Gravity

Surely you’re familiar with the gravitas of gravity. I, for one, would like to think we’re all a little smarter than Newton, because we don’t need an apple falling on us (according to the myth) to observe the immediate affect of gravity.

            Gravity is one of the fundamental forces of the universe (the others being the strong and weak nuclear forces, and the electromagnetic force). What’s ironic about gravity is that it was the first of those four forces to be discovered, and compared to the other forces; we don’t really understand it.

            Fundamental forces came into existence shortly after the big bang. After the expansion of the universe, all matter was scatter throughout the universe, and the universe would have remained a void of gasses, were it not for gravity. Gravity exerts a force on two objects. You and the earth for instance, it is this force that keeps you from falling off the Earth. You and the computer you’re reading this on exert a gravitational force on each other, but it is so small that you’d barely notice. The same is true for all matter. Eventually gravity started to pull the early universe together. Several billion years later, those gasses that made up the early universe formed the stars and planets and whatnot.

Newton managed to quantify this phenomenon into the equation F=(G(m1m2))/(r^2) .I can’t use an equation writer in the blog. Meaning that the force gravity exerts on an object (F), is equal to the universal gravitational constant (G), times the two masses of said objects (m1 and 2), over the distance between them squared (r). That being said, I leave you with a tip that my high school physics teacher told our class. The day before our prom, when some of us were nervous (Ok, it was mainly I that was nervous), our teacher told us a way to appear more attractive to our respective dates. He said we should put weights in our pockets to increase our gravitational attractiveness. Mathematically, his logic was sound but I was skeptical as I entered prom with 20kg of metal in my pockets. But, on the whole, the night went fairly well. But I digress.

Sharks With Lasers

This is the hastily made laser shark image that my friend made for me hours before my physics final. I hope you enjoy it.

Lasers

I always liked lasers. Ever since I since I first saw an Austin Powers movie, I had always wanted “sharks with frikin’ laser beams attached to their foreheads”. Apparently, that was not too much to frikin’ ask, as my friend was kind enough to photo-shop me a picture of one. But I digress.

            How a laser works (in classical theory) is a more serious matter entirely. The general principle is to get a collection of atoms and give them enough energy to get them to an “excited” state. Once the atoms are excited, the atoms will eventually lose energy and emit a photon. Upon a photon being emitted, other atoms follow suit and emit other photons because atoms want to be like other atoms. These photons are in exactly the same phase, and exactly the same wavelength. This phenomenon, results in the coherent, collimated beam. Instead of allowing all the photons to escape, a laser is constructed in such a way as to have all the photons bounce back and forth between mirrors, generating even more photons; and as long as the active gain medium has energy it’ll keep on generating photons forever. Once all the photons are bouncing between the two mirrors, a slight gap in between them is opened up, generally done naturally with a 99% reflective mirror, and the result is a coherent, collimated beam of light. A laser beam.

            Mathematically speaking, a laser operates on the principles described above, resulting in the equation ΔE=hν. E in this equation is the difference in energy of the atoms, h is plank’s constant, and ν is the frequency of the photon. This equation was derived from Einstein’s insights on the Photoelectric Effect (which we can talk about later), which won him the Nobel Prize in 1921.

            The really cool thing though is with minor differences to the construction, (such as the original collection of atoms, or the energy supply) lasers range from a bar-code scanner to a mighty weapon of fiery death, or something that is actually practical in our lives.

The More You Know

I had a math teacher in middle school that would read to us every Friday, and he would read a list of interesting facts that his friend would email him. When he’d finish reading, he’d have this little thing that he’d do. I can only assume that our teacher was under impression that Reading Rainbow’s classic “the more you know” tagline was some kind of song that nobody knew the words to. So when he’d finish his list of facts, he’d do a little jig and sing an improvised tune: “the more you know, the less you don’t…”, or something along those lines.

Being 11 at the time (and admittedly immature for my age) I dismissed this wisdom as the ranting of some old fool trying desperately to teach us something interesting, even if it wasn’t math. Years later I smartened up and realized along the way the important of knowing something. Then it occurred that I was taught the names of birds, and why police are called cops, and innumerable riddles. And most importantly I realized that I knew absolutely nothing about the point that he was trying to make.

            Around that time I started to pursue scientific endeavors and people would say to me “Christ, you’re a physics major? Why’d you do that to yourself?” and my answer was very simple. I told them that I was looking to find out more about the world. To me it’s very exciting to pursue questions to unlock the mysteries of nature. To me, it’s far more interesting to live a life looking for answers than to accept certain falsities, there’s a joy that comes in finding things out. And to others, it may be exciting to ponder why we’re here, or how we got here, etcetera. But what my teacher taught me is that any knowledge, no matter how useful without any interest in it is meaningless.

            A while ago, my friend talked me into doing a blog where I’d talk about interesting things. And I’ll diversify the subject of these things so that you will hopefully come across something that you think is meaningful. So without any further gilding the lily, and with no more adieus, I present to you, the general knowledge blog that is: The More You Know.