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.
  • #601
nsaspook said:
I think there was a movie about an alternative source.
Sorry if I ruined your setup by giving away the punchline.
 
Physics news on Phys.org
  • #602
WWGD said:
Sorry if I ruined your setup by giving away the punchline.
No, that was it.
soylent_green_demotivator_by_ravengerx.jpg
 
  • #603
WWGD said:
I don't mean to be alarmist, but given population growth, we may have no other viable long-term source of protein. We may be passing the costs out somewhere in the system when we pay $4-5 for a burger or even $10+ for a steak.
I don't think the cricket flour is what makes those candy bars expensive. It's the other gourmet ingredients plus the fact they probably haven't achieved the cheapest possible mass production methods.

At this point, I'm curious to know what those who farm the crickets feed the crickets, and could it be replaced with something even cheaper?
Captive crickets are omnivorous: when deprived of their natural diet, they will accept a wide range of different organic foodstuffs. Some species are completely herbivorous, feeding on flowers, fruit and leaves, with ground-based species consuming seedlings, grasses, pieces of leaf and the shoots of young plants. Others are more predatory and include in their diet invertebrate eggs, larvae, pupae, moulting insects, scale insects and aphids.[12] Many are scavengers and consume various organic remains, decaying plants, seedlings and fungi.[13] In captivity, many species have been successfully reared on a diet of ground up, commercial dry dog food, supplemented with lettuce and aphids.[12]
As for Soylent Green, it might work as an alternative protein source were it introduced into the system indirectly as cricket feed:
Crickets have relatively powerful jaws, and several species have been known to bite humans.
 
  • #604
Today I learned that in 2013 it was estimated that 31 million people in the world had Asperger's.
 
  • #605
zoobyshoe said:
...
At this point, I'm curious to know what those who farm the crickets feed the crickets...

I just learned that 40,000 crickets can eat a head of lettuce in less than an hour.
But this brings up a question: Will the FDA, in the future, regulate how many lettuce bits are in our cricket burgers? :biggrin:
 
  • #606
Today i learned to wait for more information before i speak.
 
  • #608
Today I learned that banana peels are good for you.
 
  • #609
Things with mass traves at different speed. Trains travel for example, 100Kmh, cars at 40kmh, air planes at 1000kmh. But, do things without mass ALWAYS always travel at "this" universal speed limit?
Yes
Today I learned that the massless photon is not heavy it is light. Is that why photon always travels at the speed of light?
 
  • #610
Stephanus said:
Today I learned that the massless photon is not heavy it is light. Is that why photon always travels at the speed of light?
Do they?
 
  • #611
Enigman said:
I don't know. I just read somewhere if the photon does not have mass but they have momentum.
If the mass weren't zero, the speed of light would not be constant; but from a theoretical point of view we would then take c to be the upper limit of the speed of light in vacuum so that we can continue to ask whether c is constant.
If the speed of light is the speed of photon(because we see light by photon entering our retina) then speed of light is not c. Altough c itself is constant. So photon can't never travel at c if it has mass, because then ##\frac{1}{\sqrt{1-(\frac{v}{c})^2}}## would be infinite, no matter how small the mass is. I don't know, I'm not an expert at particle physics much less SR. Do anybody know, supposed if photon has mass, how much is it compared to neutrino?
But thanks for the link anyway. I like SR
 
  • #612
Okay, so here goes...
Photon is a particle representing a quantum of light. Photons don't have mass. What they do have is momentum and energy.
c is constant and the highest speed achievable. Photons travel at c in vacuum. In other mediums like air, water, glass, etc. the speed is slower than c.
Neutrino DO have mass but it is tiny, with a magnitude of somewhere between the order of 10 -36 and 10 -39 kg
 
  • #613
Enigman said:
Okay, so here goes...
Photon is a particle representing a quantum of light. Photons don't have mass. What they do have is momentum and energy.
c is constant and the highest speed achievable. Photons travel at c in vacuum. In other mediums like air, water, glass, etc. the speed is slower than c.
Neutrino DO have mass but it is tiny, with a magnitude of somewhere between the order of 10 -36 and 10 -39 kg
Oh, and I just remember the formula for momentum is ##momentum = mv## if I'm not mistaken. If m is zero, than mv is zero?? Hmmh..., okay, I'll let that pass. Strange thing here isn't it.
 
  • #614
But photon ALWAYS travels at the speed of light doesn't it :smile: Because we measure the speed of light (not c, as I just understand) by the speed of protons entering our sensor (retina, radar, etc)
 
  • #615
That is the classical formula. Relativity gives ##p=\gamma . mv## or ##p=E/c##
The first is invalid for light as lorentz factor is no defined for light. E=hv for light, so
##p=h/\lambda## is the momentum for light.
(##\lambda## is wavelength, h is Planck's constant and p is momentum)
 
  • #616
Enigman said:
That is the classical formula. Relativity gives ##p=\gamma . mv## or ##p=E/c##
The first is invalid for light as lorentz factor is no defined for light. E=hv for light, so
##p=h/\lambda## is the momentum for light.
(##\lambda## is wavelength, h is Planck's constant and p is momentum)
Planck?? Is it something like quantum thing? Okay, okay I think we should stop here, before we get banned by admin for discussing specific detail about something in this thread.
Today I learned that I have to learn what I think I have learned.
 
  • #617
Stephanus said:
But photon ALWAYS travels at the speed of light doesn't it :smile: Because we measure the speed of light (not c, as I just understand) by the speed of protons entering our sensor (retina, radar, etc)
No.
Measuring of light is much more complicated. You should go through the topic on wiki and/or make a few threads in general physics / special relativity forums to clear your doubts.
 
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  • #618
Today I learned about ECT (Electroconvulsive therapy).
My long long ever asked question is why people become "crazy" - mentally ill if they were born perfectly physically and mentally healthy...Can we make someone "crazy" ? I am worried someone will turn me crazy one day and I need to know the cure right now. True!
 
  • #619
Silicon Waffle said:
I am worried someone will turn me crazy one day
I wouldn't worry about it. It's not so bad once you get used to it.
 
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  • #620
Drive someone crazy ?
Drivingdistance.jpg


Heck, with me it's just a putt.
 
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  • #621
I thought the largest airplane ever built was the Spruce Goose, but today I learned it was a Russian cargo plane:

The Antonov An-225 Mriya (Ukrainian: Антонов Ан-225 Мрія, Russian: Антонов Ан-225 Мрия, Dream, NATOreporting name: "Cossack") is a strategic airlift cargo aircraft that was designed by the Soviet Union's Antonov Design Bureau in the 1980s. The An-225's name, Mriya (Мрiя) means "Dream" (Inspiration) in Ukrainian. It is powered by six turbofan engines and is the longest and heaviest airplane ever built, with a maximum takeoff weightof 640 tonnes. It also has the largest wingspan of any aircraft in operational service. The single example built has the Ukrainian civil registration UR-82060. A second airframe was partially built; its completion was halted because of lack of funding and interest.
 
  • #622
zoobyshoe said:
I thought the largest airplane ever built was the Spruce Goose, but today I learned it was a Russian cargo plane:
Yep, it's the one that Yuri and John Cussack and Armanda Peet ride in 2012.
 
  • #623
zoobyshoe said:
I thought the largest airplane ever built was the Spruce Goose, but today I learned it was a Russian cargo plane:

I just passed the Spruce Goose on Sunday. It was the first time I'd ever seen it. I didn't stop, but saw it from the highway. I would have stopped, but traffic had been bad all day, which made me a bit cranky, and I wanted to get home asap.

2015.07.12.Spruce.Goose.jpg

file footage​
45°12'12.59" N
123°08'46.25" W
elev 159 ft

hmmm... I just learned that it still holds a couple of records:

The Hercules is the largest flying boat ever built and has the largest wingspan of any aircraft in history. [per wiki]
 
  • #624
Today I learned there's a "Singularity University".

Surely its name is blown up out of all proportion? :smile:
 
  • #625
Today I learned that in 2010 the Royal London Homeopathic Hospital was renamed the Royal London Hospital for Integrated Medicine.

New Scientist commented that presumably removing "homeopathic" from the title made it more potent...
 
  • #626
OmCheeto said:
The Hercules is the largest flying boat ever built and has the largest wingspan of any aircraft in history. [per wiki]
Today I learned the actual name of the Spruce Goose was the H-4 Hercules. I didn't know that.
 
  • #627
Today I learned Apollo 13 carried 4 kg of Plutonium-238 (supposed to stay on Moon), and the container survived atmospheric re-entry.
I also learned that New Horizons probably won't crash into a car today.

DrGreg said:
Today I learned there's a "Singularity University".

Surely its name is blown up out of all proportion? :smile:
Let's hope the students are not too dense.
 
  • #628
mfb said:
...

Let's hope the students are not too dense.
Or naked.
 
  • #629
OmCheeto said:
I just passed the Spruce Goose on Sunday.
I passed the same place a couple of weeks ago, and the coast-bound traffic was congested.
 
Last edited:
  • #630
Orphaned bear cub rescued after climbing aboard Tennessee raft
http://www.grindtv.com/wildlife/orphaned-bear-cub-rescued-after-climbing-aboard-tennessee-raft/

Sometimes one has to do the wrong thing to do the right thing.

Outdoor and river guide Danny “Shaggy” Allen faces fines for removing wildlife, when he rescued a distressed bear cub. The Tennessee Wildlife Resources Agency was called, and the cub delivered to the rescue facility.

High Mountain Guides spokesman Mark Russ, and USA Raft owner Matt Moses said they’ll gladly accept any fines. They explained that it was apparent, that after three days, the cub and its mother had become separated.
 
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  • #631
Today I learned that @Evo is The Lady of Shalott
Wikipedia said:
... the Lady of Shalott was forbidden to look directly at reality or the outside world; instead she was doomed to view the world through a mirror ...
Deep :wideeyed:
 
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  • #632
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  • #634
Astronuc said:

Reminds me of a post from a while back.

Ah! I don't think I finished the article:

Earth's Inner Fort Knox (discoverymagazine)
Searching for a pot of gold? Try the center of the Earth.
By Anne Wootton | Friday, September 01, 2006
...
Wood has calculated that 1.6 quadrillion tons of gold must lie in Earth's core. This may sound like a lot, but it is really only a tiny percentage of the core's overall mass—about one part per million. The core holds six times as much platinum, Wood notes, "but people get less excited about that than gold."

I didn't do the calculation for the platinum last time. hmmm... TIL that gold surpassed platinum in $/oz back in 2011.
Anyways, by my new calculations, the value of gold and platinum in the Earths core would yield ≈$44.4 trillion for every person on Earth.
Someone should let the Greeks know about this. Start digging! :biggrin:
 
  • #635
Today I learned: Never trust a grad student to comment their code, or even give you the most up to date code that you need for the project...
 
  • #636
All those asteroid values are pure phantasy. With the same logic, a cubic kilometer of average ground on Earth is worth more than a billion dollars, mainly from gold. Nobody wants to buy a square kilometer of desert (including the rights to dig away the top kilometer of it) for that price, however - because extracting that gold out of the cubic kilometer of dirt costs much more than a billion. Note: it costs more than a billion even here on Earth, mining an asteroid is orders of magnitude more expensive. Sure, the asteroids have a higher fraction of precious metals, but so do our gold ores on Earth.
 
  • #638
Today I learned that modern cars are hackable.

From http://www.wired.com/2015/07/hackers-remotely-kill-jeep-highway/?mbid=social_twitter,
I WAS DRIVING 70 mph on the edge of downtown St. Louis when the exploit began to take hold.

Though I hadn’t touched the dashboard, the vents in the Jeep Cherokee started blasting cold air at the maximum setting, chilling the sweat on my back through the in-seat climate control system. Next the radio switched to the local hip hop station and began blaring Skee-lo at full volume. I spun the control knob left and hit the power button, to no avail. Then the windshield wipers turned on, and wiper fluid blurred the glass.

As I tried to cope with all this, a picture of the two hackers performing these stunts appeared on the car’s digital display: Charlie Miller and Chris Valasek, wearing their trademark track suits. A nice touch, I thought.

Also today, I learned that a pair of Senators coincidentally introduced the http://blog.caranddriver.com/senate-introduces-automotive-anti-hacking-bill/. The Senators that introduced the bill have been quietly following the notices by hackers that they can make your car kill you.

My newest vehicle is a 2005. My best vehicle is a 2002, made out of cardboard. But at least it's not hackable.
 
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  • #639
see my signature...
 
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  • #640
OmCheeto said:
I just passed the Spruce Goose on Sunday. It was the first time I'd ever seen it. I didn't stop, but saw it from the highway. I would have stopped, but traffic had been bad all day, which made me a bit cranky, and I wanted to get home asap.

View attachment 85948
file footage​
45°12'12.59" N
123°08'46.25" W
elev 159 ft

hmmm... I just learned that it still holds a couple of records:

The Hercules is the largest flying boat ever built and has the largest wingspan of any aircraft in history. [per wiki]

Not today, but some day in the past - I leaned that the Spruce Goose is made almost entirely of birch.

I guess birch does not rhyme easily to make a catchy phrase.
 
  • #641
jim hardy said:
see my signature...
I don't understand what you mean.
Coherence in speeches and thoughts by old people is far more removed from that made by the young.
 
  • #642
Silicon Waffle said:
I don't understand what you mean.

I was commenting on the concept of a computer controlled automobile. I won't own one with throttle , brakes or power steering that are electronic. I won't ride Airbuses, either.

Coherence in speeches and thoughts by old people is far more removed from that made by the young.
Yes, one learns language when young..
Old folks allude to things that simply aren't in youth's experience base. I wish you'd seen the look on my grandchildrens' faces when they encountered my rotary dial telephone.
Recently i played a Mills Brothers record for son; he asked in dismay "Was this before they invented milkshakes ?"

old jim
 
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  • #643
jim hardy said:
...
Old folks allude to things that simply aren't in youth's experience base. I wish you'd seen the look on my grandchildrens' faces when they encountered my rotary dial telephone.
Recently i played a Mills Brothers record for son; he asked in dismay "Was this before they invented milkshakes ?"

old jim
Good old man! I call you old, then you show me how old you are. :(
 
  • #644
lisab said:
Not today, but some day in the past - I leaned that the Spruce Goose is made almost entirely of birch.

I guess birch does not rhyme easily to make a catchy phrase.

That's funny. I own 4 boats built by the Burchcraft Boat Company of Aberdeen Washington.
They are all made out of Douglas Fir.
The company got its name from the founder, Loren P. Burch.
Though, I was in correspondence with one of the Burch family from Minnesota, and he sent me an 1885 census bureau listing which included Loren, and his surname was listed as Birch.

hmmm... google google google

TIL that it doesn't really matter how you spell it. :smile:

wiki said:
Burch is an English surname that most likely originated in Hyndley Birch, Rusholme, Manchester, England[citation needed]. The origins of the name can be traced back as far as 1500. Burch is also likely a variation of Birch being derived from one who resides at or near a birch-tree. "John at the birch," etc.
...
 
  • #645
jim hardy said:
I was commenting on the concept of a computer controlled automobile. I won't own one with throttle , brakes or power steering that are electronic. I won't ride Airbuses, either.
I was thinking the same thing yesterday, when I saw the article. I'm never flying again. :wideeyed:
Yes, one learns language when young..
Old folks allude to things that simply aren't in youth's experience base. I wish you'd seen the look on my grandchildrens' faces when they encountered my rotary dial telephone.
Recently i played a Mills Brothers record for son; he asked in dismay "Was this before they invented milkshakes ?"

old jim
This reminds me of a story someone told me just a few years back, when I gave him a ride home in my brand new pickup truck. (It has zero fancy options):

He had rented a car, and had his two little kids with him.
They asked him where the button was, to make the windows go down.
He said there was no button, but there was a thing sticking out of the door, which you had to turn.
He said they spent the rest of the trip cranking, making the windows go up and down, laughing, all the way to their destination.
:smile:

TIL that the first "power window" was introduced in 1940:

History
Packard introduced the first power windows in the 1940 Packard 180 series. This was a hydro-electric system.

hydro-electric! :biggrin:
 
  • #646
zoobyshoe said:
I thought the largest airplane ever built was the Spruce Goose, but today I learned it was a Russian cargo plane:

Weird. Are you psychic? Or did you know something was going on?

TIL, just moments ago actually, that:

Legendary mogul Howard Hughes' Spruce Goose, a gigantic historic wooden airplane whose fate was mired in a financial dispute, will permanently stay in Oregon. [ref]
:smile:
 
Last edited:
  • #647
fixed a 42" flatscreen I found in the trash, 5 bucks for the service manual, 40 for the part, now I got a working tv.
 
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  • #650
Today I learned there is a volcano with a fantastic name: Kick 'em Jenny. And it's getting close to erupting :nb)!
 
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