The atmosphere of the Earth serves as a key factor in sustaining the planetary ecosystem. The thin layer of gases that envelops the Earth is held in place by the planet's gravity. Dry air consists of 78% nitrogen, 21% oxygen, 1% argon and other inert gases, carbon dioxide, etc.; but air also contains a variable amount of water vapor. The atmospheric pressure declines steadily with altitude, and has a scale height of about 8 kilometers at the Earth's surface: the height at which the atmospheric pressure has declined. The ozone layer of the Earth's atmosphere plays an important role in depleting the amount of ultraviolet (UV) radiation that reaches the surface. As DNA is readily damaged by UV light, this serves to protect life at the surface. The atmosphere also retains heat during the night, thereby reducing the daily temperature extremes.

Terrestrial weather occurs almost exclusively in the lower part of the atmosphere, and serves as a convective system for redistributing heat. Ocean currents are another important factor in determining climate, particularly the major underwater thermohaline circulation which distributes heat energy from the equatorial oceans to the Polar Regions. These currents help to moderate the differences in temperature between winter and summer in the temperate zones. Also, without the redistributions of heat energy by the ocean currents and atmosphere, the tropics would be much hotter, and the polar regions much colder.

A gear is a wheel with teeth around its circumference, the purpose of the teeth being to mesh with similar teeth on another mechanical device possibly another gear wheel so that force can be transmitted between the two strategies in a direction tangential to their surfaces. A non-toothed wheel can transmit some tangential force but will slip if the force is large; teeth put off slippage and permit the transmission of large forces.

A gear can mesh with any device having teeth friendly with the gear's teeth. Such devices include racks and other non-rotating policy; however, the most common condition is for a gear to be in mesh with another gear. In this case revolution of one of the gears necessarily causes the other gear to rotate. In this way, rotational motion can be transferred from one position to another. While gears are sometimes used simply for this reason to transmit rotation to another shaft perhaps their most significant feature is that, if the gears are of asymmetrical sizes, a mechanical advantage is also achieved, so that the rotational speed, and torque, of the second gear are dissimilar from that of the first. In this way, gears provide a means of increasing or decreasing a turning speed, or a torque.  

What is destiny? For many people it is how they live their lives. We may believe that everyone’s life has its own destiny or course. By other words our destiny is out fate. It may be either a good thing or a bad thing and to most people it has already been decided by a Supreme Being or God. But for us that is just the pessimistic view on destiny. Others may believe that one can decide his or her own destiny. A person has to know how to control it and become a master of it. Personally you believe that one can control his or her own destiny. This means if you strive to do that yourself. That is If you just live your life expecting that everything will fall in your lap you are wrong.

Nothing in life is pre-destined for anybody as in the people you meet, the jobs you get or the person you marry. And also If that were to be true then everyone would be happy, that is if your destiny is for you to be happy. We may think that the notion of destiny is just an excuse that people use for the misfortunes or fortunes that they encounter. During the entire course of ones life you can began to make your own destiny.

Destiny may not control a part of your life. Whether that person applies himself and goes to school and then to college and eventually gets a career on his own is his prerogative. This may makes perfection possible, for knowledge is power, and when a person knows the law and works with it, he can produce any result he chooses; he becomes master of his destiny. He only gave them a miniscule portion. So don’t think that destiny has anything to do with the person that you fall in love with.

A medication is a drug taken to treat and reduce any symptoms of an illness or medical condition, or may be used as precautionary medicine that has future benefits but does not treat any existing or pre-existing diseases or symptoms. Provision of medication is often keeping up by the government into three categories — over the counter (OTC) medications, which are available in pharmacies and supermarket's without special limitations, behind the counter (BTC), which are dispensed by a pharmacist without needing a doctor's prescription, and Prescription only medicines (POM), which must be prescribed by a licensed medical professional, as a rule a physician.Most Over the counter medications are normally considered to be safe enough that most people will not hurt themselves if they are taken as instructed. In UK, BTC medicine is called pharmacy medicines which can only be sold in registered pharmacies, by or under the supervision of a pharmacist. However, the precise difference between OTC and prescription depends on the legal jurisdiction.

In relativistic quantum mechanics, the electron is described by the direct Equation which defines the electron as a point. In quantum field theory, the activities of the electron are described by quantum electrodynamics, a gauge theory. In Dirac's model, an electron is defined to be a mathematical point, a point-like, exciting bare particle surrounded by a sea of interacting pairs of virtual particles and antiparticles. The extraordinarily precise agreement of this forecast with the experimentally resolute value is viewed as one of the great achievements of modern physics. In the Standard Model of particle physics, the electron is the first-generation stimulating lepton. It forms a weak isospin doublet with the electron neutrino, these two particles cooperate with each other through both the charged and neutral current weak interaction. The electron is very similar to the two more massive particles of higher generations, the muon and the tau lepton, which are identical in charge, spin, and interface but differ in mass.

The SYNC standard, repeatedly called DIN sync, defines an interface for electronic music instrument. It was introduced in the 1980s by Roland firm for synchronization of music sequencers, drum machines, arpeggiators and similar devices. The SYNC standard uses the signal device and start/stop. This means the low position is 0 V, the high position is about +5 V. The clock signal defines the speed of the progression or drum pattern. The start/stop signal defines if the sequence is successively ie;start/stop = 0 V -> stop, start/stop = +5 V -> running.The SYNC standard uses 5 pin DIN connectors, the same as used for MIDI, but uses a special pin-out. The term DIN sync does not mean that it is a DIN normal, only that it uses DIN connectors. In some applications the outstanding pins (4 and 5) are even used as tap, fill in or reset and start. But this differs from machine to device.To connect two SYNC devices a cable with a 3 or 5 pin plug up on each side has to be used. A standard MIDI cable is not fitting as here the pins 1 and 3 may be unconnected.

Dial indicators are instruments used to correctly measure a small distance. They may also be known as a Dial gauge, Dial Test Indicator, or as a clock. They are named so because the measurement results are displayed in a overstated way by means of a dial. They may be used to check the dissimilarity in tolerance during the check process of a machined part, measure the deflection of a beam or ring under laboratory conditions, as well as many other situations where a small measurement needs to be registered or indicated. An economic indicator is a statistic concerning the economy. The lighting system of a motor vehicle consists of lighting and signaling procedure mounted or integrated to the front, sides and rear of the vehicle. The purpose of this system is to present illumination for the driver to operate the vehicle safely after dark, to increase the visibility of the vehicle, and to display information about the vehicle's presence, position, size, direction of travel, and driver's intentions concerning direction and speed of travel.

Light is electromagnetic energy with a wavelength that is observable to the eye or, in a technical or scientific context, the word is sometimes used to mean electromagnetic emission of all wavelengths. The elementary element that defines light is the photon. The three basic properties of lights are Intensity, or alternatively amplitude, which is related to the observation of brightness of the light, Frequency, or alternatively wavelength, perceived by humans as the color of the light, and Polarization, which is only weakly perceptible by humans under ordinary circumstances. Due to its wave–particle duality, light can show properties of both waves and particles. The study of light, known as optics, is an important research area in modern physics The first successful quantity of the speed of light in Europe using an earthbound apparatus was carried out by Hippolyte Fizeau in 1849. Fizeau aimed at a beam of light at a mirror several thousand metres away, and placed a rotating cog wheel in the path of the beam from the source to the mirror and back again. At a certain rate of rotary motion, the beam could pass through one gap in the wheel on the way out and the next gap on the way back. Knowing the distance to the mirror, the number of teeth on the wheel, and the rate of rotation, Fizeau calculated the speed of light as 313 000 km/sv

Electrical resistance is a compute of the degree to which an object opposes an electric current through it. The SI unit of electrical resistance is the ohm. Its reciprocal quantity is electrical conductance calculated in siemens. Electrical resistance shares some conceptual parallels with the mechanical notion of friction. The resistance of an object determines the amount of current through the object for a known voltage across the object I=V/R, where R is the resistance of the object, measured in ohms, equivalent to J·s/C2, V is the voltage across the object, measured in volts, I is the current through the object, measured in amperes. In metals, the Fermi level lies in the conduction band giving rise to free transfer electrons. However, in semiconductors the position of the fermi level is within the band gap, closely half way between the conduction band minimum and valence band maximum for intrinsic semiconductors.

A social network is a social structure made of nodes that are tied by one or more specific types of relatives, such as values, visions, idea, financial exchange, friends, kinship, dislike, trade, web links, sexual relations, disease communication or airline routes.Social network analysis views common relationships in terms of nodes and ties. Nodes are the individual actors within the networks, and ties are the associations between the actors. Research in a number of academic fields has shown that social networks operate on many levels, from families up to the level of nations, and play a serious role in determining the way problems are solved, organizations are run, and the degree to which individuals succeed in achieving their goals.In its simplest form, a social network is a map of all of the appropriate ties between the nodes being studied. The network can also be used to decide the social capital of individual actors. These concepts are often displayed in a shared network diagram, where nodes are the points and ties are the lines.