Friday, October 14, 2011
The primary reason I'm doing it is because of the math editing. I can write my posts in LaTeX, run a quick converter (in python!) and get something that looks nice in wordpress. Let me know what you think! If it fails, then it was a worthy experiment.
Wednesday, August 3, 2011
Now, to be fair, I have not actually seen Lost, so perhaps my comments are unwarranted, but I decided not to watch Lost for the following reason. When Lost was first beginning, several friends said that I would like it. I told them that I would watch it if, and only if, at the end of the series they could tell me that the “plan” for the series actually existed. It was claimed that the series was planned from start to finish, but my friends told me afterward that it was clear it wasn’t, after watching the finale. Too many loose ends, too many mysteries.
I think that J J Abrams learned the wrong lesson about mystery, as represented by his television show “Lost”. It’s not just the mystery, for the sake of mystery, it is the solving of the mystery that yields more mysteries. Scientists are comfortable with not knowing...we are constantly at the edge of what is known and not known. However, what motivates the scientist isn’t the mystery, it is the solution to the mystery knowing that will open up more. There is nothing more dissatisfying than a book, movie, or television show that just opens up more and more “mysteries” and never resolves them...it seems artificial and disorganized. Most people assume that the mysteries will be solved by the end, so they allow themselves to be taken in by the mysteries. However, once it becomes clear that the mysteries are not going to be solved, most lose their attention and become disenchanted.
What made Babylon 5 so engaging was that there was a plan, and you could count on it. You knew that if there was a mystery, that you’d see the resolution of it. I’ll admit that the resolution of the main conflict (the Shadow War) was a bit disappointing, once it happened, but I think part of that feeling had to do with pace and not with the resolution itself. Mystery for the sake of mystery is enough to motivate, temporarily, but not forever. In the real world, solving mysteries opens up more...that’s the real motivator!
Thursday, July 28, 2011
“I almost bought your discussion until you provided the diagram from Kiehl and Trenberth which is ludicrous. The whole construct here is to create the illusion that the sun cannot heat the earth above minus 18 which is absolute nonsense based on assuming it is valid on geometric grounds to reduce the solar insolation by a factor of 4 then again by the albedo.
If this is valid how then does the surface temperature of the moon reach ~123 C - quoted by NASA.
And how do you explain daytime temperatures on Earth in excess of 50 C as has been recorded ?”
I will focus on the Moon part, just because it is the easiest, but it will be natural to see how to approach this for the Earth as well. First, I must point out the irony of the comment. In trying to defend the claim that the climate models ignore conduction and convection, and focus exclusively on radiation, the comment refers to a system (the Moon) where there is no atmosphere and thus no conduction (except within the ground itself) or convection! Second I have to wonder about how stupid the commenter thinks NASA is. Do they really think that scientists would consider models that are flagrantly in conflict with the most basic observation about the Moon’s surface (i.e. its temperature extremes)? Do they really think that scientists would come up with a calculation that Moon can’t achieve temperatures above, say, -18 C and then stare at 100 C temperature measurements and just leave the calculation as is for decades? Let’s consider how one would develop a model of the surface temperature of the Moon, and it will answer the objections raised in the comment, as well as outline how real science actually progresses.
The Average Blackbody Model
We start with a very simple model of a spherical body out in space receiving input from the Sun to the tune of 1400 W/m2. At the same time, the spherical body emits radiation with a power per square meter dependent on T4 (i.e. the blackbody law).
Notice that in this very simple model we are assuming several things:
- that the conduction within the body is instantaneous, thus the temperature of the body is uniform, and the output energy is uniform.
- the body is not rotating, so the radiation it is receiving is constant
- there is no atmosphere, thus no conduction or convection outside of the solid body
- the albedo is the average albedo of the Moon, or a=0.14. Thus this object absorbs 86% of the radiation coming in
The total energy out of the body would be the blackbody term shown, multiplied by the total surface area of the sphere: the radiation is outward in all directions. The incoming radiation, however, strikes only one side. Further, it strikes at different angles. Applying calculus one finds that the effective area is simply the cross-sectional area of the sphere, or the area of a circle the same size as the sphere.
We can then write down the change in the temperature, which depends on the material (the mass and specific heat), given the net energy input to the body. I’ll call this dependency K...its exact value, although calculable, will not be important in the model except qualitatively. We then have
When the “energy in” is greater than “energy out”, the temperature increases. When “energy in” is less than “energy out” the temperature decreases. Once it reaches equilibrium, temperature remains constant. What constant? That would be when dT/dt=0, or...
If we look up the values for the actual Moon we get the following:
So our model is not too bad, for the average value, but it could probably be improved. So, now back to the comment which motivated this all:
“If this is valid how then does the surface temperature of the moon reach ~123 C - quoted by NASA.”
The bottom line here is that, if there is an observation that is in conflict with a model, one of the assumptions of the model is probably incorrect, or perhaps you’re comparing the wrong observations to the model. We assumed that the object has a uniform temperature but we know from the 3 data points above (the min, max and mean temperatures) that this is not true! Essentially our model didn’t even attempt to describe temperature variations on the surface, so it comes as no surprise that it is not consistent with them. Many times theorists will use a model, with known deficiencies, because they are interested in different questions: perhaps we are only interested in the average value, and what happens from that average value? In that case, it doesn’t make a lot of sense to include complexities that will be averaged out anyway when we want to answer our question.
To miss this point is to miss the entire process of comparing theory with experiment. It turns out, however, in this case we can make a few simple modifications to explore some of the temperature variation.
The Infinitely Slow Surface-Conduction Model
We use the same assumptions as before, with one modification (in bold):
- that the conduction within the body takes an infinite amount of time (i.e. no surface conduction at all). Thus, each patch of surface acts as its own independent object
- the body is not rotating, so the radiation it is receiving is constant
- there is no atmosphere, thus no conduction or convection outside of the solid body
- the albedo is the average albedo of the Moon, or a=0.14. Thus this object absorbs 86% of the radiation coming in
Imagine a patch of surface 1 square meter, with the same albedo as the Moon (i.e. absorbing 86%), and a combined mass and specific heat summarized by a constant K’. The energy equation then becomes
at equilibrium we thus have
which again, is reasonably close to the real value. Notice that all we had to do is change the conduction assumption to get surface temperature variation. If you’re concerned that the maximum temperature predicted is lower than the observed, notice that I am using the average albedo of the Moon. There are parts of the Moon’s surface with a lower albedo, and will thus get hotter as a result.
Now imagine a patch of surface 1 square meter, with the same albedo as the Moon (i.e. absorbing 86%), and a combined mass and specific heat summarized by a constant K’ but with no sunlight at all coming in. The energy equation then becomes
The only equilibrium value for this is T=0. If no energy is coming in, and we have energy going out, the object will keep cooling. So in this model we have the near side T=380 K and the far side T=0 K, at equilibrium.
Although the model is clearly wrong, it demonstrates one thing: you can easily get temperatures above and below the average-model calculation simply by having not all parts of the surface heated equally, and some non-zero time of energy “communication” (i.e. surface conduction or, if you have an atmosphere, conduction and convection with the atmosphere) between the parts. The extreme version calculated here simply demonstrates the effect and is not meant to be realistic.
Adding a Few More Complexities - Qualitative Discussion
We now modify the assumptions as follows
- that the conduction within the body takes a finite, non-zero, amount of time
- the body rotates once every 28 days, like the Moon
- there is no atmosphere, thus no conduction or convection outside of the solid body
- the albedo is the average albedo of the Moon, or a=0.14. Thus this object absorbs 86% of the radiation coming in
- the maximum temperature predicted will be a bit lower than the no-conduction model. This is primarily because the moon rotates the near-side patch out of the the most direct sunlight relatively quickly. If the surface conduction is on the order of minutes, this will make little or no difference. If it is around hours to days then it will. In fact, one could use this difference to help determine the time constant (related to the constant K’) for the surface of the Moon
- the minimum temperature predicted will be higher than the T=0 predicted from the no-conduction model. This is both because the moon rotates the far-side patch out of the dark, and that energy from the previously warmed surface will conduct to the far-side patch.
This all started when I criticized someone’s commentary on climate models, where they claimed that the models exclude thermal conduction and convection, and thus the focus on greenhouse gasses was entirely inappropriate. A further comment claimed that these models put an explicit maximum temperature achievable when they calculate the surface temperature of an object from blackbody equations. The comment further criticized my use of the average model summary for the Earth for this reason.
Notice the procedure we employed to model the system, and address these concerns. We started with a very simple globally averaged model, and got an interesting temperature value similar to the data. We then added a few complexities, such a differential heating, and noticed how this gives a range of temperatures on the surface. We also noticed that the range was half right (half wrong?): the maximum was good, but the minimum was terrible. Adding rotation and non-zero conduction time gives some dynamics and can achieve reasonably close agreement. A more detailed implementation of the local albedo fixes the small errors, especially on the top end. By using this procedure, we can see exactly which parts of our model give which parts of the result. It also shows which parts of the model give the biggest effect, and which are there for small adjustments.
All that is needed to go beyond the average model, and achieve temperature well above the average, is to include differential heating of the surface and some non-zero time of energy “communication”. Once you heat different parts in different ways, and add rotations and time-delays of conductions, you get some interesting dynamics around the average, going both above and below the average. The average calculation is still useful, if you’re not interested in short-term dynamics. It is further useful as a pedagogical tool, because it is a lot simpler. Thus it is not “ludicrous” to use the diagram from Kiehl and Trenberth, as long as one is aware that this is a globally averaged model. If you attempt to infer things well beyond the point of the model, then do not criticize the model - criticize your comparison, and look for a more detailed model that addresses the questions that you’re interested in.
Wednesday, July 27, 2011
The stated goal for this change, from the NSF, is to separate knowledge from belief. You might believe that humans are created in their present form, 6000 years ago, but the new questions try to ascertain whether you know that “evolutionary theory” says something different. Is this an important distinction? Is this what we really want to measure? Which is more important for a society? What is the difference between knowledge and belief?
It is quite clear that there will be at least one effect for this rewording: given that the US falls way behind other countries on science literacy, especially with these particular questions, the rewording will most likely increase these numbers with no other work done.
Definitions and Concepts
Beliefs are representations of the world. Specifically, they are representations that we hold to be correct for the real world...as opposed to hopes, which are also representations of the world by not ones that we hold to be necessarily correct. Along with beliefs we always have a confidence in the belief, specified as a probability (either explicitly or implicitly). Knowledge is simply that collection of beliefs that we hold with such high probability or, in other words, with such confidence that we do not significantly doubt them. The belief that the sun rises in the east each morning is considered knowledge for the reason that we hold it with an extremely high probability. This is not just as a result of an inductive reasoning process (i.e. it always has, in our experience, risen in the east each morning) but because it is part of a larger body of knowledge (i.e. astrophysics) for which it is just one consequence within a whole host of other well-established predictions.
Now, on to scientific literacy. The NSF defines scientific literacy as “knowing basic facts and concepts about science and having an understanding of how science works.” Why is it important? Again, the NSF: “It is valuable not only in keeping up with important science-related issues, but also in evaluating and assessing the validity of any type of information and participating meaningfully in the political process.” The question we must ask is, does the new wording measure scientific literacy better than the old wording? To do this, we need to outline the four possible types of people answering the two forms of the questions:
- people who answer “yes” to the old and “yes” to the new
- people who answer “no” to the old and “no” to the new
- people who answer “no” to the old and “yes” to the new
- people who answer “yes” to the old and “no” to the new
- people who know both that, say, the universe began with a big explosion and that astronomers claim that this is true. This is indicative of scientific literacy.
- people who don’t know, or do not believe, that the universe began with a big explosion and that don’t know that astronomers claim that this is true. This is indicative of scientific illiteracy.
- people who don’t believe that the universe began with a big explosion but know that astronomers claim that this is true. (more on this below)
- people who know that the universe began with a big explosion, but do not believe that astronomers claim that this is true. This might at first seem to be a totally unreasonable and marginal case, but I think it is more significant than perhaps is generally appreciated. These people might think that the new wording is a trick question (e.g. they might think that physicists, as opposed to astronomers, claim that it is true). I’ve had students answer questions in this way, so it is not quite as uncommon as one might think. These students overthink the problem: they know the fact, but are distracted by the extra complexity of the question, thinking that the test is trying to trick them.
The only reason these particular questions were modified was because of the prevalence of religious belief. How do we know this? We don’t see a proposal to change “The Earth orbits around the Sun and takes a year to do it” to “According to astronomers, the Earth orbits around the Sun and takes a year to do it.” Why? Because no religion (now) has a stake in the answer to that question, and thus have no objection to the claim. Of course, if you go back to the days of Copernicus this was a different story and people were severely punished for too strongly making such a claim. The two questions that are proposed to be changed in this way are precisely the two concepts that crop up in every creationist tract, and are clearly the two major stumbling blocks for a literalist reading of the Bible or the Quran.
Aside from the motivation for the change, we can ask the question whether it is accomplishing something important anyway. Are these Case 3 people, who would answer “no” to the old question but “yes” to the new question, demonstrating scientific literacy? I don’t think so. What they’ve confirmed is that they know that some scientists claim that the universe began with an explosion, but they don’t believe it. This means that they don’t accept the data, or the methods, or both. If the question were about something on the fringes of science, then perhaps this is fine, but it isn’t the case with these two questions. Evolution theory, for example, is as well established as the Round Earth theory and the Germ theory of disease. To deny it is to deny all of the independent work in molecular biology, embryology, ecology, etc... which support it. Even though they may know that fact that biologists support Evolution theory, they have not demonstrated any scientific literacy in terms of “evaluating and assessing the validity of any type of information and participating meaningfully in the political process.” The same can be said of the Big Bang theory, to a slightly lesser degree (i.e. there isn’t quite the volume of completely independent fields of study supporting it, as there is for Evolution, but the data is nearly incontrovertible anyway). To deny either idea is akin to denying the Germ theory of disease.
Imagine someone answering “no” to the question “The world is round” but answers “yes” to “According to geographers, the world is round”. Would they be demonstrating scientific literacy? I don’t think so. Do we want to pander to the religious-motivated ignorance in this country, for the sake of increasing the appearance of scientific literacy? I don’t think so.
Tuesday, July 26, 2011
- It is a very good day for a scientist to go in to work, and to demonstrate that one of his colleagues is wrong. It’s even better if the wrong idea/theory/model is one that is popular! For those scientists to adequately demonstrate that a popular idea is wrong, we have for them the Nobel Prize. Of course, it is very hard to demonstrate that a well-established idea is wrong because, by definition, a well-established idea in science is one where many many smart people have tried to show it is wrong and have failed. For those people who claim that scientists have a conspiracy to uphold popular scientific ideas (a criticism creationists level against the support of evolution), they completely miss the goals of every scientist.
- It is also a good day when someone criticizes your idea. In the comment on my post, the criticism took the form of “if your idea is correct, how do you explain the following observation...”. Awesome! Why? First, someone bothered to read my post, and found it important/interesting enough to comment...that always makes me happy. Secondly, I’m now in a win-win situation. There are 3 possibilities:
- the criticism is flat out wrong, and I get a chance to both teach something, and to bolster my idea...I can be a bit more confident in my idea.
- the criticism is partly correct, and I get a chance to add a bit of nuance, or explore a part of my idea that I hadn’t fully considered
- the criticism is correct, and I have learned something about the world and have to modify my thinking (at the expense of scrapping my idea).
Now I need to go and address the criticism.
Wednesday, June 1, 2011
Hand in your cell phones, please.”
I’ve stated this before, in the form of removing medical treatment for those who refuse vaccines. I am never completely serious, but it is frustrating to see the dichotomy.
The issue I have with this article is one that I’ve written on before here and more here: he focusses on the comparison between evolution denial and climate denial. It really drives me nuts! I am not entirely convinced by the climate data that the situation is as dire as is claimed. I am not sure whether the climate scientists have provided a clear enough picture, without distortion, cherry-picking, and exaggeration. I don’t have to deny all of physics, chemistry, and biology to hold this position as creationists have to do. Perhaps I’m what is sometimes called a luke-warmist, but even on its best days climate science is nowhere close to as well supported as evolution.
Enough! Stop comparing global warming deniers to evolution deniers. It’s a bad comparison, and extremely misleading.
Saturday, May 28, 2011
Someone recently made a comment that they thought that there was a lot of “frivolous” research in science. They said “I don't really care how big the universe is. I am not happier because of that knowledge. My life is no better, nor my parents or my future children.[...] For me, in the end I don't see how it benefits humanity. I would much rather see that time and intellect spent on pursuing ways to improve global living standards, protect the environment, create a better education system, etc...”
There are several things I could say about this. People are notoriously horrible at predicting which lines of intellectual pursuits will yield real practical results (i.e. direct benefits to humanity). For example, in the late 1800's there was some work done on some pretty obscure mathematical concepts in wave mechanics. At the time there were very few practical results foreseen from this work, if any. However, it later became the foundation for telecommunications, which arguably makes up the bulk of the global economy today. There are many examples like this. That's why it's always good to have basic research funded well, even if it seems frivolous at the time.
Knowledge matters, no matter what it is. Your example about how you don't care how big the universe is, for instance. Let's look at a couple of contrasting beliefs, and their consequences to things like protecting the environment, something you state is important. Person A believes that the world was created specifically for humans, 6000 years ago, and that this creator is making sure things are going along well for his followers (i.e. granting miracles, giving guidance, etc...) Person B believes that the Jesus is going to come again in this lifetime, and the world will end in glory. Person C knows how big the universe really is. This means that person C realizes that 1) the Earth is a relatively small place and 2) there isn't anywhere else we can go if things get messed up here. Which person do you think would be most willing to make difficult decisions to protect the environment for the next, say, 200-300 years?
There are benefits to "frivolous" science. One benefit is in critical thinking, no matter what the topic. Another benefit is the philosophical placement of humans in the grander scheme of things. This can have direct *practical* effects on humanity, and its future. On any topic, truth beats untruth.
Wednesday, March 9, 2011
I am not sure what the best thing to do with these people. I thought about doing what Richard Saunders does, and wear 10 of them (buying them in bulk) and handing them out with a demonstration. That might get me thrown out. Someone suggested I contact the media, a month or so ahead of time for the flower show, and get them to do an investigative piece. Another thing I may do is, if they are willing, is to suggest a very simple blinded experiments. The nice thing about the balance bracelets is that they claim some very simple, reproducible effects. As a result, it is pretty easy to test it in the confines of a vendor booth at a flower show. I will need to come prepared with two identical little bags, and a fake bracelet, in order to do the test. Also, if they claim improved balance, it’d be nice to have a balance test where the the seller is not involved...something like a balance beam, perhaps. I feel confident that I can be a real pain, yet not involve lawyers, in a case like this.
Tuesday, March 8, 2011
Perhaps they should poll their audience on the question of where they believe morality comes from. If a significant fraction states that it comes from scripture, then it no longer is a strawman. I just don’t think it would come out that way.
Friday, February 25, 2011
It is important to note that every little bright smudge on this image is a galaxy with billions of stars. This image is a very small piece of the sky, around 1 out of 150 million, making estimates of galaxies in the visible universe around 100 billion. It is worth pausing and thinking about that. When I think about the majesty of the universe I find it infinitely more inspiring than the parochial, one-world God, of the major religions. Just trying to imagine our place in this vastness, and to imagine that there are other beings out there doing the same thing, wondering if they are alone, there is a sense of awe and wonder that is difficult to describe. Try it sometime: try to grasp, even for a few seconds, what billions of billions of worlds would be like, spread across a space that takes millions of years for light to cross when light can circle the earth in (literally) the snap of a finger.
Thursday, February 24, 2011
So it was refreshing to hear this talk by Prof Richard Muller at Berkeley, and to see the Berkeley Earth Project start up. It’s seems to be a reasonable look at what we know confidently, what we really don’t know, and many of the communications failures in the recent years between the climate experts and the public. I was pointed to this talk by Dr Judith Curry’s website, which also seems to be a breath of fresh air on this whole topic. It seems serious and scientific. It doesn’t resort to the hysteria of Al Gore or of Sarah Palin.
I’m looking forward to following these groups more closely in the future.
Wednesday, February 23, 2011
Another article on NPR compares Watson to a plant. “Watson, biologically speaking, if you get my drift, is a plant. Watson is big and it is rooted. Like all plants, it is deaf, blind, and immobile; it is basically incapable of directing action of any kind on the world around it.” Continuing, “Giving a plant a camera won't make it see, and giving it language won't let it think. Which is just a way of reminding us that Watson understands no language. Unlike the ant, who acts as though it has reasons for its actions, Watson acts like a plant that talks.”
I think both authors are pretty glib at stating that Watson doesn’t think like us. I am not entirely convinced. When Deep Blue defeated Kasparov in chess, it was stated that Deep Blue doesn’t play chess like a person plays chess. This is true. Deep Blue simply tries all of the possibilities, good, bad, and stupid. Chess masters don’t even see bad moves. Watson is another matter. Sure it compares the words in the question to a big database, but it is doing probabilistic reasoning at its core. This is exactly what people do. So Watson can’t handle very abstract questions, like the concept of melting snowmen, but could a child who has never experienced snow make this leap? We make this leap because we’ve been presented, throughout our life, with a regular universe and our brain has made an internal model of that universe. Watson, too, has an internal model for its universe but the difference is that Watson’s universe is sensory impoverished and conceptually limited.
Watson certainly cannot think as well as we humans, but that is a limitation more of its hardware and the training environment that it is in. But in many ways, Watson thinks just like us.
Monday, February 21, 2011
Take, for example, a recent post I saw on Facebook from one of my friends:
...poses a direct challenge to all creationists. Provide an explanation for vestigial features of living organisms without inadvertently proving evolution.
He was surprised to learn that Answers in Genesis, the go-to place for all things creationist, had a position on vestigial features. That description made use of arguments from molecular biology, and so-called microevolution. It seems as if it is a common misunderstanding that creationists reject all of the apparatus of evolution and microbiology, and a simple, strawman statements like “creationists reject evolution” don’t hold.
It really does help to look at the best arguments from each side, to really see the limits of the analysis. Going back and forth between Talk Origins and Answers in Genesis is a good way to explore the arguments. For example, in transitional fossils we look in Answers in Genesis and find articles like this one and this one which steep of arguments from authority, claims without evidence, and cherry-picking. Many of the arguments rest on criticizing small details on a small number of fossils. In the talk origins article on transitional fossils, we get a very detailed, and seemingly complete, list of transitions from all major animal types. It comes in many parts, and details the characteristics on each transition.
Try it yourself! Pick a topic, go through and find the best arguments each has. It’s a very good exercise. Throw in a good dash of the baloney detection kit, and you’re on your way.
Friday, February 18, 2011
Here’s at least one piece of wonder in the Universe. See the Earth in this picture?
This is a picture of Saturn, with the Sun behind it, taken from the Cassini spacecraft. See that little white speck in the rings, in the upper left? That’s the Earth! There are two responses I have when seeing this picture.
1) We’re really small and insignificant in this Universe
2) What an amazing thing that we can create something on the Earth, send it a billion miles, and be able to take a picture of ourselves. That’s amazing!
The universe is amazing, both in its magnitude and complexity, and we should feel a sense of awe. All this, without introducing unnecessary constructs such as deities. Although science is often accused of arrogance, I can think of no humbler activity than that which brought us the picture above.
Thursday, February 17, 2011
I’ve seen the light, and I’ve realized that in some ways it was the wrong decision to become an atheist. I think it was what I needed at the time, and now it is not. I even changed my Facebook profile!
So, what changed my mind? Sam Harris did, in his lecture on the “Problem with Atheism”. Essentially, it boils down to the fact that we don’t need a word for not believing in something, and that to attach a charged word to it undermines the position. We don’t need, as he says, a name for “non-astrologer”. We just need to espouse the positive virtues of believing with sufficient evidence, for the quantification of uncertainty, of intellectual honesty and consistency.
So, in an effort to be more positive about my beliefs in evidence, rationality, and science, from now on I am not going to consider myself an atheist. If someone asks me if I believe in God, I will say I don’t believe in Zeus, Thor or Yahweh (or any of the other gods we’ve heaped on that pile we call mythology). If asked what religion I am, I’ll just say “None”.
Wednesday, February 16, 2011
I’d wonder how this success will play into the broader discourse on the human intellect, and our view of ourselves on the universe. When Deep Blue defeated Kasparov, and the computer became (unofficially) the world chess champion, I remember having mixed feelings. We like our icons, I suppose, and hate to get rid of them. It’s like growing up, and losing Santa Claus, perhaps. The history of science has been to deflate human arrogance, and yet successes like Deep Blue and Watson are not quite the same because it is our own ingenuity which created them.
On some level, Watson feels like a different accomplishment than Deep Blue. Chess is deterministic, well formulated, and complex. It’s complexity is the only thing that challenges an easy computer solution, which was accomplished finally by brute force: get enough fast hardware attacking a well-described problem and you win....always. Watson isn’t nearly as well defined as chess, or at least it doesn’t appear to be as well defined.
Watching Watson, there is a creepy sort of feeling, probably due to too many evil AI movies (2001, Terminator, Matrix, etc...). Kids growing up today will have this sort of technology as the norm. All-in-all, an interesting series of events to keep watching!
Tuesday, February 15, 2011
I love the look of shock on David’s face right after the “tides go in, tides go out, never a miscommunication. You can’t explain that.”. I think, however, David is completely ineffectual at conveying his point and looks like a jerk. As a followup, Bill responds to a letter in this video:
Here he concedes that the Moon causes the tides, but then adds a number of other questions:
- Where did the Moon come from?
- Where did the Sun come from?
- There is order in the universe. Where did we, in all of our intricacies come from?
- Why life on this planet and not on the other planets?
Although many scientists would laugh at these questions, that is the wrong response. These are reasonable questions! They are ignorant and (because Bill should have done a bit of research before asking them), uninformed questions but they are reasonable first-questions one asks. If one is honest about getting answers (which I don’t think Bill is), there are ready answers to these direct questions but it seems to me that the intent of the questions is a bit different.
First he says we can’t explain the tides. So we explain the tides, with gravity and the Moon. Then he asks “where did the Moon come from?” He could have just as easily asked “where did gravity come from?”. It is clear from this line of questioning that there will never be a final answer to satisfy him. Each time we answer one, there will be concepts that that one builds on, etc...
This is classic God-of-the-Gaps, but it is something that I think needs to be dealt with in a more subtle way than David Silverman and many other atheists seem to do. I think most people, rightly, have a sense of wonder about the amazing order in the universe. I think most people immediately attach this order to a creator, the nearest cultural deity, because they don’t have any alternative: they are not informed. In order to dissuade them, I don’t think that insulting their deity is effective because they take that as insulting their sense of wonder, and then science seems like a sterile, arrogant, unimaginative bully.
We need to find a way to enhance their sense of wonder, and yet dismantle the notion that this requires some external deity. We need to keep the spirituality, as a secular notion espoused by Carl Sagan, Sam Harris and others, because that is what is really driving the issues for most people and we need to push the use of the deity farther and farther away from daily life. Science has to be seen as a creative endeavor, one which fully respects the wonder and awe we all see and feel as we ponder the universe.
Saturday, February 12, 2011
The full text of the resolution is here:
Expressing support for designation of February 12, 2011, as Darwin Day and recognizing the importance of science in the betterment of humanity.
Whereas Charles Darwin’s theory of evolution by the mechanism of natural selection, together with the monumental amount of scientific evidence he compiled to support it, provides humanity with a logical and intellectually compelling explanation for the diversity of life on Earth;
Whereas the validity of Darwin’s theory of evolution by natural selection is further strongly supported by the modern understanding of the science of genetics;
Whereas it has been the human curiosity and ingenuity exemplified by Darwin that has promoted new scientific discoveries that have helped humanity solve many problems and improve living conditions;
Whereas the advancement of science must be protected from those unconcerned with the adverse impacts of global warming and climate change;
Whereas the teaching of creationism in some public schools compromises the scientific and academic integrity of the United States’ education systems;
Whereas Charles Darwin is a worthy symbol of scientific advancement on which to focus and around which to build a global celebration of science and humanity intended to promote a common bond among all of Earth’s peoples; and
Whereas, February 12, 2011, is the anniversary of the birth of Charles Darwin in 1809 and would be an appropriate date to designate as Darwin Day: Now, therefore, be it
Resolved, That the House of Representatives—
(1) supports the designation of Darwin Day; and
(2) recognizes Charles Darwin as a worthy symbol on which to celebrate the achievements of reason, science, and the advancement of human knowledge.
I was reading it with some interest, but then I get to the part about “the adverse impacts of global warming and climate change”. Why is climate change in there? There are so many obvious, uncontroversial topics directly related to evolution in medicine, pharmaceuticals, ecology, physiology, etc... that it seems to be both irrelevant and counterproductive to include it. Sure, the climate change folks think that denying it is like denying the holocaust or denying evolution, but it really isn’t nearly at that level. There are not the number of independent investigations and data supporting man-influenced climate change as there are for either evolution or the holocaust, even if the science were completely unambiguous on the topic (which it isn’t). To conflate the two is a serious tactical mistake, and a serious scientific mistake.
Although I support Darwin Day, I can’t support this resolution because of this ridiculous add-on.
Friday, February 11, 2011
This simple arrangement results in a distance to the Sun of about 6500 km. The world is flat!
So, we have two different explanations of the observations. How do we distinguish between them? Answer: the way it is always done in science - spin out the consequences of each, and make predictions where they disagree.
It is easy to show that continuing this calculation would result in some striking predictions. First, given this distance, and the fact that shadows change over the day, the apparent size of the Sun would be very different from one location and another...and it is never observed to be different, even across years. This suggests a very distant Sun. Further, you’d have to make sure that the Moon was closer than the Sun (inferred from eclipses) in both models. Once you do this, then you have two objects with the apparent size problem in the flat-Earth model, again not supported by observation. There are probably many other predictions this model makes which could easily have been verified by the ancients, so it is no surprise that they did not consider it in their calculations.
It is useful, however, to think about the consequences of models beyond the data they agree with.
Saturday, January 29, 2011
The problem she is stating, however, is quite real. How can we expect the public to make decisions about medicine, global warming, evolution, the big bang, etc... when they (somewhat rightly, somewhat wrongly) observe that the scientists themselves are arguing about it? The Intelligent Design folks are currently using this observation to sow doubt with the public in their efforts to “teach the controversy” of evolution to inject creationism into the schools. It is a failure of the scientists, and the media that covers them, to communicate with the public. Can we do better?
I have a proposal, which I’ll sketch out in a toy example. The problem is not the communication of facts, or even of the procedures of science. The problem is with the communication of uncertainties. In day to day life, we easily handle claims with different levels of uncertainties. The sun rises in the east each morning has low uncertainty. The claims of the auto salesman or the politician have higher uncertainty. Quantifying it is, of course, more challenging but the qualitative features of uncertainty are known to nearly everyone. So scientists and journalists really need to take efforts to communicate the uncertainty of every claim, not just the fact of the claim or how the new observations differ from the old observations. How could this be done? I think, at least roughly, one should include a plot of the probability distribution with any claim. One doesn’t need to know advanced math to see the picture. If every claim is accompanied by a plot of the uncertainties, the public will get used to reading them. Let me demonstrate with a toy example.
Say, I am trying to determine the origin year of homo sapiens. I realize there isn’t just one year, and there is a process, but it is not much harder to include those in this simple analysis. I have several homo sapiens fossils where I’ve measured the age, which allows me to calculate my best guess of the age, and the distribution of my uncertainty shown here.
I’ve used a normal, Gaussian, distribution here although in fact it probably should be something skewed left and probably a lot flatter to reflect our greater uncertainty with age, and that we have other observations that put confident lower limits on the origin of homo sapiens. Again, the details aren’t important because all attempts at clarifying the distribution only further help with communicating the uncertainty to the public. A few observations are in order here:
- there are many possible values for the origin that lie well outside of our data yet have non-zero probability
- Our “best guess” is around the middle of this distribution, but it really can’t be interpreted as “homo sapiens originated 250,000 years ago” as it might read in a newspaper
There are a number of lessons that can be read from this.
- the new data updates our “best estimate” by only a little - the old data, combined with the new data, are used for the estimate
- our uncertainties have widened - by having a larger range of data, our uncertainties may have increased with new data.
- observations rarely overturn well-supported scientific understanding
- not all topics have equal uncertainties - doubting everything the same amount is not rational
- certainty is never an option, but sometimes the uncertainty is so low that there is a practical certainty
- nature itself, not authority, determines our best guess and some of our uncertainty
- if the thing you are measuring has a small effect, then you should expect a series of measurements of the effect to change sign: bran is good, bran is bad, bran is good, etc.... This doesn’t mean that the scientists are waffling, it only means that the effect is small and difficult to detect - and probably meaningless.
In order to do this with religion one cannot simply take the good of religion subtract the bad, come up with a positive number, and say that religion is a benefit to society. It’s like saying that the treatment for the measles is two aspirin and some juice resulting in more cases of recovery than death and saying that we shouldn’t replace this treatment with something else. As is turns out, for the measles, a vaccine will prevent nearly all contractions of the disease, and virtually all deaths.
If we replace religion with a rational perspective (as Sam Harris proposes), which includes a respect for spiritual experiences but not the supernatural explanations of them, then it may be that we essentially vaccinate people against such behavior as suicide bombings, honor killings and inquisitions.
Wednesday, January 19, 2011
Tuesday, January 18, 2011
Friday, January 14, 2011
I've been listening to the "Beyond Belief" workshop, where many very bright people discuss the role of science and religion in society. I need to go back and re-listen to some of them, but I was struck by the attached clip from the very end of Session 4.
In this 5-minute audio clip, Darren Schreiber, UCSD Political Science, make the point that science shows little humility. He continues to claim that his religion is what motivates him for humility, to face the unknown with a humble, searching perspective.
His comments are followed up by Ann Druyan, the wife of the late Carl Sagan, in which she essentially says that science and its methods promote the utmost humility. We are not afforded absolute truths, and if whatever knowledge that we are most confident in gets disproved then science will give its highest honor to the person disproving it. She points out that science brings us out of a childish narcissism, a key part of nearly all religions, which demands that we are central to the universe.
Monday, January 10, 2011
- The parameters of the universe (e.g. speed of light, gravitational constant, etc...) are extremely finely tuned for the support of living beings, and is unexplainable through science
- Our sense of morality (especially pure altruism) is unexplainable from the perspective of evolution
- Our universal longing for God is unexplainable from the perspective of evolution and rational thought
Each of the arguments has the same form: "I don't know how to currently explain something, therefore it is unexplainable in principle, therefore there must be a God." Taken to its extreme, we can find Colbert's summary "There must be a God, because I don't know how things work." particularly appropriate.
It's really a bold religious statement, ironically full of the arrogance that religious people often attribute to scientists. By saying that our current knowledge cannot explain something, therefore it can never be explained, is stating that you know better than all other future generations of people.
The problem with the statements, however, is not the arrogance. It is that they are show-stoppers: once you make the claim that something is unexplainable, then you stop looking. So-called Intelligence Design suffers from the same problem: by saying that a designer is needed to create the stated irreducibly complex mechanisms, then there is no use in searching for an explanation. It stops science, stops curiosity, stops investigation.
These types of arguments, then, are not just wrong they are dangerous because they stop the types of inquiry that could possibly show that they are wrong. In this way, they have a tendency to protect themselves in the world of memes.
I am not saying that we have answers to points 1-3 above (although I think we have some very good ideas at least for 2 and 3), but to go from ignorance to "God must have done it" is extremely sloppy logic, if it can be called logic at all.