At the other extreme, searing-hot ecosystems spring up around hydrothermal vents on seafloors. Last year scientists used a deep-sea robot to measure a 765-degree “black smoker”—as hot as a pizza oven—spitting out heat almost two miles beneath the Atlantic. Super-heat-resistant microbes can withstand boiling temperatures nearby. The four-inch-long Pompeii worm—dressed in a furry coat of gray bacteria and crowned with tubular red gills—makes its home in 176-degree water, hot enough to sanitize an egg.
A backyard sparrow (106 degrees) would shimmer. Stove-top burners (2200 degrees) would explode with color.
Land animals rarely have to deal with such extremes. The Sahara ant can handle 131-degree weather, but the sun does not get Earth’s surface much hotter than that. In the last few years, a NASA satellite recorded surface temperatures in the Lut desert of Iran as high as 159 on a bad day. The highest recorded air temperature was 136 degrees, in Libya in 1922; the coldest was about –129, in Antarctica in 1983. Only bacteria and viruses can survive such a chill.
Humans can tinker with nature to produce far greater extremes of temperature, if only for an instant. Last year a team of physicists at Sandia National Laboratories in New Mexico passed millions of amps of electricity through an array of tiny steel wires. In a matter of nanoseconds, the wires dissolved into a cloud of superheated gas that reached an astounding 3.6 billion degrees—hotter than the interior of the sun. A few years earlier, a team at MIT used gravitation and magnetic fields to slow down the atoms in a cloud of sodium gas. Their “gravito-magnetic trap” cooled the gas to –459.67, less than a billionth of a degree above absolute zero, the point at which all the molecular movement halts and our heat-vision eyes see only black. Such ultralow temperatures may allow scientists to make more precise measurements of time and gravity.
Gazing at our infrared world as a whole, we see another place where human activity might have an impact: the flow of energy into our atmosphere and back out again. All that solar heat that washes into the air and water eventually reflects back into space, maintaining the planet’s energy balance. (Earth vents heat at a rate of more than 30 trillion watts—or 7 trillion calories per second—with nearly half coming from the planet’s interior.) Without the atmosphere’s heat-trapping properties, Earth’s average temperature would be around 0 degrees Fahrenheit, and the oceans would be frozen solid. But now it appears the energy balance has become slightly lopsided due to a buildup of greenhouse gases, warming our planet overall by about 0.8 degrees in the past 50 years.
If heat were visible, everything around us would blaze with energy and movement: A backyard sparrow (106 degrees) would shimmer, leaving motion trails as it flew away, stove-top burners (2200 degrees) would explode with color, spraying out plumes of warmth. Above all, the planet would be eternally swirling with motion, seemingly in fast-forward, as the laws of thermodynamics forever drove hot into cold in a jittering frenzy.
