Most chemicals have the 3 classical phases, but with the possible exception of water, none are as fun as liquid nitrogen (LN). Sure, other gasses are chilled to liquids, but none are as common, cheap (like the price of milk), or easy to work with.
At a chilly 77K (−196 °C; −321 °F) it is the quickest way to play with cryogenics or just freeze things instantly.
Who does not love to see a drop of liquid nitrogen hover above the ground, vibrating as if it is about to rip itself apart. And notice, it doesn't touch the ground so much, as hover above it. The gas that comes from boiling from being in contact with something warm, that gas expands so much that it lifts the drop up just a bit.
Of course, that is not say it isn't good at freezing whatever it does come in contact with. It is fantastically good at that because it is so much colder than anything else we commonly come in contact with - cold enough to freeze something brittle enough to shatter, like a banana or a rose.
Of course, liquid nitrogen does have its uses beyond goofing off!
It is the best way to freeze something really solid or to preserve it indefinitely. If you need to work with something very cold or exceptionally dry.... this is the way to go. And it is standard issue for dealing with high temperature superconductors, at least until we have room-temperature ones. It is even good for freezing your head, Futurama-style until we can cure whatever ails you!
Sunday, February 13, 2011
e
e! or e=2.71828182845904523536028747135266249775724709369995... for the rest of us.
There are a few numbers out there in the universe that keep showing up in place after place, that suggests a greater significance. One of those numbers is e. It isn't like one of those integers we see everyday, that we can write out exactly. That is because e is an irrational number - there is no way we could ever write a decimal or fraction for it, out of integers. It just can't be done. It is like it is forever hiding between the cracks, and like Bigfoot, we can never get a really good look at it. Like pi, any decimal for it, would continue on forever and ever, never being perfectly expressed.
Further, e is a transcendental number. No, that does not mean it likes a lot of Ralph Waldo Emerson, though he is pretty awesome himself. It does mean that this is not a number you can express or solve for with algebra. No matter how many (finite) square roots or cube roots or complicated polynomials you have, you just can't get to it with just algebra. It requires infinity and limits. That makes it part of a class of numbers that is normally invisible and unthought of, even if there are an infinite number just between 0 and 1.
But just what can this number do? It is behind exponential growth, and decay. It is the basis of the natural logarithm. The integral and derivative of an exponential is itself. While the integral of the natural log is often necessary even for basic integrals.
e is what we can use to construct any or all of trigonometric functions, even just simple sine waves. It is necessary to calculate interest for banks or other financial institutions. Yes, true, there are ways around it, but that is just what they are, ugly kludges to get around it.
If we had to rebuild civilization with only 4 numbers, e would have to be one of them. It is that important.... and we can't even write it!
There are a few numbers out there in the universe that keep showing up in place after place, that suggests a greater significance. One of those numbers is e. It isn't like one of those integers we see everyday, that we can write out exactly. That is because e is an irrational number - there is no way we could ever write a decimal or fraction for it, out of integers. It just can't be done. It is like it is forever hiding between the cracks, and like Bigfoot, we can never get a really good look at it. Like pi, any decimal for it, would continue on forever and ever, never being perfectly expressed.
Further, e is a transcendental number. No, that does not mean it likes a lot of Ralph Waldo Emerson, though he is pretty awesome himself. It does mean that this is not a number you can express or solve for with algebra. No matter how many (finite) square roots or cube roots or complicated polynomials you have, you just can't get to it with just algebra. It requires infinity and limits. That makes it part of a class of numbers that is normally invisible and unthought of, even if there are an infinite number just between 0 and 1.
But just what can this number do? It is behind exponential growth, and decay. It is the basis of the natural logarithm. The integral and derivative of an exponential is itself. While the integral of the natural log is often necessary even for basic integrals.
e is what we can use to construct any or all of trigonometric functions, even just simple sine waves. It is necessary to calculate interest for banks or other financial institutions. Yes, true, there are ways around it, but that is just what they are, ugly kludges to get around it.
If we had to rebuild civilization with only 4 numbers, e would have to be one of them. It is that important.... and we can't even write it!
Awesome things
One of the best blogs on the planet, as far as I am concerned, is 1000 Awesome Things. It is just a simple reminder of the things in this life that are awesome and wonderful, no matter what else is going wrong. While I have no intention of capturing that lightening in a bottle, that that blog was, I do hope to express a bit of what he expresses in this blog, or even his TED talk, if you are interested.
And while imitation might be the sincerest praise, I have no intention of covering the exact same ground he has already covered better than me. Instead, I am going to revel in nerd-dom, things science, and mathematical, technical and perhaps even obscure. I am simply going to blog about things I love (or whatever guest blogger loves) and just have fun with it, because no matter what problems we have in life, or are reported on the news, life really is awesome.
David Foster,
Nerd in Chief
And while imitation might be the sincerest praise, I have no intention of covering the exact same ground he has already covered better than me. Instead, I am going to revel in nerd-dom, things science, and mathematical, technical and perhaps even obscure. I am simply going to blog about things I love (or whatever guest blogger loves) and just have fun with it, because no matter what problems we have in life, or are reported on the news, life really is awesome.
David Foster,
Nerd in Chief
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