Friday, October 27, 2017

NaNoWriMo 2017


As November approaches, writers prepare for National Novel Writing Month, an event meant to get the creative juices flowing and motivate writers to prove to themselves that they have what it takes to finish a draft of a book.

Last year I cranked out a 30,000-word science fiction novel about a space station at the end of time, called The Void Stared Back. It was rough, and there were times when I felt like I was torturing myself, but I pulled through and gained valuable experience. As December finally arrived, I breathed a sigh of relief and told myself I never wanted to do it again. For the next eleven months, I planned on not participating this year. However, once the coolness of fall arrived, I started to feel a strange sensation: that it is writing season. I became excited to write, and ideas started coming in a deluge. As October progressed, I came to realize that I actually do want to participate in NaNoWriMo again.

For my topic, I have several options. I could try for a better version of Void, I could go for the sequel to Raiders, or I could focus on Moebius and finally finish a draft. However, after realizing my skills are not at publishing level yet, I've decided to take a break from novels and practice on a series of fantasy short stories, which I will publish for free online somewhere. So this November, I am committing to write at least 1,000 words every day for this series.

Although I have a skeleton outline for the major themes of the series, I doubt I'll be able to write the 30,000 words in chronological order. Instead, I will work on the many different scenes floating around in my head, and sort through what to toss and what order to put the rest in later.

Committing to NaNo for a second time is more daunting than it was the first time, because I know the pain I will be calling down upon myself. But I also know I can succeed, and that the experience I get will give my skill and diligence a leap forward. With a sweatshirt around my shoulders and a cup of hot coffee on my desk, I will resolutely face up to the challenge.

This blog may not see much action for the next few weeks, since I will be busy writing something else most of the time, and I still have teaching and grading duties to keep on top of. However, I did manage one discussion last year, and I don't have homework problem sets to do this year, so we'll see.

Friday, October 20, 2017

Moral Theory V: The Greatest Good

Moral Theory:
I. Intuitionism
II. Authoritarianism
III. Divine Command and Attributes
IV. Ethical Egoism
V. Utilitarianism
VI. Virtue and the Golden Rule

Negative Morality:
Divine Hierarchy

Note: I did not explain good very well in this discussion, so a year later I wrote a better explanation. You can read it here.


So far, as we have examined moral systems in our search for objective morality, we have gotten lucky and found contradictions. However, there may be many moral systems that have no internal contradictions. If we want to be able to compare them objectively, we will have to approach the question from a different angle. Today, we will see what we can find out by starting with observations and building upon them with logic.

So far, we have asked “what is morality?” But when we look closer, we can see that question can be broken up into two: “what is good?” and “what should we do?” The second question looks like it depends on what “good” is, so let’s put it aside for later and consider the first one.

To begin, let’s take a step back even further and ask why we have moral systems in the first place. Why do we care about how we and others choose to live our lives? The answer is because we want to strive to create a state of affairs that satisfies us, about which we can say, “this is good.” Although each of us has different ideas of what “good” is, we all have something in common, in that we want to be satisfied by the way things turn out and the actions we and others took to get there.

Perhaps, then, we are blinded by the actions we think of as good, like helping people, being rewarded for hard work, etc., and are missing the real purpose of morality: to be satisfied with what we and others have chosen to do, and with the results that have come from it. Satisfaction is the goal of every system of morality, which means satisfaction is equal to goodness. The answer to “what is good?” is satisfaction.

Knowing this is not enough, though. We are still left with a bunch of competing moral systems, all of which differ in whose satisfaction matters and what types of satisfaction are emphasized. We need a way to take morality from the subjective view to the objective. 50 years ago, philosopher John Rawls suggested we view the world from the Veil of Ignorance, where we look at the world as if we do not know who we are. From this objective perspective, all people are equal, and no one’s need for satisfaction deserves more weight than anyone else’s. The objective good, then, is to increase the total amount of satisfaction experienced by humanity, and all creatures capable of experiencing it.

This leads us to the moral theory of Utilitarianism, the idea that the best, most moral actions are those that create the greatest good for the greatest number of people. As John Stuart Mill said 150 years ago, “actions are right in proportion as they tend to promote happiness, wrong in proportion as they tend to produce the reverse of happiness.” Mill called it “happiness,” and I call it “satisfaction,” but context shows that what we mean by these words is in principle the same thing.

Utilitarianism brings up a lot of questions whose answers are not immediately clear. For one, how do we deal with the fact that sometimes people get satisfaction out of hurting others? Do we say that some kinds of satisfaction are good and some are bad? That would seem to undermine the whole argument. However, we don’t have to say that; Utilitarianism takes care of it naturally. All satisfaction is good, but it must be totaled up over all people. If someone takes satisfaction at another’s expense, it is usually worse overall than if they had left each other alone, and always worse than if they had worked together to increase both of their satisfaction.

But what if there is no possible way for everyone to be satisfied? What if no matter what anyone does, someone will have to suffer? There is a classic counterargument to Utilitarianism that goes like this: suppose there are five patients in a hospital who each need an organ transplant, or they are going to die. In the waiting room, there is a perfectly healthy person here for a visit. Wouldn’t Utilitarianism say that it would be better to kill the one person in the waiting room and take their organs than to let the five patients die?

The answer is no, as killing someone in the waiting room has broader consequences beyond the six people in the example. If people can be killed for their organs, it creates what I call a Shadow of Fear, a stifling blanket over everyone in society, as they are afraid of being killed for their organs. The amount of satisfaction lost from everyone in society under a Shadow of Fear outweighs the satisfaction of continued life from the five people who were going to die.

What if the doctors cover it up? What if they claim the person in the waiting room died from a heart attack, and so using their organs was justified? This would seem to eliminate the Shadow of Fear, bringing Utilitarianism back under fire. However, such a lie is unstable. If the truth were to come to light, it would create a stronger Shadow of Fear than if they had been honest from the start. Not only would there be a Shadow of Fear about the possibility of being killed for one’s organs, but there would be a further Shadow of Fear about the deception; people would be worried that there are other cover-ups that they don’t know about, and they might be harmed or killed for all kinds of unknown reasons. The mere risk of such a shadow outweighs the satisfaction gained by the five saved patients, and Utilitarianism prevails again.

Another common counterargument regards sacrificing oneself for the greater good. Hypothetically, if there was some kind of monster who would gain tremendous satisfaction from eating you, so much that it would outweigh all the satisfaction you would have in the entire rest of your life, wouldn’t Utilitarianism say that it is best for you to feed yourself to that monster?

Maybe, but maybe not. Humans are extremely bad at predicting all possible futures, so in almost every case, we would have no way to know whether we would have more satisfaction in the rest of our life than the monster would gain by eating us. But there might be some kind of extreme circumstances where we would know, and that seems troubling.

However, we actually make this decision all the time; it’s called eating meat. We sacrifice the futures of animals for our own pleasure, even raising them from birth for the purpose of eating. The amount of satisfaction from the pleasure we get from eating a meal is certainly less than the amount of satisfaction the animals would have experienced in the rest of their life, yet we feel it is justified. So then, so what if Utilitarianism tells us that there are possible circumstances where it would be better to feed ourselves to a monster? What license do we have to complain about the perceived speck in Utilitarianism’s eye, when we have this plank in our own?

What about intentions? Utilitarianism is a consequentialist theory, which means the goodness of an action is determined by its consequences, not the intentions of the person who performed it. This will lead to situations where people with malicious intent end up doing good things, and people with good intent end up doing bad things. At a glance, Utilitarianism seems to say the person with good intent is worthy of condemnation and the person with bad intent is worthy of praise. But this once again ignores the broader context. People with good intentions are more likely to do good in the future, and people with bad intentions are more likely to do bad. So the desire and effort to do good can be as praiseworthy as good consequences, or even more so. It is also noteworthy that it is more satisfying to oneself to have good intentions than bad.

There are still many questions left about Utilitarianism that I don’t have the answer to. What level of satisfaction, if any, is low enough that it is equal to nonexistence, and are there states of living that are worse than death? Would it be better to have billions of people in near-death misery, or millions in luxury? What about animals, whose brains are not powerful enough to have moral intuitions, but can feel pleasure and pain? These questions are interesting puzzles for philosophers to debate over and solve. Despite the uncertainty, I am convinced that Utilitarianism is the objective foundation of morality.

There is one major problem left, though. Utilitarianism is only half the answer; it tells us what “good” is, but it does not tell us how to act. We cannot be obligated to always and only do that which is best, because it is impossible for us to know anything close to the amount of information required to make that kind of decision. Other than that, Utilitarianism does not provide a clear line between good and bad, nor give us instructions on how to increase goodness. So how can we hope to live good, moral lives? The answer is that Utilitarianism is not exclusive. It allows and even encourages other moral systems, including those we have already talked about. Utilitarianism gives a way to know when to follow rules, when to trust your intuitions, when to serve yourself, and provides a foundation for God’s nature and commands. Utilitarianism does not tell us what to do, but gives us a measure by which to compare prescriptive moral systems against each other. Next time, we will look at a final two moral systems in our quest to answer the final question, “how should we live?”

Friday, October 13, 2017

What is at the Edge of the Universe?


When we think about objects, we usually picture them as having some size, some volume of space they take up. There is an inside, and an outside. Inside, we say the object is “there,” and outside of it, the object is “not there.”

But what about the Universe? Does it have an edge? Is there some place we could go that we could say we are not in the Universe anymore? Perhaps if we got into a space ship and went far enough, we might come to some kind of boundary that stops us from going any farther. Yet once there, the next natural question to ask would be, “what is beyond this wall?” If we dug at it with picks and shovels, could we chip away at it, and maybe break through? Wouldn’t that mean there is actually more of the Universe past it?

Before we go any further, what exactly is the Universe? Our intuitive understanding is that the Universe is all of space and time and everything in it, but there are places and times where this definition gets fuzzy. So let’s try specifying it further. The Universe, for the purpose of this discussion, is all of space and time that can be gotten to by some smooth path through space and time, and everything in it. This would mean that if we came to a boundary that was the edge of the Universe, there would be nothing beyond it. In fact, there would be no “beyond it” at all. It might be possible to push against the barrier and make a dent in it, but we would be creating new space rather than discovering what was already there. This is very hard to imagine, even for me. Interestingly, such a barrier is physically possible: it could be an event horizon, a surface that requires going faster than the speed of light to pass. If nothing, not even space itself, could get to the other side, then we would have ourselves an edge of the Universe.

Such an event horizon would cause the shape of the Universe to be curved in ways that would be observable in the distribution of galaxies and how their light travels as it comes toward us. We see no sign of such things. As far as we know, the Universe is infinite in size. Nevertheless, it has a finite age, 13.8 billion years. Light takes time to travel, so the farther away something is, the closer to the beginning of the Universe we see it. In fact, there is a surface so far away that it is basically the beginning of time compared with the age of the Universe.

The entire sky unfolded.

In its cradle days, the Universe was thousands of degrees, so hot that electrons and protons could not stick together to make atoms. As the Universe expanded, it cooled, until the protons and electrons merged to form hydrogen, and the light that had been bouncing around the plasma soup became free to fly across the universe unbounded. This light started out visible, but got redshifted as the space it traveled through expanded, until today, when it is in the microwave spectrum. We now call this light the cosmic microwave background. It comes from the same distance in all directions, making its source the surface of a sphere centered on us, which we call the surface of last scattering, which for some reason sounds incredibly poetic to me.

As far as we know, there was no time before the big bang. Time literally started then, so the phrase “before the big bang” is meaningless. It is theoretically possible that future space-based gravitational wave observatories will be able to detect gravitational waves from before the big bang, but so far we have no reason to believe such a time existed. Thus, there is a certain distance that cannot cannot be seen past, because light from beyond it has not had time to reach us in all of time. This distance marks the edge of what is called the observable universe. Indeed this is not far beyond the surface of last scattering, 13.8 billion light years away.


The first moment of the big bang is not really a boundary in space, but in time. However, space and time are united by the speed of light, so if we think from the perspective that the farther something is away from us the further back in time it is, we could say the edge of the observable universe is the edge of the Universe.

On the other hand, perhaps the Universe has a finite size, but no boundary. It was once thought that the Earth had an edge, and that you could fall off. However, we now know that the Earth is a sphere; if you travel far enough, no matter which way you go, you will eventually end up where you started. It is theoretically possible for the same thing to be true of the Universe; if you go far enough in any direction, you will end up back where you started. It would be like the old arcade games, where going off one side of the screen puts you on the other side. This can be difficult to imagine for the Universe, since the Universe has three dimensions whereas the surface of the Earth has only two, but there is nothing wrong with it in theory. However, such a geometry to the Universe would leave signs in the structure of the filaments and voids, which we do not see. As far as our current knowledge can tell, the Universe is infinitely big.

The tunnel leading to the left connects with the one leading to the right.
If there were no walls, the game would be finite in size, but unbounded.

An infinite Universe brings up a new question; what is it expanding into? If the galaxies are moving away from us, wouldn’t they run into the galaxies that are farther away? The key to understanding is to realize it is not the galaxies that are moving, but the space between galaxies which is stretching out. The farther galaxies are being carried away faster than the close galaxies, and the galaxies that are even farther are being carried away even faster, and so on and so on to infinity. Bizarre, but it is theoretically solid. The reason this concept seems so strange to us is because we do not have everyday experiences with infinitely large things.

What if there is not an edge of space, but an edge of stuff? Might there be some distance we could travel, that when we got there we would see nothing beyond but an empty void for all eternity, behind us the brilliance of stars and galaxies uncountable, before us nothing but darkness? When astronomy was young, we though the bunch of stars around us making up the Milky Way galaxy was all there was, and assumed that outside of our galaxy there was a vast expanse of emptiness. Then along came Edwin Hubble, who measured the Andromeda Nebula to be far outside the Milky Way. This meant it was not a nebula at all, but another galaxy. For a time, galaxies were called “island universes,” until we decided that it was more convenient to speak of them as objects in the one Universe. But is there an edge to the galaxies? Galaxies clump into clusters, and galaxy clusters clump into filaments (sometimes called superclusters). Between filaments, there are vast empty regions called voids, which have no galaxies in them. It turns out that as far as we can see, no void is endless, and the galaxies continue on forever.


There actually is a kind of barrier in space right now. Einstein taught us that nothing can go faster than the speed of light, and Hubble taught us that the Universe is expanding. By “expanding,” we do not just mean that things are getting farther apart, although that is true, but that space itself is stretching out. Nothing can go faster than light through space, but there is no limit on how fast space can stretch. Therefore, there is a distance called the cosmic event horizon (not to be confused with the hypothetical event horizon at the edge of space we talked about above), where space is expanding away from us at the speed of light, and everything past it is expanding away faster than light. No matter how fast we go to chase this horizon, we will never be able to reach what has passed beyond it.

However, if we think about it, the cosmic event horizon does not feel like a boundary, because it never stops us from going farther. Indeed, it is always about 16 billion light years away from you in all directions, no matter where you are and how far or fast you have traveled. Everything is in the center of its own cosmic event horizon. Thus, if you were to get on a space ship and fly at the speed of light for 16 billion years, you would never be stopped by any kind of edge of space. However, Earth would pass out of your cosmic event horizon, and you would never be able to go home.

Following the cosmic event horizon to its logical conclusion, we find that sometime in the far distant future all of the galaxies that are not in our own gravitationally-bound cluster, the Local Group, will continue to expand away from us, until they have all passed the cosmic event horizon. Once this happens, the edge of the Local Group will be the edge of stuff, because no matter how far or fast we fly away from it, we will never reach anything else. Then, the age-old hypothesis of the island universe will become true.

Credit: NASA/CXC/M.Weiss

So if the Universe is infinite in all directions, with nothing stopping us from going in a straight line forever—excluding the odd bit of matter we may have to go around—there is really no edge to the Universe, right? The question does not make sense, because there is no place that would be outside the Universe. . . . Except there is still one little detail we have overlooked: the Universe has three dimensions. We have up-down, left-right, and forward-backward. Where exactly each direction points does not matter; what is important is that we can have three lines intersect at a single point and all be at 90 degree angles from each other. But what if there is a fourth dimension? Other than time, I mean; time makes everything more complicated.

A fourth dimension in space is extremely hard to visualize. We may wonder if there is any reason to think about it, since it seems impossible. However, we know of no reason why our Universe had to have three dimensions. As far as we can tell, it was more or less coincidental. There is a theory, beyond the edge of currently measurable physics, that suggests there are many universes with different numbers of dimensions. It is called String Theory.

String Theory deals with things called D-branes, which are objects with a certain number of dimensions, and to which the hypothetical 1-dimensional strings that make up all matter are attached. The only thing we know of that could be classified as a D-brane is the Universe itself. If String Theory is true, our universe is a mere 3D subspace of a 9- or 10D hyperspace, and all the matter we have ever observed is stuck to it.


Think of an infinitely large piece of paper. Imagine drawings that can move. These drawing can go up, down, left, and right, but no matter what they do they cannot get off the paper. Now think of us and the Universe. We can go up, down, left, right, forward, and backward. But if we could step even a single inch into a fourth dimension, we would find ourselves outside the Universe.

Whether or not String Theory is true, whether or not there is any higher-dimensional space or not, we have found the edge of the Universe. We won’t find it by looking out into space. No, the edge of the Universe is here. We are touching it right now. Bounded within these three dimensions, unable to reach even a millimeter into a fourth. This is the edge of the Universe.

Friday, October 6, 2017

Gravitational Waves, LIGO, and the Nobel Prize


Every year, the Nobel Foundation awards a prize of over a million dollars to people who have made groundbreaking impact in each of six categories: peace, literature, medicine, economics, chemistry, and physics. Each prize can be split between up to three people. On Tuesday of this week, the winners of the physics prize were announced: Rainer Weiss, Kip Thorne and Barry Barish, leaders of the LIGO Collaboration. LIGO, the Laser Interferometer Gravitational-Wave Observatory, heard humanity’s first gravitational wave two years ago. My own research involves looking through LIGO data for signals. Although I came on board after the famous first hit, I still feel awash in team spirit at the Nobel Prize announcement.

Left to right: Rainer Weiss, Kip Thorne, Barry Barish

A gravitational wave is a ripple in spacetime that travels across the universe at the speed of light. Put simply, gravitational waves are to gravity what light is to electromagnetism. But to understand it more in depth, we need to shake loose a common paradigm about space. We all start out thinking of space as flat. By flat, I of course don’t mean squished, but that parallel lines stay parallel no matter how far you go, the inner angles of all triangles add up to 180 degrees, and if you go in a straight line in any direction in space, you will have to turn around if you want to get back to where you started. Flat space may seem obvious to our minds, and maybe even the only possibility, but it is actually not true.

Curved space is not easy to comprehend, nor to explain, and adding time to the mix just makes everything crazy. Nonetheless, the universe we live in can and does bend, compress, expand, and warp. Have you ever had a dream where you were running down a hallway, only to find that the end kept getting farther away from you instead of closer? That’s what expanding space is like, except it’s cool instead of scary. If you imagine a hallway where you stay still but the end moves back and forth, closer and farther—on a solid foundation, without motors or anything—that is spatial expansion and compression. There is more to the curvature of spacetime, but for today, all that really matters is compression and expansion.

Image credit: NASA

Gravity is commonly thought of as the force that binds the universe together. It keeps planets moving around stars, and stars inside their galaxy. But technically, gravity is space that is ever so slightly bent. If you could measure triangles with extreme accuracy, you would find that a triangle that wraps around the sun will have interior angles that add up to ever so slightly more than 180 degrees. If that is difficult to understand, don’t worry, the important thing is that gravity is a distortion in spacetime.

What would happen if the sun were to suddenly disappear? We might think that all of the planets would immediately stop orbiting and fly off into interstellar space. But that is not correct. The effect of gravity is not instantaneous, but is limited to the speed of light. The sun is 8 light minutes from Earth, so it would be 8 minutes before the Earth stopped feeling the sun’s gravity. It would be longer for the outer planets.

The sun disappearing is completely unrealistic, but there are more realistic phenomena that cause gravity to change extremely quickly. There are things in the universe that are so massive and so tightly packed as to defy comprehension. Neutron stars, for instance, have masses slightly greater than the sun’s, but they are packed into a space the size of a mountain. Their gravity is so strong and it crams the matter they are made of so closely together that their atoms collapse and only neutrons are left. When two of these monsters orbit each other closely enough, they whip around in circles thousands of times every second. That’s some serious changing of the gravitational field! Because they orbit in a circle, the change in gravity is periodic, meaning it repeats itself. A periodic change in gravity traveling outward at the speed of light is a gravitational wave.

The waves actually go more up and down than sideways, and they are invisible. Probably.

Neutron stars whipping around each other at insane speeds is one source of gravitational waves. Black holes, objects more massive and even more dense than neutron stars, are another. But the real money comes when they collide, throwing off so much energy that they are the most powerful type of event in the universe next to the big bang itself. Indeed, all of LIGO’s signals so far have come from colliding black holes. At first they orbit, multiple times the sun’s mass whipping around hundreds of times every second, until, bam, the two black holes become one. At this point, several suns’ worth of mass is converted into gravitational energy at once and sent across the universe in something like a shockwave in all directions. When this front washes over the Earth, our detectors send out the alert.


When a gravitational wave passes over us, what does it look like? Imagine holding a large, rubber loop, between your hands in front of you so that you can see through it. You start squishing the loop and relaxing, getting a nice bouncy rhythm. As your hands move closer together, the sides of the loop get squished and the top and the bottom get longer, and when you move your hands apart, the sides of the loop get longer and the top and bottom get squished. The space a gravitational wave travels through is like the loop. As the gravitational wave passes through it, it expands space in one direction and compresses space in the other direction, and then the expanded direction compresses and the compressed direction expands.

After traveling billions of light years across the universe, gravitational waves become super weak and ridiculously hard to detect. We’re talking one part in a hundred quintillion (1 in 1 followed by 20 zeros). This number is so small that our brains are not equipped to deal with it. We are looking for a change as small as a thousandth the width of a proton compared to 4 kilometers, or the width of a human hair compared to the distance between the sun and the nearest star. That’s a big difference. To detect such infinitesimal changes, we are going to need some seriously high-tech machinery.


That’s where detectors like LIGO come in. LIGO is an interferometer with 4-kilometer arms, which act as moving hallways for the light that travels down them. A laser is shone through a beam splitter, which makes half the beam go down one arm and half the beam down the other. Mirrors at the ends bounce the light back, and the beam splitter reunites them and shines the recombined beam toward the light detector. Normally, the returning beams are out of phase, which means the detector sees nothing. But if a gravitational wave comes by and changes the length of the arms while the light is in them, even by a distance smaller than a proton, the light will change phase ever so slightly and suddenly the faintest shimmer will make it to the light detector. That shimmer is all we need to find out everything we want to know about the source of the gravitational wave.


And we have not even mentioned all the noise-countering technology involved. Wind, tiny earthquakes, a car driving by, a change in temperature or humidity—all these things will contaminate the data. So we need a plethora of other sensors around so that we can log every tiny thing that happens and cancel it out from LIGO's data. Despite how monumental the challenge, LIGO is successful. In its two six-month-or-so runs, it has confidently found four pairs of merging black holes.

Before LIGO, we had two windows into the universe. The first was light, not just what is visible, but the entire electromagnetic spectrum. This showed us that there are billions of stars in our galaxy, and billions of galaxies in the observable universe. The second was particles, cosmic rays, neutrinos, and more. These taught us about the magnetic fields between the stars and the chemical and nuclear processes that happen in stars and nebulae. Now, there is a third window open, of gravitational waves, which will let us hear the hidden mysteries that cannot be seen. It is right and just that those who contributed the most effort toward opening this window receive their due recognition and be remembered by history, as Galileo has been for inventing the astronomical telescope.