Today I Learned

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Today I learned that cleaning a white hat can be done with bleach cleaner, but it’s important to rinse it before wearing it again. I also discovered that "oyster veneering," a woodworking technique from the late 1600s, is experiencing a minor revival despite its labor-intensive nature. Additionally, I learned that the factorial of 23 (23!) equals 25,852,016,738,884,976,640,000, which interestingly has 23 digits, a unique coincidence among factorials. I found out that medical specialists often spend less than 10 minutes with patients, and that watching TV can contribute to weight gain. Other insights included the fact that a kiss can transfer around 80 million microbes, and that bureaucracy can sometimes hinder employment opportunities. The discussion also touched on various trivia, such as the emotional sensitivity of barn owls and the complexities of gravitational lensing around black holes.
  • #3,121
Today I learned that tyro means beginner.
 
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  • #3,122
Today I learned the word abecedarian as a synonym for tyro.
 
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  • #3,123
  • #3,124
TIL that fans heckling the Sign Stealing Houston Astros at a preseason game with signs about the Astro's sign stealing had their heckling signs stolen (taken) by stadium personnel.
 
  • #3,125
BillTre said:
TIL that fans heckling the Sign Stealing Houston Astros at a preseason game with signs about the Astro's sign stealing had their heckling signs stolen (taken) by stadium personnel.
AARRGHH! No good deed goes unpunished!
 
  • #3,126
Today I learned (realised) that Physics is different from Mathematics. Mathematics can help us in Physics but upto to a limited extent only.
 
  • #3,128
Adesh said:
Today I learned (realised) that Physics is different from Mathematics. Mathematics can help us in Physics but upto to a limited extent only.

You've been watching Sabine haven't you?

Cheers
 
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  • #3,129
cosmik debris said:
You've been watching Sabine haven't you?

Cheers
I don’t know what Sabine is?
 
  • #3,131
Keith_McClary said:
But I got that realisation when I tried to solve a problem
“Show that the magnetic field produced by a solenoid will be parallel to its axis regardless of its cross sectional shape”.
Due to some previous confrontations and the above question I became sure that Mathematics cannot fully describe Physics.
 
  • #3,132
Today I learned that there really is a fish called the red herring.
 
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  • #3,135
PeroK said:
Have you been watching "Grand Tours of Scotland" as well?

https://www.bbc.co.uk/iplayer/episodes/b094ndf8/grand-tours-of-scotlands-lochs
No - I looked up the expression ages ago when I realized I knew what it meant but not why it meant it. The story is that someone distracted some hounds using a red herring (smelly fish), and it became a byword for a false lead. I must say I don't think I've seen a red herring in real life, but I knew it was a real as well as a figurative thing.

I take it you're enjoying the series? I think I may be looking for ways to pass the time over the next few weeks...
 
  • #3,136
TIL (yesterday morning, actually) not all strikes on your windshield while freeway driving are necessarily gravel.

While tailing a gravel truck up a grade on I-215 freeway, I heard several loud 'Ticks' on my windshield. "Loose gravel", I thought; though the truck appeared clean as I passed it on the next down grade. Gray massive clouds roiled but no rain. 'Tick, Tick'. Finally realized my truck was being pelted by nearly invisible hail stones! The sound followed me down Iron Mountain abating around 3000' elevation.
 
  • #3,137
Ibix said:
I don't think I've seen a red herring in real life
You should find them shelved right next to the haggis.
 
Last edited:
  • #3,139
zoki85 said:
Didn't know Heron of Alexandria was a true inventor of the steam engine.
James Watt, don't you ever brag about it!
Hi zoki:

I did not find any mention of steam engine in the link you cited. Perhaps you had intended to cite a different article about Heron.

I do vaguely remember from some reference which I have forgotten that someone in that era, I think a Greek inventor, invented a more-or-less hollow spherical device filled with water and mounted to spin. The device had a few spouts at an angle along its equator. When it was heated, steam jets came out out the spouts and propelled rotation of the sphere. I believe this device had no practical use at the time. I suppose that technically this was an engine having motion generated by steam.

Regards,
Buzz
 
  • #3,140
The Greeks invented the aeolipile. While it uses steam to create motion its efficiency is really bad, it isn't practical for anything.
 
  • #3,141
Today I learned about neutron radiography:


More examples and info here.
 
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  • #3,142
mfb said:
The Greeks invented the aeolipile. While it uses steam to create motion its efficiency is really bad, it isn't practical for anything.
Come on, nobody should expect any decent efficiency from a small, primitive, steam propelled device. The important however was demonstrated principle.
 
  • #3,143
Buzz Bloom said:
I did not find any mention of steam engine in the link you cited. Perhaps you had intended to cite a different article about Heron.
Indeed. I wanted to include wiki article but forgot to do it.
Don't know how accurate is the wiki regarding Heron. I watched documentary on TV about him
 
  • #3,144
Buzz Bloom said:
I believe this device had no practical use at the time. I suppose that technically this was an engine having motion generated by steam.
Today I Learned about:
https://www.realclearscience.com/blog/2020/03/19/four_ancient_greek_inventions_that_were_way_ahead_of_their_time.html?

Heron of Alexandria was one of antiquity's great experimenters. He devised a vending machine, a basic syringe, and an ingenious fountain, but he was particularly fond of steam devices. One of his most notable and theatrical feats of technology was getting temple gates to open automatically. A roaring fire would be lit on a large altar and some of the heat would be siphoned to a pot of water below. The heated, expanding gases would force water through a siphon into another tank attached to a balance system which operates the axles of the doors. When the tank filling with water would sink down, the doors would swing open!
 
  • #3,145
  • #3,146
nrqed said:
"Dilatation" is the word we use in French. I wonder if it might have crept into English through French speaking scientists.
I suspect it crept into PF though a French-speaking OP!

We have the word "dilatory" as well in English, which means slow to act.
 
  • #3,147
It's "Dilatation" in German, too. And in Swedish. And most other related languages use something similar.
 
  • #3,148
mfb said:
It's "Dilatation" in German, too. And in Swedish. And most other related languages use something similar.
If you think about it "dilatation" is a dilation of dilation.
 
  • #3,149
Our lexicon says: late latin dilatatio = extension
 
  • #3,150
Today I learned that King George III donated his large private library to the nation and it became the British Library. And, on account of the King's interest in and patronage of astronomy, William Herschell originally named the new planet Uranus after him: Georgium Sidus.
 
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