Today I Learned

[Dewgale]

Today I learned that driving Minneapolis freeways in twilight is a terrible experience when you're a wayward Winnipeger.

 

[OmCheeto]

Good idea. If I need to use them to measure something I'll put them in my armpits for a while first.

The US Mint says they are supposed to be 0.75" in diameter. [ref]
Though, they do not give a reference temperature.
So I can't say whether or not that your micrometer is off.

According to the Engineering Toolbox, the coefficient of expansion of pennies should be around 19 microinch/(in °F) [ref]
Being 97.5% zinc, I'm assuming the copper cladding adds little to the equation

According to my calculations, and assuming you are not SATAN, the US Mint's unspecified temperature is 134°F.

In any event, TIL that eating modern zinc based pennies is toxic to both dogs and children.

 

[Astronuc]

Does the SEC inflate its numbers?
https://finance.yahoo.com/news/does-the-sec-inflate-its-numbers-165803420.html

Hmmmm - juggling the numbers?

 

[zoobyshoe]

The US Mint says they are supposed to be 0.75" in diameter. [ref]

I am sure that's what the print calls for, .750, but I'm sure there's a tolerance on that print, as well. They could stamp them out at .7495 for years and they'd all pass inspection. That's actually remarkably good for a part that isn't required to perform in any precision machine. The tolerance on, say, 3/4 washers is probably plus or minus .005.

 

[mfb]

I am sure that's what the print calls for, .750, but I'm sure there's a tolerance on that print, as well. They could stamp them out at .7495 for years and they'd all pass inspection. That's actually remarkably good for a part that isn't required to perform in any precision machine. The tolerance on, say, 3/4 washers is probably plus or minus .005.

Well, they should not be too different, otherwise vending machines won"t accept them (or need a larger tolerance, which makes them more vulnerable to foreign coins).

 

[zoobyshoe]

Well, they should not be too different, otherwise vending machines won"t accept them (or need a larger tolerance, which makes them more vulnerable to foreign coins).

The difference between .750 and .7495 is .0005, five ten thousandths of an inch, which is about 1/8 the thickness of a piece of printer paper. It's pretty small. I am sure more than that is worn off the diameter of any coin that's been in circulation a few years.

Machines that make change probably have several criteria the coin has to meet. The tolerance on the diameter could be more than you would expect, since it would have to pass other tests, as well.

 

[mfb]

The difference between .750 and .7495 is .0005, five ten thousandths of an inch, which is about 1/8 the thickness of a piece of printer paper.

Can we express it as fraction of the average distance to moon? ;)
~12 micrometers difference. Hmm... I could test that with a few coins. Probably 1 (€-)cent as they don't have grooves and I have a few of them. Iron (95%), surrounded by copper (5%).

Yesterday I learned about "secondary enforcement" in the US: You can break a law (such as not using a seat belt) in some states, and it is perfectly fine even if a police officer sees you - as long as you don't break a different law at the same time (such as speeding) you get away with it. Why is there no wikipedia page about that concept?

 

[DennisN]

Today I learned that the newly installed Windows 10 occupied 25% of the total storage space on my tablet, which made me feel like

...so I reverted back to the considerably smaller Windows 8.

 

[OmCheeto]

Today I learned that the newly installed Windows 10 occupied 25% of the total storage space on my tablet, which made me feel like

...so I reverted back to the considerably smaller Windows 8.

My original computer had a Microsoft OS that occupied 8 kilobytes. (8 bits) (1980)
My first "PC" used Windows 3.1, which occupied 12.5 megabytes. (32 bits) (1995 ?)
I see that Windows 10 occupies 10 gigabytes. (64 bits) (2015) (Comparable to my Yosemite OS @ 8 gigs)

So TIL, that if you include bit size, modern OS's are 5,000,000 times larger than my original computer.
That's kind of freaky.

This kind of reminds me of a thread I started the other day:

The internet, Physics Forums, and Dr. Neutrino [PF, circa 2008]

300 Gb? I picked up a 300 gig for $100. Try multiple terabytes! Check out the HP Blackbird, friggin' insane comp!

Are those 32 or 64 bit bytes?
My January '75 Popular Electronics magazine said that 256 bits of memory were worth about $1.75. A one terabyte drive at 32 bits per byte would have been worth over $200 billion back then. wow.

 

[mfb]

A byte is always 8 bits. Bytes are not words. Words increased in size, bytes did not.

 

[OmCheeto]

A byte is always 8 bits. Bytes are not words. Words increased in size, bytes did not.

Oh. Ok. Thank you.

I knew I should have put a disclaimer at the bottom;

I am no longer a computer nerd.
If you would like to argue about anything I've posted, please start a new thread.

But googling "byte" and "bit", perhaps we should just agree to disagree.

Byte [wiki]
The byte is a unit of digital information that most commonly consists of eight bits.
...
Various implementations of C and C++ reserve 8, 9, 16, 32, or 36 bits for the storage of a byte.

I'm sure it only gets worse.

 

[nsaspook]

Oh. Ok. Thank you.

I knew I should have put a disclaimer at the bottom;
But googling "byte" and "bit", perhaps we should just agree to disagree.
I'm sure it only gets worse.

Bytes have been 8 bits since before the Turbo_button. I think it's pretty safe (unless you program DSP chips) that it's 8 today.

 

[mfb]

Various implementations of C and C++ reserve 8, 9, 16, 32, or 36 bits for the storage of a byte.

That's a data type. It is not a quantity of storage, where a byte is always used as 8 bit.

 

[collinsmark]

Yes, a byte is always 8 bits.

It doesn't end there though. A kilobyte is typically 1024 bytes, not the 1000 bytes that you might expect. Similarly a megabyte is 1024^2 bytes and a gigabyte is 1024^3 bytes. That said, storage drive manufacturers have been known to use whichever definition suits their marketing team's whim.

But with the usual definitions, this is the one special case where the metric system is not really the base 10 system we've come to know so well.

Interestingly though, when discussing bit rates or (and sometimes [usually] byte rates), e.g., 1 megabit/second, the base ten system is used (1 Mbps is 1,000,000 bits/sec).

 

[Enigman]

Yes, a byte is always 8 bits.

It doesn't end there though. A kilobyte is typically 1024 bytes, not the 1000 bytes that you might expect.

It is sometimes and sometimes it is not. https://en.wikipedia.org/wiki/Kilobyte
To be unambiguous it is better to use Kibibyte or KiB.

 

[collinsmark]

It is sometimes and sometimes it is not. https://en.wikipedia.org/wiki/Kilobyte

Yes, typically a kilobyte is 1024 bytes, but not always. Particularly not always if your job is in the marketing department.

To be unambiguous it is better to use Kibibyte or KiB.

Less ambiguous I agree. But among engineers (well, presently anyway*), the "1024" version of kilobyte is the more commonly used and understood term.

*(perhaps this will change in the future).

 

[Astronuc]

The War of 1812 between the US and UK could have been avoided.
https://en.wikipedia.org/wiki/War_of_1812
http://www.pbs.org/wned/war-of-1812/essays/american-perspective/

Orders in Council (1807) were rescinded/repealed two days before the US declared war on the UK. However, news traveled slowly, so there was no warning of the intent of Parliament or the ministries.
https://en.wikipedia.org/wiki/Orders_in_Council_(1807)

Forty-one days after the United States Congress declared war, the word arrived in London on 29 July 1812. Two days later, 31 July 1812, the Ministry ordered its first counter-measures. It forbade English ships to sail except in convoys and restrained American ships in English ports. The Orders in Council had been repealed on 23 June 1812, but the ministers did not intend to take additional measures until they could learn the American reaction. Word of the repeal of the Orders did not reach President James Madison until 12 August 1812, some fifty days later. Even then he refused to halt hostilities because he did not know how Britain had reacted to the declaration of war.

There is a lot to be said for instantaneous or rapid communication.

The war between US and UK was a side show in the Napoleonic wars in Europe.

https://en.wikipedia.org/wiki/Napoleonic_Wars (1803–1815)
http://www.historyofwar.org/articles/wars_napoleonic.html (puts the wars from 1799 to 1815)

https://en.wikipedia.org/wiki/French_invasion_of_Russia French invasion of Russia
https://en.wikipedia.org/wiki/French_invasion_of_Russia#/media/File:Europe_1812_map_en.png
https://en.wikipedia.org/wiki/West_Galicia

 

[mfb]

Today I learned: it is not trivial that satellites in a low Earth orbit are stable.
http://arxiv.org/abs/1309.5244v1

In particular, without the rotation of Earth*, they would crash quickly.

Spoiler

*and the quadrupole moment coming from its shape due to the rotation. No general relativity here.

 

[zoobyshoe]

There is a lot to be said for instantaneous or rapid communication.

The American Civil War was the first to have any rapid communication because of the then new telegraph system. Lincoln could communicate extremely quickly with generals hundreds of miles away. I imagine they all felt like they were fighting a very new kind of modern war.

 

[Hornbein]

Today I learned that Nagasaki has a hotel staffed entirely by robots. One of the robots that works the check-in counter is in the form of a dinosaur.

 

[Silicon Waffle]

Today I learned that Nagasaki has a hotel staffed entirely by robots. One of the robots that works the check-in counter is in the form of a dinosaur.

http://www.livescience.com/49711-japanese-robot-hotel.html

I'd really love to visit it one day.

 

[mfb]

If they get cleaning the rooms done properly by robots, why limit it to that hotel?

 

[Jonathan Scott]

Today I learned that Gene Amdahl, chief architect of IBM's System/360 mainframes (and various other computers), died on Tuesday at 92.

IBM's latest z/Architecture mainframes are still compatible with user code compiled for those machines in the 1960s (and every now and then I come across some of that code, frequently without source!).

 

[Shano]

Today I learned that I should never stop learning. It may seem like a stupid thing to say, but is something that can get forgotten or overlooked in life.

 

[Astronuc]

Charles Koch wants to find 'common ground' with Obama administration
http://finance.yahoo.com/news/charles-koch-is-really-a-liberal-compromiser-201545347.html

Wonders never cease.

 

[OmCheeto]

Charles Koch wants to find 'common ground' with Obama administration
http://finance.yahoo.com/news/charles-koch-is-really-a-liberal-compromiser-201545347.html

Wonders never cease.

Wow. He almost sounds like Bernie Sanders in that interview.

Andy Serwer; "Is there too much money in politics, and, is it ... because rich people are putting too much money into politics"?
David Koch; "No, it's because of corporate welfare".
Source: your video​

Bernie Sanders; "In 1995, I introduced HR 2534, the Corporate Responsibility Act, which contained many of these provisions. While the fight against corporate welfare has been led by progressives in Congress, we've also had support from honest conservatives who are rightfully appalled at this waste of taxpayer dollars. As a result, the concept of corporate welfare is now filtering into the mainstream, and some legislation has been passed which is beginning to chip away at this outrageous waste of money".
Source: Outsider in the House, by Bernie Sanders, p. 208, 10 Jun 17, 1997​

TIL that I was right to be suspicious of the motives of these Koch brothers.

 

[OmCheeto]

TIL that the "tare weight" of one of my 3 yellow recycle bins is 1.86 kg.

Somewhat trivial, IMHO, for the rest of humanity.

But, I required this knowledge, for one of my ongoing science experiments.

Anyways..., I became curious where the word "tare" came from, and why it was spelled so goofily:

per wiki; "The word tare originates from... Arabic طرح ṭarḥ, lit. "thing deducted or rejected," from taraha "to reject""

 

[zoobyshoe]

Today I learned that the unlikely state of North Dakota has the lowest unemployment rate of any state in the country. The reason: The North Dakota Oil Boom. ND is now the largest producer of oil of any US state except Texas.

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

This boom has radically changed things in the once-sleepy state:

The industrialization and population boom has put a strain on roads, water supplies, sewage systems, and government services in the area. Some counties have increased in population by almost double from 20,000 to 40,000.[9][10]

The boom has brought with it increases in crime and social problems.[16][17] The addition of thousands of oil workers has led to a housing shortage, requiring the construction of camps for housing them. Law enforcement agencies have reported sharp increases in offenses, particularly violent crime,[18] drug trafficking,[19] gun crimes,[20] and prostitution.[21][22][23] These problems are similar to those found in other regions in which energy industry workers have taken temporary jobs.[21] A 2012 report indicated that conditions were improving.[16] As of October 2013, the FBI's Project Safe Bakken had stationed additional full-time agents in the area.[22]

 

[Hornbein]

Today I learned that the unlikely state of North Dakota has the lowest unemployment rate of any state in the country. The reason: The North Dakota Oil Boom. ND is now the largest producer of oil of any US state except Texas.

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

This boom has radically changed things in the once-sleepy state:

Yeah. I know a guy who works there. He told me that rigs producing oil are required to spend $300,000 a day. ? "It's not easy to do that," he said.

Fracking adds about 300 million dollars a DAY to the US economy.

 

[zoobyshoe]

Yeah. I know a guy who works there. He told me that rigs producing oil are required to spend $300,000 a day. ?

I don't get it. Required by whom, and why?

 

[davenn]

He told me that rigs producing oil are required to spend $300,000 a day. ?

Required to spend ?

care to elaborate please :)

 

[Hornbein]

Yeah. I know a guy who works there.

Fracking adds about 300 million dollars a DAY to the US economy.

Required to spend ?

care to elaborate please :)

His company required the drill operators to spend $300,000 a day on goods and services once it was producing.

Before it began producing they had to spend only $40,000 a day.

It doesn't make sense to me either. The only way I can explain it is that upper management owned drilling supply companies on the side and were seeking to privatize a big chunk of the profits.

Upper management is often corrupt. Read a biography of Henry Ford II if you want to know about it.

 

[Silicon Waffle]

If they get cleaning the rooms done properly by robots, why limit it to that hotel?

They have their phone numbers for public orders and inquiries, you can call and ask them.

 

[Astronuc]

Brielle, an adorable 3-year-old girl from Salinas, Calif., went on “The Ellen DeGeneres Show” earlier this week. She dazzled both the crowd and the host by accurately reciting the periodic table of elements during a quiz using pictures and abbreviations. She could even provide descriptions and uses for the elements.

http://wgntv.com/2015/11/25/this-adorable-3-year-old-knows-the-entire-periodic-table-of-elements/

She knows the names of presidents, state capitals, countries in Europe and Africa, and the periodic table. Pretty impressive. I didn't learn the periodic table until I was 10.

 

[rootone]

Today I learned that there are people who think that Portugal is part of Spain, and that Ireland is part of the UK.

 

[mfb]

Today I learned that there are people who think that Portugal is part of Spain, and that Ireland is part of the UK.

It can be worse

 

[WWGD]

Today I learned that there are people who think that Portugal is part of Spain, and that Ireland is part of the UK.

EDIT I think Bush II once referred to "the unification of North and South Germany" during one of his meetings with Angela Merkel. Maybe he also referred to the unification of Eastern Korea with Western Korea. Not so funny given he has access to nuclear bombs and would be good for him to know what's what.

 

[Hornbein]

Today I learned that 94% of US adults can find their country on a map of the world. 30% can identify Iran.

 

[mfb]

The LHC is colliding lead ions at a new record energy.

Today I calculated: the energy in a single collision would be sufficient to lift a pen by 1mm (1/25 inch for those with a weird unit system). That is a macroscopic quantity, packed into a single nuclear collision.

 

[nucleargirl]

Today I learned that the red fox habitat is expanding into the arctic fox habitat and the red fox will eat the smaller arctic fox... :S

 

[WWGD]

Today I learned that the red fox habitat is expanding into the arctic fox habitat and the red fox will eat the smaller arctic fox... :S

Yes, I think I heard something about it...in Fox news.

 

[zoobyshoe]

Today I learned how to remove a chuck from a drill:



The information that the holding screw inside the chuck is left-handed was invaluable.

 

[gleem]

Today I learned that four rare Earth metals Yttrium (Y), Terbium (Tb), Erbium (Er) and Ytterbium (Yb) are all named after Ytterby a town in Sweden.

 

[Silicon Waffle]

I learned that snakes, worms and spiders are tailless.

 

[phinds]

Today I learned why we get goosebumps. I always took it literally and assumed it was because a goose's hair will fluff up when it's cold, but It's actually because we evolved from animals with fur and when you have fur getting cold is somewhat alleviated by causing your hair to fluff up. We make the same motion (goosebumps) we just don't have any fur to stand up. Same reason as geese really but not the right derivation.

Also fright seems to cause hair to stand up on some animals necks so we sometimes get them on our necks when we see something frightening.

 

[zoobyshoe]

Today I learned why we get goosebumps. I always took it literally and assumed it was because a goose's hair will fluff up when it's cold, but It's actually because we evolved from animals with fur and when you have fur getting cold is somewhat alienated by causing your hair to fluff up. We make the same motion (goosebumps) we just don't have any fur to stand up. Same reason as geese really but not the right derivation.

Also fright seems to cause hair to stand up on some animals necks so we sometimes get them on our necks when we see something frightening.

Yes, the technical term for "goosebumps" is piloerection:

Medical Definition of PILOERECTION. : involuntary erection or bristling of hairs due to a sympathetic reflex usually triggered by cold, shock, or fright or due to a sympathomimetic agent.

 

[phinds]

Yes, the technical term for "goosebumps" is piloerection:

Cool. Thanks.

 

[JorisL]

TIL it's hard to tune a lecture to the students needs when you have both students with dyslexia and dyscalculia.
The first benefit often from a schematic way of summarizing the contents using fewer words/full sentences.
While the latter not only have trouble with arithmetic but also with visual insights.
This means they can have trouble with a schematic way of representing the contents.

Quite the conundrum when trying to (fine-)tune a lesson.

 

[jim hardy]

The information that the holding screw inside the chuck is left-handed was invaluable.

i look for burnt out drills in junkpiles and pillage those left handed screws . They must be made from Unobtanium - can't get them anyplace else !

 

[zoobyshoe]

i look for burnt out drills in junkpiles and pillage those left handed screws . They must be made from Unobtanium - can't get them anyplace else !

You made me curious. The one I took out of a 3/8 black and decker drill seems to be a 3/16-32 screw, which is a size I have never heard of before. I get a diameter of .186 and 32 TPI.

I suppose you could call a drill manufacturer and tell them you change your chucks often and are always losing the screws. Maybe they'd send you a box?