Category Archives: Science

All things scientific

Screw Greenpeace – more nuclear!

I do not support Greenpeace. That organization has been really pushing itself near the U. of Texas campus lately, and I do not like it. If the environmental situation is as bad as some would have us believe (have a look at what the UK’s top science advisor has to say) then we are on the deck of the Titanic, and saving the whales amounts to polishing the deck chairs. What bothers me about Greenpeace is not that they are polishing the deck chairs. What bothers me is that they are loudly screaming “Hey, quit fixing those life rafts! Get over here and polish these chairs! Can’t you see the ship is sinking?”

Stewart Brand is a deeply committed environmentalist. He has advocated careful ecological stewardship for over 50 years. He wrote the original Whole Earth Catalog that inspired the hippies in the 1960’s and worked for California Governor Jerry Brown and helped establish that state as an leader in environmental conservation. He is not a secret agent for “The Man,” “The Establishment,” or the PTB. He advocates nuclear power.

Why? Because nuclear power emits no greenhouse gas. Nuclear power can be scaled up immediately. Consider: if transportation fuel moves to electricity, that roughly doubles electrical demand. If the developing world moves to European standards of living, that (conservatively) quintuples electricity demand. If humanity is to move out of poverty without cheap oil (and don’t kid yourself, the era of cheap oil is over), we are looking at a total increase in electrical demand of roughly ten times over the next century. Right now, roughly 20% of electricity is nuclear, less than 2% is solar and wind. If we were to completely rid ourselves of fossil fuel, we would need to scale Nuclear up by a factor of 50 or wind/solar by a factor of 500 over the next century. Certainly, we should scale solar and wind as much as possible, but a factor of 500 is simply unrealistic. We need to double our nuclear generating capacity every 10 years or condemn ourselves to catastrophic climate change and extreme, widespread poverty.

What about nuclear waste? What about coal waste! From the NYT: “A coal ash spill in eastern Tennessee that experts were already calling the largest environmental disaster of its kind in the United States is more than three times as large as initially estimated… Officials at the [Tennessee Valley Authority]… released the results of an aerial survey that showed the actual amount was 5.4 million cubic yards [of wet coal ash], or enough to flood more than 3,000 acres one foot deep.” Moving away from coal is a great idea – and the only realistic alternative is nuclear. Natural gas is not perfectly safe. Nothing is. A typical 1 GW power plant generates as much energy in a day as Fat Man released over Hiroshima. This carries inherent risk no matter what the fuel.

Furthermore, nuclear waste is more a political problem than a technical problem. In the United States, we are committed to a once-through fuel cycle for political reasons. Most of the “waste” is un-burned fuel. It can be processed and fed back into a reactor to make more electricity. We have tons and tons of “waste” that can just as easily be re-labeled as “fuel.” Once burned down completely, this waste is only a problem for a few hundred years (not thousands or millions) and takes up vastly less space. Why don’t we do this?

Greenpeace and short-sighted fools like them have made it politically and economically impossible. The paranoia about nuclear technology is way outside of reality. A coal plant renders 3,000 acres uninhabitable and contaminated with heavy metals, and it’s barely a by-line. A nuclear plant has a glitch and it becomes headline news. Thanks Greenpeace.

From their own mouths: “The general argument that the fact that [a nuclear plant] has operated safely for a finite period of time proves that the safety level is adequate is just not statistically right…” By this premise, it is impossible to measure the safety of anything, ever. And because safety can not be measured, it can not be assured. Because perfect safety can not be assured, “The United States can avoid the next nuclear accident by phasing out the remaining 103 commercial nuclear reactors… Coupled with an increase in energy efficiency, this increase in renewable resources would produce enough electricity to supplant every nuclear reactor currently operating in the United States.”

Remember my calculation above? Yes, we could scale renewables by 10 times and replace nuclear… leaving the other 80% to be generated from fossil fuels. But that also assumes no growth. With growth of electricity demand (due to plug-in hybrids, perhaps?) that will just be moving from gasoline to coal. No, what we need is more nuclear, more nuclear research.

-Peter

On Climategate

As you know, emails leaked (read: stolen) from a climate research group suggested some inappropriate attitudes amongst the scientists – at least when carefully edited and comber for inflammatory material. Review by major publications found that the emails did not constitute evidence of fraud, but the public perception was quite the opposite.

Of course, lots of people are emotionally invested in climate research. If it’s true, a lot of our habits will have to change. If it’s not true, it is a very expensive mistake. Furthermore, lots of scientists have staked their careers on propositions that it’s a big deal. So, yes, there is a bit of incentive to defend that proposition. But a lot of the public discussion concerns the “consensus” among “scientists.”

Wrong question: “do scientists believe in global warming?”

Right question: “do specialists in the field of climate science find a credible risk?”

With regard to the second question, there is an answer. There is consensus. Yes, there is a risk. Consensus does not equal truth, of course. Nor does credible risk imply a guaranteed catastrophe. Nor does outright fraud imply a bankrupt field. Let me explain these three.

Consensus is not truth. If you had asked a well-educated ornithologist to describe swans a few hundred years ago (prior to 1790), he would have told you about white, majestic birds. There was consensus based on thousands of observations that all swans are white. This was credible science based on good evidence and it would be wise to respect the conclusion as the best given the available evidence. It was entirely wrong, of course. There are black swans. But a consensus based on the preponderance of evidence is often the most trustworthy guideline available, and we would be foolish to discount them because they might be disproven tomorrow. Of course, we must keep collecting data, and we must be prepared to throw out formerly cherished beliefs if the data contradicts them.

Credible risk does not imply a guaranteed catastrophe. It’s a risk. Like in gambling. And lots of people are trying to estimate the odds. There is some pressure to estimate high – that gets the headlines. There is another pressure to make the estimate high: the precautionary principle. An editorial in the WSJ gave this version: “precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.”
The precautionary principle is reasonable for governments and individuals, but not for scientists who are actively trying to fully establish the cause and effect relationships. Those relationships determine the risk, and we have to be honest about them. We don’t get to cheat and say “as a precaution, I estimate the risk to be 90%”
If the best estimate of the risk is 10%, that may not scare people enough. It doesn’t matter – we still have to report 10%. Let the politicians explain why avoiding a 10% risk of total economic shutdown is a lot more important than a 99% risk of inconvenience. But that principle only applies to the evaluations of the conclusions, not the interpretation of the data. Did the East Anglia fall into this trap? I have no idea, but at least that is a legitimate worry.

Isolated fraud should not discredit the whole community. To be clear, these emails do not constitute fraud. But, even if they were, and a retraction of a publication was required, that’s not the same as the whole conclusion being false. If a gold medal sprinter turns out to have used steroids, we don’t conclude that all fast people are dishonest, and that it’s impossible to run fast. There was an incident a while back where a Korean researcher claimed some amazing breakthroughs with stem cells. It was completely fabricated. Some time later, other groups actually did much of what he falsely claimed to have done. Just because one guy cheated didn’t make the achievement impossible. It was just really hard.

What we have with climate change is a consensus based on available data that there is a credible risk to humans due to anthropogenic climate change. A few people have gone to lengths to present this in a black-and-white manner. I suspect that they were trying to strip ambiguities because of a decent moral impulse (the precautionary principle) without considering the proper distinction between interpretation (assessing the risk) and evaluation (determining the appropriate response to that risk). When scientists do that, they erode the credibility of science in general, as an opinion piece in the WSJ points out. But, then, this sort of philosophizing isn’t really stressed in our training. Maybe it should be.

Cheers,
Peter

Wired article on a 1982 artificial heart

Wired has an article today on the first use of an artificial heart back in 1982. The patient survived for 112 days – pretty remarkable. I wonder if he felt any unnatural urges toward appliances… robot love, as it were. I doubt it. It sounds like it was a pretty miserable 112 days. I suspect that subtle emotional changes toward toasters… or uncomfortable fantasies about R2-D2… were secondary concerns.

Despite the derision with which the heart’s mystical associations have been dismissed, it’s a rather complex organ with a great many feedback mechanisms to keep it precisely regulated. We’ve come a long way in 30 years. In addition to thinking in terms of an improved plastic pump, there is a lot of thought going into manipulating stem cells to make new hearts from meat, the way nature intended.

-Peter

Directed Evolution: macro and micro scale

I work in a lab now that focuses on directed evolution. We typically look at a huge, diverse pool of molecules and then select and “breed” them to get molecular properties we want.

This is something that can be used on the macro scale, too. In thinking about diseases, it’s important to consider not just a patient, but the population dynamics of the pathogen. Malaria, for instance, can be exacerbated or ameliorated by the preferential treatment given to severe cases. If sever cases are allowed to go untreated and the victim is allowed to be visited by mosquitoes, then the most severe forms become more likely.

Constant vigilance in removing severe cases from the population by something as simple as bed nets for every sick person can dilute the population of virulent forms of the disease. Tricks like these are undoubtedly going to be more and more important as diseases learn to avoid our chemical cures.

Here’s a neat article on the subject over at Nature

Cheers,
Peter

Believing we are right: Why Dr. House is a good role model

Humans, doctors and grad students included, are all prone to rationalization. This can be a good thing. Think about that TV show House, M.D.. The main character is not always right, but he always is totally convinced of his own opinions. If you think about that, it’s pretty remarkable.

When his opinions are refuted by hard evidence, he drops them without remorse. But up to that point, he is sufficiently certain to risk your life on the basis of his conviction. That’s actually a pretty good thing, in the following sense: if he were unwilling to change his opinion after finding new evidence, he would be an extremely dangerous person to have as a physician. By a similar token, if he wanted conclusive proof of a given diagnosis before starting treatment, he would lose patients because they would die before he was certain.

The following formula is reasonable: get the information you can and act decisively on that until better information is available. But it’s only reasonable so long as you keep the information channels open. That’s why Dr. House is a good role model. Despite being a jerk and despite seldom acknowledging that he was wrong, he never persists in a wrong opinion once it’s disproven.

The problem is that we are prone to rationalize the facts based on the diagnosis we had before. Take people who still believe that Saddam Heussein was involved in the September 11 attack. Presented with new evidence, many people will choose to ignore or rationalize around that evidence in order to preserve their old, erroneous conclusion.

And with just a few simple, mental sleights-of-hand, we can preserve that belief. Here’s another fine example: form the NYT, an Iraqi official purchased several million dollars worth of totally useless “electrostatic magnetic ion attraction” detectors that are billed by the manufacturer as being able to detect bombs and ammunition. A few simple tests are sufficient to show that they are capable of no such thing.

Why would someone believe something patently false in light of clear data to the contrary? Before we get all proud about how we are different from them, those other people, I would offer the following words of caution: believing that we are right is seductive to all of us. The only shared standard against which anyone can test his opinions is the physical world and the data that comes from it and that’s not an easy standard to uphold.

Cheers,
Peter