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Friday, March 24, 2017

Those Not Like Us – Revisited

Some time ago I wrote a discussion called Those Not Like Us, where I talked about aliens. However, while I wanted to talk about how mind-bogglingly different life in the universe might be from humanity, I got sidetracked and instead talked about racism and how we are not ready to accept alien creatures as equals. While that topic is certainly worth discussing, it was not what I intended. So today let’s come back and get to the heart of the discussion, about the weird ways alien creatures might be different from us. And maybe we will learn something about ourselves on the way.

Photograph by Bill Curtsinger, National Geographic

Even between humans, there are differences that are hard to handle at first exposure. When someone is first exposed to a way of life different from what they have always lived with and is left tongue-tied, we call it culture shock. When everything is different, from the clothing to the language to the greetings to the table manners, it can be difficult to adjust and make us uncomfortable and suspicious. Sometimes it can lead to bitterness, and even violence. If we can get so distraught over the differences in our own species, how much stronger would that be if a space ship landed and the people who came out had bug eyes and tentacles?

There is a trope in science fiction—largely due to lack of special effects technology in early TV—that intelligent aliens will look like us, with two arms, two legs, two eyes, and a mouth that has the physical capability to speak English. But this is not realistic at all. Just look at the animal kingdom of Earth. Apart from a few select species of monkey and ape, none of the millions of varieties meet all those criteria. And look at the runner-ups for intelligence: monkeys and apes, sure, but also mice, elephants, pigs, and dolphins (and probably more; animal intelligence is a relatively new field of study). Given the right environments for natural selection, Earth’s rulers of intellect could have come in any number of different shapes and sizes. So why should we expect creatures from another evolutionary tree entirely to look like us?

The next obvious question is language. Between different human groups, all it takes to pass the language barrier is learning and practice, but there is no guarantee that we will even be able to pronounce the sounds that aliens make. Heck, their communication might not even involve sound at all. And though we could probably rig up a computer to translate, there is no guarantee that we will be able to understand them even then. Human language is very abstract, and the aliens might be abstract in different ways. In the Star Trek: The Next Generation episode “Darmok,” the crew run into an alien species that they cannot understand even with their universal translator, because the species talk completely in myths and legends. Of course we probably will figure out how to communicate with any intelligent creatures sooner or later, but it is possible that they conceptualize the world in ways that are completely different from the way we do.

One major possible avenue for this is sight. Stars emit a thermal blackbody spectrum of light in the shape of a Poisson curve. On the horizon, our sun looks red, orange or yellow, but straight up without much atmosphere in the way, it looks white. This is because the sun’s light peaks in the middle of the visible part of the spectrum, and to our eyes all colors added together equal white. Well that is a nice coincidence, that our eyes are designed to take full advantage of our star’s light, right? Well, it is actually no coincidence at all. Evolution favors that which is best adapted to the environment, and so creatures with eyes that are better suited to sunlight will survive better and pass on their genes. The same logic, however, would apply to evolving eyes around any star, so we would expect that cone cells or something like them will develop to center around their sun’s peak emission wavelength. Eyes are incredibly useful, since the universe is full of light, and we have lots of evidence that they evolved multiple times here on Earth, so we can reasonably assume that most aliens would have eyes. Whether they would see the same colors in their minds’ eyes as we do is a fair question, but if they did, then life from a blue star would see our sun as red and life from a red star would see our sun as blue. If the creatures are from a star different enough from our own, their visible spectrum and ours might not overlap at all!

In the same vein, our computer and TV monitors are specially designed for human eyes. We have only three color receptors: red, green, and blue. It is more than likely that alien creatures will have different receptors, and our screens will look like gibberish to them.  Although it probably would not be difficult to make a screen translator.

Aliens might have senses that we don’t. They might be sensitive to magnetic fields, like birds. Or imagine a creature that somehow grew ridiculously large, say, several miles across. Such a creature might evolve a gravitational wave sense (though it is difficult to imagine a scenario in which such a sense would be useful enough to be selected for). Or consider the rate at which we perceive time passing. There is no reason to assume this is an absolute. Some creatures might experience time so slowly that a day to us feels like a month for them, or so quickly that crossing interstellar distances might feel like a drive to the supermarket.

We have only just finished saying "good morning."

Aliens might have wildly different morality. Much of what we as humans consider right and wrong is based on natural instinct. Take marriage, for instance. It is nearly universal across the globe and human history that two people join together in a commitment and live the rest of their lives together, cooperating and raising children. This is because it is embedded in our psychology that the most intimate and meaningful relationships we can have are between two people, and the healthiest childhood environments are with two loving parents. But if we look to the animal kingdom, monogamous commitments are hardly universal. Many creatures mate indiscriminately, generating as many offspring as they can and betting that some will survive. Ants and bees have hives, with drones, workers, and one queen (mother). Alien creatures who evolved intelligence with mating habits like these would certainly have their own institutions and rituals, which most of us would probably find disturbing and barbaric. Yet, with enough investment in diplomatic relations, we may be able to find common philosophical ground.

        Flemming! How are the twins?        Still digesting their mother, thank you for asking.

I have spoken about many of the ways that alien life might be different from us, but have not touched on the most mind-boggling possibility of them all: alternative molecular biology. On Earth, every living thing contains DNA as the instruction code that causes it to grow, function, and reproduce. But DNA is not the only molecule of its kind. There are also RNA and PNA that we know of, though it is doubtful that we could find planets full of life based on those. But the fact that alternative nucleic acids exist means that there might be more possibilities that we have not discovered yet. If life can be made up of alternative molecules to what we find on Earth, there is no telling what might have evolved. There might be creatures whose chemistry is based on a liquid so cold that they would not feel the difference between liquid water and molten lava. There might be creatures who feed off gamma rays. When dealing with such great unknowns as the potential configurations of life in the universe, there really is no way to know the limits of what is possible.

With all the stars in the universe, it is hard to imagine that our world is the only one where civilization has arisen. Think of a species on some other planet gaining sentience, bringing forth philosophers, scientists, and astronomers, and coming to understand their place in the universe. One of these creatures, a humble and curious artist, looks up at the stars and wonders  if somewhere out there there is something like it living under a strange sky, breathing strange air, and living in strange homes it has built for itself out of the materials of the strange ground it treads upon. It watches strange sunsets, and sees love so familiar in the strange faces around it. These creatures, that the faraway alien dreams about with such wonder, are us. We don’t live in The World, we live on a planet around a star in a remote corner of the universe, and no matter how different the other inhabitants of this universe may be from us, this, we share in common.

Friday, March 10, 2017

What is Science?

A few months ago, I wrote a discussion called “What is Not Science?” trying to understand the philosophical difference between science and magic. I gave a quick definition of science in order to get to the meat of the discussion, but there is so much more to science than can be stated in a few sentences. But I can do better than that. Today, I will get to some of the machinery that puts the power in science.

The Atomium in Brussels, Belgium

We awaken in this world, and try to make sense of it. We see this and that, and think we have figured it out. But the human mind is easy prey to error and bias. So we build up a repertoire of tools to obtain valid data and conclusions, minimizing the window for human interpretation. Science is, in essence, no more than this.

I grew up young-earth Creationist, believing that the Earth and the Universe were around 6000 years old, as you get by counting the begats in the Bible. I believed that biological evolution and the Big Bang theory, along with plenty of other mishmash that were lumped in together as “historical science,” were ad hoc pieces of a disjointed and convoluted attempt to explain the world without allowing for the possibility of a God. When I got to college, I chose to major in physics, thinking about black holes and wave functions, things I was taught were “observational science.”
          I learned the concepts of physics, and as I went, they made sense to me. I learned of the Doppler shift, the difference in the pitch of the sound a car makes when it comes toward you or goes away from you. It is due to the peaks of the sound waves being produced at different places, and arriving at your ear stretched or compressed. I learned that the same is true for light, that something moving away from you will be “redshifted” as its wavelength arrives stretched out, and something moving toward you will be “blueshifted,” as its wavelength arrives compressed. Sure, this made sense. I could see it in my head, and could do the calculations. I learned about how we measure distances in space by using “standard candles,” phenomena that always put out the same absolute brightness. By observing how bright a type 1A supernova looks in some galaxy, we can calculate how far away that galaxy is. Then I learned about how Edwin Hubble discovered the universe was expanding. He looked at a number of galaxies and plotted their distance against their redshift, and found that the farther away a galaxy was, the faster it was moving away from us. Made sense to me.
          But then the professor did something that blind-sided me like the twist in a Brandon Sanderson novel: he took the slope of the line on the plot, Hubble’s Constant, and inverted it so it had units of time. The value was 20 billion years, and it was the time in the past that every galaxy would have been at the same place. This was the first hint of the model that would later be known as the big bang. My teachers did not try to dogmatically shove it down my throat, but presented a series of logical steps, each simple enough in its own right, the same way they had taught me everything else. Of course this alone isn’t proof of the big bang theory’s validity, but I was forever changed by the realization that “observational science” and “historical science” are exactly the same thing.

In my journey since then, my respect for science has grown into nothing short of awe. Not just for what it has revealed about life, the world, and the universe, but by the methods used and the historical struggle to find new and better ways to study things. In the rest of this discussion, I am going to describe the various philosophical theories of science, and then get nitty and gritty with some of the definitions and tools science uses to uncover the picture of reality in insanely fine detail.

In my “What is Not Science?” post, I mentioned four philosophical theories of science, which I learned about from a YouTube lecture course from the University of Hannover, Germany. I wanted to get onto the rest of the discussion, so I didn’t take the time to explain them. But now I have all the time in the world, so here we go.

The first theory of science suggests that if we make an observation enough times, we can inductively conclude that it is always true. If we measure objects falling at 9.8 m/s2 enough times, we can conclude that objects will always fall at that acceleration. If every swan we observe is white, we can conclude that all swans are white. Yet Inductivism has a major problem: all it takes is one counterexample to prove an induced conclusion false. All it takes is the discovery of one Australian black swan to show that not all swans are white.

To remedy the problem of induction, we might turn to Deductivism, which says we start with something we know is true, and follow the logic to predict a conclusion. For example, if Newton’s Law of Gravity is true, then we can predict what the strength and direction of the gravitational field will be at any point in space. But how do we know Newton’s Law of Gravity is accurate to reality? In order to deduce anything, we have to know something to begin with. We could test it with experiments, but how will we know when we are done? Does the result change if I pour a cup of coffee before doing the experiment? What about two cups? If we don’t test every possible variation, we’re left back at Inductivism. Deductivism works well in mathematics, where it is acceptable to define axioms into existence, but the truths of reality are already there, and we cannot deduce them if we have no facts to build from.

Paradigm Theory:
How do we avoid the assumptions of induction, yet have a foundation for deduction? One possibility lies in paradigms. A paradigm is a model that describes something, considered the common knowledge of the day, or a consensus among experts. For instance, Europe went through a paradigm shift 500 years ago from Ptolemy’s model of the heavens with the Earth at the center to Copernicus’s model with the sun at the center.
          Paradigm Theory says that science starts from a blank slate. There is a period of exploratory experimentation, from which scientists extrapolate a model via induction. They then agree to take the model as the scientific paradigm, and conduct deductive research assuming it is true. They continue to take the paradigm for granted until too many problems accumulate and the model gets too convoluted, and the field goes back into an exploratory phase, where a new model which can better fit all the data, old and new, is sought. A new paradigm is adopted, and the cycle continues.
          Yet Paradigm Theory has its own share of problems. Science can only have revolutions when the current paradigm is challenged, which will not happen very often if the paradigm is merely accepted. In practice, the theory would lead to scientific stagnation.

Systematicity Theory:
Sometimes scientists use induction, sometimes they use deduction, and sometimes adopt a paradigm. Sometimes they do something else entirely. It all depends on what works at the moment. But this begs the question; what is the standard by which we determine the best course of action? Well remember the goal of science: to understand reality to the best of our abilities. The standard is determined by what course of action is the most systematic, that is, what is the best way to gather accurate, relevant information and organize it into a model, which leads to technology and more questions.
          For example, Einstein’s General Theory of Relativity is one of the most robust theories in science, standing strong after 100 years of refining fire. Even now new tests are being proposed, with new telescopes and gravitational wave observatories. There are also a collection of alternative theories people work on, on the slim chance that one of them will turn out to more accurately reflect reality than General Relativity.

This may not seem like a very satisfying answer, because it does not give us a simple rule as to how this should be done, but only tells us that it should be done. You may have heard of something called “the Scientific Method,” and expect this is what I am building toward. But the truth is that there is no single scientific method, rather a collection of tools that get updated and improved all the time. What we call science today is the culmination of thousands of years of philosophy, and it is reaching new heights faster today than ever before. So what are those tools? What have our centuries of thought and improvement given us? Here are a few.

One of the first things students learn in school science lab is significant figures. No measurable value will be a rational number; it will have an infinite number of decimal places. When you take a measurement, you must know how precise your tool is and where to round. When you make calculations, you have to know which decimal places to keep and which to throw away. Done properly, you get good data. Done improperly, your rounding errors can add up and give you a completely different result. College science students often complain that their online homework programs are too picky, but the students would have no problems if they carried their significant figures properly and avoided rounding errors.

Because real values have an infinite number of decimal places, but we can only measure them with some finite precision, we need a way to show the maximum amount our measurement might be off. You might see a number reported as 1.348 ± .0024. The ± .0024 is called the uncertainty, and it is taken from how precise the measuring tool is. For instance, on a ruler that goes to millimeters, the uncertainty would be about 0.7 of a millimeter, perhaps less if you are well-trained at estimating between tick marks.

The lines extending upward and downward denote each data points uncertainty. There are a range of possible fits, but the line definitely slopes upward.

In everyday speech, uncertainty is synonymous with doubt. Saying you are uncertain is like saying you are insecure or worried your conclusion is not true. This leads to a lot of confusion when scientists talk about uncertainty in measurements. The classic example is human-caused climate change. Naysayers will claim that scientists are “uncertain,” and take that to mean they don’t know what they are talking about. But this is scientific uncertainty, the quantifiable spread of each data point. That spread is minimal enough that, though there is wiggle room in exactly how much we are affecting the global climate or exactly what the long-term effects will be, there is no question that we are affecting it, and the average global temperature is rising much faster than usual.

Believe it or not, there is a whole branch of mathematics committed to determining the quality of data, and comparing models to see which fits the data better. New and better methods are being developed every year. I wish I could explain it—this part of the discussion feels incomplete without any of the technical details—but unfortunately I don’t understand it well enough. If you want to do some research on your own, you can look up “5 sigma significance,” “p-value,” or “Bayesian inference,” and see where that takes you.

Back in the day, every calculation had to be done by hand. But now, we have machines to do them for us. In fact, computing technology is so fast today that university supercomputers can simulate the evolution of the universe from an early stage of dust particles to the present-day cobweb-looking galactic supercluster structure of filaments and voids. Computers can save tremendous amounts of time and eliminate human errors, provided the right parameters are entered. Today, we can do things that the scientists of past centuries would never have dreamed of being able to do.

Every dot in this picture represents a cluster of galaxies.
Peer review:
You could be the smartest person alive, and make breakthroughs in all kinds of fields from modern physics to cell biology to statistics to computer science, and yet be blind to some lines of evidence leading in a slightly different direction. We all have biases; it’s part of being human. You can train your mind in logic and reason, and use all of the techniques I’ve talked about, but even all that cannot get you to perfect objectivity. The best way to overcome this is to have other people around who understand your field, and do their best to poke holes in your work from all different angles. This is the peer review process. Whenever someone tries to publish a paper, there is a committee of experts who put it under the knife and make absolutely sure that their work is up to scientific standards. After a paper is published, it is open for criticism by anyone on planet Earth, including every scientist who is working in a similar field. Once the fiery rigors of the review process are over, the ideas that most reflect reality stand tall while the garbage vanishes.
          Sometimes people ask why science refuses to study this or that, suggesting scientists might have some kind of conspiratorial agenda. But there are two possibilities that such ideas almost always fall into. Perhaps, like consciousness, scientists don’t yet know how to study it. Or perhaps, like extra-sensory perception, the idea has already been tested and discredited. In any case, the only agenda scientists have is to adhere to the high standards of making sure an idea accurately reflects the relevant data, follows the logic, and addresses any and all assumptions made.

Challenging the norm:
Science is all about following trails of evidence to uncover truth about reality, whatever that may turn out to be. This means that, no matter how well established an idea is, no matter how well a model has held up to experiment so far, it is not beyond question. If an alternative meets all the standards of the time, papers get published. I laugh whenever someone talks about scientists being biased or close-minded, caught in unbreakable tradition. Overturning tradition is what science is all about. The new idea just has to fit into the puzzle better than the old.

Science is not just a collection of knowledge, but an ever-improving set of methods of understanding. The scientific landscape is riddled with checks and balances to further completeness and minimize the influence of human imperfection. I once spoke to a man who thought, since scientists change their minds, that they are unreliable and do not know what they are talking about. “I always take what scientists say with a grain of salt,” he said. I have always wondered who he does trust, if not the people who study things for a living. Science is all about research, and research introduces new information that you have to take into account along with the old. As the economist Paul Samuelson said, “When my information changes, I alter my conclusions. What do you do?” Change is absolutely central to scientific thought, and though it may appear to flit this way and that, in the long term we are brought closer to the truth.