A simple IR experiment to prove that the North Carolina Sea Level Rise Bill is just flat wrong

Last month, North Carolina's Senate passed a bill that would have required the state's Coastal Resources Commission to base predictions of future sea level rise along the state's coast on a steady, linear rate of increase. This has sparked controversies across the nation amid the record heat waves in many states.

If the lawmakers had done our very simple IR experiment on visualizing thermohaline in a cup, published in the July issue of last year's Journal of Chemical Education (see the image to the left), they would have had a better understanding about the possibility of the nonlinear acceleration of ice shelf melting: The less salty the seawater is, the faster the ice shelf above it melts. And the faster ice melts, the less salty the seawater will become. This creates a positive feedback loop that accelerates the melting process. If the speed of ice melting in systems as simple as a cup of saltwater is not as nice as the "steady, linear" rate some of the lawmakers would like to see, who can be sure that systems as complex as the Earth would follow a "steady, linear" trajectory of change?

If you bother to read on, this experiment uses just a cup of tap water, a cup of salt water, and some ice cubes. The two cups are placed next to each other on a table for comparison. (a) An IR image right after an ice cube was added to a cup of freshwater (left) and a cup of saltwater (right). (b) An IR image taken after four minutes showing a downwelling column in the freshwater. (c) An IR image taken after nine minutes showing the tabletop was cooled significantly near the freshwater cup. (d) An IR image taken after 16 minutes showing that the bottom of the freshwater cup became cooler than the top whereas the bottom of the saltwater cup remained warmer than the top.

To see the entire process caught under an IR camera, you can watch the embedded YouTube videos in this blog post. Feel free to send these videos to your representatives if you happen to live in the coastal area of North Carolina. Or send to a science teacher in North Carolina in the hope that the bill will be revised in the future to consider the possibility of nonlinear acceleration.

Note that these videos do not represent any political view and should not be considered as in support of any agenda, my purpose is only to provide a humble scientific demonstration to prove that things do not always go smoothly as we wish.

Investigating thermoimaging in augmented multisensory learning about heat transfer

Jesper Haglund from Linköping University presents a poster about our Sweden-US collaborative research on thermal visualization at the 2012 World Conference on Physics Education held in Istanbul, Turkey. Below is the abstract of the poster:

"Infrared (IR) thermal imaging is a powerful technology which holds the pedagogical potential of ‘making the invisible visible’, and is becoming increasingly affordable for use in educational contexts. Science education research has identified many challenges and misconceptions related to students’ learning of thermodynamics, including disambiguation of temperature and heat, and a common belief that our sense of touch is an infallible thermometer. The purpose of the present study was to explore how thermal imaging technology might influence students’ conceptual understanding of heat and temperature. This was carried out by investigating three different conditions with respect to students exploration of the thermal phenomena of different objects (e.g. wood, metal and wool), namely the effect of students’ use of real-time imaging generated from a FLIR i3 IR camera, students’ interpretation of static IR images, and students’ deployment of traditional thermometer apparatus. Eight 7th-grade students (12-13 years old) worked in pairs across the three experimental conditions, and were asked to predict, observe and explain (POE) the temperature of a sheet-metal knife and a piece of wood before, during and after placing them in contact with their thumbs. The participants had not been exposed to any formal teaching of thermodynamics and the ambition was to establish if they could discover and conceptualise the thermal interaction between their thumbs and the objects in terms of heat flow with minimal guidance from the researchers. The main finding was that a cognitive conflict was induced in all three conditions, as to the anomaly between perceived ‘hotness’ and measured temperature, with a particular emotional undertone in the real-time IR condition. However, none of the participants conceptualised the situation in terms of a heat flow. From the perspective of establishing a baseline of the understanding of thermal phenomena prior to teaching, extensive quantities, e.g. ‘heat’ or ‘energy’, were largely missing in the participants’ communication. In conclusion, although an unguided discovery or inquiry-based approach induced a cognitive conflict, it was not sufficient for adjusting the students’ conceptual ecologies with respect to the age group studied here. Future research will exploit the promise of the cognitive conflict observed in this study by developing a more guided approach to teaching thermal phenomena that also takes full advantage of the enhanced vision offered by the thermal camera technology."

If you happen to be at WCPE 2012, drop by his poster: Session - 1.04, Date & Time: 7/3/2012 / 13:00 - 14:00, Room: D406 (3rd Floor).

If you don't know what thermal visualization is, visit our InfraredTube website.

Investigating the Kármán vortex street using Energy2D

Run this simulation.

The Kármán vortex street is a repeating pattern of swirling vortices caused by the unsteady separation of flow of a fluid over bluff bodies. It is named after the great scientist Theodore von Kármán who co-founded NASA's JPL. This effect is observable in nature like in a stream, but you need some luck since it requires some picky conditions that are not always there for you.

Now, with our online simulation program Energy2D you can create and investigate the Kármán vortex street in your browser without depending on Mother Nature to give you an opportunity window.

For example, you can test how big an obstacle should be in order to produce this effect. You will find that an obstacle must be large enough to create a steady vortex street. If the shape of the obstacle is not streamlined, what will you see?

If you stick a thermometer in a thermal vortex street, you should see that the temperature will swing pretty regularly between a high value and a low value (see the image to the right). This means this effect could be used to warm and cool an array of things periodically. Could there be some engineering use of this?

YouTube Physics features our infrared videos

AAPT's Physics Teacher runs a column called YouTube Physics edited by Diane Riendeau, an award-winning physics teacher. In May, the entire column featured five intriguing YouTube videos from our IR website and recommended instructional strategies to use them effectively in the classroom.

Diane recently wrote about the YouTube Physics Column: "Through the use of YouTube, we can show our students demos that we do not have the capability of doing in class. We can use these videos to inspire them and show them some of the cutting-edge discoveries in our field. We can also show them videos from around the world. Students need to realize that the physics community is global, not just national. They should learn to marvel in the discoveries made by physicists from all nations."

We resonate with her vision, which is why we are publishing our IR videos on YouTube to allow students from all over the world to learn thermodynamics, heat transfer, chemistry, and other science subjects in everyday phenomena through IR vision. In the long run, we hope this effort will give birth to an "IRTube" that collects IR views of many scientific phenomena. With the introduction of thermal imaging technology into the classroom, we hope students will begin to upload their own IR videos to the IRTube. Darren Binnema, a student from the King's University College in Edmonton, Canada, has contributed the first IR video to the "IRTube." His IR video visualizes the heat of solutions of NaOH and KCl (see the above image).

For more IR videos, please visit the IRTube website.