In the Age of Enlightenment, philosophers Thomas Hobbes, John Locke and Jean-Jacques Rousseau wrote books about social contracts. They saw good government as coming from social contracts. Rousseau wrote a book called "The Social Contract". Both the United States Declaration of Independence and United States Constitution use the theory of social contracts.
Social capital
Social capital is the willingness of people to help each other.
It often replaces money which people would use to buy the same help.
Society works best when there is plenty of social capital. The less social capital there is, the more social problems there usually are. If there is no social capital, war and revolution often results.
People who have no money and cannot get help from society may have to agree to do things they do not want to do, or force others to do things they do not want to. Organized crime grows in this way, and so do forced labour and slavery.
Most ways of measuring social capital have to do with trust - people who trust that favours and help will be available when they need it will favour and help others more. Those who are seen as trying to get a free ride will get much less help. A social climber tries to earn social capital by making friends with those who have it but without actually helping. Some call this kind of person a social parasite. They are very hard to detect, unlike people who cheat or commit fraud. When there are too many of these kinds of people, especially when they are politicians, people begin to mistrust their government. Rather than work with a political party to change law, they may start to look for direct revenge for things.
Social capital is a lot like real capital. The more money a person or a society has, the easier it is to do things and the better off people are. The less money, the more difficult things become and the worse people feel.
The Social Capital Foundation
Site
A site is a real fixed physical location where something will or has happened or a place where something is.
It is used very often in building trades to mean the place where a building will go up.
A gravesite is a place where a person will be buried after they die.
The words onsite and offsite refer to work that must take place on the site, or which can take place somewhere else. For instance, a prefabricated building can be "built offsite" and then "moved onsite".
"Site" is also a common abbreviation in net jargon for "website". In this case no real physical location exists other than the place where the computers are, and one "goes to the site" simply by using a web browser to "go to" that URL. This is a conceptual metaphor. It can be confusing. Someone who uses it is also likely using other jargon.
Subtraction
Subtraction is the arithmetic operation for finding the difference between two numbers, though it can also be generalized to other mathematical objects such as vectors and matrices. The special names of the numbers in a subtraction expression are, minuend - subtrahend = difference. For example, the expression 7 - 4 = 3 can be read as "seven minus four equals three," "seven take away four leaves three," or "four from seven leaves three."
If the minuend is less than the subtrahend, the difference will be a negative number. For example, 17 - 25 = -8 . This can be read as "Seventeen minus twenty-five equals negative eight."
Subtraction is how cash registers determine the change a buyer receives, when the buyer pays with more money than the purchase cost.
String theory
String theory tries to model the four known fundamental interactions—gravitation, electromagnetism, strong nuclear force, weak nuclear force—together in one theory. This tries to resolve the alleged conflict between classical physics and quantum physics by "elementary units"—the one classical force: gravity, and a new quantum field theory of the other three fundamental forces.
Einstein had sought a unified field theory, a single model to explain the fundamental interactions or mechanics of the universe. Today's search is for a unified field theory that is "quantized" and that explains matter's structure, too. This is called the search for a theory of everything (TOE). The most prominent contender as a TOE is string theory converted into superstring theory with its six higher dimensions in addition to the four common dimensions (3D + time).
Some superstring theories seem to come together on a shared range of geometry that, according to string theorists, is apparently the geometry of space. The mathematical framework that unifies the multiple superstring theories upon that shared geometrical range is M-theory. Many string theorists are optimistic that M-theory explains our universe's very structure and perhaps explains how other universes, if they exist, are structured as part of a greater "multiverse". M theory/supergravity theory has 7 higher dimensions + 4D.
Introductions to string theory that are designed for the general public must first explain physics. Some of the controversies over string theory result from misunderstandings about physics. A common misunderstanding even for scientists is the presumption that a theory is proved true in its "explanation" of the natural world wherever its "predictions" are successful. Another misunderstanding is that earlier physical scientists, including chemists, have already explained the world. This leads to the misunderstanding that string theorists began making strange hypotheses after they became unaccountably "set free from truth".
Newton's law of universal gravitation (UG), added to the three Galilean laws of motion and some other presumptions, was published in 1687. Newton's theory successfully modeled interactions among objects of a size we can see, a range of phenomena now called the "classical realm". Coulomb's law modeled electric attraction. Maxwell's electromagnetic field theory unified electricity and magnetism, while optics emerged from this field.
Light's speed remained about the same when measured by an observer traveling in its field, however, although "addition of velocities" predicted the field to be slower or faster "relative" to the observer traveling with or against it. So, versus the electromagnetic field, the observer kept losing speed. Still, this did not violate Galileo’s Principle of relativity that says the laws of mechanics work the same for all objects showing inertia.
By law of inertia, when no force is applied to an object, the object holds its velocity, which is speed "and" direction. An object either in "uniform motion", which is constant speed in an unchanging direction, or staying at rest, which is zero velocity, experiences inertia. This exhibits Galilean invariance—its mechanical interactions proceeding without variation—also called Galilean relativity since one cannot perceive whether one is at rest or in uniform motion.
In 1905, Einstein's special theory of relativity explained the accuracy of both Maxwell's electromagnetic field and Galilean relativity by stating that the field's speed is absolute—a universal constant—whereas both space and time are local phenomena "relative" to the object's energy. Thus, an object in relative motion shortens along the direction of its momentum (Lorentz contraction), and its unfolding of events slows (time dilation). A passenger on the object cannot detect the change, as all measuring devices aboard that vehicle have experienced length contraction and time dilation. Only an external observer experiencing relative rest measures the object in relative motion to be shortened along its travel pathway and its events slowed. Special relativity left Newton's theory—which states space and time as "absolute"—unable to explain gravitation.