Science – Page 41 – a sibilant intake of breath

Try f/8

The relative aperture of a photographic lens is really important, when it comes to the quality of the photos that arise in most situations.

If you have the sort of camera where you can specify an aperture – as is possible on all film SLR camera, all digital SLR cameras, and many point and shoot digital cameras – try taking some photos using f/8. Almost regardless of the lens being used, this will often generate rather lovely images.

If the shutter speed your camera picks when you set the aperture to f/8 is slower than one over the focal length of your lens, do something to keep the camera still. That is to say, if you are using a 50mm lens with a shutter speed of less than 1/50th of a second, you are likely to end up with a blurred shot. To avoid that, you can brace against something solid if you are just a bit below. If you are looking at really long exposures – say, more than half a second – either put your camera on a tripod or rest it on something solid and use a countdown timer.

f/8 is usually beautiful. It excludes stray photons that are problematic, and it doesn’t usually cause diffraction. Please give it a try.

Sustainability as an intergenerational project

I think this quotation from Richard Feynman is rather wonderful:

We are at the very beginning of time for the human race. It is not unreasonable that we grapple with problems. But there are tens of thousands of years in the future. Our responsibility is to do what we can, learn what we can, improve the solutions, and pass them on.

It would be a splendid thing for humanity to have tens of thousands more years of history. In order to accomplish that, however, we need to find ways to keep from snuffing ourselves out, or pushing ourselves back down below the level of ‘civilization.’

Accomplishing that seems to require a process similar to the one Feynman outlines for scientific advancement. We must learn what we can about truly sustainable human societies, implement that knowledge, and then pass along that combination of learning and physical achievements to be carried forward by those who will come after.

I can’t help feeling that if Feynman was still alive, our societal discussion about climate change would be a bit more sophisticated and productive.

Unscrupulous climate graph

This post on A Few Things Ill Considered is a great demonstration of how graphs and statistics can be abused. Show CO2 and temperature data from a short stretch of time, with misleading axes, and you can produce the impression that they are unrelated. Present the information in a fair way, and the correlation between the two looks very plausible.

Combine that with the theoretical framework about greenhouse gases trapping energy (in the form of longwave radiation) within the planet system, and you have a hypothesis that is defensible on both theoretical and empirical grounds.

Disasters and environmental awareness

Every day, I find myself thinking about the huge risks associated with unchecked climate change, as well as the reality of how little humanity is doing overall to counter them. One odd consequence of this is ambiguous feelings about disasters like the British Petroleum oil spill in the Gulf of Mexico. On the one hand, it is a human and ecological catastrophe. At the same time, part of me hopes that each of these catastrophes gives a bit more of a psychological push to the population as a whole to deal with our major energy and climate problems. We are driving straight towards the edge of a cliff, and perhaps it is bumps like these that will convince the population at large that we would be wise to slow down.

The same goes for things like summer Arctic sea ice minimums. On the one hand, I know that vanishing ice is a positive feedback, and that warming in the Arctic risks causing massive methane release. On the other, every time the decline of sea ice seems to slacken, climate change deniers and delayers make hay from it, and use public confusion to further delay effective climate policies.

The really worrisome thing is that by the time there is massive evidence of just how dangerous climate change is, it will be too late to prevent truly catastrophic outcomes. Having global emissions peak soon is essential, if we are not to pass along an utterly transformed world to those who will come after us. If some moderately sized environmental catastrophes help that outcome to occur, perhaps we should be grateful for them in the final analysis.

I have speculated before that perhaps only perceived crises can generate real change.

State of the climate video

Last night, I gave a short talk outlining my current thinking on climate change.

I am interested to know which things people think I am wrong about. Also, about which things seemed to be effectively expressed, and which poorly expressed.

An improved version may be worthy of being recorded in a more aesthetically appealing manner.

Carbon capture and storage (CCS), always around the corner

One odd thing about following climate change as a scientific, political, and ethical issue is the disparity between different sorts of relevant timelines. There is a rate at which scientific reports come out, a rate at which public opinion about climate change shifts, and a rate at which firms feel the need to change their public images. There are also much slower shifts – slower primarily because they are costly and require massive physical changes to energy systems.

Back in 2008, in a presentation at Cambridge University, the UK Environment Secretary Ed Miliband expressed his view that carbon capture and storage (CCS) was just around the corner. He says that all of the necessary technologies have been tried successfully, and the next step is a demonstration facility. He goes on to quote the European Commission’s hope of: “every new power station in Europe being carbon capture and storage ready by 2010 and using carbon capture and storage by 2020.”

We’re still waiting for that demonstration plant. This is not to say that CCS has no contribution to make to fighting climate change. Indeed, paired with power plants burning biomass, it could remove CO2 from the air in a promising way. Rather, there has been a persistent notion that CCS is just around the corner. We need a demo plant, then we can somehow magically retrofit the world’s coal stations and solve our climate problems without shutting them down or abandoning coal as a source of energy.

I can see why that is appealing, even for those not beholden to coal-dependent utilities or coal mining interests. China has lots of coal, and it is scary to think what will happen if they burn it all. That fear can give people a powerful reason to hope that CCS will mop up the whole problem without much fuss.

In the near term, CCS seems to have more potential to delay action – keeping us clinging to the belief that some wonderful technology will save the day. Meanwhile, the window in which we can take action to avoid catastrophic climate change is shrinking, and the total costs of the transition are rising as the time we have left in which to complete it diminishes.

Long-term changes in happiness

The final lecture of the psychology course I have been following focuses on the question of what makes people happy.

In addition to a lot of things that are already common knowledge – such as how winning the lottery is not all it’s cracked up to be – it includes a couple of examples of things that have a persistent effect on your happiness. This contrasts with things like the acquisition of a new gadget, which prompts a brief spike that soon falls back to normalcy.

One thing that makes people persistently happier is plastic surgery. Apparently, this is because time doesn’t desensitize us to how other people respond to our appearance. Neither does it affect how our own perception about our experience affects our mental lives. For those who don’t want to go to the extreme length of surgery, it seems plausible that improving your wardrobe could have a similar effect. Replace some shabby garment with one that you are proud to wear, and it may well make you happier for as long as you own it. I can speak to this from personal experience. Replacing my squeaky, ugly, plastic Rockport shoes with some nice leather Allen Edmonds shoes has made me feel consistently more qualified and capable at work.

Another thing that affects happiness persistently, though in a negative way, is noise. I know plenty about this personally, since I live right beside a busy street, on the ground floor, with my bedroom window right beside a speed bump that people often damage their cars on. This has bothered me every single day since I moved in, particularly when cars wake me up in the morning. I recall being annoyed by similar circumstances in the past, such as the noisy birds outside the Totem Park residence at UBC, or the booming clock beside my house in North Oxford.

The practical message of all of this seems to be: don’t spend your money on electronic gadgets, photo gear, or other expensive trinkets. Definitely don’t spend it on lottery tickets, which are likely to leave you less happy in the very unlikely situation where you win. Spend it on quiet housing and improving your appearance. Another good investment might be Professor Paul Bloom’s forthcoming book: How Pleasure Works. The New Science of Why We Like What We Like.

James Bond is a psychopath

Another interesting observation from the Paul Bloom psychology course I have been following concerns this fictional character, as well as real-life individuals who share some of his features:

They’re typically male. They are defined as selfish, callous, impulsive, they’re sexually promiscuous. They seem to lack love, loyalty, normal feelings of affiliation and compassion, and they get into all sorts of trouble because they’re easily bored and they seek out stimulation. Now, when you hear this, you’ve got to realize that this sort of person is not necessarily an unattractive person to imagine or think about or even under some circumstances to encounter. You have to avoid the temptation when you think about psychopath to think about a guy like this, to think about Hannibal Lecter. The most famous psychopath, of course, is James Bond who is a perfect psychopath in every regard as played… by Sean Connery.

Bloom elaborates in talking about real-life individuals, and whether psychopathy is an illness:

[P]sychologists study psychopaths but the psychopaths that they study are by definition unsuccessful psychopaths. And what some people have argued is the real psychopaths, the successful ones, are the ones that run the world, that excel in every field because they are successful enough that they don’t look like psychopaths. They have no conscience, no compassion, love, loyalty. They are cold-blooded and ambitious but they don’t go around making this so obvious that we throw them in prison. And so, it’s an interesting and subtle and complicated case.

It does seem inherently plausible that the kind of people who can attain positions of great power have these tendencies, and also have the ability to conceal them from others. This is where the wisdom behind Douglas Adams’ insightful perspective on politicians: “Anyone who is capable of getting themselves made President should on no account be allowed to do the job.”

What lessons can we draw from this? Perhaps it tells us something about the nature of authority and power dynamics in human societies. Perhaps it should inform us to some extent about what to expect from elected officials, as well as those who attain power by other means (such as leaders of coups). It may be even more applicable to the world of business or the military than to democratic politics. In those cases, the number of people who you need to impress with your competence is smaller, and the people who you are impressing are likely to be more tolerant of ruthlessness and a lack of empathy.

Alcohol as fuel and drug

I occasionally encounter people who are surprised to learn that alcohol itself contains many of the calories contained in alcoholic drinks. In some sense, the surprise is understandable; after all, we think of alcohol as a drug and a poison more than as a food. That being said, when ethanol enters the human body, it “is converted into acetaldehyde by alcohol dehydrogenase and then into acetic acid by acetaldehyde dehydrogenase.” Both of these reactions produce energy that your body can use.

In another sense, it is a bit obvious that ethanol is full of energy. Remember, alcohol has been used before as a fuel for vehicles, and even for rockets. Gasoline contains about 32 megajoules of energy per litre. By comparison, pure ethanol contains 23.5 megajoules: 73% of what is in the gasoline.

As a consequence, vodka (40% ethanol) contains 9.4 megajoules per litre: about 30% of what is in gasoline. So, to get a sense of the energy content of your drink, multiply the quantity of pure ethanol it contains by 0.73. Then, think about the energy that volume of gasoline would release, when burned. A six pack of beer (two litres at 5% alcohol) contains about as much energy as as two shotglasses (70mL) full of gasoline. A bottle of wine (750mL at 12% alcohol), is about the same.

Expressed another way, a bottle of wine contains enough energy (2.1 megajoules) to lift a small apple 2.1 million metres. It also represents the same amount of energy as a 2.1 tonne vehicle going 160km/h. A drop of beer contains 100 joules.

Doctors and conditional probabilities

While it is not surprising, it is worrisome that doctors have trouble with statistics, particularly conditional probabilities. 25 German doctors were asked about the following situation. It is clearly a tricky question, but it is surely a type of question that doctors are exposed to constantly:

The probability that one of these women has breast cancer is 0.8 percent. If a woman has breast cancer, the probability is 90 percent that she will have a positive mammogram. If a woman does not have breast cancer, the probability is 7 percent that she will still have a positive mammogram. Imagine a woman who has a positive mammogram. What is the probability that she actually has breast cancer?

The results of this small trial were not encouraging:

[The] estimates whipsawed from 1 percent to 90 percent. Eight of them thought the chances were 10 percent or less, 8 more said 90 percent, and the remaining 8 guessed somewhere between 50 and 80 percent. Imagine how upsetting it would be as a patient to hear such divergent opinions.

As for the American doctors, 95 out of 100 estimated the woman’s probability of having breast cancer to be somewhere around 75 percent.

The right answer is 9 percent.

You would think that this sort of quantitative analysis would play an important role in the medical profession. I am certain that a great many people around the world have received inappropriate treatment or taken unnecessary risks because doctors have failed to properly apply Bayes’ Theorem. Indeed, false positives in medical tests are a very commonly used example of where medical statistics can be confusing. It is also a problem for biometric security protocols, useful for filtering spam email, and a common source of general statistical errors.

The proper remedy for this is probably to provide doctors with simple-to-use tools that allow them to go from data of the kind in the original question to a correct analysis of probabilities. The first linked article also provides a good example of a more intuitive way to think about conditional probabilities.