A common lay misunderstanding of the term refers to quantum mechanics, where, if the outcome of an event has not been observed, it exists in a state of '', which is something like being in all possible states at once. In the famous thought experiment known as Schrödinger's cat, the cat is empirically neither alive nor dead until observed – until that time, the cat is theoretically "both" alive and dead (technically half-alive and half-dead in probability terms). However, most quantum physicists, in resolving Schrödinger's seeming paradox, now understand that the acts of 'observation' and 'measurement' must also be defined in quantum terms before the question makes sense. From this point of view, there is no 'observer effect', only one vastly entangled quantum system. A significant minority still find the equations point to an observer; , who probably worked more deeply on this subject than any physicist thus far, devised a graphic in which the universe was represented by a "U" with an eye on one end, turned around and viewing itself, to describe his understanding.
The Heisenberg uncertainty principle is also frequently, confused with the "observer effect". The uncertainty principle actually describes how precisely we may measure the position and momentum of a particle at the same time – if we increase the precision in measuring one quantity, we are forced to lose precision in measuring the other. Thus, the uncertainty principle deals with "measurement", and not "observation". The idea that the Uncertainty Principle is caused by disturbance (and hence by observation) is not considered to be valid by some, although it was discussed in the early years of quantum mechanics, and is often repeated in popular treatments.
There is a related issue in quantum mechanics relating to whether systems have pre-existing – prior to measurement, that is – properties corresponding to measurements that could possibly be made on them. The assumption that they do is often referred to as "realism" in the literature, although it has been argued that the word "realism" is being used in a more restricted sense than philosophical realism. A recent experiment in the realm of quantum physics has been quoted as meaning that we have to "say goodbye" to realism, although the author of the paper states only that "we would [..] have to give up certain features of realism". These experiments demonstrate a puzzling relationship between the act of measurement and the system being measured, but it is unclear if they require a conscious observer or not.
In information technology, the observer effect refers to potential impact of the act of observing a process output while the process is running. For example, if a process records its progress in a log file, the act of viewing the file while the process is running could cause an I/O error in the process, which could, in turn, cause it to stop.
Another example would be observing the performance of a CPU by running both the observed and observing programs on the same CPU. This will lead to inaccurate results because the observer program itself affects the CPU performance (modern, heavily cached and pipelined CPUs are particularly affected by this kind of observation).
Observing (or rather, "debugging") a running program by modifying its source code (such as adding extra output or generating log files) or by running it in a debugger may sometimes cause certain bugs to diminish or change their behavior. This makes more difficulty for the person trying to isolate the so-called "Heisenbug".
In the social sciences and general usage, the effect refers to how people change their behavior when aware of being watched (see Hawthorne effect). For instance, in the armed forces, an announced inspection is used to see how well soldiers can do when they put their minds to it, while a surprise inspection is used to see how well prepared they generally are.
The related social-science term observer bias is error introduced into measurement when observers overemphasize behavior they expect to find and fail to notice behavior they do not expect. This is why medical trials are normally organized as double-blind tests. Observer bias can also be introduced because researchers see a subject doing something, and interpret it according to what it means to them, whereas it may mean something else to the subject.
Canton Township, Michigan
Canton, Michigan is a township in Wayne County in the U.S. state of Michigan. About 93,704 people live in it according to an educated guess of the U.S. Census Bureau. The FBI decided that it is the 20th safest city in the United States.The average household in Canton earns $84,000 dollars.
Probability theory
Probability theory is the part of mathematics that studies random situations. Probability theory usually studies random events, random variables, stochastic processes, and non-deterministic events (events that do not follow a simple pattern).
Tossing a coin, winning the lottery, or rolling a die are random events. However, random events have certain patterns, which can be studied and predicted, using probability theory.
Scientists can use probability theory to obtain information about things that would be too complex to deal with, like statistical mechanics. Also, scientists discovered (in the 20th century) that atoms, and everything that we know, obeys something called quantum mechanics, which uses lots of probability theory.
The theory of probability was created by Gerolamo Cardano, a medical doctor and gambler who tried to calculate his luck. Years later, Pierre de Fermat and Blaise Pascal helped develop Cardano's theory.
Today, probability theory is used in statistics, which is useful to all kinds of areas: like medicine, economy, Science, Mathematics...
The Raven
"The Raven" is a narrative poem by American writer Edgar Allan Poe, first published in January 1845. It tells the story of a mysterious talking raven who visits a lover; it shows how the lover is slowly going insane. It is often called Poe's most famous poem, its publication made him famous in his day, and today it is still one of the most recognized and respected poems in American literature.
Mayan civilization
The Maya civilization and Maya religion. They lived there for a long time and some of the Maya people live there even today.
The Maya lived there 4,000 years ago (about 2000 BC). At that date complex societies were living in the Maya region. The staple foods of the Maya diet were cultivated. Their food included maize, beans, squashes, and chili peppers. The first Maya cities developed around 750 BC.
The Maya people used a written language and a numeral system. They were good at art, building, and Their priests studied stars and planets, which helped them make calendars.
The Maya civilization was biggest between the years of 420 AD and 900 AD. The Maya civilization spread all the way from central Mexico to Honduras, Guatemala, and northern El Salvador. It is estimated that at its maximum, the civilization had at least ten million people. The Maya people traded with other people in the Americas. Their art and buildings have many different styles. This shows they traded a lot. They made changes to their buildings to make them even better. The Maya civilization started getting smaller after 900 AD.
The Conquistadors arrived in the 15th century and took over Mexico and later Central America, even in the Mayan areas. However, the Maya people still live there today. They live in the same areas the Mayan civilization used to live in. They keep the old Mayan traditions and beliefs.
There are many Mayan languages still spoken today, including one called the Achi language. A play called "Rabinal Achi" is considered important.