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February 21, 2024

SciTech Talk: Why it’s so hard to capture flies

By MIKE YAMAKAWA | September 21, 2013

LIFE IN SLOW MOTION

Have you ever wondered if the idea of time is universally constant? I mean, is your second the same as my second? Yes, the hand on some watches may move faster than others, but does the perception of time vary amongst us? You may wonder if baseball athletes find the ball to be moving much slower than the average, mediocre player. It’s one of philosophy’s intriguing questions, and one that you may think is impossible to find out.

A team of researchers, hailing from various universities in Ireland and Scotland, found a way to finally find the elusive answer. Yes, people can have different perceptions of time. Yes, bugs, who live shorter life spans, can process lot more information than we can in a second. Dogs, who seem to innocently be watching the afternoon soap opera on the couch, are actually watching each static frame of the show at a time, when we can watch it in one fluid, comfortable session.

So how were they able to find this out? They used a technique called critical flicker fusion frequency, where they shine pulses of light at increasing frequencies until the pulses look like a constant ray of light. They performed this technique with different animals, ranging from insects to mammals, and found that species who look apparently agile can perceive the pulses of light at a very high frequency. It’s no wonder that fruit flies can evade our rolled up newspaper so well. They basically see everything in slow motion!

The results may not be as trivial as they initially seem. This research opens up a very new dimension for studying nature. We’ve discovered a myriad of things about the various niches that animals have comfortably resided in. With the knowledge that animals can perceive time at different speeds, we can begin to understand a completely different world that other animals can apparently, uniquely perceive.

YOU’RE SO  SENSITIVE

It’s truly amazing how our senses are so incredibly powerful. The eye can detect light intensities within a extremely broad range — many of us can detect a very dim speck of light in a pitch dark environment. Our noses can tell the difference between the smell of a ham and cheese sandwich and a turkey sub. Our tactile senses are fascinatingly sensitive, too. Our parents can predict if we have a fever just by placing their hands on our forehead, and you probably would flinch if a tiny ant managed to bite you. If you close your eyes and reach for your notebook, you can tell if is open or not. Try it out! You can feel and tell apart the roughness of the white paper in your notebook from the smooth plastic cover that contains it.

For the first time, researchers from Sweden were able to provide a physical description of the smallest “wrinkle” that we can detect with our fingertips. The smallest wrinkle had an amplitude, or height, of 13 nanometers! That’s a billion times smaller than your meter stick — an order of magnitude that corresponds to the size of a very large molecule. Still hard to fathom? Think this way: If your finger was the size of earth, it would be like being able to feel the presence of a car, just by rubbing the planet. To these researchers, and maybe to some readers, this is a ground breaking discovery in the field of tactile research. It’s analogous to understanding how we see color, for instance. Our fingers can differentiate the roughness of extremely tiny wrinkles, by detecting the vibration that it causes due to friction. This is not merely a trivial fact that we can learn about. This can lead to new smartphone screen designs, robotic tactile senses, and new virtual experiences. Without compromising the texture and quality of phone screens, one can add very small vibrations to change how the screen feels. Instead of having a plastic feel, screens could induce vibrations so it feels like wood when you are looking at a picture of a tree, for example. Or you can change the components of shampoo to make your hair feel considerably different! Maybe Braille can be improved and be much more accessible for blind people! The possibilities may really be endless.

DON’T WASTE WASTE

Oxygen is obviously a very important element for us. We need it to create energy. Eventually, oxygen allows for the transport of electrons to occur in our mitochondria, the power plant in our cells, to create energy units called ATP from the food that we eat. There are some organisms, however, that live deep beneath the surface of the ocean with no access to oxygen. They have instead evolved to utilize other oxides, like hydrogen sulfide, to convert their food to energy. They are called exoelectrogenic microbes.

We have been using bacteria to perform all kinds of things, like creating biofuels, or helping our digestive system. Recently, Stanford engineers have been doing research on how to use the ability of exoelectrogenic microbes to our advantage. And they found the ultimate, alternative source of energy: sewage. Instead of depleting our natural resources to produce fuels, why not use the waste that we produce to do work?

The microbes seem to be able to extend biological “wires” from their bodies to expel electrons they build up upon digesting organic materials, or waste. We can use the electrons to create a current, and therefore electricity. The researchers estimated that about 30% of the wasted energy in waste can be extracted from these bacteria.

While this may be an alternative form of fuel one day, a major concern of a device with these bacteria is the cost. They used silver plates as the cathode, the positive end of a battery. While releasing the electrons are not a problem, they must find a cheap material that will have enough potential to attract the electrons to create a current. As many other alternative energies, costs always seems to be a theme that is holding us back from clean energy!

 


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