Today I Learned

[fresh_42]

What, then, is the maximum possible speed of a spacecraft ?

Interesting question: What is a lower boundary of the drag coefficient in space due to CMB resistance?
It hasn't been said in the documentary I saw (who wonders?).

 

[PeroK]

Interesting question: What is a lower boundary of the drag coefficient in space due to CMB resistance?
It hasn't been said in the documentary I saw (who wonders?).

The 28 years is not very important, unless you are talking about human crew - and, even then, we'd be talking about a cryogenic system of some sort.

 

[fresh_42]

The 28 years is not very important, unless you are talking about human crew - and, even then, we'd be talking about a cryogenic system of some sort.

No. The $c_w$ value is.

 

[jack action]

TIL (or more precisely I was reminded) that we all have to start somewhere:

This Giant Abandoned Soviet Spaceship Made of Wood Looks Like the Ultimate Children’s Playground Feature​

This decaying wooden spacecraft was used as a wind tunnel model in the 1980s for the VKK Space Orbiter, the largest and most expensive Soviet space exploration program conceived as a response to the United States’ Space Shuttle.

 

[DaveC426913]

So, the idea of making satellites out of wood is not so new after all...

 

[fresh_42]

So, the idea of making satellites out of wood is not so new after all...

And it would definitely resolve the re-entry problem!

 

[Klystron]

TIL (or more precisely I was reminded) that we all have to start somewhere:

This Giant Abandoned Soviet Spaceship Made of Wood Looks Like the Ultimate Children’s Playground Feature
View attachment 276931​

From an artistic point of view, this aging replica with railroad cars visible in the background represents numerous tropes of modern technology. The wooden structure slowly weathers into the surrounding trees.

 

[BillTre]

TIL that as someone who works for an eyebank, removing corneas from corpses,
I am part of the Death Care Industry (like undertakers etc.).

 

[mfb]

Interesting question: What is a lower boundary of the drag coefficient in space due to CMB resistance?
It hasn't been said in the documentary I saw (who wonders?).

It doesn't act like a drag coefficient.
It's in principle just an engineering challenge that can be overcome. There is no physical limit on the speed.

 

[Keith_McClary]

The worlds smallest vertebrate is a recently [2011] discovered frog measuring 0.3 inches long (7.7 millimeters).
(Image: © Christopher Austin, LSU)

Smaller than:

The newly discovered Nano-Chameleon (Brookesia nana) is the smallest known reptile in the world
Frank Glaw (SNSB/ZSM)

 

[nuuskur]

TIL he who went by @Math_QED isn't in the forum anymore. He still around or anyone know what happened?

 

[DaveC426913]

The worlds smallest vertebrate

Really? I would have thought some fish were smaller.
Ah.

"It ousts Paedocypris progenetica, an Indonesian fish averaging more than 8 millimeters, from the record. "

 

[jedishrfu]

TIL he who went by @Math_QED isn't in the forum anymore. He still around or anyone know what happened?

While we can’t comment on specific cases, we can say that sometimes folks priorities change and that they need to focus on more immediate needs.

The advent of the Right to be Forgotten law of the EU places an additional burden on website owners to respect requests for removal of any kind of content associated with an EU member.

The combination of these two circumstances can make it appear that a site member has completely vanished with no explanation when in fact it’s due to these priorities and laws that are beyond our control.

 

[gmax137]

TIL about the Right to be Forgotten law. I don't remember hearing about it before.

 

[fresh_42]

TIL about the Right to be Forgotten law. I don't remember hearing about it before.

The name became as famous here as "the Bosman judgement".

 

[gmax137]

The name became as famous here as "the Bosman judgement".

Well I had to look that one up as well. But I'm confused by the wiki article, as I didn't think you all played football over there...

 

[jack action]

TIL a fun fact about back to the future:

(source: www.facebook.com/FTLOSF/videos/769589736988388)​

 

[Keith_McClary]

"Look at my new girlfriend! Isn't she pretty?"
"Yeah, you're right! She isn't - pretty."

TIL about Question tags.

 

[berkeman]

Watching the evening news on TV tonight (in Northern California, US), TIL about avalanche "parachutes" / "air bags" that can help skiers and snowmobilers survive getting caught in avalanches. I never knew about these things before tonight!

https://www.switchbacktravel.com/sites/default/files/images/articles/Alpride E1 avalanche airbag pack (Scott Patrol E1).jpg

https://www.evo.com/guides/how-to-choose-avalanche-airbag

 

[jack action]

TIL the wonderful story of Duct Tape. It was invented by a woman during WWII, Vesta Stoudt, to seal ammo boxes.

The most fascinating thing is that the original name was Duck Tape, because it was waterproof like a duck and was made with cotton duck fabric. And that, way before it was used to seal ducts.

The Woman Who Invented Duct Tape

 

[berkeman]

The most fascinating thing is that the original name was Duck Tape, because it was waterproof like a duck

Interesting! And I always thought "Duck Tape" was a malapropism. Now I know it's not!

 

[BillTre]

I have seen Duck Tape for sale, but I live in Eugene, Oregon, home of the Fighting Ducks!

 

[Drakkith]

Today I learned that the translunar injection burns for the Apollo missions accelerated the spacecraft up to the equivalent of about Mach 30. The burns were actually visible from the Earth's surface for those in the right locations at the right times.

Supposedly, Neil Armstrong yelled out, "Eat my exhaust, Blackbird!" during their TLI burn, referring to the SR-71 Blackbird.*

*Citation needed.

 

[DaveE]

TIL that the interwebs doesn't really know what "canonical form" really means. All* of my search results described a particular discipline and how they use canonical forms. Mathematics, Chemistry, Electronics, Physics, Computer Science, Linguistics... They all have their canonical forms that are well described in a google search. But nowhere did anyone actually describe why humans use canonical formulations to improve the efficiency of communication or understanding. There doesn't seem to be a generalized description of a common feature of diverse disciplines.

*OK, I'm lazy and not THAT interested, All = about 6 pages of google searches.

 

[fresh_42]

A canon (Greek: measure) is a law or a principle in the catholic church. It demands how something is done - always. Hence the canonical forms are the way things have to be done.

 

[mfb]

TIL: The worst natural disaster in the history of Finland was...

Spoiler

The 2004 earthquake in the Indian ocean. It killed 179 Finns.

 

[Keith_McClary]

worst natural disaster

Does that include pandemics and weather events (and shipwrecks blamed on weather).

 

[mfb]

I assume no pandemics. Weather events should be included.
That statement is older than the COVID-19 pandemic but the 1918 pandemic will have killed more, too.

 

[epenguin]

Today I learned that Sheikh Yamani who died on 23rd Feb and who for a quarter of a century made the weather in the world oil market and was the mastermind of the 1973 oil shock that quadrupled the oil price wasn't really a Sheikh - that was only a courtesy title given to this technocrat whom the Saudi king had picked out for his legal expertise and newspaper articles.

He wasn't really rich either, with a mere $500 million to his name, pretty humble for the circles he mixed in, or could have, for he was no socialite either.

 

[rsk]

Today I learned that Algeria has the highest % of female engineering graduates in the world. This isn't news, but it was news to me.
All the Maghrebi countries fare well, though I think Peru comes second after Algeria.

 

[BillTre]

TIL that Russian artist Nikita Golubev does really good drawings on dirty vehicles:

 

[Drakkith]

Today I learned that it is possible for lightning to strike lightning.
See 6:37 in the following video.

 

[mfb]

TORNADOES OF 2020 - Is it over yet?

Quite sure it is.

Lightning produces a channel of good conductivity, so it's a great target for lightning strikes.

 

[jasonRF]

TIL that the $9 lightening-to-headphone adapters for iPhones have a digital to analog converter inside.
https://www.ifixit.com/Teardown/Apple+Lightning+to+Headphone+Jack+Adapter+Teardown/67562

The link is 4.5 years old so I’m guessing many here already knew that, but for some reason I had been assuming that Apple simply routed analog through the lightning connector.

 

[Tom.G]

...I had been assuming that Apple simply routed analog through the lightning connector.

Naw. Then they would have to include the A/D in the original price.
Much more profit in selling it seperately as a sole-source item, you see.