Damn cool things you've learned...

Site Notices

[ARCHIVED THREAD] - Damn cool things you've learned... (Page 1 of 2)

Posted: 11/12/2011 6:27:07 PM EDT

Let's get a thread going about things that caused aha moments for you, or things that gave you an appreciation for the area you were studying.

Something I found damn interesting was "Maxwell's" equation:

Where C is the speed of light and the two terms under the radical are the electric and magnetic constants. I found it interesting because it showed me how there might be a fundamental connection between everything. I didn't know that the speed of light could be defined as such.

I've got another one, that I'll share when this thread picks up some steam.

Posted: 11/12/2011 8:27:15 PM EDT

[#1]

Practical applications of Maxwell's equations led to, essentially, understanding of radio waves in what we now call the microwave region and beyond. It touches virtually every wireless electronic device that we use in our lives.

Proper understanding of the practical application of Maxwell's equations allows RF circuit designers to literally draw out every component

except for active components, on a substrate, and have it work according to theory. All passive RF components (resistors, capacitors,

inductors, filter networks, tank circuits, etc) can simply be drawn on a PC board in conductive metallic patterns. This gets more practical

as the operating frequencies increase.

Now, if you can create a formula that ties gravitation, the Strong force, the electroweak force, and electromagnetism together in one neat package, you have achieved one of the Holy Grails: A Grand Unified Theory.

Unified Field theory says that all forces are connected. But no mathematical model has yet been developed that supports that theory.

Not one that survived mathematical analysis, that is.
CJ

Posted: 11/13/2011 9:34:45 PM EDT

[#2]

Everything about neutron stars and pulsars. I find it fascinating that something nearly double the size of our sun could be compacted far enough to fit in Manhattan. A sugar cube volume of a neutron star has a mass of several billion tons.

Posted: 11/14/2011 3:35:18 PM EDT

[#3]

The central limit theorem and related topics were big ones for me.

Posted: 11/15/2011 5:47:03 AM EDT

[#4]

Euler's Formula

Posted: 11/16/2011 12:11:00 PM EDT

[#5]

No so much learned as realized.

The one real, "Aha" moment in my life was when I was about 8 or 9 and understood how truly small we are with respect to the universe. It was quite emotional for me.

Posted: 11/21/2011 6:13:20 PM EDT

[#6]

That magnets are the only thing that hold us up and prevent us from walking through walls. Well maybe not magnets but the electromagnetic force of atoms.

MAGNETS!!!!

Posted: 11/21/2011 6:55:33 PM EDT

[#7]

A moebius strip has only one surface and one boundary.

If that ain't cool I don't know what is.

Posted: 11/21/2011 7:02:34 PM EDT

[#8]

If a single cubic centimeter of the sun's core were to suddenly be transported to the surface of the earth, the energy radiated from it would be lethal for a distance of several miles. It would burn, vaporize, or melt down everything around it for a distance of several thousand yards.

I confess, I do find that hard to wrap my head around.

Posted: 11/21/2011 7:16:25 PM EDT

[#9]

You guys speak awesome Chinese.

Posted: 11/21/2011 8:04:45 PM EDT

[#10]

In every known example of real world classical physics, all magnetism is based on a dipolar model: For every north magnetic pole, there is a complementary south magnetic pole.
But, quantum mechanical theory allows for the existence of magnetic MONOPOLES, which could exist separately and independently of the complementary pole.
Classical magnetics operate on the inverse cube law, where the strength of a magnetic field degrades with distance, that falloff being

the function of the inverse cube law. The strength of a magnetic field at a specific poiint is proportional to the cube root of the distance between the magnet and the point at which the measurement is taken.

All other known forces operate on the inverse square law.
It is believed that it is the dipolar nature of classical magnetism that dictates that magnetism must operate according to the inverse cube law.
But, if magnetism were to exist without the dipolar limitation, that is, as per the theorized magnetic monopoles that are suggested in quantum mechanics, then monopolar magnets would operate on the square root law instead of the inverse cube law.

The implications for a form of magnetism that operates on the inverse square law are considerable. It could lead to new sources of energy

and new ways to control energy and matter.
What's perhaps most interesting about this theory is that it is implied in conventional electromagnetic theory. It has long been believed that electromagnetic energy (Radio waves, and as the frequency increases, microwaves, X-rays, IR light, visible light, UV light, gamma rays, and ultimately, cosmic rays) consists of electric and magnetic fields intertwined and rotating around each other 90 degrees out of phase with each other. But electromagnetic energy works on the inverse square law. This implies that the electric AND magnetic components of the EM wave must BOTH operate on the inverse square law, although classical magnetics operate on the inverse cube law.

Posted: 11/22/2011 6:16:02 AM EDT

[#11]

I never thought about magnetism following the inverse cube law, that's cool to know.

This paper gives a (relatively) pretty simple explanation of why dipoles follow the inverse cube rather than inverse square:
http://blazelabs.com/inversecubelaw.pdf

Posted: 11/26/2011 2:47:05 PM EDT

[#12]

One cubic centimeter (a sugar cube) of neutron star material placed on the north pole would weigh so much, it would literally fall through the planet like a bullet. Further, if you dropped a baseball from the height of 1 meter onto the surface of a neutron star, that baseball would reach a speed of 4,300,000 MPH before impacting the surface.

One table spoon of antimatter has enough energy to send a manned mission to Pluto in a matter of a few months. The cost of this anti-matter would be roughly 6 Trillion USD. if created today using processes we currently employ.

Posted: 11/26/2011 7:54:44 PM EDT

[#13]

Quoted:
One cubic centimeter (a sugar cube) of neutron star material placed on the north pole would weigh so much, it would literally fall through the planet like a bullet. Further, if you dropped a baseball from the height of 1 meter onto the surface of a neutron star, that baseball would reach a speed of 4,300,000 MPH before impacting the surface.

One table spoon of antimatter has enough energy to send a manned mission to Pluto in a matter of a few months. The cost of this anti-matter would be roughly 6 Trillion USD. if created today using processes we currently employ.

Whoa, that's cool... I never thought about that. According to wikipedia, positrons are about $25B per gram. That's a lot cheaper than I thought. Funny thing: according to that estimate, it is almost exactly 1 dollar per watt hour of antimatter.

($25B)/(1g)

($25B)/(9*10^13J)

($1B)/(3.6*10^12J)

($1B)/(1GWh)

$1/Wh

If I calculated correctly, that's about 25,000 times more expensive than natural gas.
I thought it would be on the scale of millions of times more expensive.

Posted: 11/26/2011 8:10:13 PM EDT

[#14]

Sometimes, I use a toothpick to get the dirt out from under my toenails.

Posted: 11/26/2011 8:13:20 PM EDT

[#15]

Quoted:

Quoted:

One cubic centimeter (a sugar cube) of neutron star material placed on the north pole would weigh so much, it would literally fall through the planet like a bullet. Further, if you dropped a baseball from the height of 1 meter onto the surface of a neutron star, that baseball would reach a speed of 4,300,000 MPH before impacting the surface.

One table spoon of antimatter has enough energy to send a manned mission to Pluto in a matter of a few months. The cost of this anti-matter would be roughly 6 Trillion USD. if created today using processes we currently employ.

Whoa, that's cool... I never thought about that. According to wikipedia, positrons are about $25B per gram. That's a lot cheaper than I thought. Funny thing: according to that estimate, it is almost exactly 1 dollar per watt hour of antimatter.

($25B)/(1g)

($25B)/(9*10^13J)

($1B)/(3.6*10^12J)

($1B)/(1GWh)

$1/Wh

If I calculated correctly, that's about 25,000 times more expensive than natural gas.

I thought it would be on the scale of millions of times more expensive.

Huh I didn't know it had gotten so 'cheap'. My info was about 2y old.

Posted: 11/27/2011 6:26:09 AM EDT

[#16]

Quoted:
Sometimes, I use a toothpick to get the dirt out from under my toenails.

That's OK. Some people prefer to use their teeth to get the toejam.

Posted: 11/30/2011 10:24:43 AM EDT

[#17]

From the point of energy needed, once you're in orbit, you're halfway to anywhere in the Solar System.

Posted: 12/12/2011 7:06:03 AM EDT

[#18]

It was a long time ago but I was enormously pleased to learn that the way in which to indicate the precision of a measurement in quick and dirty (and useful) fashion had already been figured out.

Significant Figures!
http://en.wikipedia.org/wiki/Significant_figures

Some time thereafter I was crestfallen to learn that most people, even educated people, can not take a halfway useful measurement to save their lives.
My kids' growth charts at the pediatrician's office look like some wierd amplifying wave -up and down, up and down but with a generally upward trend.

Posted: 12/13/2011 5:42:11 PM EDT

[#19]

Quoted:
It was a long time ago but I was enormously pleased to learn that the way in which to indicate the precision of a measurement in quick and dirty (and useful) fashion had already been figured out.

Significant Figures!
http://en.wikipedia.org/wiki/Significant_figures

Some time thereafter I was crestfallen to learn that most people, even educated people, can not take a halfway useful measurement to save their lives.
My kids' growth charts at the pediatrician's office look like some wierd amplifying wave -up and down, up and down but with a generally upward trend.

I sat through hours of chemistry class with a teacher who tried to explain the notion of significant figures to the students. The fail boat took many passengers those days. It was like a two for one sale.

Personally, I was intrigued by periodicity. Exploration of that concept has led to an impressive store of knowledge.

Posted: 12/21/2011 10:37:50 PM EDT

[#20]

Jupiter is so massive that the barycenter for it and the sun actually is 7% of the radius of the sun outside of the sun.

Posted: 12/26/2011 12:15:34 PM EDT

[#21]

drinking 10 or more [_]] of coffee over a months time, will give a person a pot belly...

Posted: 1/2/2012 9:35:59 PM EDT

[#22]

The other "really cool" thing I learned was Jacobians, or rather the Jacobian determinant. It's a method used when you change variables, while your evaluating a multiple integral over a region within the domain. Basically, it tremendously simplifies "complex" multiple integrals. Sure the problems in my book sometimes took my 3 pages to do

, but for some reason, it had a significant impact within me. I saw it as something extremely beautiful, and I truly admired it, like one would admire fine art, an epic film, et cetera; it just about brought a tear to my eye.

Posted: 1/17/2012 6:46:15 PM EDT

[#23]

Infinity.

It's mind blowing.

Posted: 4/28/2012 5:44:24 PM EDT

[#24]

I was once trying to figure out the amount of water in a cubic kilometer of cloud.

I stumbled across the fact that the density of water vapor is less than the density of dry air.

I had one of those aha moments when it clicked that thats why low pressure occurs under clouds.

A cloud "weighs" less than the surrounding air.

Posted: 4/29/2012 4:34:02 AM EDT

[#25]

Quoted:

Sometimes, I use a toothpick to get the dirt out from under my toenails.

That works on your eyes, too. Try it.

Posted: 4/29/2012 7:52:20 AM EDT

[#26]

Thought controls matter.

It's absolute truth.

Every time you move your body, it moves in reaction to neural impulses that were triggered by thoughts.

Your body is matter.

Thus, thought controls matter. Simple and verifiable truth.

Now, the hard part is extending your DIRECT control of matter beyond your body. Figure that out and it'll be epic.

CJ

Posted: 4/30/2012 5:54:46 AM EDT

[#27]

Quoted:
Every time you move your body, it moves in reaction to neural impulses that were triggered by thoughts.
Your body is matter.

Thus, thought controls matter. Simple and verifiable truth.

This is why I went into Neurology (Not to figure out how to move matter directly with my mind, though that would be pretty amazing).

Posted: 4/30/2012 3:49:18 PM EDT

[#28]

Quoted:
Thought controls matter.

It's absolute truth.

Every time you move your body, it moves in reaction to neural impulses that were triggered by thoughts.

Your body is matter.

Thus, thought controls matter. Simple and verifiable truth.

Now, the hard part is extending your DIRECT control of matter beyond your body. Figure that out and it'll be epic.

CJ

What is a thought?

Posted: 4/30/2012 4:18:26 PM EDT

[#29]

Quoted:

Thought controls matter.

It's absolute truth.

Every time you move your body, it moves in reaction to neural impulses that were triggered by thoughts.

Your body is matter.

Thus, thought controls matter. Simple and verifiable truth.

Now, the hard part is extending your DIRECT control of matter beyond your body. Figure that out and it'll be epic.

CJ

Can't prove that. In fact you might not even exist.

Posted: 5/2/2012 5:58:56 PM EDT

[#30]

Quoted:
Thought controls matter.

It's absolute truth.

Every time you move your body, it moves in reaction to neural impulses that were triggered by thoughts.

Your body is matter.

Thus, thought controls matter. Simple and verifiable truth.

Now, the hard part is extending your DIRECT control of matter beyond your body. Figure that out and it'll be epic.

CJ

What's interesting and kind of scary (although controversial), is that it's been studied and supposedly proven that your psychical actions are determined before you think them, in that your thoughts are actually formed based on the decision you're brain is making, not the other way around. Max Brook's book on 13 Things that Don't Make Sense has a chapter on this and he describes the experiments that have shown this.

Basically, decisions are being made and we're agreeing to them but with the illusion our thoughts are deciding them. Read the book, he points out the studies and a machine that proves it, basically uses electronic waves to stimulate parts of the brain that make your limbs move and as he (the author) describes it, when it happened he "thought" about doing that movement before it happened.

Posted: 5/17/2012 10:28:07 AM EDT

[#31]

Probably one of the most badass threads I've ever read on ARFCOM...

Even if some of it is waaaay over my head.

Posted: 5/21/2012 9:35:26 PM EDT

[#32]

Pretty much everything in Statistical Thermodynamics. When I learned about Flory-Huggins Theory, and how the # of small monomers in a polymer chain set the colligative properties, which means you should use volume fractions for polymer solutions, I thoguht that was pretty neat.

Oh, and the classic entropy quiz of finding the temperature change from stretching a rubber band!

Posted: 9/24/2012 6:47:24 PM EDT

[#33]

99% of every atom is space, thus everything is 99% absolutely nothing.

"The Dancing Wu Li Masters", best book ever.

Posted: 10/6/2012 8:19:04 AM EDT

[#34]

Quoted:

Quoted:
Thought controls matter.

It's absolute truth.

Every time you move your body, it moves in reaction to neural impulses that were triggered by thoughts.

Your body is matter.

Thus, thought controls matter. Simple and verifiable truth.

Now, the hard part is extending your DIRECT control of matter beyond your body. Figure that out and it'll be epic.

CJ

What's interesting and kind of scary (although controversial), is that it's been studied and supposedly proven that your psychical actions are determined before you think them, in that your thoughts are actually formed based on the decision you're brain is making, not the other way around. Max Brook's book on 13 Things that Don't Make Sense has a chapter on this and he describes the experiments that have shown this.

Basically, decisions are being made and we're agreeing to them but with the illusion our thoughts are deciding them. Read the book, he points out the studies and a machine that proves it, basically uses electronic waves to stimulate parts of the brain that make your limbs move and as he (the author) describes it, when it happened he "thought" about doing that movement before it happened.

+1. Imagine your brain-body connection as a computer/operating system display. LOTS of things going on behind the scenes that you never see or think about, all you see are the results of that work...

Posted: 10/6/2012 7:50:48 PM EDT

[#35]

Magnetism: A very useful item for a knifemaker who does back yard hardening, tempering and so on. When heating up a blade prior to water, brine, or oil quench, the critical temperature is the temperature where the blade will no longer attract or hold a magnet. Once the blade stops sticking to a magnet, it is at the correct temperature to quench it.

Posted: 10/9/2012 9:32:51 AM EDT

[#36]

Quoted:
Magnetism: A very useful item for a knifemaker who does back yard hardening, tempering and so on. When heating up a blade prior to water, brine, or oil quench, the critical temperature is the temperature where the blade will no longer attract or hold a magnet. Once the blade stops sticking to a magnet, it is at the correct temperature to quench it.

When molecular structure changes to face-centered cubic (austenite). Quenching gives you martensite.

Posted: 10/12/2012 5:44:48 PM EDT

[#37]

Quoted:

Quoted:
Thought controls matter.

It's absolute truth.

Every time you move your body, it moves in reaction to neural impulses that were triggered by thoughts.

Your body is matter.

Thus, thought controls matter. Simple and verifiable truth.

Now, the hard part is extending your DIRECT control of matter beyond your body. Figure that out and it'll be epic.

CJ

What's interesting and kind of scary (although controversial), is that it's been studied and supposedly proven that your psychical actions are determined before you think them, in that your thoughts are actually formed based on the decision you're brain is making, not the other way around. Max Brook's book on 13 Things that Don't Make Sense has a chapter on this and he describes the experiments that have shown this.

Basically, decisions are being made and we're agreeing to them but with the illusion our thoughts are deciding them. Read the book, he points out the studies and a machine that proves it, basically uses electronic waves to stimulate parts of the brain that make your limbs move and as he (the author) describes it, when it happened he "thought" about doing that movement before it happened.

Didn't somebody have a series of MRI images that demonstrated this?

Posted: 10/13/2012 5:44:37 PM EDT

[#38]

I just had an "aha" moment relating to asymptotic properties of OLS estimators.

I was staring at my proofs based econometric homework all week, trying to understand notes and failing, the book made no sense, and then "click". Yesterday I started feverishly writing and today I finished up the proofs and did the MATLAB. DONE.

Most of those moments are not too terribly interesting to the outside observer, but they keep me interested and make me feel like I accomplished something.

I'm hoping one day I'll have a research job and my "aha!" moment will mean a Nobel prize, but I won't get my hopes up.

Posted: 10/31/2012 5:34:26 PM EDT

[#39]

Trig. Was cool when I first learned it.

Posted: 10/31/2012 5:42:04 PM EDT

[#40]

Back in the late 60's my Dad had a remote controlled T.V. You push the button, and the channel knob would turn.

Do you know what happened if you held the knob and pushed the button?

You got your ass beat!!!!

Posted: 11/1/2012 9:30:24 AM EDT

[#41]

Gradients and calculus in general were really interesting. Differential equations were fun too, especially phase planes and eigenvectors.

Something really interesting things though are some of the equations that get used in petrophysics. Props to the guys who spend time in the lab coming up with that stuff.

Also, shale porosity and morphology... while it may not be an ah ha just yet, the notion of measuring something that essentially did not/does not exist, and then using that knowledge to find and extract gas is awesome.

Posted: 11/1/2012 9:48:23 AM EDT

[#42]

I find it really cool, that we have figured out that many elements come directly from an exploded supernova.

TXL

Posted: 11/2/2012 11:37:41 AM EDT

[#43]

Quoted:
Let's get a thread going about things that caused aha moments for you, or things that gave you an appreciation for the area you were studying.

Something I found damn interesting was "Maxwell's" equation:
http://upload.wikimedia.org/wikipedia/en/math/d/8/e/d8edf943fec3f1b74e9c729c13724dec.png
Where C is the speed of light and the two terms under the radical are the electric and magnetic constants. I found it interesting because it showed me how there might be a fundamental connection between everything. I didn't know that the speed of light could be defined as such.

I've got another one, that I'll share when this thread picks up some steam.

Another cool thing about Maxwell's equations is that they are relativistically correct, even though they were published about 40 years before Einstein's first paper. Unlike Newton's laws of motion, Maxwell's equations didn't require any changes to agree with relativity. The idea that Maxwell's equations are universal was Einstein's main motivation in developing relativity.

Posted: 1/24/2013 3:26:18 PM EDT

[#44]

On my way to a physics degree, my favorite "a-ha" moment was when I finally wrapped my head completely around relativity. Since then, every time I hear someone say the equation is E=mc^2 I want to scream "WRONG! That's only half the equation, without the rest it makes NO sense!" Ah well.....

My favorite "factoid" is the "gravity train:"

If I bored a hole, directly through the center of the Earth, and dropped a payload in the hole, with ZERO friction, the payload will arrive at the opposite altitude in 42 minutes. Well, I can't go through the center for obvious reasons, however...

Any two points connected by a straight line, perpendicular to the center of the Earth, calculates to the exact same time constraints when using gravity as the only power source and maintaining ZERO friction.

So.... New York to L.A.? 42 minutes. London to Beijing? 42 minutes. My house to the grocery store? 42 minutes. OK, London to Beijing would break through the crust, but you get the idea.

Posted: 1/24/2013 4:45:25 PM EDT

[#45]

Quoted:
Thought controls matter.

It's absolute truth.
Every time you move your body, it moves in reaction to neural impulses that were triggered by thoughts.
Your body is matter.
Thus, thought controls matter. Simple and verifiable truth.
Now, the hard part is extending your DIRECT control of matter beyond your body. Figure that out and it'll be epic.
CJ

That is all to the good, but "thoughts" are the products of electro-chemical interactions in the "test tubes" of your brain, i.e. they are the byproducts of matter.

Can a thought be formed or exist outside of a human mind or brain?

Posted: 2/8/2013 4:03:32 PM EDT

[#46]

My first post on ARFCOM - cant resist the geek stuff.

Reading about astronomy, the universe, (and looking at the pictures) and modern physics is cool. Even though i cant wrap my head around some of the weirder stuff these days.
Also the planetary probes we have sent out over the years, with some absolutely stunning NASA images from the Mars Science Lab.

I took a EE degree in the 70's and was wowed by Maxwells equations (govern energy propagation and fields) but never used them in my EE job.

Strangely, I still remember a few things that popped up, like this:
A shape generated from a simple equation that has calculable finite volume, but infinite surface area.
Thus you can fill it with paint, but you can never paint it.
Gabriels horn

Posted: 2/8/2013 4:53:47 PM EDT

[#47]

Quoted:

Quoted:

Thought controls matter.

It's absolute truth.

Every time you move your body, it moves in reaction to neural impulses that were triggered by thoughts.

Your body is matter.

Thus, thought controls matter. Simple and verifiable truth.

Now, the hard part is extending your DIRECT control of matter beyond your body. Figure that out and it'll be epic.

CJ

That is all to the good, but "thoughts" are the products of electro-chemical interactions in the "test tubes" of your brain, i.e. they are the byproducts of matter.

Can a thought be formed or exist outside of a human mind or brain?

Ever talked to someone you trust implicitly who had a near death experience?

I believe that thought can occur outside of the limits of a functioning brain and neuron network.

Posted: 2/8/2013 5:06:07 PM EDT

[#48]

For me it is that the more I learn, the more I realize we don't know. Current technology/engineering/science or what ever you call it is often based on ideal cases and application is often full of assumptions. While the assumptions are often valid they are never 100%. The reason behind most assumptions is there is no easy way to solve the problem analytically or numerically. So what do we really know? As most of what we think we know is based on some smart fella making an observation, applying some math he knows to it, and then follows up with assumptions. We really don't have a choice to tackle issues otherwise, and it works for the most part.

Something I find disturbing is the lack of a basic understanding of science for a large portion of the world. I don't know how many arguments I've gotten into about perpetual motion, or how you can't create something from nothing. When I try to explain with what is know about science I am told that I'm just supporting the gov't, big oil, the aliens or who knows what and the science I am trying to explain is my opinion. Sorry about the rant.....