No, ionizing radiation is only harmful to an organism as a whole when its amount gets too high. We are constantly bombarded with very small amounts of ionizing radiation that occur naturally, and we get along just fine with our lives without being seriously harmed by this radiation. There are

Yes, human blood is green in the deep ocean. We have to be careful about what we mean by color. Objects don't really have an intrinsic color. Rather, the color of an object is determined by three factors: 1) the color content of the incident light that is illuminating the

The outer layer of skin cells on your finger does not detect anything. The outer layer of your skin contains cells that are dead. In fact, the outermost 25 to 30 cell layers of your skin consist of dead cells that do nothing beyond providing a physical barrier that keeps

Doctors did not create your belly button (or navel). The navel is not the scar or knot left by a doctor that cut your umbilical cord at birth. This fact is obvious to anyone that has ever had children or bathed newborns, but it is sometimes misunderstood by others. While

Healthy humans use all of their brain. There is no part of the brain that goes unused. Certain tasks work certain parts of the brain more, but they all play important roles, as explained by neurobiologist Dr. Eric Chudler. Brain maps, as found in modern anatomy books, indicate that each

Humans can taste more than four flavors on their tongue. Depending on how narrowly you define "taste", there are between five and several dozen independently experienced sensations on the tongue, according to the book "Taste and Smell: An Update" by Thomas Hummel. The seven most common flavors in food that

Yes, poppy seeds contain narcotics. Poppy seeds are used to add flavor to many baked goods, salads, and pasta dishes; ranging from lemon bread to chicken salad. Poppy seeds are produced by the opium poppy plant, a plant that has been famous since ancient times for containing psychoactive chemicals. All

Despite the fact that the name "koala bear" is used in the popular culture of some countries, koalas are actually not bears. The more accurate name of "koala" is used in this animal's native land of Australia. Koalas are marsupials, just like kangaroos and possums. Like most other marsupials, koalas

Yes, blind people do indeed dream in visual images. For people who were born with eyesight and then later went blind, it is not surprising that they experience visual sensations while dreaming. Dreams are drawn from memories that are stored in the brain as well as from brain circuitry that

Yes, there are nuclear reactions constantly occurring in our bodies, but there are very few of them compared to the chemical reactions, and they do not affect our bodies much. All physical objects are made of molecules. A molecule is a series of atoms linked together by chemical (electromagnetic) bonds.