Ever try killing a fly, feel like you just aren’t fast enough, well, you aren’t…at least most of us aren’t
Actually, from the fly’s perspective, you quite literally are moving in slow motion, because every species experiences time differently. The reason? Differences in sight.
All animals, including humans, see the world in what’s essentially a seamless movie. What’s really happening, however, is that the brain is taking individual images sent from the eye at a fixed rate per second in distinct flashes and piecing them together.
The rate at which this occurs is called “flicker-fusion frequency,” which is measured by determining how rapidly a light needs to be switched on and off before it appears to an animal as a continuous stream. Scientists measure this in insects by hooking up tiny glass electrodes to the photoreceptors of its eyes and flashing light at increasingly fast speeds, all while a computer graphs the signals sent from the photoreceptors.
It turns out this rate is different for every animal. The general rule is: the smaller the species, the quicker the vision.
Humans see about 60 flashes per second while flies see about 250 – a full four times faster than humans.
In fact, the majority of flying animals, including vertebrates, have faster vision than humans – possibly because it’s mortally important that they’re to quickly react and dodge obstacles.
Continue reading “Why It’s So Hard to Kill a Fly” »
via [The Verge] The system can even send an email warning
Forget bomb-sniffing dogs, we can now use spinach to detect explosives. Scientists have implanted the leafy greens with tiny tubes that let them sense when an explosive is nearby and even alert someone by email.
This is all part of the field of “plant nanobionics,” which is about embedding plants with tiny nanomaterials that basically give them superpowers. In today’s study, published in the journal Nature Materials, MIT researchers put sensors into the part of the spinach leaf where photosynthesis happens. These sensors can detect a chemical that is often in landmines and other explosives: nitroaromatic compounds.
For this process to actually work, the spinach plant has to absorb the chemicals through its roots. That happens if the nitroaromatic compounds are in the groundwater. From the roots, the chemicals travel to the leaves in about 10 minutes, where they activate the plant’s sensors.
These sensors emit a fluorescent signal that can be seen from an infrared camera nearby. This camera is hooked to a tiny computer, so it can send an email alerting someone about this change.
This same technique can be used with almost any living plant, researchers say. The same team has also programmed spinach to pick up the chemical dopamine. In the future, researchers could “teach” plants and trees to warn us if there are any pollutants nearby. It could be much more convenient than installing complicated manual sensors, especially because plants are everywhere around us — including in your backyard or lining up your city streets.
Science journalist Tom Siegfried on the misuse of statistical methods in science: “It’s science’s dirtiest secret: The ‘scientific method’ of testing hypotheses by statistical analysis stands on a flimsy foundation. Statistical tests are supposed to guide scientists in judging whether an experimental result reflects some real effect or is merely a random fluke, but the standard methods mix mutually inconsistent philosophies and offer no meaningful basis for making such decisions. Even when performed correctly, statistical tests are widely misunderstood and frequently misinterpreted. As a result, countless conclusions in the scientific literature are erroneous, and tests of medical dangers or treatments are often contradictory and confusing.”