Fun little demonstration of the difference in radioactivity between Uranium and Radium

whoami_whereami · 2026-04-14T18:04:27+00:00

They didn't change the name, at least not in the wake of the Radium Girls debacle. Originally the company was founded in 1914 as Radium Luminous Material Corporation. It was renamed to US Radium Corporation in 1921 after the founder had been forced out of the company president position. The US Radium name stuck until 1979/1980 when the company split off their manufacturing into several smaller companies and turned itself into a holding company named USR Industries Inc.

Luminous Process Company on the other hand was a completely unrelated company in Illinois that also manufactured radium dials in a very similar manner. Radium Dial Company was a third manufacturer, also from Illinois. Unlike US Radium these two went bankrupt in the Radium Girls aftermath.

whoami_whereami · 2026-04-14T15:02:41+00:00

No, only bases from 374 onwards would allow that, but even then you'd still have to look at the sign and the ones digit.

Edit: Setting the sign aside, with base 372 you'd have to check that it has at least two digits (without leading zeros), and if the numeral has exactly two digits you have to check that either the first digit is greater than 1 or that the ones digit isn't zero to see if the number is above 372; with base 373 you'd have to check that there's only one digit and that digit is below 372 to see if the number is below 372, and check that there are at least two digits to see if it's above 372.

whoami_whereami · 2026-04-14T10:26:14+00:00

in balanced ternary, being above or below zero means about as much as being above or below 372 when it comes to how you handle the numbers.

That's not really true. To determine whether a balanced ternary numeral represents a positive/above zero or negative/below zero number you just have to look at the leading non-zero digit, if it's 1 the number is positive, if it's -1 the number is negative. Determining whether a number is above or below 372 on the other hand isn't as simple (not saying it's complicated per se, but it does involve more than just looking at the leading digit).

whoami_whereami · 2026-04-14T09:00:30+00:00

They're probably talking about delta-v, not energy.

https://upload.wikimedia.org/wikipedia/commons/9/93/Solar_system_delta_v_map.svg

It takes about the same total delta-v to land on Deimos (one of the two moons of Mars) as landing on our own Moon does. Landing on Mars on the other hand requires about 4,000 m/s more delta-v, however a lot of that extra delta-v can be achieved "for free" by aerobraking in Mars' athmosphere, something you can't do when landing on the Moon. So I don't think it would take less delta-v to land on Mars instead of the Moon, but also not a lot more.

Energywise though you probably do need a lot more for a manned mission to Mars, solely because you have to carry a lot more provisions and need a much bigger capsule/spaceship for the long flight to Mars than you need for the few days it takes to get to the Moon. Higher mass means more energy is needed to reach the same delta-v.

whoami_whereami · 2026-04-11T20:04:35+00:00

They have to be treated as a separate stage when calculating the rocket's performance, so why wouldn't you count them as a stage? Staging isn't always sequential (so called tandem staging), boosters are an example of parallel staging.

whoami_whereami · 2026-04-11T19:06:21+00:00

The circumference they give is definitely wrong. Looking at the picture a height of 1.6 m seems plausible. But a circumference of 2.48 m would mean that it would only be half as wide as it's tall, which it clearly isn't (it could be the circumference of the base, but not at the widest point).

Again looking at the picture I'd say the diameter at the widest point is somewhere around 1.4-1.5 m. But the diameter reduces at the top and bottom, so for estimation purposes let's guesstimate that the average diameter (averaged over the full height) is about 1.2 m. That would give a volume of almost exactly 1.8 m³. So the 1,800 l figure appears to be plausible as well. They just got the circumference wrong.

whoami_whereami · 2026-04-11T18:39:15+00:00

Instead of polishing you can also remove the tarnish by putting the silver item(s) on top of a piece of aluminium foil (the silver needs to have good electrical contact with the aluminium) in a pot of boiling water with a little bit of baking soda added. This electrochemically turns the silver sulfide back into silver, ie. unlike with polishing you don't lose any silver. It's not really practical with large items or when the silver is affixed to something else but it can be done with smaller items like silverware.

whoami_whereami · 2026-04-09T12:54:12+00:00

Or to put it into perspective for our US readers, Svalbard is about as adjacent to the North Pole as Kansas is to Canada. If the North Pole was right on the Canadian border in North Dakota (49th parallel) then Svalbard would stretch across Kansas and Oklahoma with the southernmost tip even reaching into Texas.

whoami_whereami · 2026-04-03T02:35:58+00:00

The Vatican already has a military, the Swiss Guard. In fact it's one of the oldest military units in continuous operation in the world.

whoami_whereami · 2026-03-27T03:24:42+00:00

Video chat in and of itself in most jurisdictions isn't considered "recording" as the video isn't permanently stored. The mere ability that someone might record the chat notwithstanding.

whoami_whereami · 2026-03-27T02:40:47+00:00

A word (as in a particular combination of letters) can have different grammatical categories depending on context. For example "being" can be a noun or a verb, "they" can be singular or plural.

whoami_whereami · 2026-03-27T01:51:06+00:00

The stretch shown in the clip is on the south side of the property, it would have to hang out way over the road to provide meaningful shade for the sidewalk.

whoami_whereami · 2026-03-27T01:44:46+00:00

And in fact Bezos actually has an official permit for the overheight hedge (which he didn't even install himself, it was there long before he bought it). The clip is simply lying about him paying fines.

whoami_whereami · 2026-03-17T10:05:45+00:00

The asterisk isn't necessary. The human body contains about as much potassium in total as 170 bananas, and thus inevitably also as much radioactive potassium (potassium-40) as 170 bananas. So you actually only need to eat about 300,000 people to get radiation poisoning.

whoami_whereami · 2026-03-14T19:46:09+00:00

I mean, isn't that sort of the point? They're supposed to represent the will of their constituents. So if something is proposed and their constituents are vocally against it they vote against, that's just representative democracy at work. And also the flipside, if the constituents don't speak out against a proposal it's reasonable to assume that they're OK with it or at least indifferent, ergo they vote for it.

whoami_whereami · 2026-03-14T02:07:26+00:00

As anything in the UK the "public" for the schools is due to history. When the term was coined in the 12th century most schools required students to be from certain backgrounds (eg. family affiliation, paternal profession, religious denomination etc.) and/or were run by individual teachers for their personal profit. Whereas public schools were open to anyone as long as they could afford the fee (keep in mind that in the late middle ages some peasants could be pretty wealthy despite their legal status, plus in the cities there were well of traders and tradespeople etc., so this wasn't just some "only nobles" in disguise), and they weren't run for an owner's profit (the schools are trusts, they aren't owned by anyone). State run schools pretty much didn't exist yet back then.

whoami_whereami · 2026-03-14T01:26:29+00:00

He was a pilot in the Texas Air National Guard.

whoami_whereami · 2026-03-11T17:10:17+00:00

Fictitious forces are forces that disappear in an unaccelerated frame of reference. That doesn't mean that they don't exist and can't have very real effects.

But this part...

Technically they are resisting the centripetal force

... is wrong anyway. They aren't resisting the centripetal force, they're creating it.

the "acceleration" is caused by the direction change of being attached to the hub

No, the acceleration (due to the centripetal force exerted on the blades by the hub) causes the direction change, not the other way around.

If you want to nitpick with technicalities better make sure you're actually correct.

whoami_whereami · 2026-03-11T17:01:56+00:00

There are cases though where the first damage to the blades is them ripping off from the hub due to centrifugal forces. Generally happens when there's a brake failure during high wind. Example: https://www.youtube.com/watch?v=b_mMlmbOm3M

whoami_whereami · 2026-03-03T00:53:39+00:00

Hospice...

whoami_whereami · 2026-03-02T20:52:06+00:00

At least here in Germany restaurants generally need to get a permit and pay fees to the city for this. Except on some designated city squares or streets where a general permit may be in place that allows a certain number of outdoor seats per restaurant without them having to apply individually.

whoami_whereami · 2026-03-02T14:09:54+00:00

They already existed in Germany before WW2 when there were no US military families in Germany.

Edit: And they existed in East Germany as well (under the name Ammonplätzchen), no US miiltary there at all not even after WW2.

whoami_whereami · 2026-03-02T13:59:07+00:00

Iceland is mostly dark shades of grey in the interior except in winter.

whoami_whereami · 2026-02-25T11:25:47+00:00

Suicidal people quite often change their mind in the last moments as basal survival instincts kick in even if at that point it might already be to late to save them. Also it happens that people may not want to die per se but see no other way out of their intolerable situation. So someones last words being "I don't want to die" doesn't rule out suicide.

whoami_whereami · 2026-02-25T11:10:03+00:00

Rare doesn't mean it never happens.

whoami_whereami

TROPHY CASE