Since the advent of satellite positioning, such coordinate systems are typically geocentric: the axis is aligned with the Earth's ( conventional or instantaneous ) rotation axis.

Since the beginning of civilization, people have used stone, ceramics and, later, metals found on or close to the Earth's surface.

Since nuclear chain reactions only require natural materials ( such as water and uranium ), it is possible to have these chain reactions occur where there is the right combination of materials within the Earth's crust.

Since Alpha Centauri is the star system closest to Earth, it indicates that, in the altered timeline, the Romulans invaded Earth's stellar region, despite not even being prompted by Earth's role in the encouragement of interplanetary cooperation.

Since tidal forces generate currents in conducting fluids in the Earth's interior, they in turn affect the Earth's magnetic field.

Since the ozone layer prevents most harmful UVB wavelengths ( 280 – 315 nm ) of ultraviolet light ( UV light ) from passing through the Earth's atmosphere, observed and projected decreases in ozone have generated worldwide concern leading to adoption of the Montreal Protocol that bans the production of CFCs, halons, and other ozone-depleting chemicals such as carbon tetrachloride and trichloroethane.

Since the gyrocompass's north-seeking function depends on the rotation around the axis of the Earth that causes torque-induced gyroscopic precession, it will not orient itself correctly to true north if it is moved very fast in an east to west direction, thus negating the Earth's rotation.

Since the intensity of cosmic rays is much larger outside the Earth's atmosphere and magnetic field, it is expected to have a major impact on the design of spacecraft that can safely transport humans in interplanetary space.

Since about 950 million years ago, the Earth's climate has varied regularly between large-scale or just polar cap wide glaciation and extensively tropical climates.

Since opposite poles ( north and south ) attract, the Earth's " North Magnetic Pole " is thus actually the south pole of the Earth's magnetic field.

Since the 1960s, the Earth's gravity field has been measured by analyzing the motion of satellites.

Since the physical structures of the Earth's surface have changed over geologic time, palaeogeographers have coined various names for ancient regions that no longer exist, from very large regions such as the supercontinents Rodinia, Pangaea, and Pannotia, to relatively small regions like Beringia.

Since Chile extends from a point about north of the Tropic of Capricorn to a point hardly more than north of the Antarctic Circle, a broad selection of the Earth's climates can be found in this country.

Since the surface was farther from the Earth's center at Cayenne than at Paris, gravity was weaker there.

Since human economic productivity is largely reliant on Earth's ecosystems, adequate bioproductivity needs to be maintained.

Since the Earth's mean solar day is almost exactly 24 hours, an analemma can be traced by plotting the position of the Sun as viewed from a fixed position on Earth at the same clock time every day for an entire year.

Since geosynchronous satellites are close to the Earth, their analemmas vary substantially depending on the location of the observer on the Earth's surface.

Since the Earth is in motion, two main possibilities were considered: ( 1 ) The aether is stationary and only partially dragged by Earth ( proposed by Augustin-Jean Fresnel in 1818 ), or ( 2 ) the aether is completely dragged by Earth and thus shares its motion at Earth's surface ( proposed by George Gabriel Stokes in 1844 ).

Since cosmic X-ray radiation is absorbed by the Earth's atmosphere, space-based telescopes are needed for X-ray astronomy.

Since the solid parts of the Earth are ductile, the Earth's equatorial bulge has been decreasing in step with the decrease in the rate of rotation.

Since asteroids travel in an orbit not much larger than the Earth's, their magnitude can vary greatly depending on elongation.

Despite all these amazing powers, Ultraman has one main weakness: Since Earth's atmosphere leeches away his solar energy, Ultraman can only physically exist on Earth for approximately three to five minutes of Earth time.

Since the Industrial Revolution, emissions of sulfur dioxide and nitrogen oxides into the atmosphere have increased.

Chaplin decided not to re-enter the United States, writing: " Since the end of the last world war, I have been the object of lies and propaganda by powerful reactionary groups who, by their influence and by the aid of America's yellow press, have created an unhealthy atmosphere in which liberal-minded individuals can be singled out and persecuted.

Since originally taking interest in climate studies in the 1970s, Dyson has suggested that carbon dioxide levels in the atmosphere could be controlled by planting fast-growing trees.

Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases.

Since the rebranding in 2010, Sporting have seen dramatic growth in their fan section, with several fan groups adding their voice to The Cauldron culture and atmosphere.

Since most of the atmosphere's quantity of such triatomic gases is contained within the troposphere, this portion of the atmosphere is readily heated by the earth's radiation.

Since the heat exchanged is related to the entropy change by, the equation governing the temperature as a function of height for a thoroughly mixed atmosphere is

Since 1978 Microwave sounding units ( MSUs ) on National Oceanic and Atmospheric Administration polar orbiting satellites have measured the intensity of upwelling microwave radiation from atmospheric oxygen, which is proportional to the temperature of broad vertical layers of the atmosphere.

Since 1972 it has measured a variety of atmospheric and climatic phenomena, including the levels of ozone, nitric oxide, sulphur dioxide and various hydrocarbons in the atmosphere as well as meteorological data such as the levels of temperature, dew point, relative humidity, pressure, wind, global and direct irradiance.

Since the edges of the Orbital are built as high walls, the rotation prevents the atmosphere from escaping, thus protecting the inhabitants from radiation.

Since three of the Vanguard satellites are still orbiting, with their drag properties essentially unchanged, they form a baseline data set on the atmosphere that is 50 years old and counting.

Since there are living cells within the cambium layers that need to exchange gases during metabolism, these lenticels, because they have numerous intercellular spaces, allow gaseous exchange with the outside atmosphere.

Since the 1960s a puzzling phenomenon has been observed in the atmosphere of Venus whereat the atmosphere above the cloud base is seen to travel around the planet about 50 times faster than the rotation of the planet surface, or in only four to five Earth-days.

Since 2007 the South Stand has been made officially accessible to over-18s only, due to its hyper and somewhat provocative atmosphere.

Since the upper atmosphere is not homogeneous and contains significant magnetic structure, the solar ultraviolet ( UV ), EUV and X-ray flux varies markedly in the course of the solar cycle.

Since blue light is at the short wavelength end of the visible spectrum, it is more strongly scattered in the atmosphere than long wavelength red light.

Since it could not be refuelled, and no longer had the fuel to sustain manned operations, Salyut 5 was deorbited on 8 August 1977, and broke up as it reentered the Earth's atmosphere.

Since the optimal survival conditions for this life-form ( low-temperature vacuum ) are drastically different from those needed by humans ( room temperature aerial atmosphere and adequate water supply ), Lilly predicted ( or " prophesised ", based on his ketamine-induced visions ) a dramatic conflict between the two forms of intelligence.

Since the Moon, with an angular speed with respect to the stars of 0. 55 arcsec / s or 2. 7 µrad / s, has no atmosphere and stars have an angular diameter of at most 0. 057 arcseconds or 0. 28 µrad, a star that is occulted by the moon will disappear or reappear in 0. 1 seconds or less on the moon's edge, or limb.