Albert Einstein

b. 14 March 1879
d. 18 April 1955

I will not attempt to explain the contributions that Einstein made to physics in this little biographical sketch. For one thing, I don't understand the majority of what he wrote. For another, I would like to focus instead on his character and life as an interesting and important glimpse into his mind.

Though born in Germany, Einstein did not die a citizen thereof. In fact, he renounced his citizenship for the small price of three German marks and became a naturalized citizen of Switzerland five years later, paying twenty francs. The price of his citizenship notwithstanding, national affiliation was extremely important to him. He both detested and rejected the nationalistic and militaristic government of Germany and embraced the peaceful attitude of Switzerland. To the end of his life, Einstein remained a pacifist, conceding only that military force should be used to combat institutions which "pursue the destruction of life as an end in itself."

He further hated the German educational system which consisted of rote studies and a particular deference to authority. Though it is often stated that Einstein was a poor student, the more accurate statement is that he did not thrive in the stifling classroom being forced into a discipline in which he was not naturally engaged.

In fact, after being rejected from the Zürich Polytechnic Institute, Einstein spent a year in Aarau, Switzerland where he succeeded in a flexible education with a casual teacher who allowed Einstein a liberty of thought that was necessary for his future discoveries. About the necessity of such liberty he wrote that "it is, in fact, nothing short of a miracle that the modern methods of instruction have not yet entirely strangled the holy curiosity of inquiry; for this delicate little plant, aside from stimulation, stands mainly in need of freedom."

His ability to thrive in a self-determined schedule accounts for his eventual success at the Zürich Poly (having been accepted after a second application). He largely ignored his classes, showing up only for the exams which he passed due to the copious notes of his studious friend Marcel Grossmann. After graduation, Einstein found his desired freedom in an unlikely place. He was refused a position as an assistant at the Zürich Poly (perhaps due to some underhanded manipulation by a professor who disliked him) and accepted a job at the Bern Patent Office in 1902 where he was assigned to read and approve patent applications. The job proved useful, however, in that it was not difficult. He spent his spare time theorizing and conducting gedankenexperiemnts (literally: thought experiments) which are designed to prove a principle without actually having to conduct the experiment physically.

Einstein was so successful in this free environment that he published three papers in the 1905 edition of Annalen der Physik each on a different subject. The first, for which he eventually won a Nobel Prize, explained the connection between the photoelectric effect and quantum mechanics. The second paper treated molecular behavior. The third was his inspired explanation of relativity which gave rise to spacetime. To restate for emphasis, during seven years working as a patent clerk, Einstein published—among others—a Nobel Prize winning paper and the foundational paper for the most (culturally) famous development in science.

Inevitably, Einstein was noticed by the scientific community. He subsequently worked in Berlin at the Prussian Ministry of Education with Max Planck (a great scientist in his own right who wrote of him, "All in all, one can say that among the great problems, so abundant in modern physics, there is hardly one to which Einstein has not brought some outstanding contributions.") and at Princeton. But the former was overrun with Nazis and the latter boring yet peaceful enough for him to, as he wrote to the Queen of Belgium with whom he had apparently frequent correspondence, "create for [himself] an atmosphere conducive to study . . . free from distraction."

He was married twice. And though the first marriage failed due probably to a lack of attention to his family in favor of scientific pursuits, he remained supportive of his first wife and children, sending them his prize money after receiving the Nobel Prize in 1921 (two years after his marriage to his second wife, Elsa). Elsa was described as "gentle, warm, motherly, and prototypically bourgeoisie." She enjoyed the fame of her husband's publications and tolerated his absence and distractions.

Notably, Einstein's genius was not happened upon, nor was it easy to obtain. Though none can deny his natural ability in theoretical physics, the secret to his success was work. Though some concepts eventually unfolded before him, others such as his Unified Field Theory never came to fruition. Yet he never ceased his work nor became discouraged. "After all," he wrote, "to despair makes even less sense than to strive for an unattainable goal." Three months before he died, Abraham Pais, one of Einstein's biographers, visited him at home and spoke with him for a half an hour. Einstein had been at his desk working when Pais entered and before Pais was able to leave (a journey of approximately five steps), Einstein was hunched over his desk "oblivious to his surroundings" yet again.

Now, fifty years after his death, Einstein remains one of the most well known names in scientific and even in common history. His developments in theoretical physics, along with those of Planck, de Broglie, Schrödinger and others, laid the groundwork for most if not all of the scientific developments that came thereafter.

Quantum Tunneling

Classical Mechanics

Quantum tunneling allows us a fascinating glimpse at the workings of the subatomic world. We have learned in the last one hundred years or so that atoms aren't really the miniature solar systems that we all imagine them being—a relatively huge nucleus with tiny electrons swirling around it like planets. In fact, we can't really say much of anything about where electrons are or where they're going. It turns out that all we can really say is where they might be at a given time. Let's back up a little and try to illustrate this principle with an example.


Imagine a roller coaster on a track shaped like the black line pictured to the right. It's pretty easy to imagine that if you started on the left side where the red line intersects the slope that when they drop, the cars would easily roll over the middle hump and up the other side to the red-black intersection point on the right side (in fact, it would go to that point exactly if we neglect air resistance and friction). Even though the roller coaster dips pretty deeply just to the left of the center hump, it's not difficult to imagine that the cars would be going fast enough to get over the hump with speed to spare.


Now imagine that we start on the left side again, but this time at the point where the blue line intersects the track. Dropping from this height, we can see that the cars don't have enough energy to get up over the hump. Starting on the left side means never getting to the right side and vise-versa. We'd need some kind of chain (like the ones that they use in roller coasters to pull you up the first hill) to do enough work on the cars to get them over the hill. In other words, unless the roller coaster cars got energy from somewhere else (like being pushed at the beginning or dragged up the slope with a chain) they will never see the right side of the track.

Everything we just discussed comes from "classical" mechanics, which imagines that everything is solid and exists where it's supposed to exist in the way that it's supposed to exist. Unfortunately classical mechanics breaks down when the system is really small (such as in an atom). We'll talk about one way that it stops working after a little lesson in terminology.

Terminology

The term "potential well" refers—in effect—to the dips in the track. In the case of a roller coaster, the "well" is formed by gravity in that the deeper you go into it, the more energy you need to get out. We can see a more solid example of this in the system of the earth. Imagine that our planet is resting on a large rubber sheet, causing a depression. To get into outer space, we must climb out of the hole first which means that we need to have enough energy to get out without falling back in. Once out, we are free to shut off the engines and simply coast (which is how we got to the moon) because there is no danger of falling back into the earth's potential well.

Potential wells can be made from all sorts of things. For instance, a large chunk of positive charge (such as an atomic nucleus) creates a potential well into which negative charges, like electrons, fall (the reason they don't ever fall into the absolute center is a complex question that we won't get into here). In the same way as with gravity, for an electron to escape a nucleus' potential well, it must have at least enough energy to climb out of the hole.

The other term that we need to understand is the "wave function." We refer more to the wave functions of tiny particles than to where they are or how fast they're moving because it allows us a little more accuracy in measurements. In effect, we say that particles have a tendency to behave like waves under the right conditions. For example, electrons (which have definite mass) have a wavelength and a frequency and can even diffract (bend around obstacles) like water waves do. As a result, when an electron is in a potential well, instead of thinking of it as a ball rolling back and forth between to peaks of maximum energy (like a roller coaster), we think of it as being a wave bouncing back and forth between two walls (think of dropping a pebble in a bowl of water and watching the waves bounce around). The size of the wave function at a certain point represents the probability of the electron being found at that spot. That is, the bigger the wave function, the more likely it is to find an electron there if we choose to measure it.

Quantum Tunneling

Remembering the blue track example, imagine an atomic potential well of that shape. Perhaps there are two nuclei of differing charge (so that one is deeper, or has a greater propensity to pull an electron than does the other) close enough together to affect a single electron. We can imagine that the larger of the two nuclei could, under the right circumstances, trap the electron in the deeper well, making it impossible to overcome the hump and orbit the other, smaller nucleus. Classically, this is exactly how we'd explain it.

However, we have observed that sometimes the electron, after having been trapped in a potential well and without enough energy to get out of it, sometimes escapes. This is evidence that the electron is behaving like a wave. Imagine clapping (thus making a sound wave) in a room with closed doors. Can a person outside the room hear you? If you clap loud enough, the sound wave will hit a wall and make it vibrate a little, causing the air on the other side of the wall to vary in pressure a little. That pressure variance becomes a pressure (sound) wave that can travel to another person's ear. It's not as loud, but it's still the same sound.

So also with an electron, when it's wave function hits against a wall, it sometimes tunnels into it. If there is another potential well on the other side close enough and deep enough, the electron will be transmitted to the other side (though with a much weaker wave function). Unlike with sound, the fact that the wave function has a smaller amplitude does not indicate that the electron is any less of one. In fact, it is the same electron that was on the other side of the well. The fact that it has a smaller wave function only means that it is less likely to be there if we chose to measure it. However, that probability only applies to the exact time of measurement. In all other times, the two nuclei behave as if the electron were always with it (even though measurements may seem to indicate that it is with one particular nucleus 80% of the time).

Maybe this all sounds obscure as if it couldn't possibly matter to a normal person, but what I've just described is a covalent bond which is the kind of bond that keeps two hydrogen atoms attached to an oxygen atom in water molecules (and, consequently, the bond that makes most or all of the molecules in air stay together).

Conclusion

The take-home message of quantum tunneling is that small particles act very differently from large ones. I guess, technically that grapefruits have wavelengths too, but for reasons associated with the Uncertainty Principle, the effect that quantum mechanics has on large objects is negligible. But on very small scales, classical mechanics breaks down. Objects that we imagine to be solid become waves, Newtonian mechanics breaks down, and nothing seems to work the way we expect it. The usefulness of knowing exactly how they act on that scale is important, though, as we can see by examining its effects. Knowledge of quantum tunneling leads us to innovations such as flash memory (which the thumb drive in your pocket uses), semiconductors (a fundamental component in computers) and chemistry.

Universe Synthesis: Part III

In the last two installments of the Universe Synthesis series, I explained in relatively simple terms what happened during the first 380,000 years of the life of the universe. In the first trillionth of a second or so, the four major forces that we know today split from the single force that they started out as, and then the first inklings of matter formed. We left off with the creation of hydrogen and helium.

The problem with an expanding universe is that as is expands, it loses kinetic energy. Imagine two pots of boiling water (each with an equal amount of water in them). If you set one on the stove and dump the other one on the floor, which will cool down faster? Clearly, the water, as it expands, radiates (and conducts) more heat away from it at a faster rate. In the same sort of way—as the universe expands—it cools down. Unfortunately, it takes energy to force atoms together to make heavier atoms. At 380,000 years after the Big Bang, the universe is overwhelmingly (if not completely) devoid of any element heavier than helium. With the matter in the universe cooling and spreading out at an alarming rate, how did the rest of the periodic table form? Where do we get carbon, oxygen, nitrogen, iron, and gold?

The answer is—in the simplest form—gravity. The fast expanding space is filled, intermittently with enormous clouds of hydrogen (mixed with a very little helium). But the clouds aren't homogeneous; they're clumpy. In some places there are a few more atoms per cubic centimeter, making the region very slightly more massive than the areas around it. Believe it or not, this is the beginning of a star.

The slightly-more-massive clump has just a little stronger gravity than the other slightly less dense regions. As a result, other hydrogen atoms are statistically more likely to fall into the clump and join it. Over a very long time, the clump gets larger and larger, becoming more dense and more compact. As it gains matter (again, only hydrogen), the matter tends to fall towards the center of gravity, causing a particularly large mass of hydrogen gas to start forming there. The gas pushes on itself, or rather, it pulls it self together by its own gravity until the pressure is so great that it ignites.

Ignition, here, does not have the same meaning as it does on earth. The hydrogen is not burning, per se, it's fusing. The pressure is so great that the atoms are fused together. Two protons (which is just a hydrogen atom without its electrons) are fused into deuterium (still hydrogen, but with an extra neutron), deuterium and another proton make helium. Helium fuses into lithium, which fuses into beryllium. This is called the proton-proton chain. In heavier stars, there's enough thermal energy to initiate the CNO cycle, which creates primarily carbon, nitrogen, and oxygen. With each fusion reaction, a little bit of energy is released as light. The light you see when you look at the sun (note: don't look at the sun) is the byproduct of the proton-proton chain.

Atoms continue to fall toward the center of gravity. As they do, and because they do not fall uniformly in every direction, the whole mass begins to spin. As it does, a disc that is perpendicular to the axis of rotation begins to form around the newly formed star. Matter begins to collect into the disc. Soon a star is happily burning. Around it, other pockets of dense hydrogen have started to burn. The whole collection of them is now a galaxy.

In course of time, the star runs out of material to burn. Heavy stars can get big and hot enough to force helium, carbon, and other heavier elements to burn, but eventually the matter in the star ceases to fuse. Either gently, bit by bit, or in a violent explosion, the layers of new elements are ejected into the interstellar medium (left-over hydrogen), enriching the surrounding area with new elements. In the particularly large explosions, the atoms gain enough energy to fuse into extremely heavy elements such as gold, copper, tungsten, or mercury. Since the interstellar medium is still, even after all that, predominantly hydrogen, the whole process stars again. Only this time, the conglomerating gas is enriched.

When the disc forms around this new star, the heavier elements stay behind as the hydrogen and helium fall towards the center. Close to the star, almost all of the hydrogen falls into the giant fusion reactor leaving behind rocky clumps of carbon. These clumps eventually collide and conglomerate themselves, forming huge spinning rocks that eventually form terrestrial planets. Further out, lots of hydrogen and helium remains to collect into large, dense clouds not big enough to become stars; they become gas giants. The further away a gas giant is from the star, the more molecules are able to form in its atmosphere (being cool enough to form them without immediately breaking them apart again) such as methane (which is what give Neptune and Uranus that nice, blue color).

Lest you think that we'll one day run out of building materials, consider that after 14 billion years of element synthesis, the detectable matter in the universe is still 75% hydrogen and a little less than 25% helium. That is, everything else that is not those two elements comprises much less than 1% of the total matter in the universe. Even then, consider your car, your kitchen appliances, a gold deposit in a mountain, or the circuitry in your computer. A long time ago, in a galaxy far away (I couldn't resist, but seriously...) every single one of those atoms was being shoved together in the first few seconds after a violent supernova explosion. And every single breath of air you take is filled with atoms that were fused inside a star millions of years ago. We live and breathe stardust.
__________

So, that's how it happened. Or, at least, that's the best we can do at explaining it right now. This model is constantly being reformed and reworked, and new processed are constantly being discovered. One of the most amazing things to me is that almost all of this information was deduced by astronomers looking at the sun and other stars (note: do not look at the sun unless you are a trained professional). The only information from those sources that we can get is the light that they give off. In other words, astronomers found a way to deduce all of this just by looking at patterns of light given off by stars and combining it with what we already know about physics on earth. That, to me, is an amazing accomplishment.

Heisenberg Uncertainty Principle

Imagine that you take a picture of a moving car. Depending on the kind of camera you have, your pictures will develop in one of two ways. First, it is possible that your camera has a really slow shutter and that the car is blurry. If you knew the shutter speed of your camera, you could make a pretty good guess at how fast the car was going by studying the size of the blur. Even then, however you wouldn't be exact. The only problem would be to describe exactly where the car was at the moment you took the shot. In fact, you couldn't say that it was anywhere precisely at the time you took the picture. All you could do with any degree of certainty is decide that the car was between two definite points (the beginning and end of the blur) during the entire second that you took the picture.

The other kind of shot would have been taken with a camera that had a very, very fast shutter speed. The picture would turn out crisp, with almost no blurs at all. Finally, we know exactly where the car was at the instant the picture was taken. Unfortunately, by gaining this information, we've lost information that we could have known. Now, looking at the picture, we have no way of saying how fast the car was moving. For all we know, it could be standing still.

In either case, the picture cannot ever tell us everything we want to know about the car. We get one side or the other. And it has nothing to do at all with the quality of the camera. Even if we were using the best camera in the world, a slow shutter would tell us lots about velocity and a fast shutter would give us a good idea of position. This conundrum is the basic idea of the Heisenberg Uncertainty Principle.

Before the advent of quantum physics, it was believed that if we knew the exact position and velocity of a particle then we could determine exactly where it would be at any point in the future. I suppose we could still think of that as being true. The problem is trying to measure both of those quantities simultaneously. We encounter the same problems as we did with the camera. We can only simultaneously determine momentum and position to a certain degree of accuracy.

It's important to realize that the illustration that I gave above with the car is only a metaphor to help us describe the real Uncertainty Principle. In actuality, that "certain degree of accuracy" is an extremely small number (≈10^-34) and is thus only really an issue when we are talking about very small things like electrons.

The issue is not, however, as trivial as the particles are small. What are the implications of the Uncertainty Principle? First, we learn that it is impossible, regardless of the quality of the instrument, to learn everything about everything. The information provided to us on the sub-atomic scale is finitely limited. But, that's not necessarily a bad thing. Sometimes it is useful to know in precise terms that which we do not know. Such limits imposed on us by the universe have helped us to understand the shape, size, and configuration of an atom, and thus to describe more completely atomic interactions.

Further, the very idea that we cannot be exactly precise in our measurements caused a paradigm shift that defines the way we think about science today. Before this principle (and others such as de Broglie's wave mechanics and wave-particle duality), people were generally under the impression that the universe was deterministic—that every future event could theoretically be predicted. Now, we view the universe as being probabilistic instead—that we can only know the probability of a future event to happen. The probabilistic ideology, though seemingly less "correct" was something of a step away from perfect—though ultimately incorrect—answers and a step toward the best philosophy of understanding at which we can arrive.

Lasers

Introduction

The first laser was built by Theodore Maiman and is recorded as having been first displayed on 16 May 1960. This invention is particular, in my opinion, because it is not a naturally occurring phenomenon in the visible spectrum. Unlike lots of other inventions which come simply from us harnessing phenomena that we have discovered, lasing is a step ahead of what nature gives us, a complex application of several principles together to create something new.

Explanation

Laser is really an acronym—Light Amplification by Stimulated Emission of Radiation—which was first postulated by Einstein in 1917. As the name suggests, a laser is really the combination of two separate optical phenomena, stimulated emission and light amplification, which we will explain here.

Stimulated Emission

Emission, as its name connotes, is the term we use for a photon which is created by an atom. To understand this phenomenon, we need to understand atoms a little bit more.

When you picture an atom in your head, you probably imagine a small solar system sort of design with a nucleus of protons and neutrons in the middle and little electrons spinning around it in circles. Sadly, this is not the case, but the model serves well to illustrate emission; so we'll use it with the understanding that it is really not particularly accurate. Electrons in every atom under normal conditions orbit the nucleus in the closest possible orbit (which, for quantum mechanical reasons, is not physically touching the nucleus). Certain molecules (H₂ gas, for example) undergo excitation when they are hit by photons of sufficient energy which means that the electron is temporarily pushed to an orbit further away from the center. However, as things in physics tend towards the lowest and most stable energy state, the electron jumps back down to the ground state. The effect can be imagined as being like marbles in a funnel. The faster you push the marbles, the higher they rise in the funnel as they spin around. But over time, no matter how hard you first pushed them (assuming that they can't leave the funnel) gravity will pull them back to the lowest available spot. And since energy can't just disappear, the energy that the electron lost by jumping back down to a lower orbital is emitted as a photon of light of that exact amount of energy (we'll call this precise value ΔE). This is emission.

Stimulated emission is somewhat more complicated. An excited electron in a higher orbital will, obviously, spend some amount of time (it's really short) in the excited state before jumping back to ground state. If a photon whose energy is exactly ΔE passes very very close by the excited electron, the electron will jump before it normally would. Thus the emission was artificially stimulated.

Light Amplification

Light amplification is a direct result of stimulated emission under correct circumstances. If there is an excited medium (maybe an energetic cloud of H₂ gas), we can imagine that eventually one of the excited atoms will revert to ground state and emit a photon with energy ΔE. That photon will almost definitely pass near enough to another excited atom (if the cloud is big and dense enough) and stimulate the emission of another photon. Luckily for us, when a photon is emitted by stimulation, it is released in phase with and in the same direction as the incident photon. In other words, where there was one photon, now there are two traveling in exactly the same direction at the same time and in basically the same space. The light is now twice as bright. But these two photons will eventually collide with other excited electrons and stimulate more emission in the same direction. A chain reaction causes a short, bright burst of energy as all of the excited electrons in the direction of stimulation are forced to revert to ground state.

Lasing

The problem with the described situation above is that the cloud of gas runs out of excited electrons extremely quickly. To produce a laser, we need a continuous stream of stimulated photons. To produce this effect, we continually excite the gain medium by a very energetic source of light (a flash lamp or another laser) so that every time an electron jumps to ground state, it is quickly re-excited. Then we put the gain medium between two mirrors that face each other. Eventually, stimulated emission happens in the direction of the mirrors and an amplified light source bounces back and forth between the gain medium, becoming even more amplified. If the optical pump is strong enough, the cloud will never run out of electrons to stimulate. The amplification cycle is infinite (not that it increases in brightness forever, only that it will forever produce a continuous beam of light of a certain brightness that is unidirectional and in phase). To release the beam from the mirrors, we make a part of one of the mirrors semi-translucent so that some of the photons escape when the beam hits that mirror. The escaping photons come out in a beam which we call a laser.

Applications

We use lasers more than you might think. The ubiquitous laser pointer is, of course, one use. However, lasers now assist in medical surgeries, read CDs, cut and weld metals, and are used in printers (you know, laser printers) among many other things. They have become widely used and are on the forefront of our active scientific pursuits today.

Photoelectric Effect

Einstein won the Nobel Prize in Physics in 1921. Lots of people assume that he won it either for his work in relativity or for the immensely influential equation E=mc². However, it was for his groundbreaking discoveries in a physical phenomenon known as the photoelectric effect for which he was awarded the Prize. Herein we will discuss the phenomenon and its subsequent applications and implications.

Explanation:

Simply, the photoelectric effect is the emission of electrons from a metal as a result of incident light. In other words, sometimes, when you shine light on a piece of metal, some of the electrons in the metal come unbound and fly freely though space. I guess we need to back up and talk a little about metals.

One of the properties of metals is the configuration of its electrons. When a whole lot of iron atoms (to use one of many metals in the periodic table) get together, they start to share their electrons. However, unlike other solids, metals share their electrons with the entire solid. The top layer of electrons are free to flow anywhere about the surface of the metal, bound to no specific atom. Incidentally, this property is what makes metals such good conductors of electricity; the "fluid" electrons on the surface carry and transport charge very efficiently in much the same way as it is easier to slide over a wet surface than a dry one.

This property of metals is what makes the photoelectric effect possible. When you shine light on metal, the sea of electrons (as it is often called) receives lots of energy, causing some of the electrons to shoot off. However, not just any kind of light can make it happen. Imagine a swimming pool that is only filled up half way with water. If you were to throw a rock into the pool, you could make some of the water splash out, but only if the rock was traveling fast enough. Even a whole bunch of rocks traveling too slow would only make lots of splashes that didn't remove any of the water. In the same way, light needs to be energetic enough to cause the electrons to escape from the sea. The minimum energy that is required for a photon to remove an electron from a metal is called the work function (symbolized by the Greek letter φ).

Implications:

The implications of this discovery were shattering to the world of physics. There was a huge debate at the time concerning the nature of light--whether it was a particle or a wave. Einstein's discovery helped us to understand the truth. As I mentioned before, only light with a certain minimum energy (equal to φ) could make electrons leave the metal. Einstein discovered that this minimum energy could only be achieved by changing the color of light, not the intensity. That means that red light, no matter how bright, will never induce the photoelectric effect, whereas very very weak ultraviolet light will always do so. We learned some great truths through this. First, the frequency of light (its color) is directly related to its energy. In fact, frequency is the only factor that determines photon energy. Intensity (brightness) of light corresponds not to energy, but to the number of photons hitting the area per unit time.In other words, shining really bright, red light on the metal was like throwing lots and lots of rocks really slowly into the pool. But shining really weak UV light was like throwing just a few rocks really really fast, causing a large splash (but only a few times). To induce a large photoelectric current, one needs only to produce an intense UV source.

Applications:

The applications of the photoelectric effect are many and influential. This is the basic idea that makes solar energy possible (taking light and making electrical energy out of it). Also, from this idea came photomultipliers (which created such devices as night-vision goggles) and CCDs (which are the imaging devices in digital cameras and telescopes), to name just a few.

Isaac Newton

b. 25 December 1624
d. 20 March 1727

Noteworthies:

• Authored Principia, defining the basic laws of motion
• Invented calculus
• Lucasian Professor of Mathematics at Cambridge

Everyone has heard of Isaac Newton, and for good reason. He's very much the father of mechanics as well as the reason that we are able to calculate everything the way that we do. I'll get to that a bit later, but let's first talk about his character.

Newton was supremely inquisitive. Even as a child he was extremely curious about his surroundings. He drew pictures, invented tools and appliances, experimented, and was eternally posing questions to himself. Interestingly, he was totally apathetic to school and performed terribly. But either the prospect of having to manage the family estate or an alleged attack from an elementary school bully changed his mind and he eventually got accepted to Cambridge. There, he worked his way through school waiting tables and doing janitorial work until he was accepted on scholarship.

In 1665, the campus was closed for 18 months due to an outbreak of the bubonic plague. Oddly, the year and a half he spent at home was Newton's self-termed annus mirabilis (miraculous year), during which his scientific career exploded. While at home he invented calculus and began solving previously unsolvable problems with apparent ease.

Calculus can be termed as the study of infinitesimal progression. Take a falling ball, for example. Imagine that you took a picture of it one time every second until it hit the ground. Developing the pictures, you could analyze how far the ball fell each second and would probably be able to determine that the ball fell more at the end of its flight than at the beginning. Now imagine that you took a picture of the ball every tenth of a second. Suddenly, you might be able to calculate exactly how much further the ball has fallen in each successive shot (think of making a flip book out of each set of pictures, the one-second pictures would depict a ball with very choppy movement, whereas the other set would show a much smoother trajectory). As the time between successive pictures decreases, so also does the accuracy of our measurement for any given period of time. If it were possible that there was an infinitely small separation between one instant and the next, we would know as much as was possible to know about the falling ball.

This is effectively the concept of calculus. Newton developed a way to take infinitesimally small "pictures" of mathematical situations and was thus able to analyze every single instant from the start of an action to its finish. He developed the idea during what was effectively an overly long summer break. It became an enormously powerful tool.

Another scientist named Robert Hooke once proved a hypothesis made by Kepler that planets travelled in elliptical orbits but refused to share it with his coworkers presumably to avoid having to credit them. The coworkers consulted Newton who replied that he had solved the problem four years prior and simply threw it aside and eventually lost it. He then spent 18 months working furiously to publish before Hooke, at which he succeeded.

Here we encounter another one of Newton's more colorful personality traits: ego. It was perhaps his towering pride that led to his most influential discoveries. Frequently his books were published out of spite for another scientist. Any derogatory remark made about him or his work threw him into a black depression that could only be cured by besting the man who made the comment. As a final blow to his then lifelong enemy, Newton even refused to publish his groundbreaking discoveries in the field of optics until Hooke was dead, thus never revealing to him what had been discovered.

Among the body of scientists at the time, problems were frequently shared so as to facilitate their discovery. Johann Bernoulli once posed the problem of the curves of quickest descent (the Brachistochrone curve), which is the path an object must take between two points that causes it to get there the fastest (hint: it is not a straight line unless one point is directly above the other). Only a few responded, one (Newton) anonymously, as if to say that anyone could solve it. But when Bernoulli read the nameless proof he immediately named Newton as the author proclaiming, "Ah! I know the lion by its paw."

Among other publications, Newton wrote a book known as The Mathematical Principles of Natural Philosophy or Principia for short. It outlines the basic laws governing motion and forces and defines the basic terms that we now consider commonplace (force, mass, velocity, acceleration, inertia, etc.). He proved that all masses are acted upon by gravity in the same way (the moon and an apple, for example), and most importantly, gave us the mathematical tools to solve basically every problem with perfect (yes, perfect) accuracy given the correct conditions. Still, of his own accomplishments, he said, "I do not know how I may appear to the world, but to myself I seem to have been only like a boy, playing on the sea-shore, and diverting myself, in now and then finding a smoother pebble or prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me."