The Joshua tree is a desert tree that grows in southwestern North America, in California, Arizona, Utah, and Nevada. A native of the Mojave Desert, these droughttolerant trees thrive in the open grasslands of California’s Joshua Tree National Park. The Mormon pioneers named this tree after the prophet Joshua, because its extended branches resembled the outstretched arm of Joshua as he pointed with his spear to the ancient city of Ai. The trees are twisted and spiky, with tough leaves, and look a little bit like a tree from a Dr. Seuss book. Joshua trees can grow from seed or from an underground rhizome of another Joshua tree. They grow very slowly, sometimes 3.9 to 7.8 inches (10 to 20 centimeters) in their first few years.
The tallest trees reach about 49 feet (15 meters) tall. The trunk of a Joshua tree is made of thousands of small fibers and does not have yearly growth rings, Which makes it hard for scientists to tell the tree’s age. Although the fragile tree has shallow roots, if it survives the harsh desert environment, it can live hundreds— even thousands—of years.
Living species of sequoias are some of the biggest and widest trees in the world. The tallest trees are the coastal redwoods of California, while the widest ones are the giant sequoias, which have much larger trunks and branches. These trees grow in the Sierra Nevada mountains of Central California at elevations of about 6,500 feet (1,981 meters). The trees have survived for 2,000 or 3,000 years. Some of the largest sequoia trees measure 35 feet (10.6 meters) in diameter and up to 300 feet (91 meters) in height.
Their bark can be 4 feet (1.2 meters) thick! Many are found in California’s Sequoia National Park. The General Sherman, for example, is one of the tallest giant sequoias in the world, with a height of about 275 feet (85 meters).
Rain clouds are generally dark gray because light cannot penetrate them due to the deep and densely packed water droplets and ice inside the cloud. Generally, the color of a cloud depends on the cloud’s relationship to the sunlight: Clouds appear gray when they block sunlight.
The thicker the cloud, the more light it blocks. When a cloud is about 3,000 feet (914 meters) thick, hardly any sunlight will make its way through the cloud.
Living creatures need oxygen to survive, and fish are no exception. Human beings 68 use their lungs to take in oxygen, and fish breathe using their gills. A fish’s gills are full of blood vessels that absorb the tiny particles of oxygen from the water.
The fish sucks the water in through its mouth and squirts it out through its gills; during this process, the gills take the oxygen from the water into the blood vessels. A fish’s gills are not constructed to take oxygen from the air, so they cannot breathe on dry land.
The fastest growing hairs on the human body are men’s beard hairs. If the average male never trimmed his beard, it would grow to almost 30 feet (9 meters) long in his lifetime.
Most adult insects, including bees and dragonflies, have two large compound eyes, made up of separate, sometimes thousands, of lenses. They all point in different directions to give the insect a very wide field of vision.
The lenses also help the insect see movement, enabling it to react quickly to seize its prey or escape danger. You can witness this yourself as you try to swat a fly in your home it’s almost impossible to catch a flying insect!
Scientists don’t really know why we cry when we’re unhappy or hurt (or sometimes, even joyful). But tears help express deeply felt emotions and often release stress and tension from the body. From our earliest days, when we were babies and could not yet communicate through language, crying let the people around us know that we needed something.
Frequently, even after we become older, crying still serves as a wordless signal that something help or comfort is needed. In places all over the world, no matter what language is spoken, crying expresses emotions that are easily understood by all.
Constipation occurs when your body has a hard time having a bowel movement, or going poop. When you digest your food, it collects in the last part of the colon, or the end of the large intestine. If the feces doesn’t have lot of fiber or bulk to it, it stays in the colon longer than it normally would.
Water continues to draw out of the feces, making it hard and compact instead of squishy and moveable. The rectum has to push extra hard to get your poop out. Constipation usually resolves itself, but your body can avoid constipation by eating plenty of fresh fruit, vegetables, and bran, and drinking plenty of water each day.