Weirdest/things that blew your mind when you learned them

[BWV]

Having only a superficial understanding of both, how biology is so much more complex than any of the physical sciences.

 

[sysprog]

Having only a superficial understanding of both, how biology is so much more complex than any of the physical sciences.

In my view, biology is part of physical sciences, just as org chem is part of p chem, and p chem is part of physics.

 

[BillTre]

In my view, biology is part of physical sciences, just as org chem is part of p chem, and p chem is part of physics.

True.

And each level generates greater complexity through interactions among the elements that exist in the other levels that they are built upon.

The complexity however is mostly studied at the level at which it is found.
Physicists study the complexity of physics, chemists study the complexity of chemistry, biology studies the complexity of biology, etc...

 

[sysprog]

Well said, @BillTre

 

[Keith_McClary]

In my view, biology is part of physical sciences, just as org chem is part of p chem, and p chem is part of physics.

https://xkcd.com/435/

 

[sysprog]

Well, biology, physics, chemistry, whatever; I'm a boy person (old enough to have started to be in my 60s), and I think that (fully-grown) girls rule, wherefore, whatever they say, right?

 

[BWV]

Also the 90-95% population declines in the Americas from the introduction of European diseases. Most native Americans who died in this never saw a European, and when the Europeans did move inland, they thought they had found a pristine wilderness which in fact was just a result of the collapse of the indigenous populations that had actively managed the land for centuries.

 

[sysprog]

Also the 90-95% population declines in the Americas from the introduction of European diseases. Most native Americans who died in this never saw a European, and when the Europeans did move inland, they thought they had found a pristine wilderness which in fact was just a result of the collapse of the indigenous populations that had actively managed the land for centuries.

Really? They "managed the land for centuries"? That looks like 'noble savage' nonsense to me -- after they resorted to crossing the ice-age land bridge they maybe were hungry and didn't forget to extinctionate the wooly mammoth while they were on their way to the Southern end of the so-called 'Americas' -- what is now called Peru.

 

[Keith_McClary]

Southern end of the so-called 'Americas' -- what is now called Peru.

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

 

[BWV]

Really? They "managed the land for centuries"? That looks like 'noble savage' nonsense to me -- after they resorted to crossing the ice-age land bridge they maybe were hungry and didn't forget to extinctionate the wooly mammoth while they were on their way to the Southern end of the so-called 'Americas' -- what is now called Peru.

It’s science, nothing else. Looks like you maybe are the one with an agenda

https://www.theatlantic.com/magazine/archive/2002/03/the-pristine-myth/303062/

https://www.sciencedaily.com/releases/2011/03/110321134617.htm

 

[bhobba]

By simply using Euler's formula how easily the formula for capacitors, inductors, resonance etc is explained. Then came the granddaddy of them all - Noether's Theorem - that is just so beautiful, but strange, and the most convincing evidence I know of that god (however you conceive of him/her) exists. At first I was amazed at Godel's Theorem, but later understood it was just Cantors diagonal argument in disguise - a tricky use of it - yes - but it's still the crux:
http://www.math.hawaii.edu/~dale/godel/godel.html

Thanks
Bill

 

[scottdave]

That phase velocity can travel much faster than the "thing" (wave, particle beam, etc) that created it - for example, an electron beam trace on a Cathode Ray Tube can "travel" faster than light! Yet nothing is violated.

Gyroscopic precession took me awhile to wrap my head around.

 

[collinsmark]

Gyroscopic precession took me awhile to wrap my head around.

(Source: https://xkcd.com/332/)

 

[NTL2009]

... Gyroscopic precession took me awhile to wrap my head around.

I'm not a physicist, and until this moment I hadn't realized that I never really thought about the why/how of a gyroscope. I've only understood that it does what it does (like gravity).

I'm afraid I might hurt my brain if I tried, so I'll go on with life just admiring it. If one day, one of my grand-kids ask "Why", maybe I'll have him/her post here!

 

[collinsmark]

I'm not a physicist, and until this moment I hadn't realized that I never really thought about the why/how of a gyroscope. I've only understood that it does what it does (like gravity).

I'm afraid I might hurt my brain if I tried, so I'll go on with life just admiring it. If one day, one of my grand-kids ask "Why", maybe I'll have him/her post here!

Years ago I bought a book on Lagrangian mechanics specifically because I was interested in wrapping my head around gyroscopes. It didn't necessarily work, but it did get me to appreciate Lagrangian mechanics.

 

[sysprog]

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

You're right; I forgot about Chile, too . . .

 

[osilmag]

Time Dilation

 

[Swamp Thing]

A few years ago I read a book on prime numbers by Marcus du Sautoy. That's where I learned one of the most amazing ideas I've ever come across -- that the zeros of the Riemann Zeta Function contain information that you can use to list out all the prime numbers.

 

[sysprog]

A few years ago I read a book on prime numbers by Marcus du Sautoy. That's where I learned one of the most amazing ideas I've ever come across -- that the zeros of the Riemann Zeta Function contain information that you can use to list out all the prime numbers.

Those methods are even more inefficient than the sieve of Eratosthenes.

 

[Klystron]

Those methods are even more inefficient than the sieve of Eratosthenes.

True when one measures computation complexity. Teaching sieve techniques to students gives insight into the processes of multiplication and division using only an integer list, simple counting and elimination.

In most basic form the students take prime number 7, count seven places and eliminate 14, already marked as a multiple of 2, progress to 21, etc.; learning common factors, multiplication and division plus counting skills. Rather profound for a simple exercise.

A few years ago I read a book on prime numbers by Marcus du Sautoy. That's where I learned one of the most amazing ideas I've ever come across -- that the zeros of the Riemann Zeta Function contain information that you can use to list out all the prime numbers.

Good for you. I try to read books about mathematics whenever I encounter them. As history books need accurate maps, math books require formulas, functions and graphs for understanding. Last few years I have read two fascinating books on solving/proving Fermat's Last Theorem, two about the number zero, and several books about integers including an exhaustive history of numerical symbols.

 

[sysprog]

Your post #90 in this thread was in my view an especially nice post @Klystron.

 

[pleeb]

Years ago I bought a book on Lagrangian mechanics specifically because I was interested in wrapping my head around gyroscopes. It didn't necessarily work, but it did get me to appreciate Lagrangian mechanics.

Color doesn't exist. Only the totally color blind see the world as it really exists. Maybe that's why B&W photography is so fascinating.

 

[sysprog]

Years ago I bought a book on Lagrangian mechanics specifically because I was interested in wrapping my head around gyroscopes. It didn't necessarily work, but it did get me to appreciate Lagrangian mechanics.

Color doesn't exist. Only the totally color blind see the world as it really exists. Maybe that's why B&W photography is so fascinating.

In my non-colorblind view, this is nonsense; color is part of the visual information; that's why our retinas have cones, along with all those rods.

The point that @collinsmark raised regarding gyroscopes and Lagrangian mechanics has nothing to do with color or black-and-white vision. It was about the development of his intellectual vision by his being appreciative regarding something newly learned. That seems to me to be on-topic in this thread.

Your preference for 'noir et blanc' may be worthy of expression, but was not responsive to the post that you quoted.

 

[Merlin3189]

I can't remember exactly when I learned about shunt wound motors speeding to destruction when they lost their field current. May not have blown my mind, but I was pretty sceptical and took a lot of convincing.

I'm reminded by it's popping up in a thread today with someone else who can't believe it.

 

[pleeb]

In my non-colorblind view, this is nonsense; color is part of the visual information; that's why our retinas have cones, along with all those rods.

The point that @collinsmark raised regarding gyroscopes and Lagrangian mechanics has nothing to do with color or black-and-white vision. It was about the development of his intellectual vision by his being appreciative regarding something newly learned. That seems to me to be on-topic in this thread.

Your preference for 'noir et blanc' may be worthy of expression, but was not responsive to the post that you quoted.

You're quite correct, we have cones that give us the illusion of color. But nothing is actually colored. We simply interpret shades of gray as color. There is only light and the absence of light to various degrees. Are you a tetrachromat?

 

[BillTre]

You're quite correct, we have cones that give us the illusion of color. But nothing is actually colored. We simply interpret shades of gray as color. There is only light and the absence of light to various degrees.

Well, only grey scales of different frequencies (which are real), which the brain codes as different colors (to represent that reality).
The fact that natural selection has selected for these mechanisms gives credence to that reality as well as its significance to the organism's survival.

 

[sysprog]

You're quite correct, we have cones that give us the illusion of color. But nothing is actually colored. We simply interpret shades of gray as color. There is only light and the absence of light to various degrees. Are you a tetrachromat?

That's just plain wrong. @BillTre beat me to it, but color perception is not just grayscale being interpreted as color. For example, there's a real and measurable difference between infrared and ultraviolet light even though we can't see either of those. I imagine that you don't suppose that the differences between the frequencies of EMR from your lightbulb and those that cook your food in your microwave oven are merely grayscale variation illusions.

 

[Dr_Nate]

I like to show my students a visible spectrum and ask them to point out where the color white is. Then I show them that their minds are tricking themselves(?) by using a handheld spectroscope and looking at the emission lines from white fluorescent lights.

 

[Dr_Nate]

From walking my dog at night, I learned that I can tell from a distance whether the colour from xmas lights are made from two different LEDs or not, or whether a car's brake lights are incandescent or an LED. I think it has to do with persistence of vision and the pulse rate of LEDs.

I just flutter my eyes back and forth. For brake lights, I can see dots for the LEDs and a line of red for the incandescent. I never took apart someone's brake lights to truly confirm it, but I think it's true because I think I tell the difference normally. For the xmas lights I see dots of different colour that when added together would produce the colour I normally see.

 

[Keith_McClary]

I just flutter my eyes back and forth.

Jocelyn Bell Burnell, who co-discovered the first pulsar PSR B1919+21 in 1967, relates that in the late 1950s a woman viewed the Crab Nebula source at the University of Chicago's telescope, then open to the public, and noted that it appeared to be flashing. The astronomer she spoke to, Elliot Moore, disregarded the effect as scintillation, despite the woman's protestation that as a qualified pilot she understood scintillation and this was something else.

 

[Dr_Nate]

Jocelyn Bell Burnell, who co-discovered the first pulsar PSR B1919+21 in 1967, relates that in the late 1950s a woman viewed the Crab Nebula source at the University of Chicago's telescope, then open to the public, and noted that it appeared to be flashing. The astronomer she spoke to, Elliot Moore, disregarded the effect as scintillation, despite the woman's protestation that as a qualified pilot she understood scintillation and this was something else.
View attachment 260602

Thanks, I had never heard this anecdote before. I'll have to check out the Crab Nebula sometime.

 

[sysprog]

From walking my dog at night, I learned that I can tell from a distance whether the colour from xmas lights are made from two different LEDs or not, or whether a car's brake lights are incandescent or an LED. I think it has to do with persistence of vision and the pulse rate of LEDs.

I just flutter my eyes back and forth. For brake lights, I can see dots for the LEDs and a line of red for the incandescent. I never took apart someone's brake lights to truly confirmed it, but I think it's true because I think I tell the difference normally. For the xmas lights I see dots of different colour that when added together would produce the colour I normally see.

The fastest fast-twitch muscles in the body are those that you use for this purpose: "I just flutter my eyes back and forth" -- such fluttering eyes can move fast enough to cause perturbation from the normal frame rate of visual processing -- that can allow you distinguish visual inputs the differences between which might otherwise be not perceived.

 

[pleeb]

Well, only grey scales of different frequencies (which are real), which the brain codes as different colors (to represent that reality).
The fact that natural selection has selected for these mechanisms gives credence to that reality as well as its significance to the organism's survival.

Agreed; it's how sighted organisms distinguish dangers, poisons, threats, and mates. When I was young I could read only 5 of the 38 Ishihara color plates other than the two neutral standards. Now that I'm in my seventies I can't read any of them. I had no idea I was RG color blind until I was tested when I joined the army, the doctor falsified my record so I could enlist. It was the Vietnam era and they took anybody they could.

 

[Dr_Nate]

Agreed; it's how sighted organisms distinguish dangers, poisons, threats, and mates. When I was young I could read only 5 of the 38 Ishihara color plates other than the two neutral standards. Now that I'm in my seventies I can't read any of them. I had no idea I was RG color blind until I was tested when I joined the army, the doctor falsified my record so I could enlist. It was the Vietnam era and they took anybody they could.

I was told that colour blind snipers are less fooled by camouflage and are thus more valuable.

 

[pleeb]

I like to show my students a visible spectrum and ask them to point out where the color white is. Then I show them that their minds are tricking themselves(?) by using a handheld spectroscope and looking at the emission lines from white fluorescent lights.

But aren't they just seeing frequencies of what we call light? For instance; why is there no magenta in a rainbow? Birds, insects, and fish in the dark zone see in the UV spectrum but they still see colors although sunlight doesn't penetrate the depths. All heating coils produce the same hue of red. I'm no physicist but I can still do research and I've yet to find any claim of innate color on any object. Astrophysicists claim the sun is green, but I've never seen that. I grew up under a yellow sun, millennials have never seen a yellow sun due to the atmospheric changes in gas composition. Superman's powers came from our yellow sun, isn't it odd that his cultural influence waned when the sun turned white? Is our atmosphere filled with kryptonite now? LMAO!