“Science is a way of thinking much more than it is a body of knowledge. Its goal is to find out how the world works, to seek what regularities there may be, to penetrate the connections of things - from sub-nuclear particles, which may be the constituents of all matter, to living organisms, the human social community, and thence to the cosmos as a whole. Our intuition is by no means an infallible guide. Our perceptions may be distorted by training and prejudice or merely because of the limitations of our sense organs, which, of course, perceive directly but a small fraction of the phenomena of the world. Even so straightforward a question as whether in the absence of friction a pound of lead falls faster than a gram of fluff was answered incorrectly by Aristotle and almost everyone else before the time of Galileo. Science is based on experiment, on a willingness to challenge old dogma, on an openness to see the universe as it really is. Accordingly, science sometimes requires courage - at the very least the courage to question the conventional wisdom.”—Carl Sagan (via cwnl)
Your body is composed of different types of tissues: Fat, bones,teeth, brain, the nervous system, connective tissue, blood, lymph, the digestive tract, urine, and the air in your lungs.
But by mass, 65–90% of our body’s cells are water (H2O). So, oxygen takes up a large portion of our body mass. Almost 99% of the mass of the human body is made up of the six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. About 0.75% of the remainder is composed of only five elements: sodium, phosphorus, potassium, sulfur, and chlorine.
The average 70 kg adult has about 6.7 x 1027 atoms. Doesn’t seem like so much with scientific notation, but really, that is a lot! To give you a better idea, let’s show the real number without scientific notation. That is 67000000000000000000000000000 atoms!
The body is composed of 60 elements from the Periodic Table; but the amount of each element vary by individual.
Let’s view it another way:
There is water in your cells, and proteins such as that in your hair, skin, and nails; there is the fat in your body/cells, and the apatite in your bones; there are carbohydrates, such as glycogen and glucose DNA; Dissolved inorganic ions such as sodium, potassium, chloride, bicarbonate, phosphate; Gases such as oxygen being carried through your blood, carbon dioxide, nitrogen oxide, hydrogen, and carbon monoxide. These may be dissolved or present in the gases in the lungs or intestines. There are also many other small molecules in your cells, such as amino acids, fatty acids, nucleobases, nucleosides, nucleotides, vitamins, cofactors.
However your view it, your body is a very complex, giant system composed of many small details.
“Anthropologists believe wisdom teeth, or the third set of molars, were the evolutionary answer to our ancestor’s early diet of coarse, rough food – like leaves, roots, nuts and meats – which required more chewing power and resulted in excessive wear of the teeth. The modern diet with its softer foods, along with marvels of modern technologies such as forks, spoons and knives, has made the need for wisdom teeth nonexistent. As a result, evolutionary biologists now classify wisdom teeth as vestigial organs, or body parts that have become functionless due to evolution.”