Science Outreach is Alive and Well

indexTrying to explain why Canadians’ perception of science is not as favorable as it can be,  a scientist on CBC’s Cross-Canada Checkup blamed it on himself and on the rest of the scientific community. He claimed that scientists do not engage in sufficient science outreach. What an odd thing to say! And yet I have heard that unfounded complaint before.

Here is some evidence to the contrary.

Walk into any public library and you will find several shelves filled with popularizations in every scientific discipline, and a fair percentage of those books such as Oxford’s Very Short Introduction series are written by researchers. Many of those scientists may be in the twilight of their careers, but that does not make them less qualified to communicate with the public. There are also younger and active scientists who maintain blogs or youtube channels, and although some may not find the time for such a medium, it’s been my experience that most respond to emails about their research.

Every week on CBC Radio’s Quirks and Quarks, scientists share their latest endeavors . With the help of the show’s producers and host, the jargon is kept to a minimum to make things understandable. The British Broadcasting Corporation and the Australian Broadcasting Corporation have comparable quality programs such as Crowd Science and Ockham’s Razor, both of which involve active researchers. Even in pre-World-Wide-Web days, university science departments held free public lectures, which are still ongoing. In addition, accessible to anyone with an internet connection are free introductory and first year undergraduate online courses in earth sciences, chemistry, biology and physics at www.mooc-list.com and at MIT (Massachusetts Institute of Technology). Other institutions such as the University of Waterloo specifically reach out to physics and chemistry teachers through their Chem13 News newsletter and the Perimeter Institute, respectively.

We can extend the list by adding popular science magazines such as Scientific American and Natural History which still have articles directly written by researchers; television programs such as Nature of Things and Nova who consult scientists; science museums such as the Exploratorium and the Boston Museum of Science and Technology who collaborate with outreaching professionals; and NASA’s astronomical efforts to educate the public. And if my list of examples seems to exclude certain continents, consider the long list of researchers involved in Science Circus Africa.  It is a pioneering science-outreach project that brings fun-filled science exhibits, shows and teacher workshops to South Africa, Botswana, Zambia and Malawi.

So why do we have a persisting belief that scientists in general don’t do enough outreach? Prejudice, if we borrow a razor-sharp definition from a recent Philosophy Now editorial, “is a preliminary opinion that is mistaken for a final conclusion.” In the same way that people of a certain ethnicity are not immune from prejudices that do not favor their native culture, scientists can also hold mistaken beliefs about their own kind.

OSCAt the root of our discussion is last year’s (August 2017) Ontario Science Center’s Canadian Science Attitude Research poll. Leger’s online panel was used, and they interviewed 1,514 Canadians. (A probability sample of the same size would yield a margin of error of 2.5%, 19 times out of 20). The poll unfortunately revealed that 75% of Canadians believe that “scientific findings can be used to support any opinion” and 43% believe that scientific findings themselves are “a matter of opinion”.

sfw_cardinal-pecking-at-reflection-best-2015-02-13
Source: National Audubon Society

Almost half of our citizens, 47%, believe that the science behind global warming is still unclear. If you consider what the poll reveals about Canadians’ sources for confirming scientific resources —-only 44% rely on scientists and professors, while 50% rely on the internet, media and family—that could be the crux of the problem. The voices of scientists and professors on the internet, in the media and within their families are often overshadowed, not because scientists don’t do enough outreach, but because their voices are largely outnumbered by those of non-scientists. Special interest groups and the general population can easily express themselves online, dominate comment threads and publish blogs and websites. And when a minority of scientists engages in disingenuous outreach, if they become effective, it’s only because their opinions resonate with political and economic viewpoints. If quality-science outreach is like the voice of a songbird amid the noise of major highway traffic, all we have to do is get away from the road.

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Fun With Shadows on the Winter Solstice

Walking back from an errand yesterday morning, I was startled by the length of my shadow, almost 10 meters long. Yesterday, the first day of winter, marked the pinnacle of shadow-length. From today onward, as the days will begin to lengthen, as solar angles become more generous, concentrating solar radiation on less area, the march towards spring begins and shadows will shorten.

For a variety of reasons, on any day the halfway point between sunrise and sunset is most often not exactly 12 PM  (It will only be so, after adjusting for daylight savings time, for a couple of days in January and for part of July and August). The so-called solar noon yesterday occurred at 11:52 PM at our longitude and latitude in Montreal, Canada. Like most people,  I made sure I was out in the cold, standing upright on my deck with a tape measure to determine the length of my shadow.

At that time, my 75.0 inch frame, including the one inch hat, cast a shadow 196 ± 2 inches in length. (Using the actual solar angle corrected for atmospheric refraction  it should have been a bit over 194.7 inches).shadows

Using the fact that at a point directly south of us along the Tropic of Capricorn at a latitude of 23.5º South, the sun is at the zenith, so no shadow is cast. This is a situation similar to what Eratosthenes used to estimate the circumference of the Earth. But here we could also use the alternate and equal angles to derive an expression for latitude. Substituting h = 75.0″ and the measured shadow length = s = 196″, Montreal’s latitude works out to be 45.6º, pretty close to its accepted value of 45. 5º.

The nice thing about measuring the shadow at solar noon is that since the solar angle changes very slowly around midday, the shadow-length is relatively stable for several minutes. At about three in the afternoon I went out and measured my shadow, which was much longer than what was of course the shortest shadow of the day at solar noon. Fifteen minutes after 3 PM, the shadow had lengthened considerably. This not only happened because the sun does not sweep across the sky at a constant rate, but also because the tangent ratio is more sensitive to changes in smaller angles that occur shortly after sunrise and before sunset. Here is a plot to make what I just pointed out more obvious:

winterShadows

If you enjoy these types of experiments and calculations, and you want to verify your results, there is a great spreadsheet online with all sorts of astronomical calculations. They are set up so that you could easily adapt them for your own space and time coordinates. It is made available at no cost by the NOAA Earth System Research Laboratory.  Using their formulas, here is a graph of maximum solar angles I created for all days of the upcoming year for Montreal , Canada. As elevation angles increase, it’s not only shadows that get amplified. Ultraviolet rays also intensify, and knowing which months of the year receive the most helps us take precautions for our skin’s sake.

solarNoon

Life at the End of Quantum Tunnels

Recently a biochemistry student told me that her classmates looked like they had seen a ghost when their professor seemingly took a left turn from a lecture on cellular respiration and started to discuss quantum tunnelling. But this 90-year discovery keeps surfacing in different contexts, reminding us that without the tunnelling effect, there would be no life in the universe.

Part of the lecture focused on iron–sulfur clusters, which play a role in the oxidation-reduction reactions of mitochondrial electron transport. The clusters are part of four protein complexes that sequentially shuttle electrons. The latter are ultimately gained from the breakdown of food molecules and are destined for oxygen. In so doing, protons are consumed inside the mitochondrial membrane while others are pumped out, creating a potential difference that helps motor the synthesis of adenosine triphosphate (ATP). Then ATP goes on to facilitate a host of energy-requiring reactions that keep an organism alive.

ElectronFlow
Each green arrow represents an electron jump due to quantum tunnelling.   http://www.pnas.org/content/107/45/19157/F2.large.jpg

But each time an iron cluster transfers an electron, it does so against a potential energy barrier. How does it do it? Because of the wave-like properties of a tiny particle like the electron, when it’s up against a thin-enough barrier, such as the 2.2 to 3.0 angstrom gaps (0.22 to 0.30 nanometers) shown in the diagram, there is a small but non-zero probability that the electron will be in the gap, and more importantly, also beyond it.  The best way to convince yourself that quantum tunnelling is physically possible is to go through the math and physics, and if you’re interested, it’s found here.  The author does not show every tedious algebraic step, but if you get stuck, I will gladly help in the comments section. It’s great fun while the laundry is being done.

Life involves a struggle against entropy made possible by a continuous energy source. For the planets and presumably moons that harbour life, the most important energy source is fusion from the sun. If you are like me in that you once assumed that the prodigious gravitational force at the core of a sun could provide hydrogen atoms with sufficient energy to overcome Coulombic repulsion and bring about fusion,

5-13-Nuclear-Fusion.jpg
Image credit: E. Siegel

then you were also incorrect. It turns out that the kinetic energies are too small by a factor of 1000. So how does fusion take place? Like electrons in iron clusters, hydrogen atoms, although more massive, are small enough, and thanks to gravity, close enough to overcome the thousandfold barrier working against them. So quantum tunnelling is ultimately working with gravity to make stars shine.

The fact that tunnelling probability decreases steeply with lower thermal velocities extends the duration of smaller stars, those weighing less than 1.5 solar masses. This is important in that it gives life enough time to evolve in solar systems with appropriate conditions. One of the prerequisites of life, we imagine, is the presence of water on the surface of a moon or planet. Whether water is out-gassed or brought in via a comet or asteroid, it has to be first synthesized in molecular clouds according to this reaction between molecular hydrogen and hydroxyl radicals:

OH + H2  →  H + H2O

The extremely cold temperatures combined with adsorption on dust particles create boundaries small enough for quantum tunnelling to allow the production of molecular hydrogen from its atomic counterparts. There is even evidence that the hydroxyl reaction itself benefits from the same phenomenon.

From deep space back to our bodies, can tunnelling cause unwelcome changes in the DNA molecule? In the double helix or “twisted ladder” of DNA, each nucleotide of one strand of the ladder is attracted to its complement on the other strand by means of a hydrogen bond. A hydrogen bond consists of a lone pair of electrons from one nucleotide attracted to the hydrogen bonded to an oxygen or nitrogen atom of the nucleotide on the other side of the strand.

c5cp00472a-f1_hi-res.gif
from Modelling Proton Tunnelling in the Adenine–Thymine Base Pair
A. D. Godbeer , J. S. Al-Khalili * and P. D. Stevenson

But there is a small possibility that the proton (hydrogen without electrons) can overcome the potential energy barrier and end up bonded to the hydrogen-less atom on the other strand. If the effect would be common enough, it could lead to a mutation. It should be noted that this a very active area of research and these authors have concluded that, at least in the adenine-thymine base pair, tunnelling does not occur. Less controversial is the ideas that quantum tunnelling plays a key role in the repair of DNA from ultraviolet damage, specifically in the electron-transfer needed to undo the dimerization of pyrimidines.

If those shocked biochemistry students read this blog, I am not sure that it would erase the “seen-a-ghost” expression from their faces. As educators we don’t often empathize enough with their survival-mode of trying to focus on the “essentials” that will get them through a given course. Quantum tunnelling and quantum phenomena are central ideas, but grasping them rests on an above average foundation of mathematics, physics and chemistry concepts. Is it realistic to assume that most biochemistry freshmen have already acquired that? We have to be patient, fuel them with enthusiasm and make sure that we don’t muddy the waters of key concepts with too much content in our courses.

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