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Our future, our universe, and other weighty topics

Monday, November 23, 2015

His Book Forgot to Mention the Main Way You Can Fight Global Warming

I just read a new book by climate change expert Tim Flannery entitled Atmosphere of Hope: Searching for Solutions to the Climate Crisis. Very strangely, the book seems to make no mention of what is probably the top way you can help fight global warming.

In the third part of his book, Flannery looks at various ways to respond to global warming. The first thing he discusses is what he calls adaption. Under this category, he says this: “By painting infrastructure white, cities may more than offset the warming they currently experience.”

I can imagine how this might work. Giant spray trucks might drive down city streets, spraying all the buildings and streets white. When they were done, the streets of our cities  might look like this:  

Flannery even approvingly mentions a plan to spray-paint a mountain white.

Then Flannery mentions geoengineering, various proposed attempts to fight global warming through high-tech monkeying with the planet. These attempts include: injecting sulfur or soot high in the atmosphere, causing more sunlight to be reflected back into space; deploying giant mirrors in space to reflect more sunlight; and releasing iron into the ocean to promote plankton growth. After discussing the complicated issue of biochar, Flannery discusses how giant seaweed farms might be useful in fighting global warming, and makes a complicated discussion of carbon capture and storage.

But what about the individual – what can he or she do? Flannery discusses this in a chapter entitled “The Growing Power of the Individual.” He seems to have two main ideas for how you can fight global warming: (1) install solar panels on your rooftop, or (2) join some citizen's group that is trying to fight global warming.

This chapter neglects to discuss the main way in which ordinary citizens can fight global warming: by reducing consumption. You can reduce consumption by doing things such as: living in a smaller home, eating less meat, buying a smaller car (or not buying a car at all), taking fewer trips by air, traveling shorter distances by air, and buying fewer things. Not only does Flannery neglect to discuss such things in his chapter on the power of the individual, but he also seems to fail to mention them anywhere in his book. Looking at the index of his book, I see no index entries on consumption, diet, meat eating, carbon footprints, travel, lifestyle, or vegetarianism. Those are topics that should be thoroughly discussed in any book subtitled “Searching for Solutions to the Climate Crisis.”

People should not think that fighting global warming can only be done if they make some “big commitment” step such as painting their rooftop white or spending lots of money on a solar power system. There are 100 varieties of easy-to-do, small steps you can take to reduce your carbon footprint. You can start by buying less meat at the food store at your next visit. The production of meat is a major cause of global warming. Other small steps you can take is to reduce your shopping, and to take a vacation some place closer to your home. Too lazy to paint your rooftop or join some citizen's group? No problem, there are many lazy man's ways to fight global warming.

Thursday, November 19, 2015

A Web of Speculations, Decorated with Dinosaurs

Dark matter is a hypothetical substance postulated by scientists to help explain astronomical observations. When astronomers peer out at distant objects, they find certain clusters and galaxies behaving in a way that we cannot seem to account for by using merely the gravitational attraction of visible matter. So astronomers speculate that a large fraction of the universe's matter is some completely invisible form of matter that they call dark matter.

Despite some astronomers who speak as if dark matter is fact, there is so far no conclusive evidence that dark matter actually exists. This has not stopped physicist Lisa Randall, who has written a highly readable new book entitled Dark Matter and the Dinosaurs. Like many of her colleagues, Randall is a fearless speculator, not afraid to spin a web of speculations that seems to be built of gossamer threads.

In Chapter 16 of the book, readers will learn one of the reasons why dark matter isn't actually on very solid ground: the fact that scientists have not identified any particles of which dark matter is made up of. The triumphant Standard Model of Physics tells us nothing at all about dark matter particles. In Chapter 17 of the book, Randall discusses attempts to observe dark matter, which have come up short, despite a few false alarms and ambiguous hints.

In Chapter 18 of the book, Randall discusses how computer simulations using dark matter have come up short:

Explaining why density profiles look flat or cored and not cuspy, as per dark matter predictions, is an important challenge to the simplest dark matter models. This, along with the missing satellite problem (fewer dwarf galaxies than predicted orbiting around bigger central galaxies) and the too big to fail problem (a related issue in which the predictions for the densest, most massive galaxies do not agree with observations), possibly point to inadequacies of the standard cold dark matter paradigm.

But Randall has a solution that seems to satisfy her: make the model more complicated to try to explain these discrepancies. Much more complicated. While scientists often claim that they will cheerfully give up a theory when it falls short, it seems that usually when observations conflict with a scientist's favored theory, he or she will prefer not to give up the theory but just to make it more complicated to try to explain away the discrepancies.

What Randall proposes is a model she calls “partially interacting dark matter.” Below are some of her speculations (page 320-321):

I'll call the force that is experienced by the interacting dark matter dark light, or more generally I'll call it dark electromagnetism....It would be an entirely different influence acting on particles charged under a distinct additional force that is communicated by an entirely different new type of particle – a dark photon if you will...Two types of electrically charged particles in the same place that don't interact with each other is really not so mysterious.

What Randall proposes is that dark matter has some type of electromagnetism physics similar to the electromagnetism physics of regular matter, but one that only works with dark matter. This is, of course, wild speculation. One would think that the likelihood of such a thing would be extremely small. It would seem far more likely that dark matter might follow its own weird rules rather than duplicating the rules followed by regular matter. The chance of the two sets of rules matching would seem like the chance of marriage customs on some alien planet matching the marriage customs in America.

Another problem is this: the idea of dark matter was introduced so scientists could avoid having to speculate about “dark forces” – undiscovered laws of nature that might supplement gravitation. But why propose a combination of dark matter and dark forces, when dark forces alone could explain any observational discrepancy?

Randall also proposes that there is a “dark disk” of dark matter that occupies our galaxy, occupying much of the space of our galaxy's disk. She proposes that this “dark disk” somehow had some role in causing a comet to stray from the Oort Cloud that surrounds our solar system, and that such a comet may have wiped out the dinosaurs. 

 The Oort Cloud (Credit: NASA)

This is all speculation run rampant, and there is no good evidence for such a “dark disk” in our galaxy. I would estimate that the likelihood of dark matter existing is only about 50%, that the likelihood of such a “dark disk” existing in our galaxy is only about 10%, and that the likelihood that dark matter had anything to do with the demise of the dinosaurs is no greater than 1%.

One almost wonders whether the idea for Randall's book wasn't hatched by some book publisher looking to boost sales. You can imagine a conversation like this:

Joe: We can't call it All About Dark Matter. No one will buy that.
John: What about the combo approach? We can call it Dark Matter and Jesus.
Joe: No, those markets don't mesh. What about Dark Matter and Lady Gaga?
John: How can you write a book with that title?
Joe: I've got it! Dark Matter and the Dinosaurs.
John: That's it!

Randall's book is well-written and entertaining, but I am puzzled by why the Midtown branch of the New York Public Library has purchased seven copies of this not terribly important book, and placed them right in the physics section, next to textbooks of physics. It would have been more appropriate to have the book placed in the section with equally speculative books about things like ancient astronauts.

Sunday, November 15, 2015

What Neil deGrasse Tyson Doesn't Want You to Know About the Cosmos

In order to understand the sophistry of Neil deGrasse Tyson's recent comments on the universe, we must look at the fascinating issue of cosmic fine-tuning. Let's start at the beginning of time. Astronomers say that the universe suddenly began in the unexplained event known as the Big Bang, in which the universe suddenly began to expand from an infinitely dense point. Decades ago, cosmologists figured out that the initial expansion rate of the universe must have been fine-tuned to at least fifty decimal places, with what is known as the critical density exactly matching the actual density to fifty decimal places. You can do a Google search for “flatness problem” to find many sources stating this. There's a theory (or a family of theories) called the cosmic inflation theory designed to explain away this astonishing correspondence. But that theory requires a great deal of fine-tuning itself, in many places (as discussed here). So it's not clear that you end up with less fine-tuning if you believe in such a theory. Regardless if whether such a cosmic inflation theory is true, we can say that the universe's beginning was astonishingly fine-tuned, and that an incredibly tiny change in the Big Bang would have meant that we would not have ended up with a life-compatible universe such as we live in. (Universes that expand too fast don't form galaxies, and universes that expand too slow have their matter all collapse into black holes, or one big black hole.)

So the Big Bang was very fine-tuned, but we also find abundant and very precise fine-tuning in the fundamental constants of the universe. A dramatic example (another case of two numbers coincidentally matching to many decimal places) is found in the charges of the proton and the electron. Each proton has a mass 1836 times greater than each electron, and so you might think that each proton has an electric charge much greater than each electron. But no, we couldn't exist if that were the case. Instead each proton has a charge exactly the same as each electron, the only difference being that the sign of the electron charge is negative. The exact equality of the proton charge and the electron charge has been measured to 18 decimal places. We know that planets like the earth would not even hold together if the electron charge and the proton charge differed by even 1 part in 1,000,000,000,000,000,000,000,000,000 (as discussed by a scientist quoted here).

There are still many other cases of fine-tuning in the universe's fundamental constants. One is the astonishing case of the cosmological constant or vacuum energy density, where we see that nature seems to have miraculously balanced the books to 60 decimal places. This is again something on which our existence depends, because if things were not so precisely balanced, ordinary space would have more mass-energy than steel, as discussed here. There are also reasons why we would not be here if the gravitational constant were a little bit different, or the strong nuclear force were a little different, or the fine structure constant were a little different.

The following visual illustrates how right things have to be in order for creatures such as us to exist. Imagine someone pulling the lever on this slot machine. In order for you to get the jackpot (the appearance of life), you have to get a coincidental match on each of the rows. The chance of this happening is almost infinitely small. (This post discusses the particular items in this visual, and why each is extremely unlikely to be coincidentally compatible with life.)

cosmic fine tuning

The “lucky numbers” are only half the story, for in order to have life the universe also needs lucky laws, such as strange quantum mechanical laws assuring that electrons don't fall into the atomic nucleus, lucky laws of electromagnetism that assure that chemistry can take place, lucky laws of nuclear physics assuring that an atomic nucleus can hold together, other lucky laws of particle physics restricting the number of types of stable particles to only a handful, and a lucky Pauli exclusion principle allowing for solid matter.

So the evidence for cosmic fine-tuning is immense. This evidence has been widely discussed by scientists over the past few decades, often in discussions that used the word “anthropic.” So when Neil deGrasse Tyson was asked about this question, we expected to hear from him some substantive comments. Instead we got the following reasoning:

I look out to the universe and yes, it is filled with mysteries, but it's also filled with all manner of things that would just as soon have you dead. Like asteroid strikes, and hurricanes, and tornadoes, and tsunamis, and volcanoes, and disease, and pestilence. There are things that exist in the natural world that do not have your health or longevity as a priority. And so I cannot look at the universe and say that yes, there's a God, and this God cares about my life -- at all. The evidence does not support this.

This reasoning can be summarized like this: there exist various forms of death, so there does not exist a God who is interested in you living. This is, of course, a very bad argument. The evidence that we have is entirely consistent with the idea that there exists some higher power who wants beings such as you to exist (and who set up the universe so that you and similar beings would exist), but who does not want you to live forever in a physical existence on this planet (something which would cause various problems such as extreme overpopulation and cultural stagnation). The existence of various forms of death do nothing to argue against such a possibility. Since such a possibility is strongly suggested by abundant evidence of astonishingly precise fine-tuning in the universe, it would seem to be very well supported by evidence. The claim “the evidence does not support this” is very misleading in this case. To the contrary, there is a great mountain of evidence that Tyson has done nothing to explain away.

At the core of Tyson's statement is a most absurd non-sequitur.

There are things that exist in the natural world that do not have your health or longevity as a priority. And so I cannot look at the universe and say that yes, there's a God, and this God cares about my life -- at all.

So from the fact that there are things in the natural world that “do not have your health or longevity as a priority” we can conclude there is no God? Asteroids don't care about us, so there is no God? That's a ridiculous argument.

Tyson's argument is similar to arguments like this, and every bit as fallacious:

Somebody died in the house, therefore nobody built the house.
The house was hit by an earthquake, therefore nobody built the house.

Another related comment was this one by Tyson.

I think of, like, the human body, and I look at what’s going on between our legs. There’s like a sewage system and entertainment complex intermingling. No engineer of any intelligence would have designed it that way.

I cite this merely as an example of how absurd Tyson gets when he starts reasoning about theological topics. There is no sound basis for complaining about the design of the human penis on the basis Tyson has given, and I know of no male other than Tyson who has ever complained about the same organ being used for sex and urination. It is generally regarded as being a sign of good design when a designer gives a single object two capabilities – for example, no one complains that hammers are poorly designed because they can both hammer nails and remove nails. We also do know of intelligent designers who combine a waste disposal system and an entertainment complex. That is done by every architect who designs a movie theater, and includes bathrooms in the design. 

Having assumed the job of educating the public about the universe, Tyson should be educating the public about one of the top developments of cosmology during the past 30 years, the fact that scientists have found countless ways in which our universe is astonishing fine-tuned. But when Tyson had 13 hours of television time in his series Cosmos, he found time to discuss all kinds of unimportant digressions, but apparently neglected to even discuss the evidence that our universe is exquisitely well-calibrated for life. (I am judging from this lengthy summary, which makes no mention of such a topic.) Tyson is also director of the Hayden Planetarium, but nowhere in its vast exhibit spaces is the visitor informed about this very important conclusion of modern cosmology.

It would seem that Tyson doesn't want you to know about all the ways in which our universe is fine-tuned for life (in repeated defiance of enormous odds), because that might mess up Tyson's gloomy type of talk that emphasizes a universe “filled with all manner of things that would just as soon have you dead,a thesis we might describe as “the universe is trying to kill you.” Neil apparently doesn't want you to think about how perfectly balanced the electrical charges in your atoms are (in a coincidence we would expect to find in less than 1 in 1,000,000,000,000,000,000 random universes, the coincidence of the proton charge exactly matching the electron charge to eighteen decimal places, despite the proton mass being 1836 times greater than the electron mass). Neil would probably be much happier if you fret about some asteroid that has maybe 1 chance in a million of killing you. I may note that it doesn't make sense to cite asteroids as evidence that the universe is stacked against us. A future generation of asteroid-mining humans (with the power to deflect asteroids) may regard asteroids as one of the greatest blessings of the solar system.

Wednesday, November 11, 2015

Why It's Silly to Disparage Anecdotal Evidence

My most recent post was a science fiction story which took a jab at the strange thought patterns of some of today's scientists. In the story, invading extraterrestrials arrive near our planet, and start leaving more and more dramatic evidence of their arrival. The scientists advising the US president keep denying that anything paranormal is going on, despite the evidence piling up to extremely high levels. The US president is lulled into inaction by these assurances, and the chance to defend against the attack is lost, resulting in the conquest of planet Earth.

At one point in the story, a scientist says this in response to massive testimony about extraterrestrial activity:

You can't trust anecdotal evidence like that. We don't trust the reports of ordinary people. Our motto is: only believe it if it was reported in a scientific journal.

Now, upon reading that, you might complain that this is a crude caricature of what scientists say. But two days after writing the story, I read a scientist say almost exactly this. The scientist (Alex Bezerow) makes this claim:

Testimonials mean nothing. Period. Anybody with a modicum of scientific training understands that.

The scientist then goes on to offer what he claims is an “excellent example of how dangerous and misleading anecdotal evidence can be” by citing a debunking of the famous Erin Brokovich lawsuit, a debunking which is itself debunked in this article.

Bezerow's claim that “testimonials don't matter” is a wholesale dismissal of all anecdotal evidence. This is nonsensical. Anecdotal evidence is simply evidence in which a person describes what he did, or what happened to him. Such evidence is a key pillar of our legal system, and (as I will show in a moment) is actually a key pillar of modern science.

When someone makes a ludicrous claim such as “testimonials mean nothing,” or claims that anecdotal evidence doesn't count, you have to ask: what is their motive? What would motivate someone to advance such a bizarre principle, so contrary to common sense?

I can think of two motives that a scientist might have for advancing such a principle. The first is that a dismissal of anecdotal evidence is very convenient for someone who wishes to advance a narrow, restrictive view of reality, particularly a view dominated by mechanistic or materialist principles. If you want to maintain that there is nothing but matter and energy, you have the problem that a significant fraction of the population report psychic, paranormal, or spiritual experiences that go beyond such a limited reality. It is very convenient, therefore, to be able to “cross out” all such reports by claiming that anecdotal reports aren't good evidence.

Another motive that a scientist might have for advancing such a principle is that he might be trying to shore up scientists' attempts to establish a kind of knowledge monopoly, in which scientists are regarded as some special priests of learning who are the sole possessors of the keys to truth. Such attempts have grown more and more brazen in recent decades. What better way to help enthrone our scientists as the sole judges of truth than to tell the lowly masses that what they observe and experience doesn't count, that only the work of scientists counts towards establishing the truth?

But such attempts are futile. One reason is that a large fraction of our scientific papers are themselves anecdotal evidence.

Consider a scientist who does experiments with rats or chemicals, and publishes the results in a scientific journal. The account of the experiment is itself anecdotal and testimonial. So if we disregard anecdotal evidence, we must then disregard all of the scientific papers in which individual scientists describe particular things they did in an experiment. Bang, you've just wiped out a large fraction of modern science.

It is futile to rebut this objection by saying, “Such evidence isn't anecdotal-- it's experimental.” A typical account of an experiment that a scientist performed is both experimental and anecdotal, so you don't show it's not anecdotal by showing it is experimental.

It's also futile to rebut this objection by claiming that when a scientist makes a claim in a scientific journal about his experiences, that this has more weight than a non-anonymous account by an ordinary person, on the grounds that the scientific journal is peer-reviewed. When a scientific paper is peer reviewed, the reviewers do not question the author, and do not ask to see corroborating evidence.  So the testimonial report of a scientist as to his experience while running an experiment has no more weight than the typical published account of a non-scientist who gives his correct name.  A scientist doesn't sprinkle some magic truth dust on his anecdotal account by publishing it in a journal. 

Of course, scientists don't actually follow the principle that “testimonials don't matter” or that “anecdotal evidence doesn't count.” But a scientist may occasionally evoke such a principle when he or she finds it convenient to dismiss some evidence that he doesn't wish to accept.

We can imagine how following the “ignore anecdotal evidence” principle might lead to the unnecessary death of thousands. A pharmaceutical company might introduce a new drug with baleful side effects. Many people might report that their spouses died or had a stroke after taking the drug. Such reports could be ignored as mere “anecdotal evidence.” The death toll might mount, until tens of thousands died. Finally, lagging far beyond the anecdotal evidence, some scientific studies might show the drug was dangerous, and the drug might be withdrawn by the pharmaceutical company.

This scenario isn't imaginary. It's the actual history of a drug called Vioxx, which is estimated to have killed 38,000 people.