The electric eel can stun their prey by delivering a shock of up to 860 volts. According to one study, the shocks from leaping electric eels are powerful enough to drive away animals as large as horses by activating the nociceptor sensory neurons in the horse. The electric eel stacks some 6,000 electrocytes in series (longitudinally) in its main organ; the organ contains some 35 such stacks in parallel, on each side of its body. The eel can either use its electrical discharge to locate pray (electrolocate) or to stun them. It is said that Volta was inspired by the electric eel in inventing the voltaic pile, the first electrical battery that could continuously provide an electric current to a circuit. Volta does casually mention the electric eel in this essay.
Lightning can heat the air it passes through to temperatures of about 30,000 °C (54,000 °F). That is regarded as 5 times hotter than the surface of the sun. The discharge process, or return stroke, of the lightning is the most luminous part where the electric current moves through the channel. One observation found that the rate at which the return stroke current traveled was around 100,000 km/s (or one-third the speed of light). Global monitoring indicates that lightning on Earth occurs at an average frequency of approximately 44 (± 5) times per second.
In the 17th century, Isaac Newton discovered that prisms could split up white light into a spectrum of colors. He also showed that the spectrum could be recombined to recreate white light. Newton was the first to use the word spectrum in describing his experiments. Today we call the band of the electromagnetic spectrum that is visible to the human eye the visible spectrum. We call the colors such as red, orange, yellow, green, cyan, blue, and violet the spectral colors and they correspond to narrow bands of wavelengths. Light that has longer wavelengths than the spectral colors are called ultravoilet, while light that has shorter wavelengths are called infrared. Humans cannot generally see ultraviolet or infrared, but there are some animals that can. Most animals evolved to have a visible range that matches what is called the optical window, which is the range of light that can pass through the atmosphere.
Neptune’s winds in the equatorial region have speeds of around 1,200 km/h (750 mph), with some storm systems having wind speeds that reach up to 2,100 km/h (1,304 mph) making them near-supersonic. For comparison, the fastest wind gust ever recorded on Earth was 408 km/h (253 mph). The average airliner flies at around 500 mph. The speeds of the winds on Neptune show just how different weather systems can be on other planets, and highlights another way that Earth is rare in its habitability.
If you look at a gram of soil under a microscope, you will find that it can contain billions of organisms. Most of the organisms are microbial and unexplored by science. Some of the bacteria fix atmospheric nitrogen, while some fungi extract phosphorus and increase good carbon levels in the form of glomalin. Microbes make nutrients in the soil more available to plants. A more diverse soil microbiome results in fewer plant diseases. Scientists now use the term “Soil Health” to describe how well it sustains plant and animal activity, enhances biodiversity, maintains water and air quality, and sequesters carbon, among other aspects.
