske Talgo. De indsættes på ruterne til Hamborg. Læs mere her →

Show threadKalle Kniivilä26m ago
@jens @sorenhave @seelefand @philippbirken Charging big batteries like that on a train is not necessarily a good idea.
Show threadJesper Kamstrup Linnet7h ago

@seelefand Yes, I believe that the flex areas will have room for bicycles (and prams etc.)

@sorenhave @philippbirken

Show threadHolger Seelefand7h ago
@jesper_linnet @sorenhave @philippbirken that is great news. It will simplify the logistics of future cycle trips to Danmark immensely.
Show threadBruno Girin10h ago
@philippbirken I took it once 18 years ago from Hamburg to Copenhagen. It was slow but roughly on time. From what you say, the service has got worse since then.
Show threadPhilipp Birken10h ago
@brunogirin Well, they used to have trains that go on the ferry to Puttgarden, but the ferry was cancelled a few years back, in connection with the construction starting for the new tunnel. Additionally, the decent train sets were replaced by the current older ones.
Show threadTor Lillqvist10h ago

@brunogirin @philippbirken Nah, you can't draw that conclusion. There are more trains now. In June 2003, there were six direct trains København–Hamburg per day. This June there are eight. And unless I am mistaken there are clearly more seats in the current sets.

(But the IC3 DMUs were more comfortable at least in 1st class, sure.)

Show threadTor Lillqvist10h ago
@philippbirken it is actually not that awfully slow, the average speed is a respectable 108 km/h for EC 392, for instance. But sure, that is much less than the SJ Snabbtåg between Stockholm and Malmö (around 130–140 km/h), not to mention actual high-speed trains on high-speed lines.
Show threadPhilipp Birken10h ago

@tml I would argue that Copenhagen-Odense-Kolding is the most important train line in Denmark and that should be high-speed.

But the real slow part of the ride is Kolding-Padborg. Additionally, it's boring with only flat fields and meadows!

Show threadTor Lillqvist10h ago

@philippbirken It is partially newly built semi-high-speed (200 km/h), the bit between Copenhagen and Ringsted that runs closer to the coast through Køge Nord and avoids Roskilde.

Also the new line between Nykøbing Falster and Rødby is 200 km/h, which is where trains through the Fehmarn tunnel will run. (According to openrailwaymap.org. )

Show threadNiels J7h ago

@philippbirken
It's getting there. Here are the steps:

1) Build bridge. 30 years the trains were still carried by ferry across the Great Belt.

2) The new line Copenhagen-Ringsted is high speed, built for 250 km/h. But trains going faster than 200 need their approval renewed every year instead of every three, so they don't. And till the new rolling stock is approved, only DB trains go over 180.

@tml

Show threadNiels J6h ago

@philippbirken
3) Electrify the whole stretch. That was stupidly postponed in the 90s. Happened sine 2015.

4) A new 250 km/h line is under construction Odense-Middelfart. I passed by on the motorway recently, they move lots of soil.

@tml

Show threadNiels J6h ago

@philippbirken
5) Ringsted-Korsør can be cheaply upgraded to 200 km/h most of the way. The slowest sections can also get faster, but not 200. So high speed, barely.

6) The Great Belt tunnel can probably also do 200 with hardly any change. The bridge can't.

7) All of Denmark is replacing old analog mish mash signals with new EU standard. It's slow and expensive. Point 5 and 6 have not been decided, but look more likely to happen along with new signals, maybe 2028-9?
@tml

Show threadNiels J6h ago

@philippbirken
So in five years most of it could be high speed. The rest is either in cities or on bridges, except for 40 km which is mostly 180 km/h, some 160 and 140, not much to gain.

A lot is happening on Danish railroads.

If anyone wants to check this out (or any other railroad worldwide) I recommend https://openrailwaymap.org
@tml

OpenRailwayMap

OpenRailwayMap - An OpenStreetMap-based project for creating a map of the world's railway infrastructure.

Show threadNiels J6h ago
@philippbirken
And there is lots of interest from rail companies wanting to run from Stockholm/Oslo/Copenhagen to Hamburg, even before the Femern Belt Fixed Link opens. So better times ahead, probably.
@tml
Show threadRuth Mottram10h ago
@philippbirken you never know, other family members just arrived precisely on time in Hamburg on the same route... Sometimes DSB surprises us! God tur.
Show threadPhilipp Birken10h ago
@Ruth_Mottram Thanks!
Show threadJWcph, Radicalized By Decency10h ago

@philippbirken The Fehmarn tunnel project is completely bonkers 🤯 each tunnel segment is cast in one piece, over 200 meters long - they have to work 24-hour shifts or the concrete would set unevenly during casting, which would obviously be bad...

https://www.youtube.com/watch?v=zf7C5DiEVpA

How the Fehmarnbelt Tunnel is being built

YouTube
Show threadGraham Perrin9h ago

@jwcph @philippbirken @aslakr wow.

https://femern.com/the-tunnel/fehmarnbelt-tunnel/

Fehmarnbelt tunnel

Show threadTor Lillqvist9h ago

@philippbirken I have taken the direct train between København and Hamburg, in both directions, five times this year, and it has been roughly on time each time. At most maybe ten minutes delay, and some times arriving in Hamburg a few minutes earlier than scheduled.

But yes, the rolling stock is old and often broken. And there apparently are few if any spare carriages, all available ones that can be used are in use.

Show threadTor Lillqvist9h ago
@philippbirken The different electrification in Denmark (25 kV 50 Hz) compared to Germany (15 kV 16.7 Hz) means that also the electricity provided from the locomotive to the carriages is different, so they can't just take any random old domestic (Denmark only or Germany only) carriages into use. And presumably there are many specific technical requirements because of the Great Belt tunnel.
Show threadPhilipp Birken9h ago
@tml Is that why they can't use the short ICEs they were using when going on the ferry? These were neat!
Show threadTor Lillqvist9h ago
@philippbirken Might well be. I think I never used those, for some reason (small kids, likely) I apparently didn't do much interrailing during the time they were in use.
Show threadKalle Kniivilä6h ago
@tml @philippbirken Is there a reason for not using 50 Hz? Seems odd.
Show threadTor Lillqvist5h ago
@kallekn @philippbirken There were technical reasons back in the days. See https://en.wikipedia.org/wiki/15_kV_AC_railway_electrification
15 kV AC railway electrification - Wikipedia

Show threadKalle Kniivilä5h ago

@tml @philippbirken "Norway also has two hydro-electric power plants dedicated for railway power with 16+2⁄3 hertz output"

Wow, had no idea. Seems somewhat irrational, but we do a lot of weird stuff for historical reasons.

Show threadJonas Boström5h ago
@kallekn It was very rational 100 years ago. Sweden first started electrifying with 15 Hz, but later increased the frequency a bit. @tml @philippbirken
Show threadKalle Kniivilä5h ago

@Jonas_Bostrom @tml @philippbirken I'm sure it was rational at the time. Most things are. But when the rest of the grid is 50 Hz it seems cumbersome. If only Sweden had not electrified the railways so early...

🤔

Show threadJonas Boström4h ago
@kallekn It's not that cumbersome, and also has some advantages. Sure you can't just connect the railway to the grid with a transformer inbetween. But since you have to change frequency, it means the load is spread evenly among all three phases. @tml @philippbirken
Show threadTor Lillqvist4h ago
@kallekn @Jonas_Bostrom @philippbirken It could be worse, you could have 1.5 kV DC. Or 600 V DC third rail;)
Show threadJonas Boström4h ago
@tml @kallekn Sant, det hade varit värre!
Show threadAslak Raanes4h ago

@kallekn @Jonas_Bostrom @tml @philippbirken In modern time frequency changers https://en.wikipedia.org/wiki/Frequency_changer?wprov=sfti1# aren't mechanical which make things bit simpler.

If Denmark had started their electrification some years later, maybe when the Øresund bridge was planned, I would guessed that they would have used the same voltage and frequency as Germany, Sweden, Norway etc.

Many trains sets and locomotives can handle multiple voltages/frequencies but it add weight and complexity.

Frequency changer - Wikipedia

Show threadAslak Raanes4h ago

@kallekn @Jonas_Bostrom @tml @philippbirken It is simpler to just do a transformation to 25 kV and not to additional frequency changer, and that might be worth it if electrification is non-continuous as someone has suggested for partly electrifying the Nordland line.

On the other hand, higher voltage means longer security distance to the overhead line.

Show threadJonas Boström4h ago
@philippbirken No, the small ICEs were diesel powered, so different voltage and frequency are not a problem for them. But they were not famous for their reliability and used a lot of fuel, and were also pretty short. @tml
Show threadTor Lillqvist4h ago
@Jonas_Bostrom @philippbirken I thought Philipp meant that the ICE TDs might not have been approved for the Great Belt tunnel.
Show threadPhilipp Birken4h ago

@Jonas_Bostrom @tml The german language wikipedia has a treasure trove of information about the ICE TDs and states that they used 2.2l per person per 100 km for Berlin-Copenhagen. So good riddance!

https://de.wikipedia.org/wiki/DB-Baureihe_605

DB-Baureihe 605 – Wikipedia

Show threadMorten Grøftehauge10h ago
@philippbirken The view from the train is even worse when you cross Storebælt because the train goes in a tunnel while only the cars go on the suspension bridge.
So if you are a bigger bridge than train fan then the optimal way is to cross Denmark is in a double-decker bus and book tickets at the front of the bus, top floor. And it's prettiest around sunset (if the skies are clear, of course).
Show threadTor Lillqvist9h ago
@drgroftehauge @philippbirken On the other hand, on a train you get to cross the Kiel Canal on the Rendsburger Hochbrücke.
Show threadTor Lillqvist10h ago

@philippbirken And Drogdentunnelen is even an exciting immersed tube one. https://en.wikipedia.org/wiki/Immersed_tube . Which probably many traveling between Malmö and Copenhagen don't realise.

It used to be relatively common in the Tågsemester group on Fb, when I was there, for people to ask "I have this phobia, I can't use tunnels, are there many between Hamburg and wherever?". Not realising that even just going to Copenhagen involves a tunnel that is not even safely in rock but just a big pipe on the seabed.

Immersed tube - Wikipedia

Show threadJWcph, Radicalized By Decency10h ago
@philippbirken Tiny note: Saltholm isn't actually artificial; it's a natural islet which is about 4000 years old - the artificial one is the other island which is part of the structure, Peberholm (salt & pepper, get it? 😂).
Show threadPhilipp Birken10h ago
@jwcph Sorry, a typo on my part, I corrected it! Saltholm can be seen in the image in the background.
Show threadJWcph, Radicalized By Decency10h ago
@philippbirken Well, I said that Saltholm is part of the structure, which I guess isn't technically completely accurate either, so... 😂
Show threadTodd Unctious9h ago
@philippbirken the artificial island is called Peberholm, and is just south of Saltholm which is a real island, maximum elevation 2m and population 2 people (although I met a guy once who claimed to be from Saltholm so did I really meet half the population?). It's super rugged and often very visible from the plane on approach to Kastrup