U-Bahn station in Berlin is decorated with radioactive uranium glazed tiles
chaos.social
chaos.social
There are other stations on the U-Bahn with uranium tiles too, you can find them with the crowdsourced Safecast radiation map: https://map.safecast.org/?y=52.5002&x=13.4852&z=13&l=0&m=9
(Wish we had quote-posts on Mastodon, would make it more obvious)
The Twitter-like quoting was used way too much for abuse. It had legitimate uses, but the abuse it generates does not warrant the legitimate uses.
Plus, it always made things so weird to read.
2. The reply
1. The original
3. The replies to the reply
For anyone unfamiliar, “toot” is the sound an elephant makes and a mastodon is a prehistoric elephant. Just like a bird tweets, a mastodon toots.
Quote toots offer a functionality not offered by other functions, which is the ability to show two toots at once as well as notify the original toot owner of this activity. Linking another toot has a pretty horrible UX in comparison. Last time I clicked on a linked toot, it opened a new tab to view it, and then in order to click like on that toot I was instructed by the UI to copy the toot address to yet another mastodon window in to the search bar. An absolute mess.
Quote toots allow side discussions while allowing everyone to see what is being discussed. And they’re great when someone has a long thread and you want to pull out one piece to share with your followers and add context like “this piece of the puzzle is particularly important.”
The fact that it changes the order of the conversation is the point. Conversations fork in ways not always conducive to a reply-only view.
I primarily want quote toots so I can quote myself to start fresh threads that build on old ones. I did this all the time on Twitter where I posted a thread of updates for every evening that I worked on a project, with a new thread quoting the last one for each new evening. Since replies and links don’t show the other posts, it’s not as clear what I’m talking about when I link to an old toot and say “I made progress on this project tonight” given the awful UX on link toots.
It's pretty funny due to it's usage in UK slang. It can mean everything from smoking a cigarette, to snorting cocaine, to oral sex.
It's much more of a friendly word for toddlers than it is a slang word for debauchery. (Example: "Toot! Toot! Packed full of fun and games, it's the Thomas & Friends Annual 2022!", https://www.amazon.co.uk/Thomas-Friends-Annual-Packed-games/...)
They officially switched from "toot" to "post" a few months ago.
Also it's silly and all of the other silly associations you have with it are a plus. "Twitter", "tweet", "google", "facebook", "amazon", "apple", "mac", "tumblr", "kindle" are all also pretty stupid names we've just gotten used to, but "toot" is OUR stupid name, and we made it ours, and if its silliness delays the corporate takeover of Mastodon, that's a huge plus.
Oooh that's nice. I wish they'd have those kits in sale again. Would buy one instantly but no time for fiddling myself this year unfortunately...
(I'm aware that I'm writing this on "the orange site"…)
And people collect them. I remember being a kid and looking at my grandmother's display of plates and being told they were radioactive. But only a little. You can also still find them on eBay easy enough.
[1] https://www.orau.org/health-physics-museum/collection/consum...
[0]https://www.orau.org/health-physics-museum/collection/consum...
glancing at my living room and seeing second-hand 70s orange antiques, glasses and dinnerware everywhere
Here's a good subreddit for it in the wild: https://www.reddit.com/r/uraniumglass/
You know, because of all the silicates in your lungs. The radioactivity would probably not be very significant.
For those not in the know, JFK immortalized the pastry from Berlin in his famous "Ich bin ein Berliner" speech.
"Ich bin Berliner" -> I'm a citizen of Berlin
"Ich bin ein Berliner" -> I'm a jelly donut.
Sometimes they're even sold as "Donut".
Also, as a native German speaker, saying "Ich bin ein Berliner" is not unusual if you are talking about being a citizen of Berlin.
I don't think that was a common association at the time as well. Especially since (pastry) "Berliners" are not called "Berliners" in Berlin but "Pfannkuchen" instead.
Speaking of which, good thing Kennedy never visited Hamburg.
I'm not German nor a linguist, YMMV.
Compare "Danish" as an American term for a Viennese pastry, "he's Danish" doesn't sound odd.
We don't generally abbreviate foods named after places, but:
"Cheddar is 200 miles from both Sandwich and Stilton."
These are all places in England.
I agree that no native speaker would think of the pastry when hearing "Ich bin ein Berliner." Just like I wouldn't think of a sausage if someone were to say "Ich bin ein Frankfurter."
Edit: what chiki said
[0] https://en.wikipedia.org/wiki/Ich_bin_ein_Berliner#%22I_am_a...
[1] https://language.mki.wisc.edu/essays/ich-bin-ein-berliner/
Of course you can say "Ich bin Clown" just as you can say "Ich bin Kaminfeger" or "Ich bin Physiotherapeut"
FWIW, I'm not a native speaker but I did study German in high school and college, and used my moderate proficiency extensively while traveling in Germany (including Berlin in 1990), and Austria, and living in Prague. I've laughed with native Germans about the JFK speech (which story was first related to me by my hs German teacher), and regardless of its provenance / veracity, it makes for an interesting discussion. :)
There's also a European liquor, bright blue in color, aptly named "Blau" (which word, "blau", is slang for drunk or intoxicated).
As for varieties of sausage, "wieners" (Wien/Vienna), and Frankfurters (Frankfurt) were referred to as "hot dogs" by Parisian college students jokingly(?) describing their mysterious ingredients... (citation needed, but I did read that in a seemingly-reputable magazine.)
On the other hand, it is a toxic heavy metal so please, please don't eat it.
And your body needs potassium. In fact most humans don't get enough.
If you have a 1/r^2 decreasement from a point source, the if you have an infinite wall it becomes a constant value that does not decrease with the distance.
Clearly the wall is not infinite, but when the distance from the wall is much smaller (1/5?) than the distance to the border of the wall, the approximation is good enough. The wall is like 8 tiles tall , so I expect the radioactivity at 1/2 tile (15cm, 5in) to be almost equal to the radioactivity when the counter is touching the wall.
Eventually at large distances, any finite object will have the apparent radius decay as 1/r and solid angle as 1/r^2.
I think in this case it could be atmospheric absorption or just getting near a peak point of emission.
The coherent case is similar I believe, but because for an antenna (emitter) the field is usually tangent to the surface, you get some additional trigonometric factors (not purely solid angle). But by my calculations it's still 1/r^2.
For gravity, it's clear the orientation of a small surface doesn't influence its gravitational force. In fact the source can be replaced by a point of equivalent mass.
For radiation, it seems the angle of a surface matters? For example, lambertian surfaces (everyday diffuse surfaces) do depend on their angle for total incoming radiation? Does only reflection exhibit lambertian behavior? There's something funny at work here.
In the lambertian case, there's a cosine term making your terms go to zero and sum converge.
When observing a small oblique (lambertian) surface, you get less radiation by a factor of cos(angle). I believe this is true for black body radiators as well (think a small glowing plate emitting red light). I'm not completely sure it would be true for x-ray and high energy radiation, and intuitively I suspect it indeed isn't. It seems like for high energy emissions, or generally isolated emissions (discounting opaqueness), only the total power is relevant like in gravity. I think self-absorption might be the culprit here.
If we say self-absorption (material absorption) in the high energy case is roughly negligible, then it becomes more strongly non-lambertian and the received power is simply a 1/r^2 integral (which would also explain why radiation gets stronger as it approaches the surface).
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Here's a simple proof of the solid angle formula I've found I believe is correct for lambertian surfaces: chop your object into infinitesimal pieces (limit goes to 0). For each piece, it tends to behave like a point, so we expect the radiation scaling with distance to be 1/r^2. But solid angle also scales as 1/r^2 for small enough pieces. (it's probably missing many technicalities to make the proof work, but I think it works). Note that for oblique surfaces their solid angle is a function of cos(angle), which follows Lambert's cosine law exactly as well.
I made a mistake and assumed it was Beta or Gamma radiation that travel easier in air.
It will still decrease with distance. If you represent the wall as a collection of point sources distributed over a plane, as the distance to the plane diminishes, the distance to individual points do not diminish to and from the same distance as each other, and do not diminish at the same rate. However they still all diminish, and thus the sum intensity must diminish. Though the appropriate function describing the sum of the contributions from each point is no longer 1/d^2.
There will be some continuous equation to describe this... someone more familiar with radiance feel free to chime in!
I feel like I want to plot this now to build an intuition.
The situation is similar for an opaque light source (apart from the lack of atmosphere in the way, I don't think the sun would be much brighter if you were much closer to it and looking through a pinhole), but I'm not sure it applies to gamma radiation which is emitted uniformly in all directions from each point and treats most stuff as pretty transparent - unless there's some weird interference you don't get to cancel out the parts coming from different directions.
What I'm suspecting is that under a certain distance for a given finite plane it's almost constant similar to the infinite version, but outside of that distance there must be some non uniform falloff function.
A rectangle is a mess. It's easier with a circle. The approximations at short and long distance are the same, but a circle has an "easy" formula in between. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elelin.h... 1-x/sqrt(x^2+R^2) where R is the radio of the circle. Let's use R=10 to keep it simple.
For a short distance 0<x<R/10, then it's almost a constant https://www.wolframalpha.com/input?i=1-x%2Fsqr%28x%5E2%2B10%...
For a long distance, x>4R it's almost like R^2/(2*x^2) https://www.wolframalpha.com/input?i=1-x%2Fsqr%28x%5E2%2B10%...
There are some trick to add more term to the approximations to reduce the middle part where both approximations are bad, like using A+Bx or A+Bx+Cx^3 for short distance and D/x^2+E/x^4 or D/x^2+E/x^4+F/x^4 for long distance. It depends on how much you care about the precision and how many calculations you want to do.
In some particular cases like a circle or the shell of a sphere there are closed formulas for the intermediate distances. In other cases there is no nice formula.
> Auch an einem eher ungewöhnlichen Ort haben die Mitarbeiter der Behörde schon Messungen durchgeführt. Der U-Bahnhof Rosenthaler Platz rückte wegen seiner vielen orangefarbenen Kacheln ins Visier der Behörde. „Die Farbe wird mit dem Schwermetall Uran hergestellt, weil es beim Brennvorgang sehr hitzebeständig ist“, sagt Leps. Die Strahlung ist laut dem Experten jedoch belanglos. Auch für Menschen, die sich länger auf dem U-Bahnhof aufhalten, besteht keine Gefahr.
In short: "According to experts the radiation is trivial."
Source (from the toot thread): https://www.tagesspiegel.de/berlin/bleibende-werte-1545553.h...
11.37 mR/h? Not great, not terrible.
Or, alternatively, the average yearly background radiation of about 2 milisievert takes about 18 hours of being glued to those tiles.
I'm actually astounded this is allowed to be there in a public place, because at home you can reasonably expect protect against someone shattering a tile, but in public? One drunk guy is all you need.
Then again there are well practiced methods for removing sources of similarly hazardous air-bourn particulates such as asbestos, i'm not sure how much difference there is between the two beyond the low risk of pure exposure (inhalation being the serious risk here).
There's also the difference that this is a U-Bahn station in use, in the rough middle of a line. Closing it down for a prolonged period of time, and fully sealing it from the rest of the line to avoid the spread of dust through the metro tunnels would be a significant and disruptive undertaking.
And keep in mind that this is a subway station, places where the pm2.5 levels are routinely extremely high because of the dust released by train breaks, so a microscopic amount of uranium dust is really negligible in such an environment.
I saw 11.37 on the display, wouldn't that be 0.01137 ?
Roentgen (R) used by the instrument only measures exposure, but this is not the same as absorption which depends on the type of radiation, the type of biological tissue exposed, the duration of exposure etc. The parent is using Sv which measures absorption for the purpose of more usefully assessing biological risk. I'm not sure how the parent is converting them, there are probably some good rules of thumb.
At the other end of the scale the minimum annual dose with a clear link to increased risk of cancer is supposedly 100 mSv [1]. But the risk is different depending on the distribution over time, so if we make it hourly for comparison that is 0.0114 mSv/h making this reading about 1000 times higher than that risk threshold (but the risk is over a year is effectively assuming continuous exposure).
Seconds or minutes isn't going to be terrible, but in only 9 hours leaning against it you would get a years worth of high risk cancer dose!... I'd stay away from the wall. happy to be corrected, this stuff is hard to interpret if you are not an expert. The falloff is really fast though, so it's basically harmless if you are just walking through... maybe the original intent was to stop people touching the walls :D like an electric fence without the need for power.
[0] https://en.wikipedia.org/wiki/Background_radiation
[1] https://upload.wikimedia.org/wikipedia/commons/9/9f/Exposure...
[edit]
Fixed various calculations.
Speaking of which, radon gas is the main way in which uranium affects the health of people. Depending where you live and the construction methods, it may be worth getting your basement checked, and ventilated properly if necessary.
Even the extreme scenario there is still far short of causing acute radiation sickness. People who live in such regions are sometimes exposed to such levels their whole lives, which can still be long and healthy. But not quite as long and healthy as those without such exposure, on average.
- You work about 2k hours per year in the orange office
- That would then be about 200 mSv per year
- "Exposure to 100 mSv a year is the lowest level at which any increase in cancer risk is clearly evident" (https://www.reuters.com/article/us-japan-quake-radiation-idU...)
I guess then that maybe we could (barely) observe a higher incidence of cancer for those who spend a lot of time next to the walls?
Besides, Uranium radiation is mostly absorbed by the skin, and your skill will be replaced many times on that timeframe.
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EDIT 2: Looking more closely it appears that the dosimeter in the video is switched to µSv/h, so it's reading 0.1 mSv/h anyway and the whole discussion below can be skipped if you're not interested in the difference between Gy and Sv.
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If I remember my lectures correctly (Wikipedia did help me here), the conversion is 1 Roentgen ~ 00.1 Gray (Gy), which is a slightly different unit from Sievert (Sv).
1 Gy is 1 J/kg of absorbed energy, however the biological effects change depending on the type of radiation. Sv is Gy adjusted by a weighing factor. It's 1 for gamma rays, where 1 Gy = 1 Sv, but for alpha particles it's 20 [0].
Uranium-238 emits alpha particles, which get stopped by a few cm of air or even dead skin. So the effective dose you are receiving from the decay of U-238 is probably closer to 0 mSv/h.
Or, if you eat it and it's inside you, 2 mSv/h, at which point you should probably be quite worried.
The decay products of U-238 however are beta emitters, which changes the calculation again. The beta particles can penetrate the skin, but the weighing factor for beta radiation is 1, so it can reach you but is also less dangerous. So what's the actual final value? I honestly don't know, radiation can be complicated, and I just wanted to share the difference between Gy and Sv!
[0]: https://en.wikipedia.org/wiki/Sievert [1]: https://en.wikipedia.org/wiki/Uranium_tile
Apparently there was a brief period in the 20th century when this was a popular way of making yellow glazing.
Hell, even chernobyl is projected to cause at most 4k premature deaths over 50+ years.
But generally, the effect of frequent low doses isn't very well understood, and you could even find specific circumstances where it might be beneficial.
But I've seen homeless guys openly smoking Heroin in the U-Bahn stations. And many of them drink a lot of alcohol.
I think it's funny that Uranium has this connotation of "glowing in the dark" which has nothing to do with the nuclear properties at all but rather very interesting optical phenomena that happen when you have an atom with a huge number of electrons like the way Thorium Oxide is good for gas lamps because it emits thermally in the visible range but not so much in the infrared.
That's very different scaling from this kind of thing
Personal radiation doses are well known. https://www.nrc.gov/about-nrc/radiation/around-us/calculator...
Social. Chaos. OK.
"Chaos" likely relates to "Chaos Computer Club" https://en.wikipedia.org/wiki/Chaos_Computer_Club and related activities in that part of the world.
A person running around Berlin with a Geiger counter (not on official business) is a CCC kind of hacker.
Of course this comes to us via Jonty Wareing (@jonty@chaos.social ), who is involved with the related EMF ( https://www.emfcamp.org/ ) event in the UK.
The Suffix "social" means "this is the social media (mastodon) host".
In fact it says here https://chaos.social "chaos.social – a Fediverse instance for & by the Chaos community"
I'm not really sure about the unit of the measure here. So how does it compare really?
You need to realize, we are exposed to radiation all the time.
The "banana equivalent dose" is an error that refuses to die. Based on tables that estimate the effect of various radioactive isotopes acting for 50 years, people ignoring physiology decided that the average K40 in a banana will produce 0.078 microsievert of damage (rounded to 0.1 because it's close enough for jazz and comics).
The reality is that, due to homoeostasis, the excess potassium you ingest is eliminated the next time you piss, so there's no accumulation inside the organism. Those 50 years become something like 12 hours and the radiation exposure is more in the ballpark of 0.00000213 microsievert.
But that value is now too small to use it in science fanboyism, isn't it?
https://www.epa.gov/sites/default/files/2015-05/documents/52... - page 156. That's where these people took the effective dose equivalent for K^40 from, but those values are for 50 years of exposure.
"For radioisotopes of elements that are under tight homeostatic control by the human body, the inhalation or ingestion risk coefficients given in this document may not be appropriate for application to some exposure scenarios. For example, the ingestion risk coefficient for ^(40)K would not be appropriate for application to ingestion of ^(40)K in conjunction with an elevated intake of natural potassium. This is because the biokinetic model for potassium used in this document represents the relatively slow removal of potassium (biological half-time of 30 d) that is estimated to occur for typical intakes of potassium, whereas an elevated intake of potassium would result in excretion of a nearly equal mass of natural potassium, and hence of ^(40)K, over a short period." - ["Federal Guidance Report No. 13: Cancer Risk Coefficients for Environmental Exposure to Radionuclides"](https://www.epa.gov/sites/default/files/2015-05/documents/40...) - page 16
So, if you accept that the duration of exposure from eating a banana is 12 hours instead of 50 years, a dental x-ray is the equivalent of eating 2,347,417 bananas.
I don't understand, what is "science fanboyism"?
"90 μSv/h: Natural radiation on a monazite beach near Guarapari, Brazil."
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EDIT 2: Looking more closely it appears that the dosimeter in the video is switched to µSv/h, so it's reading 0.1 mSv/h anyway and the whole discussion below can be skipped if you're not interested in the difference between Gy and Sv.
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Seems to be milliroentgen/h according to another commenter, which is an older unit. Today you'd use Gray (Gy), which is 1 J/kg of energy deposited in material, and Sievert (Sv), which is Gy adjusted by a factor to account for different radiation types and body parts to get comparable biological effects.
For soft tissue (~= humans) 1 R = 0.01 Gy, so the dose would be ~0.1 mGy/h. Converting that to Sievert is more complicated. Uranium is an alpha emitter, for which you'd use a weighing factor of 20 [0], getting 2mSv/h.
1 mSv/h = "NRC definition of a high radiation area in a nuclear power plant, warranting a chain-link fence." [0]
However alpha radiation also gets blocked by very flimsy barriers, such as a few cm of air, or the layer of dead skin cells on your skin. So the effective dose might be closer to 0!
You also have to consider that the decay products or Uranium are beta emitters. Beta rays have a weighing factor of 1, but they do penetrate deeper (stopped by a few feet of air, can penetrate the skin).
The real effective dose in Sv depends on the exact ratio of decay products to U-238, and how deeply the beta rays of those products penetrate your body (there's different weighing factors for different body parts!).
In conclusion: probably not too much, but radiation and radiation shielding is a complicated subject we managed to spend a whole semester on.
[0]: https://en.wikipedia.org/wiki/Sievert [1]: https://en.wikipedia.org/wiki/Uranium_tile
Also, famously, the dose of radiation in one of the long term storage facilities nearby (measured on the floor, outside containers) is lower than in the main church in that town, which, you've guessed it, is built from granite blocks.
A major rock-forming mineral is Potassium Feldspar (K-spar to geologists). The weathering products of K-spar include many varieties of clay. Those, in turn, wind up incorporated in sedimentary rocks
When logging a well for permeability -- an activity that occurs for both hydrocarbon and geothermal projects -- detection of radio-emissions due to K is an indicator of sedimentary strata that are unlikely to have much permeability because the clays clog up the fluid-flow pathways.
This has been today's lesson in geoscience. :D
(Edit: typo.)
If I were to build a house, I would walk all materials with a geiger counter, especially alpha particles. Sometimes difficult to replace material, if it is already worked into the structure.
This reminds me of cloisonné paint.
Many antique pendants, earrings, etc., used Uranium Oxide orange paint.
Orange is actually a difficult color to make. Another dangerous orange is Cadmium Orange (I used to be an artist, and probably breathed in the paint, as I used it in an airbrush).
Some new watches have luminescent dials that contain tritium, also a radioisotope.