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 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 is the distance from a given number to the mean, one way to interpret this property is as saying that the numbers to the left of the mean are balanced by the numbers to the right of the mean.

Since about the 3rd century CE, the Jewish calendar has used the Anno Mundi epoch ( Latin for “ in the year of the world ,” abbreviated AM or A. M .; Hebrew ), sometimes referred to as the “ Hebrew era .” According to Rabbinic reckoning, the beginning of " year 1 " is not Creation, but about one year before Creation, with the new moon of its first month ( Tishrei ) to be called molad tohu ( the mean new moon of chaos or nothing ).

Since each sample is a random variable, the sample mean is a function of random variables and hence a random variable itself, whose distribution can be computed and properties determined.

Since the energy ultimately comes from fuel, these considerations mean that rockets are mainly useful when a very high speed is required, such as ICBMs or orbital launch.

Brill criticised physical treatments for homosexuality such as bladder washing, rectal massage, and castration, along with hypnosis, but referred approvingly to Freud and Sadger's use of psychoanalysis, calling its results “ very gratifying .“ Since Brill understood cure of homosexuality to mean restoring heterosexual potency, he claimed that he had cured his patients in several cases, even though many remained homosexual.

Since most physicists would consider the statement of the underlying rules to suffice as the definition of a " theory of everything ", most physicists argue that Gödel's Theorem does not mean that a ToE cannot exist.

Since only the relative weights are relevant, any weighted mean can be expressed using coefficients that sum to one.

Since the standard unit for expressing the mass of molecules or atoms ( the dalton or atomic mass unit ) is defined as 1 / 12 of the mass of a < sup > 12 </ sup > C atom, it follows that the molar mass of a substance, measured in grams per mole, is exactly equal to its mean molecular or atomic mass, measured in daltons ; which is to say, to the substance's mean molecular or atomic weight.

Since shot noise is a Poisson process due to the finite charge of an electron, one can compute the root mean square current fluctuations as being of a magnitude

Since the chain conformations of a polymer sample are quasi infinite in number and constantly change over time, the " radius of gyration " discussed in polymer physics must usually be understood as a mean over all polymer molecules of the sample and over time.

Since a word marked with an asterisk could mean either " unattested " or " impossible ", it is important in some contexts to distinguish these meanings.

Since longitudinal waves have a much greater phase velocity than transverse waves, V < sub > long </ sub > is much greater than V < sub > trans </ sub >, and the relaxation length or mean free path of longitudinal phonons will be much greater.

Since there are two elements in this remaining list, the median is their arithmetic mean, ( 3 + 7 )/ 2

:" Since the Dorians were regarded as uncivilised by the Athenians, ' Doric ' came to mean ' rustic ' in English, and was applied particularly to the language of Northumbria and the Lowlands of Scotland and also to the simplest of the three orders in architecture.

Since the time of the apostles, the term ' anathema ' has come to mean a form of extreme religious sanction, known as excommunication.

In Egyptian, “ Naz ” means “ Sent ,” while “ Seir ” means “ Prince ” or “ Chief .” Therefore, the title “ Naz Seir ” can mean “ Sent Prince .” Since “ Naz ” and “ Zar ” both mean “ Prince ” in Hebrew, Naz Seir could also mean “ Prince of princes ,” a fitting title for Jesus as the King of kings.

Since he was the one who discovered the civilization, and the term could not have been in use to mean it previously, he did coin that specific meaning.

Since the required return on government bonds for domestic and foreign holders cannot be distinguished in an international market for government debt, this may mean that yields on government debt are not a good proxy for the risk free rate.

Since the College also incorporates Middleton Hall ( see above ) and owns St Giles House, the former judge's house north of the college, the opening of Kendrew Quadrangle mean that the College extends for almost the entire length of the east side of St Giles, as well as owning parts of the opposite side.

Since the Celtic year was based on both lunar and solar cycles, it is most likely that the holiday would be celebrated on the full moon nearest the midpoint between the winter solstice and vernal equinox, or when the primroses, dandelions, or other spring flowers rise up through the snow, or when the sun aligned with the passage tombs in the pre-Celtic megaliths.

Since the solar wind is continuously flowing outward, the magnetopause above, below and to the sides of the planet are swept backward into the geomagnetic tail as shown in the artist ’ s concept.

Since stratospheric ozone is produced by solar UV radiation, one might expect to find the highest ozone levels over the tropics and the lowest over polar regions.

Since sunspots are darker than the surrounding photosphere it might be expected that more sunspots would lead to less solar radiation and a decreased solar constant.

Since most of the material is located near the plane of the solar system, the zodiacal light is seen along the ecliptic.

Since the energy crises of the 1970s, interest in this quiet and potentially renewable marine energy source has been increasing steadily again, especially as solar cells became available, for the first time making possible motorboats with an infinite range like sailboats.

Since outside temperatures can possibly range from-40 ° C (- 40 ° F ) to 46 ° C ( 115 ° F ), with varying degrees of solar loading, along with humidity levels ranging from below 10 % up to 100 %, significant environmental stresses within the enclosure or facility can be produced.

Since 1980, passive solar expert Douglas Balcomb has recommended that Trombe walls should not be vented to the interior.

Since Biot's time, analysis of meteorites has resulted in accurate measurements of the chemical composition of the solar system.

Since the solar wind carries disturbances which affect the magnetosphere and ionosphere, IMP-8 demonstrated the utility of continuously monitoring the solar wind.

Since counter-earth is always within our own universe ( and our own solar system ), travel to it can be accomplished with ordinary space travel.

Since the time of Laplace ( 1799 ), scientists had been puzzled as to why pressure variations measured at the Earth's surface associated with the semi-diurnal solar tide dominate those of the diurnal tide in amplitude, when intuitively one would expect the diurnal ( daily ) passage of the sun to dominate.

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 the frequency of solar eruptive events is strongly modulated by the solar cycle, the degree of cosmic ray scattering in the outer solar system varies in step.

Since the angular speed of rotation of the galactic disk varies with distance from the centre of the galaxy ( via a standard solar system type of gravitational model ), a radial arm ( like a spoke ) would quickly become curved as the galaxy rotates.

Since March 2007, Ullevi has one of Sweden's largest solar power plants, consisting of 600 m² of solar photovoltaic panels situated on the roof of the luxury boxes section.

Since a calendar year has 12 or 13 new and full moons, it is sufficient to evaluate the solar term for 12 representative phases of this annual cycle, and put these in another table.