Does altitude have the same effect on animals as it does on people? Does my dog, raised at 7,000 feet, have a better chance of catching a squirrel when we visit sea level?
Madeline Kelty, Santa Fe, New Mexico
Animals unused to high altitude can, like humans, suffer from altitude sickness, which usually starts at 8,000 feet. And for animals used to high altitudes, studies on rats and dogs found cardiovascular changes that might lead to a temporary increase in endurance at lower altitudes, says Don Moore, senior scientist at the National Zoo. But then again, the effects of high-altitude training on humans have been widely debated.
Is any single work recognized as the first symphony? If so, when was it first performed, and who wrote it?
Mary Fonseca, New Orleans
There is no recognized first symphony, says Kenneth Slowik, artistic director of the Smithsonian Chamber Music Society. In the 17th century, “symphoniae” referred to a wide variety of works, many of which could be played by small groups of musicians. What we call a “symphony”—a large-scale, multi-movement orchestral work—evolved in the next century. More than 13,000 18th-century symphonies have been cataloged, from Finland to Sicily to North Carolina; there is no consensus on which came first.
Do solar panels, in absorbing solar energy, keep the earth’s surface from getting hotter, even if only a little bit? If that does happen, then would significant solar panel utilization help to alleviate the earth’s warming problems?
Alan Arthur, Grand Isle, Vermont
Like any solid object in direct sunlight, a solar panel shades whatever lies beneath it, providing a slight change in temperature. But the process of absorbing solar energy and converting it into other forms of energy still heats the air and land eventually, so energy is not lost to the overall system, says David DeVorkin, senior curator of history of astronomy and the space sciences at the National Air and Space Museum. Even so, widespread use of solar panels would indirectly reduce the warming of the earth by decreasing the burning of fossil fuels.
Since Arctic dwellers had no access to citrus fruits before modern trade, how did they avoid getting scurvy?
Vivian Davis, Surrey, British Columbia
Citrus fruits aren’t the only source of vitamin C, which human beings need to avoid contracting scurvy. Arctic dwellers could get enough of the vitamin by eating raw organs, such as liver, brain and skin, from animals that synthesized it, says Antonio Curet, curator at the National Museum of the American Indian. Kelp, a plant in the Inuit diet, also contains vitamin C.
Why did some of the life on the planet become mammals and the other reptiles?
Michael Hailparn, Mahwah, New Jersey
The lineages leading to reptiles and to mammals were already separate when they first appear in the fossil record some 305 million years ago, says Hans-Dieter Sues, curator of fossil vertebrates at the National Museum of Natural History. They share a common ancestor—one that produced amniotic eggs—but what led to that divergence is unknown. The popular notion that mammals evolved from reptiles is wrong.