What Is Static Friction

Static friction is a force which resists the lateral movement of two objects which are touching each other. A simple example of static friction might be a wooden block sitting on a ramp. Unless sufficient force is exerted, the block will not slide down the ramp, because static friction holds it place and resists sliding. When objects have a high coefficient of friction, it means that a lot of force will be required to break through the force of static friction and create movement, while a low coefficient means that less force will need to be exerted.

A number of things determine the strength of static friction. Some friction takes place on the electromagnetic level, in the form of charged particles which are attracted to or repelled by each other. The texture of the objects also plays a role. For example, a silk sheet has a very smooth texture which creates less resistance, while a dry asphalt road is coarse, generating more resistance.

Many people are familiar with static friction, since they interact with it on an almost daily basis. For example, when someone slides a book across a table, static friction is at work. Initially, a small level of force needs to be exerted to get the book to move. Once it is moving, however, kinetic friction comes into play, and less effort will be required to move the book. The amount of force required can vary. For example, if a book has a library cover on it and it got damp, the wet book will require more force to move, while a brand new paperback book might slide very easily across a dry wooden table with a varnished surface.

Sometimes, static friction may be such a negligible force that people don't even realize that it is present. In other cases, it can be quite significant. For example, a car has a tremendous amount of static friction which makes it very difficult to push a stopped car into motion. Some friction is actually specifically desired with cars, because it allows the driver more control; when a car loses friction, it can slide out of control, as seen on icy roads in the winter.

A number of formulas can be used to determine the coefficient of friction of various objects. Calculating friction can get complicated, because it is subject to many variables, including gravity, which can make it difficult to plug values into an equation and quickly generate a coefficient. Coefficients of static friction have been calculated for some well-known objects for convenience: for example, two pieces of Teflon®, a very slippery substance, have a coefficient of friction of .04.

What is Mitosis

Mitosis is the scientific term for nuclear cell division, where the nucleus of the cell divides, resulting in two sets of identical chromosomes. Mitosis is accompanied by cytokinesis in which the end result is two completely separate cells called daughter cells. There are four phases of mitosis: prophase, metaphase, anaphase and telophase.

The first phase of mitosis is prophase. In this phase the chromosomes which are normally spread throughout the nucleus begin to condense into a tight ball. The DNA molecules of the chromosomes begin to interact with enzymes and proteins that assist in the replication of the genes. The compact coiling of the chromosomes at this stage of mitosis is called mitotic chromosomes. Nearing the end of prophase, the material enclosing the nucleus and the cytoskeleton disappears. The cytoskeleton is transformed into what is called a spindle apparatus which works to pull the duplicated chromosomes apart during the anaphase.

The second phase of mitosis is metaphase. In this phase the chromosomes of the dividing cell begin to line up and are coordinated with the spindle apparatus. The soon to be divided chromosomes are symmetrically positioned on the metaphase plate typically at the equator of the parent cell.

Anaphase is the third step of mitosis. Abruptly the spindle apparatus pulls the two identical sets of chromosomes apart from one another. Each new set of chromosomes is moved to opposite spindle poles. These two sets of chromosomes will soon develop into the nuclei of two daughter cells perfectly identical to each other as well as identical to the parent cell.

The final stage of mitosis is telophase which means end. Telophase is best described as the opposite of prophase. As the chromosomes begin to move toward the spindle pole they start to uncoil and spread out. Then the spindle apparatus made of the former cytoskeleton is deconstructed. Finally the nuclear envelope or membrane is formed around the chromosomes. Although this is the last phase of mitosis, telophase will not be complete until cytokinesis has been carried out. Cytokinesis is similar to mitosis except it involves the cell’s cytoplasm and organelles where mitosis is the division of the nucleus or control center of the cell. Once mitosis and cytokinesis are properly completed there are two new functioning cells.

What is Taurine

Taurine is an amino sulfonic acid that is found in high levels in the skeletal and heart muscles of humans, as well as in white blood cells, and the central nervous system. It is also found in some plants, such as seaweed, fungi and bacteria. Taurine is a main ingredient in bile and aids in the digestion of fats and the absorption of vitamins that are fat soluble. It is a necessary acid that our body produces naturally.

Austrian scientists Friedrich Tiedermann and Leopold Gmelin first identified taurine in 1827 in the bile of an ox. This is where the name originates—taurine comes from the Latin word for bull, Taurus. While we know for sure that taurine aids in the breakdown of fats and absorption of vitamins, there are many other claims that have been made concerning its usefulness in the human body. In infants and some animals, specifically cats, taurine is a requirement for eye health and development. Premature infants who cannot naturally produce taurine must have formula with taurine added to ensure proper development.

Taurine has many known benefits, although some have not been definitively proven. It may reduce high blood pressure in adults and is being tested as a potential treatment for bipolar depression. Studies on mice have shown that taking taurine supplements while on a high fat diet kept them from gaining weight. In other studies, diabetic rats saw improvement in losing weight, and lower blood sugar levels.

Taurine is possibly best known as a health supplement, and is used in a variety of products. Bodybuilders take supplements of taurine coupled with creatine which may help in reducing muscle fatigue and soreness. Energy drinks, which are becoming hugely popular, especially among the teen and young adult set, often list taurine as one of its main supplemental ingredients. Drinks like Monster™ and Rockstar™ both contain up to 2000 mg of taurine, which is within daily suggested doses of 50 mg to 3 grams.

University of London researchers claim that taurine may counteract the effects of heavy drinking on the liver because it prevents fat from building up in the organ. Although this is not the intended or most responsible use of taurine, news of this have led many to believe that drinking an energy drink with high levels of taurine may be the perfect “morning after” treatment after a night of heavy drinking.