As we all know, rockets are tricky. Many exceedingly smart people have spent a lot of time getting these canisters of controlled combustion (or "directed explosion tubes") to transport people and equipment off the surface of our planet to many other places safely. I don't plan on discussing all of how that works today, because I don't even understand all of how rockets work (there's physics, chemistry, (biology if you're bringing people) and some pretty intense math for some things). Instead, I'm going to go back to when putting a man-made satellite into orbit was but a distant dream, and discuss the rocket equation.

It's one week later, and I still find myself playing Breath of the Wild, so I'm going to continue with my theme of Zelda and lift physics from last week. However, as there really isn't much else to discuss about lift in Breath of the Wild, we're going to jump backwards in the series to my favorite 3D Zelda game: Majora's Mask. For the uninitiated, in Majora's Mask, there are two main mechanics to the game: looping time and transformation masks. We're going to focus on the second one, because one such transformation mask turns you into a creature which appears to be made of wood called a deku scrub, and, as a deku scrub, you can launch yourself into the air (with the assistance of flowers—if you haven't played it, just don't ask) and then hover around via two propeller-like flowers held above your head. I think you all know where this is going now...

So, last Friday I got the Nintendo Switch, and The Legend of Zelda: Breath of the Wild. At this point, I've put 30+ hours into the game, and I can say with some confidence that it's really, really good (not sure yet whether it beats my favorite Zelda games, Majora's Mask and A Link to the Past). Good enough that halting my playthrough of it to write up this post is torturous. But, Fizzix Phriday must go on, and there is one thing that has bothered me, in the back of my brain, about the much-touted physics engine of Breath of the Wild. So, to continue in the series of "Austin ruins everything," as I have already done with Mass Effect, The Flash, and Sonic the Hedgehog, I'm now going to nitpick away at some less-than great physics in Breath of the Wild. Because I wreck everything that I love.

In 1967, Jocelyn Bell Burnell and Antony Hewish observed, in the night sky, strong radio pulses separated by 1.33 seconds, like some sort of cosmic alarm clock. While these radio bursts were all but certain to be natural, the source was named Little Green Men-1, or LGM-1. What Burnell and Hewish had, in fact, observed was what has come to be called a pulsar.

But what, exactly, is a pulsar? ...

What is entropy? The most common definition people tend to have for this is that it is the measurement of the disorder in a system. Some people who try to be too clever for their own good reply that it's the change in heat with respect to time divided by the absolute temperature (this is the thermodynamic definition of entropy, but my initial question was implied to be conceptual, so answering with a definition is just pedantic and showy). Really, entropy is a rather interesting concept, because the "disorder" definition, while it fits, really isn't the best way to explain it. So let's try to understand it better.

Important contributions to physics don't always come from career physicists. The fields of theoretical physics and mathematics overlap, well, a lot. Theoretical physics is mainly math, and there are times when mathematicians contribute landmark theorems to physics. One such person, whom no-one ever seems to learn about in high school or even introductory college physics (I certainly had no idea this person existed until late in my physics education) was Emmy Noether. Described by such heavyweights like Albert Einstein, Norbert Wiener, and Hermann Weyl as "the most important woman in the history of mathematics," it's a bit surprising that more people don't know her name, or what she did. It may be due to the fact that her eponymous theorem in physics requires rather advanced physics and mathematics, but I'm going to endeavor to explain it anyway.

Early on, everyone learns that there are three basic states of matter: solid, liquid, and gas. That's not entirely correct, as there are also fun things like plasma (the fourth state of matter) and not-quite-states like supercritical fluids, but it's correct and reasonable enough for us to go on. Also, usually, we think of these states as existing in a line: solid, at a high enough temperature, becomes a liquid; liquid, at a high enough temperature, transitions to a gas. We imagine these states to exist on a temperature line like so:

Hello everyone, and welcome to another installment of "Cool Things About Superconductors." Oh, wait. That's not a thing I'm doing. Despite that, there are so many cool things about superconductors, and I'm going to cover one of them today (well, technically, one and a bit): the Meissner Effect. What is the Meissner Effect? Well, it's something that happens when a normal conductor hits its critical temperature. That temperature is the temperature that, below it, the ordinary run-of-the-mill conductor begins superconducting. This means that it goes from having a normal, everyday amount of resistance to electric currents, to having exactly zero resistance to electric currents. And while there are so many other cool things that happen as a consequence of this, we're going to talk about what happens right at that moment.

All the matter that is around you is made up of atoms. That's a pretty well-known fact at this point, and, while it gets increasingly interesting and strange the more you think about it (the properties of each different element are just functions of how many protons it has, which is pretty wild), an atom is not the fundamental unit of matter, as its name, derived from the Greek atomos, which means indivisible, would suggest. No, the physicist John Dalton disabused us of that notion back in the 1800s, and since then we have learned that an atom consists of three constituent particle types: protons, neutrons, and electrons. Hans Geiger, Ernest Marsden, and Ernest Rutherford came up with the model of an atom with those pieces (as covered in the very first Fizzix Phriday blog post), and that most of the mass of an atom...

Prior to this posts, I've discussed the history of the universe, as we currently can observe and understand it, up to present day (give or take a few million years). If you missed those, here's Part I and Part II, which will catch you up. But really, as cool as the history of the universe is (and it's pretty neat), I wrote those posts so that I could write this one, about what happens next. Fair warning, it's fairly bleak and existential, albeit fascinating. Now, with Halloween around the corner, I've got a scary story for you: how the universe will (likely) end.

So, a year and some change ago I did an absurdly wordy post that may have had slightly too many run-on sentances about the early history of the universe (If you didn't read it, here's A Brief History of the Universe, Part I). I then promised to follow it up with more history up until present day or so, and never did. Until now. And while you may think it took me a long time to follow up with a part II to that post, that time span is just peanuts to the universe. In fact, it's been around for about thirteen billion times longer than the wait between the first part of this series and this follow-up. So, cosmologically speaking, the delay was perfectly acceptable. Now, let's get on with it.

Sonic is a blue hedgehog from a series of SEGA video games (dating back to just after the Mario games came out) that collects rings and goes fast. In fact, going fast is the premise of most of the Sonic the Hedgehog games, with the primary goal of each level being getting from the beginning to the end as quickly as possible (and hopefully looking rad on the way). One of the level elements that appears many a time is a loop-the-loop, both to demonstrate how fast Sonic is moving, and to be a barrier which cannot be surmounted unless Sonic is moving at the necessary high velocities. So, this brings us to the question: how fast does Sonic need to go to complete a loop-the-loop without falling?

On Fizzix Phriday, we sometimes endeavor to answer the questions other physics don't ask—nay, are too scared to ask. So today, I'm going to answer a question I am reasonably sure has never been asked. Is this because people were to scared of the answer, or because the question itself is simply nonsense? The solution is left as an exercise to the reader. The subject of today's Fizzix Phriday blog is: Could you build a star (similar to our sun) out of LEGO bricks? Let us take the mad journey to the answer to this bizarre question together.

Let's say you take two conducting plates, each one meter square or so, and put them in deep, deep space. Far enough away that nothing external should influence them, and they're sitting in the near-vacuum of interstellar space. Just to make things easier, we'll say this part of space lacks even the one hydrogen atom per cubic centimeter density of space, and is actually a perfect vacuum. Now, you make one place negatively charged, and the other positive. What do they do? Well, they attract due to electromagnetic forces. Obviously. So let's take away the charge. What do they do? Well, they attract due to electromagnetic forces. Wait, what?

This week, I just finished re-watching the first season of The Flash, and while it's a perfectly enjoyable show (Grant Gustin is great) that exists in the strange Hollywood land of nonsensical computer user interfaces and perfectly polished and machined electronic prototypes, the whole basis has a few serious flaws of the physical variety. So, in my quest to ruin all things that are good and fun, I'm going to examine the physics of the character The Flash himself, and how he would operate if the world the show was based in accurately reflected our own.

Today on Fizzix Phriday, it's time for some physics phistory (the p is silent). Let's take a jaunt back in time to the year 1571. Nicolaus Copernicus (born Mikolaj Kopernik) had published his revolutionary work, De revolutionibus orbium coelestium (in English: On the Revolutions of the Celestial Spheres) just 23 years ago, where he described, mathematically, a universe where the Earth was not the center, and all the planets revolved around the Sun, rather than the Earth. While this was a revolutionary idea, it was largely seen as incorrect or ignored, due in no small part to Copernicus's death around the time of its publication, and being therefore unable to defend his work from criticisms that arose from going against the established ideas in science and religion. Even worse, a note was prepended to his work before publication that basically said "everything in here about the Earth revolving around the sun and not the other way around is just a neat mathematical exercise..."

Often on Fizzix Phriday, it seems that I talk about things that are crazy far away in space, or so small you can't see them, or weird esoteric things, which, while super cool, aren't something you can go out and see yourself. So today, I'm going to talk about something that's probably near you, unless you life in a desert or grassland: trees. Now, I've been known to be upset and angry about how big trees can get, because the General Sherman tree (a Giant Sequoia) is just too big to be imaginable. But it's not the tallest tree out there. The tallest trees are the redwoods, which are also mind-bogglingly huge. I'd highly recommend seeing them at some point in your life. However, I'm not here to talk about how tall the California Redwoods are, I'm here to figure out how tall they are allowed to be. And that allowed means we're bringing in some physics.

There are many things that we can observe about the universe which lead us to assert that it all started with a Big Bang. There is the velocity of galaxies further away from us being faster, or the fact that when we look back to a younger universe we see more primitive structures that would precede what our universe looks like now. But probably the best evidence of the Big Bang is called the Cosmic Microwave Background Radiation. Which sounds really cool, and totally is. So what exactly is it?

Today we're going to discuss an interesting idea in general relativity (GR), but I'm going to try to do it without getting into any math. This will, unfortunately, limit us to a bird's eye (worm's eye?) view of it, however. In order to discuss the details of why some things are the way they are, you have to get into the nitty-gritty math of general relativity, so when I simply assert certain things to be true, you're going to have to trust me (or the physicists who said these things were true first, and proved it mathematically). So, let's talk about wormholes.

What exactly causes the tides? That question was something humanity wondered on and off for quite some time, though people did notice that it had something to do with the moon. In fact, Johannes Kepler was the first to suggest that an attractive pull from the moon caused Earth's tides (by observation and analysis of recorded data). However, it wasn't until about eighty years later that Newton pinned down what exactly was going on (with an actual physical theory of tides). Having described the mathematics of gravity and how it relates both to our attraction to the Earth and the movement of the planets, he tackled how the pull of the moon should create differing levels of water on the Earth. What he described was the Tidal Force, which is a force that results from gravitational attraction from a secondary body (the moon) on another body (the Earth) being unequal on all sides...

Here's something rather interesting about the sun, and stars in general, in regard to light. A single photon (a particle of light) takes about 8 minutes and nineteen seconds to travel from the surface of the sun to the surface of the Earth. The photon, is, of course, traveling at the speed of light through space, and the earth is about 8.3 light-seconds away from the sun (and light travels at a staggering 670,600,000 miles per hour). However, after that photon is created at the center of the sun as a result of fusion at the sun's core, it takes somewhere between one hundred thousand to ten million years to make it to the sun's surface.

Oh, man, is space big. I get upset thinking about it sometimes. It's just too big (then again, my general reaction to the largest living thing on the planet, the General Sherman Tree, was to get angry). But it's not that space is just so large, it's also that it's so empty. And that is what I'm here to talk about today.

The visible universe is about 93 million light-years from one side to the other. That means we can see about 46 million or so light-years in any given direction, if we look hard enough (you'd need impossibly good eyes, though, or you could just use a really powerful telescope and also be in space because the atmosphere really gets in the way of seeing that far)...

Oh what a tangled state we weave,
When first we practise to deceive!
(With apologies to Sir Walter Scott)

Quantum Entanglement. Spooky action at a distance. Quantum teleportation. Instantaneous transfer of information. Oh, man, does the science media love to talk about this. As does everyone who read a few articles and starts thinking of the wild possibilities. But quantum mechanics is a very, very tricky subject, which may be why I've held off on talking about it until now. No doubt someone will find something wrong with what I say, because I don't have any sort of advanced degree in the subject, and hoo boy is it complicated. Today, though. we're just going to talk about entanglement, one of the fun aspects of quantum mechanics that doesn't really mean what most people think, in its simplest form (because it gets complex fast)...

This week marks the 47th anniversary of the first human steps on the moon (July 20th, 1969), so we're going to celebrate with some cool physics facts (fizzix phacts) about the moon.

First of all, let's get a sense of how far away the moon is. On average, the moon is 238,855 miles away from us (384,400 km). That's all fine and dandy, but as humans, we're absolutely terrible at understanding very long distance, as I sort of covered with far larger distances previously. So, let's give ourselves a sense of scale...

Time is a tricky thing. The idea of the Big Bang has become common knowledge, but a question many still have as to the birth of the universe is what came "before" it, or indeed what was the "cause" of the Big Bang. While one might answer these questions with "nothing," that's not really correct, because the answer is actually much simpler and at the same time so much harder to grasp in any intuitive sense. The answer, which I understand intellectually but still makes no sense to me in an intuitive way, is that there was no before, nor a cause, because time itself, which the idea of before and causation is predicated upon, began its existence synchronously with the Big Bang. I find this nearly impossible to grasp in a fundamental way, because our entire existence is based around and upon a notion of time as a strict linear progression of one thing to another, with every event having a causation and time preceding it.

Let's talk a little bit about our galaxy. You probably know that it's a spiral galaxy, with several "arms" reaching out from a central bulge, and is shaped like a disk. Most of our galaxy's mass is centered in that central bulge, with is about 13,000 light-years from top to bottom (which is really, really big), and has a density of around 1,600 stars per cubic light-year. To put that in perspective, out where we are in the Milky Way it's only a few thousand light-years thick (which is still really big), and the stellar density is closer to 0.004 stars per cubic light-year.

Time is a funny thing. It's passage may seem constant, but it totally isn't. And I'm not just talking about how boring or tedious days drag by. See, this pretty obscure physicist by the name of Albert Einstein managed to codify a new area of physics back in the early 1900's which we call Special Relativity. He was the main reason the idea of the luminiferous aether (which I talked about in my post on Light) was discarded, because it showed the speed of light to be an absolute, universal constant, regardless of reference frame. Which is cool and all, but what does light have to do with time?

For a long time (well, relatively) astronomers believed they had this whole "solar system" thing figured out. They had this theory which governed its formation, called the "core-accretion theory," which described stellar and planetary formation. Basically, as all the dust and gasses that make up a star star coalescing into a star, they also begin spinning. As they spin faster, the gasses condense into a kind of spinning disk which is thicker at the center (like spinning our a blob of pizza dough, but a lot more complicated). Finally, this central mass gets hot and dense enough to trigger fusion, and the proto-star becomes a real star. Around this time, as the star is finishing its formation, the heavier elements in the spinning disk start clumping together, with the denser elements forming the smaller, rocky planets we see as the "inner planets" in our solar system, and lighter elements and compounds forming gas giants further out.

Many of you have probably heard of the thought experiment known as Schrödinger's Cat. The basic premise of it is that you have a cat in a box. Also inside that box are a flask of poison gas, a radioactive element, and a detector hooked up to a small hammer to smash the flask. Now, if the radioactive element, well, radiates, the detector will detect it, smash the flask, and the poison will kill the cat. It is important to note that this experiment has never been performed, and actually performing it may get you labeled as a psychopath (or just someone who really, really hates cats). While the box is sealed, there is no way for an observed to know if the cat is alive or dead—that is, if the radioactive element has triggered the detector. The goal behind this experiment is the idea that, at some point during this experiment, the cat is both alive and dead—that is, a superposition of those states. Erwin Schrödinger himself came up with this scenario to demonstrate...

Light is maybe one of the more important things in the universe (though this is debateable—some sensible people rank chocolate above it). It also has a rich history of people not really knowing what it was, how fast it moves, or even how it moves. So, in order to better understand it, let's turn back time, and cover a bit of light history (these puns never get old).

For a very long time, people believed light to be instantaneous, and for good reason. When is the last time you could see light move from place to place? Some folks disagreed, including a man born on February 15th in 1564 by the name of Galileo Galilei. Galileo attempted to measure the speed of light much like one might measure the speed of sound. In fact, you and another person could get a rudimentary measurement of the speed of sound using this method, so let's cover the sound applications first:

So in my post from the other week I alluded to the idea that negative mass is absurdly awesome, and that I may talk about it in the future. Well, folks, the future is now. So let's get to talking about negative mass.

First of all, negative mass falls under the category of exotic matter, which is pretty much filled with stuff, that, while not mathematically impossible, is unlikely to exist and has never been observed anywhere in the universe. This does not stop exotic matter from being the most interesting kind of matter (it may actually be part of the reason it is so cool). So, as we know, all matter seems to have mass, a property intrinsic to matter, and, according to the Standard Model, imparted upon the matter via interaction with the Higgs Field (that's what all the Higgs Boson hullabaloo was about a while back—that was the boson which would act as the "force carrier" for the Higgs Field, and give objects mass (and, by extension, gravity))...

If you haven't played any of the Mass Effect games, you really should. However, sometimes the physics of the very wonderfully developed fictitious future galaxy doesn't quite hold up. In this case, the very effect they've named the games after. Now, I'm not going to discuss Element Zero or the idea of manipulating mass (which is the titular Mass Effect), but rather how this manipulation doesn't make possible many of the things they claim it does. But first, let's start with a primer for those of you whop haven't played the games, or didn't pay a whole lot of attention to the sciency stuff in them:

Picture yourself on the surface of the Earth (or in a boat on a river). Now, if you were to toss something up into the air, it would eventually be pulled back down, due to the effects of gravity. Obviously, this force is not indomitable, as we've escaped the Earth's gravitational well many a time (most recently, when we sent something awesome to Mars—because orbit doesn't really count as escaping the Earth's gravity). In fact, if you were to toss something up with enough force, it would fly away forever, never to be seen again. The speed you instantaneously imparted on that object when you threw it is the Earth's escape velocity. Now, let's say we increase the mass of the Earth to that of Jupiter, but keep the size the same (we make the Earth much, much more dense). Now, in the instant before you were liquified by it, you'd notice the gravity has become much, much stronger than it was. This makes perfect sense, as gravity is a property of mass.

Matter. It's basically everything. Anything you can see and touch (except holograms), and some things that you can't see or touch, is matter. There's plain old boring matter, which is all the things you see around you all the time, and is composed of atoms you see on the periodic table. But then there's all that cool weird matter (not necessarily strange or exotic matter, because those are actual, real names of types of matter). Since you're already probably pretty familiar with prosaic matter, having been interacting with it all your life, let's talk about some of the more interesting matter.

Every object* that is above 0 Kelvin (read: everything in the universe) radiates somewhere on the electromagnetic spectrum. Stick with me, and I'll explain why. But first, every object* also absorbs light somewhere along the electromagnetic spectrum. For example, let's take glass. Now, in the visible spectrum (390<λ<700 nm), glass doesn't really absorb, reflect, or emit light (which is why it's transparent). This is due to a quantum mechanics phenomenon called "quantization." Essentially, electrons and the like can only exist in discrete levels of energy, and nowhere in between (like steps on a staircase—you can be on one step or another, but not between them (at least not without falling)). This is odd, and somewhat counter-intuitive because it doesn't appear to occur at the macroscopic level (our daily lives), but it's completely true (as far as we know). When an object absorbs light, it's because that specific wavelength of light is enough to jump an electron...

One thing you should know about space: it's huge. Mind-bogglingly huge. If you were to think of the biggest thing you could possibly imagine, it would still be more than a billion times bigger than that (and don't say you imagined infinity, because you can't. And stop being clever). The problem with just saying "the universe is huge" is that it doesn't really convey the distances involved. We can talk all we want about light-years and parsecs (unit of distance, not time, sorry George Lucas), but it doesn't really mean much. They're just words. And, as wonderfully evolved as language is, a lot of scientific terms fail to covey conceptual content with them, because our brains simply didn't evolve to deal with this sort of stuff. So this Friday, I'm going to try to take a stab at this comprehension.

Let's begin with a journey through time (and space, if you live any distance from Cambridge). The year is 1909, nearly seventy years since the death of John Dalton, the physicist who pioneered atomic theory. It's a little over ten years since Sir Joseph John Thomson (J.J. Thomson—not to be confused with the other J.J. Thomson, who was a philosopher) discovered the electron, and created the "plum pudding" model of an atom. This model stated that atoms were a more or less homogeneous mix of positively-charged and negatively-charged particles (protons and neutrons respectively). Electrons were the negatively-charged ones, because Ben Franklin said so in the eighteenth century (simplification, and possibly slightly farcical). Atoms were more of less the coolest kid in town when it came to physics, but scientists still didn't really know all that much about them—the "plum-pudding" model was mostly a wild guess.