Today I Learned

[Ivan Seeking]

Let me try to understand this: Something you wrote 4 days earlier reminded you of something else?

LOL! Yes, when I looked back at the thread. The thing about Willie smoking weed at the WH reminded me of the entire business. If he had left some of his weed in that tray I may have had more to tell.

 

[Hornbein]

​

Today I learned that

The accumulation and bursting of carbon dioxide bubbles can cause a peanut in a glass of beer to repeatedly float and sink. The process may help in understanding phenomena in Earth’s magmas.​

According to Michael Manga this is a thing in the bars of Argentina.

In a highly carbonated beer, such as a craft beer, the peanuts stay bobbing at the surface for longer than they do in a less carbonated beer, such as the lager they used for their experiments.

The Manga magma study is reviewed here.

https://physics.aps.org/articles/v16/121

 

[Frabjous]

TIL that a formal peace treaty was signed by the mayors of Rome and the modern city of Carthage on 5 February 1985; 2,131 years after the 3rd Punic War ended.

https://cherwell.org/2016/02/05/lessons-from-history-the-end-of-the-third-punic-war-1985/

 

[Hornbein]

TIL that a formal peace treaty was signed by the mayors of Rome and the modern city of Carthage on 5 February 1985; 2,131 years after the 3rd Punic War ended.

https://cherwell.org/2016/02/05/lessons-from-history-the-end-of-the-third-punic-war-1985/

One might hope that they mutually swore to refrain from the environmentally destructive practice of sowing the Earth with salt. Elephants would of course be banned as weapons of war. Will there be inspections to verify compliance?

 

[Frabjous]

The modern historical consensus is that Carthage was not salted. Regretfully, the North African Elephant has gone extinct.

 

[Astronuc]

TIL about The Medieval Kingdom of Pengwern that was Erased from History



https://en.wikipedia.org/wiki/Cynddylan

https://en.wikipedia.org/wiki/Northumbria
https://en.wikipedia.org/wiki/List_of_monarchs_of_Northumbria

 

[BillTre]

TIL, from the NY TImes, its been hot recently:

[Mentors’ note: Stray text unrelated to the TIL theme removed]

 

[jack action]

TIL about an helicopter technique: autorotation.

[...] they go on to demonstrate how to safely land a helicopter when its motor has failed using a technique called “autorotation.” Using this technique, Gerry Friesen [...] even believes landing a failed helicopter is safer than landing an airplane with a busted engine.

[...]

As Destin explains in the video: "If the rotor blade quits turning you are going to fall like a brick – but helicopter pilots have a physics trick to keep that from happening." All it requires is a simple lever and a hell of a lot of practice. Check it out for yourself in the video below.

​

 

[BillTre]

I like curry and I found an article in Science Advances on its early history about 2,000 years ago.
It has an interesting map of ancient spice availability:

 

[Hornbein]

I like curry and I found an article in Science Advances on its early history about 2,000 years ago.
It has an interesting map of ancient spice availability:

View attachment 329500

The Dutch East Indies company grew fabulously wealthy selling nutmeg as a quack cure for the plague. The tree grew only on three islands in the Moluccas. Nutmeg traveled well and could not be counterfeited

 

[Hornbein]

TIL that Tour de France riders to beat the heat wore ice vests.

https://www.bnnbloomberg.ca/the-tour-de-france-already-has-one-winner-ice-vests-1.1946080

 

[Hornbein]

TIL that the US military keeps accidentally sending highly sensitive information to email addresses in Mali because they write “.ml” instead of “.mil.” The Dutch company managing Mali’s domain has collected 117,000 emails this year alone.

 

[Ivan Seeking]

I wish I could talk about it.

 

[jack action]

TIL that the US military keeps accidentally sending highly sensitive information to email addresses in Mali because they write “.ml” instead of “.mil.” The Dutch company managing Mali’s domain has collected 117,000 emails this year alone.

How is the US military sending "highly sensitive" information without encrypting it first? That would be the real mistake.

 

[DaveC426913]

How is the US military sending "highly sensitive" information without encrypting it first? That would be the real mistake.

True. Horny didn't say they could *read* it...

 

[Flyboy]

TIL about an helicopter technique: autorotation.

Yep. Turning physics from a cold hearted sonofabitch into a temporary ally.

Unfortunately, tilt rotors like the V-22 or the upcoming V-280 don't have that luxury. Nor do they have enough wing area to glide worth a damn. If you lose both engines in a tilt rotor... you're ****ed.

 

[jbriggs444]

How is the US military sending "highly sensitive" information without encrypting it first? That would be the real mistake.

It is doubtful that the sending mail servers in the U.S. would be running mandatory TLS to a random domain such as .ml. I've been out of the business for over a decade, but last I knew, mandatory TLS was only for designated targets that you know can handle it and should never not do so.

But that's transport security. Possibly you are talking about end to end security between cooperating user agents. Like PGP

Where I worked (DoD Contractor) we were taught to just not send sensitive material via Internet email. But users do what users do. And the poor mail admins had to clean up classified spills from time to time.

 

[jack action]

Possibly you are talking about end to end security between cooperating user agents. Like PGP

Yes, that one.

 

[pinball1970]

TIL some mammals preyed on dinosaurs larger than themselves according to this fossil find.

Estimated 125 mya

Forgeries are not unheard of – see “Assessment of fossil association” section of the paper.

https://www.nature.com/articles/s41598-023-37545-8

Fossil

Artist impression

 

[Bystander]

From Wiki:
When the wasp dies, it is broken down by enzymes (Ficain) inside the fig. Fig wasps are not known to transmit any diseases harmful to humans.

 

[BillTre]

 

[Ivan Seeking]

View attachment 329636

Even the climate change deniers are starting to wilt away.

I worked very hard for most of my life to try to help avoid this. Now part of me is glad I will die before it gets much worse.

 

[Borg]

Even the climate change deniers are starting to wilt away.

Don't bet on it.
https://www.gocomics.com/tomthedancingbug/2023/07/21

 

[BillTre]

Even the climate change deniers are starting to wilt away.

I worked very hard for most of my life to try to help avoid this. Now part of me is glad I will die before it gets much worse.

There are still enough around here to get posts on the subject removed or censured.

 

[Ivan Seeking]

Don't bet on it.
https://www.gocomics.com/tomthedancingbug/2023/07/21

The extended temps of 110 degrees F and greater are starting to get peoples attention. For example, Phoenix has been 110 F or more for I think 25 days now.

I have seen the doubt in their eyes for the first time. My boss caught himself complaining that we never needed air conditioners around here before.... then he stopped himself and changed the subject.

 

[Borg]

I'll agree that I haven't seen as many stories (or tweets) about it being fake but I do have a friend who still belives that the science is all made up because "someone in England, deleted their data". Explaining to him that there are far more than one person researching it, didn't really matter.

 

[pinball1970]

I'll agree that I haven't seen as many stories (or tweets) about it being fake but I do have a friend who still belives that the science is all made up because "someone in England, deleted their data". Explaining to him that there are far more than one person researching it, didn't really matter.

No longer tweets. They are now called "X's"

 

[pinball1970]

I'll agree that I haven't seen as many stories (or tweets) about it being fake but I do have a friend who still belives that the science is all made up because "someone in England, deleted their data". Explaining to him that there are far more than one person researching it, didn't really matter.

Also, no one in England deleted their data, I asked them. We are a tiny little country and I know them all. Trust me.

 

[topsquark]

Even the climate change deniers are starting to wilt away.

Naw. Just wait for record cold temperatures this winter and they'll be back because cold temperatures and global warming can't possibly be related.

-Dan

 

[BillTre]

It was too cold in a local swimming hole (38˚F):

that would be:
https://www.kezi.com/news/officials...cle_f7d1ad1c-2b42-11ee-99eb-e7933b44d814.html

 

[pinball1970]

TIL https://phys.org/news/2023-07-nasa-lab-life-blocks-asteroid.html

"A precious cargo is currently aboard OSIRIS-REx, a US space probe launched in 2016 to Bennu, which orbits the Sun..."

"scheduled to land in the Utah desert on September 24, carrying an estimated 8.8 ounces, or 250 grams of material"

For analysis:

",,,,,precursors that may have fostered life in our solar system and on Earth."

 

[Hornbein]

It was too cold in a local swimming hole (38˚F):
View attachment 329649

that would be:
https://www.kezi.com/news/officials...cle_f7d1ad1c-2b42-11ee-99eb-e7933b44d814.html

? The hike is dangerous so they are going to unenforceably ban swimming in order to discourage hiking.

 

[BillTre]

? The hike is dangerous so they are going to unenforceably ban swimming in order to discourage hiking.

That's what it sounds like.

The hike is not that dangerous, but it takes a while to get there and EMs probably don't want long delays in treating people. There also cliff areas involved which would make transporting injured people out more difficult.

There are also some nude beaches on some isolated river areas.
You aren't supposed to be nude there, but no one there is going to stop you.
Seems the same.

 

[Hornbein]

TIL that the Nazis had a TV station in 1935.



The first television broadcasts in the UK were in 1929. The BBC stopped at 11pm so a private company used BBC radio transmitters after then. In 1930 they got simultaneous picture and sound and broadcast a play.

My mother told me that all US TV had at first was professional wrestling. People would watch for the novelty of it. Sort of the ChatGPT of that day.

George Burns wrote "when they brought a television up onb the stage so the audience wouldn't miss Amos and Andy I knew vaudeville was finished."

Desi Arnez Jr. was largely responsible for getting television out to Hollywood. Even though the most popular star on television Lucille Ball got in serious trouble for having joined the Communist Party. She got off because she had only done it to please an uncle and had never attended a meeting or given them any money. Lucille said McCarthyism was worse under the Truman administration.

 

[Bystander]

TIL:

I don't know about Bridge, but in casinos I often see the dealers "washing" the cards, ie, mixing them up the way a kid who can't shuffle would.

 

[DaveC426913]

Even the climate change deniers are starting to wilt away.

Wilt away? Or retire to their private islands now that they've made their money off the lie...

 

[Ivan Seeking]

Wilt away? Or retire to their private islands now that they've made their money off the lie...

Through my personal interactions, I have observed a subtle but significant change in how deniers react to this subject. My impression is that their confidence has been shaken.

 

[Hornbein]

TIL that the largest known galaxy has a diameter of 1,764,000 light years.

 

[PeterDonis]

TIL that the largest known galaxy has a diameter of 1,764,000 light years.

Which galaxy?

 

[Ibix]

Which galaxy?

ESO 383-76 according to Wikipedia.

 

[DrGreg]

TIL that the largest known galaxy has a diameter of 1,764,000 light years.

To put that into perspective, that's about 20 times the diameter of our own galaxy (again according to Wikipedia).

(Caveat: all these numbers are estimates, and different estimation methods can give substantially different answers, yet again according to Wikipedia -- this is a subject I know nothing about.)

 

[BWV]

To put that into perspective, that's about 20 times the diameter of our own galaxy (again according to Wikipedia).

(Caveat: all these numbers are estimates, and different estimation methods can give substantially different answers, yet again according to Wikipedia -- this is a subject I know nothing about.)

Or over half the distance to Andromeda

 

[pinball1970]

Or over half the distance to Andromeda

68%!
First thing I did!

 

[DaveC426913]

Or over half the distance to Andromeda

To put that in perspective...

 

[Ivan Seeking]

TIL that the largest known galaxy has a diameter of 1,764,000 light years.

What is the centripetal force acting on an object on the outermost edge of that galaxy?

 

[DaveC426913]

What is the centripetal force acting on an object on the outermost edge of that galaxy?

I should clarify that - despite my deliberate artistic licensing - it's actually an elliptical galaxy.

The force shouldn't be too hard to approximate (by pretending it's of uniform density).
Mass: 2.3×10¹⁴M☉ (230 trillion Sols) = 4x10⁴⁴kg
Distance: 882kly = 8.3x10¹⁸km

(I'm doing something wrong; I get like 7x10²⁰Newtons). I'll show my work...

M = 2.3 x 10^{14}\\D=8.8x10^5 light years\\<br /> (1 light year = 9.4 x10{12} )

_{(OK, I give up on LaTeX or MathJax or whatever it is. The commands they say work don't work.)}

 

[strangerep]

I should clarify that - despite my deliberate artistic licensing - it's actually an elliptical galaxy.

The force shouldn't be too hard to approximate (by pretending it's of uniform density).
Mass: $2.3\times 10^{14}$ M☉ (230 trillion Sols) = $4 \times 10^{44}$ kg
Distance: 882kly = 8.3x10¹⁸km

(I'm doing something wrong; I get like 7x10²⁰Newtons). I'll show my work...

$$ M = 2.3 x 10{14} ~~;~~ D=8.8x10^5 \mbox{light years} $$
(1 light year = 9.4E12 ?what?

I don't know what you're trying to do. Were you trying to use $a = GM/r^2$ ?

Regardless, you'll have to use a MONDian modification of the Newtonian formula to get anywhere near the actual physical result.

(OK, I give up on LaTeX or MathJax or whatever it is. The commands they say work don't work.)

They do work if you RTFM. I fixed yours a bit.

 

[strangerep]

What is the centripetal force acting on an object on the outermost edge of that galaxy?

If it were a spiral, you should be able to get a reasonable approximation to the outer tangential velocity using the Tully-Fisher/MONDian formula $v_{\text{tan}}^4 = GM a_0$, where $a_0$ is the Milgrom constant. From that you can calculate centripetal acceleration.

Elliptical galaxies are a bit different, however. One must use the Faber-Jackson relation between velocity dispersion and luminosity, but I won't attempt to explain that here since it involves some tricks such as the Virial theorem.

 

[DrGreg]

What is the centripetal force acting on an object on the outermost edge of that galaxy?

To be pedantically and relativistically correct, the answer is zero.

(Gravity isn't a force in relativity, but of course in Newtonian theory it is a force.)

 

[Ivan Seeking]

To be pedantically and relativistically correct, the answer is zero.

(Gravity isn't a force in relativity, but of course in Newtonian theory it is a force.)

Heh. I doubt we get into velocities great enough or gravity strong enough to require GR. But if the word "force" doesn't apply at all, perhaps it should be dropped altogether. Why are we teaching false physics?

Teaching Newtonian physics makes sense because it is accurate enough for most applications. But calling something a force when it isn't actually a force is another matter.