Category Archives: IR

Personal thermal vision could turn millions of students into the cleantech workforce of today

So we have signed the Paris Agreement and cheered about it. Now what?

More than a year ago, I wrote a proposal to the National Science Foundation to test the feasibility of empowering students to help combat the energy issues of our nation. There are hundreds of millions of buildings in our country and some of them are pretty big energy losers. The home energy industry currently employs probably 100,000 people at most. It would take them a few decades to weatherize and solarize all these residential and commercial buildings (let alone educating home owners so that they would take such actions).

But there are millions of students in schools who are probably more likely to be concerned about the world that they are about to inherit. Why not ask them to help?

You probably know a lot of projects on this very same mission. But I want to do something different. Enough messaging has been done. We don't need to hand out more brochures and flyers about the environmental issues that we may be facing. It is time to call for actions!

For a number of years, I have been working on infrared thermography and building energy simulation to knock down the technical barriers that these techniques may pose to children. With NSF awarding us a $1.2M grant last year and FLIR releasing a series of inexpensive thermal cameras, the time of bringing these tools to large-scale applications in schools has finally arrived.

For more information, see our poster that will be presented at a NSF meeting next week. Note that this project has just begun so we haven't had a chance to test the solarization part. But the results from the weatherization part based on infrared thermography has been extremely encouraging!

Infrared imaging evidence of geothermal energy in a basement

Geothermal energy is the thermal energy generated or stored in the Earth. The ground maintains a nearly constant temperature six meter (20 feet) under, which is roughly equal to the average annual air temperature at the location. In Boston, this is about 13 °C (55 °F).

You can feel the effect of the geothermal energy in a basement, particularly in a hot summer day in which the basement can be significantly cooler. But IR imaging provides a unique visualization of this effect.

I happen to have a sub-basement that is partially buried in the ground. When I did an IR inspection of my basement in an attempt to identify places where heat escapes in a cold night, something that I did not expect struck me: As I scanned the basement, the whole basement floor appeared to be 4-6 °F warmer than the walls. Both the floor and wall of my basement are simply concrete -- there is no insulation, but the walls are partially or fully exposed to the outside air, which was about 24 °F at that time.

This temperature distribution pattern is opposite to the typical temperature gradient observed in a heated room where the top of a wall is usually a few degrees warmer than the bottom of a wall or the floor as hot air rises to warm up the upper part.

The only explanation of this warming of the basement floor is geothermal energy, caught by the IR camera.

Visualizing thermal equilibration: IR imaging vs. Energy2D simulation

Figure 1
A classic experiment to show thermal equilibration is to put a small Petri dish filled with some hot or cold water into a larger one filled with tap water around room temperature, as illustrated in Figure 1. Then stick one thermometer in the inner dish and another in the outer dish and take their readings over time.

With a low-cost IR camera like the FLIR C2 camera or FLIR ONE camera, this experiment becomes much more visual (Figure 2). As an IR camera provides a full-field view of the experiment in real time, you get much richer information about the process than a graph of two converging curves from the temperature data read from the two thermometers.
Figure 2

The complete equilibration process typically takes 10-30 minutes, depending on the initial temperature difference between the water in the two dishes and the amount of water in the inner dish. A larger temperature difference or a larger amount of water in the inner dish will require more time to reach the thermal equilibrium.

Another way to quickly show this process is to use our Energy2D software to create a computer simulation (Figure 3). Such a simulation provides a visualization that resembles the IR imaging result. The advantage is that it runs very fast -- only 10 seconds or so are needed to reach the thermal equilibrium. This allows you to test various conditions rapidly, e.g., changing the initial temperature of the water in the inner dish or the outer dish or changing the diameters of the dishes.

Figure 3
Both real-world experiments and computer simulations have their own pros and cons. Exactly which one to use depends on your situation. As a scientist, I believe nothing beats real-world experiments in supporting authentic science learning and we should always favor them whenever possible. However, conducting real-world experiments requires a lot of time and resources, which makes it impractical to implement throughout a course. Computer simulations provide an alternative solution that allows students to get a sense of real-world experiments without entailing the time and cost. But the downside is that a computer simulation, most of the time, is an overly simplified scientific model that does not have the many layers of complexity and the many types of interactions that we experience in reality. In a real-world experiment, there are always unexpected factors and details that need to be attended to. It is these unexpected factors and details that create genuinely profound and exciting teachable moments. This important nature of science is severely missing in computer simulations, even with a sophisticated computational fluid dynamics tool such as Energy2D.

Here is my balancing of this trade-off equation: It is essential for students to learn simplified scientific models before they can explore complex real-world situations. The models will give students the frameworks needed to make sense of real-world observation. A fair strategy is to use simulations to teach simplified models and then make some time for students to conduct experiments in the real world and learn how to integrate and apply their knowledge about the models to solve real problems.

A side note: You may be wondering how well the Energy2D result agrees with the IR result on a quantitative basis. This is kind of an important question -- If the simulation is not a good approximation of the real-world process, it is not a good simulation and one may challenge its usefulness, even for learning purposes. Figure 4 shows a comparison of a test run. As you can see, the while the result predicted by Energy2D agrees in trend with the results observed through IR imaging, there are some details in the real data that may be caused by either human errors in taking the data or thermal fluctuations in the room. What is more, after the thermal equilibrium was reached, the water in both dishes continued to cool down to room temperature and then below due to evaporative cooling. The cooling to room temperature was modeled in the Energy2D simulation through a thermal coupling to the environment but evaporative cooling was not.

Figure 4

The National Science Foundation funds large-scale applications of infrared cameras in schools


We are pleased to announce that the National Science Foundation has awarded the Concord Consortium, Next Step Living, and Virtual High School a grant of $1.2M to put innovative technologies such as infrared cameras into the hands of thousands of secondary students. This education-industry collaborative will create a technology-enhanced learning pathway from school to home and then to cognate careers, establishing thereby a data-rich testbed for developing and evaluating strategies for translating innovative technology experiences into consistent science learning and career awareness in different settings. While there have been studies on connecting science to everyday life or situating learning in professional scenarios to increase the relevance or authenticity of learning, the strategies of using industry-grade technologies to strengthen these connections have rarely been explored. In many cases, often due to the lack of experiences, resources, and curricular supports, industry technologies are simply used as showcases or demonstrations to give students a glimpse of how professionals use them to solve problems in the workplace.


Over the last few years, however, quite a number of industry technologies have become widely accessible to schools. For example, Autodesk has announced that their software products will be freely available to all students and teachers around the world. Another example is infrared cameras that I have been experimenting and blogging since 2010. Due to the continuous development of electronics and optics, what used to be a very expensive scientific instrument is now only a few hundred dollars, with the most affordable infrared camera falling below $200.

The funded project, called Next Step Learning, will be the largest-scale application of infrared camera in secondary schools -- in terms of the number of students that will be involved in the three-year project. We estimate that dozens of schools and thousands of students in Massachusetts will participate in this project. These students will use infrared cameras provided by the project to thermally inspect their own homes. The images in this blog post are some of the curious images I took in my own house using the FLIR ONE camera that is attached to an iPhone.

In the broader context, the Next Generation Science Standards (NGSS) envisions “three-dimensional learning” in which the learning of disciplinary core ideas and crosscutting concepts is integrated with science and engineering practices. A goal of the NGSS is to make science education more closely resemble the way scientists and engineers actually think and work. To accomplish this goal, an abundance of opportunities for students to practice science and engineering through solving authentic real-world problems will need to be created and researched. If these learning opportunities are meaningfully connected to current industry practices using industry-grade technologies, they can also increase students’ awareness of cognate careers, help them construct professional identities, and prepare them with knowledge and skills needed by employers, attaining thereby the goals of both science education and workforce development simultaneously. The Next Step Learning project will explore, test, and evaluate this strategy.

SimBuilding on iPad

SimBuilding (alpha version) is a 3D simulation game that we are developing to provide a more accessible and fun way to teach building science. A good reason that we are working on this game is because we want to teach building science concepts and practices to home energy professionals without having to invade someone's house or risk ruining it (well, we have to create or maintain some awful cases for teaching purposes, but what sane property owner would allow us to do so?). We also believe that computer graphics can be used to create some cool effects that demonstrate the ideas more clearly, providing complementary experiences to hands-on learning. The project is funded by the National Science Foundation to support technical education and workforce development.

SimBuilding is based on three.js, a powerful JavaScript-based graphics library that renders 3D scenes within the browser using WebGL. This allows it to run on a variety of devices, including the iPad (but not on a smartphone that has less horsepower, however). The photos in this blog post show how it looks on an iPad Mini, with multi-touch support for navigation and interaction.

In its current version, SimBuilding only supports virtual infrared thermography. The player walks around in a virtual house, challenged to correctly identify home energy problems in a house using a virtual IR camera. The virtual IR camera will show false-color IR images of a large number of sites when the player inspects them, from which the player must diagnose the causes of problems if he believes the house has been compromised by problems such as missing insulation, thermal bridge, air leakage, or water damage. In addition to the IR camera, a set of diagnostics tools is also provided, such as a blower-door system that is used to depressurize a house for identifying infiltration. We will also provide links to our Energy2D simulations should the player become interested in deepening their understanding about heat transfer concepts such as conduction, convection, and radiation.

SimBuilding is a collaborative project with New Mexico EnergySmart Academy at Santa Fe. A number of industry partners such as FLIR Systems and Building Science Corporation are also involved in this project. Our special thanks go to Jay Bowen of FLIR, who generously provided most of the IR images used to create the IR game scenes free of charge.

Comparing two smartphone-based infrared cameras

Figure 1
With the releases of two competitively priced IR cameras for smartphones, the year 2014 has become a milestone for IR imaging. Early in 2014, FLIR unveiled the $349 FLIR ONE, the first IR camera that can be attached to an iPhone. Months later, a startup company Seek Thermal released a $199 IR camera that has an even higher resolution and is attachable to most smartphones. In addition, another company Therm-App released an Android mobile thermal camera that specializes in long-range night vision and high-resolution thermography, priced at $1,600. The race is on... Into 2015, FLIR announced a new version of FLIR ONE that supports both Android and iOS and will probably be even more aggressively priced.

Figure 2
All these game changers can take impressive IR images just like taking conventional photos and record IR videos just like recording conventional videos, and then share them online through an app. The companies also provide a software developers kit (SDK) for a third party to create apps linked to their cameras. Excited by these new developments, researchers at several Swedish universities and I have embarked an international collaboration towards the vision that IR cameras will one day become as necessary as microscopes in science labs.

Figure3
To test these new IR cameras, I did an easy-to-do experiment (Figure 1) that shows a paradoxical warming effect on a piece of paper placed on top of a cup of (slightly cooler than) room-temperature water. This seemingly simple experiment actually leads to very deep science at the molecular level, as blogged before.

I took images using FLIR ONE (Figure 2) and SEEK (Figure 3), respectively. These images are shown to the right for comparison. As you can see, both cameras are sensitive enough to capture the small temperature rise caused by water absorption and condensation underside the paper.

The FLIR ONE has a nice feature that contextualizes the false-color IR image by overlaying it on top of the edges (where brightness changes sharply) of the true-color image taken at the same time by the conventional camera of the smartphone. With this feature, you can see the sharp edges of the paper in Figure 2.

The time of infrared imaging in classrooms has arrived

At the Consumer Electronics Show (CES) 2014, FLIR Systems debuted the FLIR ONE, the first thermal imager for smartphones that sells for $349. Compared with standalone IR cameras that often cost between $1,000 and $60,000, this is a huge leap forward for the IR technology to be adopted by millions.

With this price tag, FLIR ONE finally brings the power of infrared imaging to science classrooms. Our unparalleled Infrared Tube is dedicated to IR imaging experiments for science and engineering education. This website publishes the experiments I have designed to showcase cool IR visualizations of natural phenomena. Each experiment comes with an illustration of the setup (so you can do it yourself) and a short IR video recorded from the experiment. Teachers and students may watch these YouTube videos to get an idea about how the unseen world of thermodynamics and heat transfer looks like through an IR camera -- before deciding to buy such a camera.

For example, this post shows one of my IR videos that probably can give you some idea why the northern people are spraying salt on the road like crazy in this bone-chilling weather. The video demonstrates a phenomenon called freezing point depression, a process in which adding a solute to a solvent decreases the freezing point of the solvent. Spraying salt to the road melts the ice and prevents water from freezing. Check out this video for an infrared view of this mechanism! 

InfraMation Keynote Delivered

Orlando is the center of the thermal imaging universe in November 6-8 when it hosts the largest infrared imaging conference in the world: InfraMation. Invited by FLIR Systems, I gave a Keynote Speech on the educational applications of IR imaging in this morning's Opening Plenary and I felt that it was very well received. The PEPSI joke about how to use an IR camera to produce a PEPSI logo (see the second image in this post) was a hit. Everyone laughed.

Here is the link to download my slides in PDF format (34MB). 

Once again, I was thrilled by the power of IR imaging and how this kind of technology can knock down the barrier between disciplines.Even if we are an educational technology firm with a primary mission to teach science, we are in no place to be humble because the science we are seeing through our IR cameras is exactly the same as the science the industry folks are seeing through theirs. Our original discoveries, intended to teach students science concepts, were equally recognized by world leaders in IR imaging technologies such as Prof. Dr. Michael Vollmer from the University of Applied Sciences in Brandenburg, Germany in their publication intended for researchers and professionals. With cutting-edge and yet easy-to-use technologies like IR imaging, the line between research and education is never so blurry. This ought to get science educators to think about the possibilities opened up by new technologies. We keep hearing some educators pushing back by asserting that children are not scientists and cannot think or act like scientists. This kind of argument largely neglects the advancement of technology and throws away the opportunities they bring along. It is time for a change, at least a try.

Think Molecularly: An Infrared Imaging Experiment Opens a Door to Deep Scientific Explorations

Figure 1
The most fascinating part of science is the search of answers to strange phenomena. In the past nine months, I have posted more than fifty IR videos on my Infrared YouTube channel. These experiments are all very easy to do, but not all of them are easy to explain. In this blog post, I will try to explain one of those experiments, with one of my other skills -- molecular simulation.

This simple IR experiment concerns with putting a piece of paper above a cup of room temperature (nearly) water (Figure 1). I hear you saying, what is the big deal of it? You have probably done that several times in your life, for whatever reasons.

If you happen to have an IR camera and you look at this process through it, you may be surprised. Many of you know that water in an open cup is slightly cooler ( 1-2°C lower) than room temperature because of evaporative cooling: constant evaporation of water molecules from liquid water brings away thermal energy from the cup and causes it to remain a bit cooler than the room environment (which is why you feel cold when you step out of a swimming pool). You may think that the paper would also cool down because at room temperature paper is a bit warmer than the water in the cup and, based on what your science teacher has told you, heat would flow from the warmer paper to the cooler water, causing the paper to cool down.

Figure 2 (Watch it in YouTube)
But the result is exactly opposite -- the paper actually warms up (Figure 2)! And the warming appears to be pretty significant -- up to 2°C can be observed in a dry winter day. I don't know your reaction to this finding, but I was baffled when I saw it because I was expecting to see cooling and this effect appeared to be a violation of the Second Law of Thermodynamics (which, of course, is impossible)! In fact, the reason I did this experiment was to figure out how sensitive my IR camera could be. My intention was to exploit the small temperature difference resulting from evaporative cooling of water as a stable lower-temperature source. I was examining if the IR camera could catch the miniscule heat transfer between the water and the paper.

Figure 3 (Watch it in YouTube)
I quickly figured out that the culprit responsible for this strange heating phenomenon must come from the water vapor, which we cannot see with the naked eye. But what we can't see doesn't mean it doesn't exist. When water molecules in the vapor encounters the surface molecules of the paper, they will be captured. When more and more water molecules are captured and condense onto the paper surface, they will return to the liquid state and, according to the Law of Conservation of Energy, release the excessive energy they carry, which causes the paper to warm up. In other words, the paper somehow recovers the energy lost in the cup through evaporation. As you can see now, this is a pretty delicate thermodynamic cycle that connects two phase changes, evaporation and condensation, in two different places and their latent heats. The physicists among us would appreciate if I say that this shows entropy at work: evaporation is an entropic effect that is caused by water molecules wanting to maximize their entropy by leaving their more organized liquid state. The interaction between the vapor and the paper acts to reverse this process by returning the water molecules to the condensed liquid state and a certain amount of net energy can be extracted from this (known as the enthalpy of vaporization).

Figure 4: Sensor results.
At this point, I hope you have been enticed enough to want to try this out yourself. If you don't have an IR camera, you can use a temperature sensor or an IR thermometer as a substitution to observe this phenomenon (of course, nothing beats an IR camera in terms of seeing heat -- with a point thermometer you just need to be patient and be willing to do more tedious work).

But wait, this is not the end of the story!

If you keep observing the paper, you will see that this condensation heating effect will diminish in a few minutes (Figure 3). This trend is more clearly shown in Figure 4 in which the temperature of the paper was recorded for ten minutes using a fast-response surface temperature sensor. What happens?

Figure 5 (Watch it in YouTube)
The answer to this question can be illustrated using a schematic molecular simulation (Figure 5) I designed to explain the underlying molecular physics (in that simulation water molecules are simplified as single round particles). After water molecules condense onto the paper surface, a thin layer of condensate will form. When it becomes thick enough, water molecules will evaporate from it, too, just like from the surface layer of water in the cup. When the rate of evaporation equals the rate of condensation, there is no more net heating: The condensation heating and evaporative cooling will reach the "break-even" point. Reaching this equilibrium state doesn't mean that condensation and evaporation on the surface of the paper will stop. In fact, water molecules will keep condensing to the layer and evaporating from it. This is known as "dynamic equilibrium." If you move the paper, you will break this dynamic equilibrium. Figure 6 shows a pattern in which evaporative cooling and condensation heating occurred simultaneously on a single piece of paper after the paper had been shifted a bit. In Figure 6, evaporation dominated in the blue zone that was shifted out of the cup area, condensation dominated in the white zone that was shifted into the cup area, and the overlap zone in the middle remained close to the equilibrium state because it was the zone that still remained inside the cup area -- so business as usual.

Figure 6 (Watch it in YouTube)
As you can see, there is a lot of science in this "simple" experiment! Nothing we have done so far requires expensive materials or supplies. Everything needed to do this experiment is probably within the reach of your arm if you are reading this article at home (and you happen to have a digital thermometer, or better, an IR camera, nearby). If you are a science teacher, this experiment should fascinate you because you know this will be a perfect inquiry activity for your students. If you are a building professional, this experiment should fascinate you because you know how important hygrothermal dynamics is in driving moisture transport in the building envelope. If you are a scientist, this experiment should fascinate you because what I have shown you is in fact an atomic layer deposition experiment that anyone can do -- some Fermi calculation suggests that the thickness of the layer is in the nanometer range (only a few hundred layers of water molecules or 1/10,000th of the diameter of your hair). What we are seeing is in fact a signal from the nanoscale world! Isn't that cool?

Figure 7 (Watch it in YouTube)
Does our story end now? Absolutely no. The new questions you can ask will be practically endless if you keep "thinking molecularly." The following are six extended questions I have asked myself. You can try all of these without leaving your kitchen.

When will the paper cool down?

Returning to the original purpose of my experiment (looking for cooling due to heat transfer), can we find a situation in which we will indeed see cooling instead of heating? Yes, if the water is cold enough (Figure 7). When the water is cold, the evaporation rate drops. There will be less water molecules hitting the surface of the paper. The energy gain from weaker condensation heating cannot compensate the energy loss due to the heat transfer between the paper and the cold water. (By the way, I think the heat transfer in this case is mostly radiative, because air doesn't conduct heat well and natural convection acts against heat transfer in this situation.)

What if the paper has been atop the water for a long time?
Figure 8 (Watch it in YouTube)

If you leave the paper atop the cup of water for a few hours and you come back to examine it, you would probably be surprised again: The paper is now cooler than room temperature (Figure 8). I wouldn't be surprised if you are totally confused now: This heating and cooling business is indeed quite elusive -- even though everything we have done so far has been limited to manipulating paper and water. To keep the story short, I will tell you that this is because water molecules have traveled through the porous layer of the paper through capillary action and shown up on the other side of the paper (this molecular movement is often known as percolation in physics). Their evaporation from the upper side of the paper cools down the paper. The building science guys among us can use this experiment to teach moisture transport through materials. Can the temperature of the upper side be somehow used to gauge the moisture vapor transmission rate (MVTR) of a porous material? If so, this may provide a way to automatically measure MVTR of different materials. The American Society for Testing and Materials already has established a standard based on IR sensors. Perhaps this experiment can be related to that.

Different materials have different dew points?

Figure 9 (Watch it in YouTube)
Do water molecules condense to other materials such as plastic? We know plastic materials do not absorb water (which is why they are good vapor barriers). If plastic materials are not cold enough, water molecules do not condense to them. Figure 9 shows this difference by using a piece of paper half-covered by a transparency film taped to the underside. Heating was only observed in the paper part, indicating water molecules do not condense to the plastic film. This experiment raises an interesting question: The so-called dew point, the temperature below which the water vapor in the air at a constant barometric pressure will condense into liquid water, may not be an entirely reliable way to predict condensation. Condensation actually depends on the chemical property of the material surface. Hydrophobic (water-hating) materials like plastic tend to have a low dew point, whereas hydrophilic (water-loving) materials tend to have a high dew point. The porosity of the material should matter, too, because a more porous material will provide a large surface for interaction with water molecule -- paper happens to be such a material because of its fiber texture. If you are a building professional and you worry about moisture, you probably should have this in your mind.

Figure 10 (Watch it in YouTube)
Vapor pressure depression

What will happen if we add some salt (or baking soda or sugar) to the water? Figure 10 shows that the condensation heating effect becomes weaker. For our chemist friends, this is known as vapor pressure depression. The salt ions do not evaporate themselves, but their presence in a solution slows down the evaporation of water molecules.

A vapor column?

Figure 11 (Watch it in YouTube)
What will happen if the paper approaches the water from a different angle like in the vertical direction? How does the shape of the water vapor distribution above a cup of water look like? Does it look like a steam from a cup of coffee? Figure 11 could probably give you some clue.

What about alcohol?

So far we have used only water. What about other liquids? Alcohol is pretty volatile. So I tried some isopropyl alcohol (91%). Once again, I was baffled. Our experience with applying rubbing alcohol to our skin says that alcohol cools faster than water. So I expected that when the isopropanol  molecules condense, they would release more heat. But this is not what Figure 12 suggests! Given the fact that the enthalpies of vaporization of alcohol and water are 44 and 41 kJ/mol, respectively, the only sensible explanation may be that the heating effect is not only due to the condensation of the vapor molecules, but also the interaction between the vapor molecules and the surface molecules of the paper. If the interaction between an alcohol molecule and a paper molecule is weaker, then the adsorption of the alcohol molecule onto the paper surface will produce less heat. I don't know how to prove this now, but this could be a good topic to research.
Figure 12 (Watch it in YouTube)

Final words

Even if this is a lengthy blog post (and thanks for making it to the end), I am pretty sure that the scientific exploration does not stop here. There are other questions that you can ask yourself. For me, I have been intrigued by the fascinating thermodynamic cycle and have been wondering if that could be used to engineer something that can harvest that latent heat. In other words, could we turn a cup of water into a tiny power plant to charge my cell phone? The evaporation of water molecules from an open cup is a free gift of entropy from Nature. Perhaps something could be done about it.

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.