However, iron is the most abundant element ( by mass ) making up the Earth, and oxygen is the most common element in the Earth's crust.

However, this means that Earth's geomagnetic north pole is the south pole of its dipole moment, and vice versa.

However, Clarke states that the Star Child is not concerned that many would be killed by the fallout passing through Earth's atmosphere.

However, the scientists of this civilization tried to control the Earth's climate by creating a weather machine, so the Earth created the Black Mothra, named Battra.

However, it was incompatible with the expected aether wind effect due to the Earth's ( seasonally varying ) velocity which would have required a shift of 0. 4 of a fringe, and the error was small enough that the value may have indeed been zero.

However, the distinction between mass and weight becomes important for measurements with a precision better than a few percent ( because of slight differences in the strength of the Earth's gravitational field at different places ), and for places far from the surface of the Earth, such as in space or on other planets.

However, " relatively high ," in the case of ozone, is still very small with regard to ordinary oxygen, and is less than ten parts per million, with the average ozone concentration in Earth's atmosphere being only about 0. 6 parts per million.

However, most of the heat generated when a meteor enters the Earth's atmosphere is carried away by ablation and the interiors of freshly landed meteorites are rarely heated much and are often cold.

However, they are of danger only to astronauts, since they are deflected by the Earth's magnetic field and then stopped by its atmosphere.

However, development of the Shuttle was delayed, and Skylab reentered Earth's atmosphere and disintegrated in 1979, with debris striking portions of Western Australia.

However, in 1854, J C Adams caused the question to be re-opened by finding an error in Laplace's computations: it turned out that only about half of the Moon's apparent acceleration could be accounted for on Laplace's basis by the change in the Earth's orbital eccentricity.

However, the slowdown of the Earth's rotation is not occurring fast enough for the rotation to lengthen to a month before other effects make this irrelevant: About 2. 1 billion years from now, the continual increase of the Sun's radiation will cause the Earth's oceans to vaporize, removing the bulk of the tidal friction and acceleration.

However, he was one of the first scientists to recognize that the oxygen, nitrogen and carbon dioxide in the Earth's atmosphere result from biological processes.

However, when a star is located along the Earth's axis of rotation, it will remain in the same position and thus is called a pole star.

However, by its very design, the rocket would discharge massive quantities of extremely radioactive waste and could only be safely operated well outside the Earth's atmosphere and perhaps even entirely outside earth's magnetosphere.

However, the ozone hole is most usually measured not in terms of ozone concentrations at these levels ( which are typically of a few parts per million ) but by reduction in the total column ozone, above a point on the Earth's surface, which is normally expressed in Dobson units, abbreviated as " DU ".

However, there is a lack of evidence for the nature of the subduction in the Atlas region, or for the thickening of the Earth's crust generally associated with continental collisions.

However, many geophysical phenomena – such as the Earth's magnetic field and earthquakes – have been investigated since the ancient era.

However, an invasion by an unknown alien race forced the colonies to unify under Earth's leadership.

However, it dawns on Trevize that the answer may not be on Earth, but on Earth's satellite — the Moon.

However, when vast alien spaceships suddenly position themselves above Earth's principal cities, the space race is halted, forever.

However, according to tropical astrology, which divides the ecliptic in twelve 30º sectors, starting with the vernal equinox, the Sun is always entering Cancer at this time, as the Earth's axial tilt is most inclined towards the Sun.

However, because X-ray emissions are blocked by the Earth's atmosphere, observation of celestial X-ray sources is not possible without lifting instruments to altitudes where the X-rays can penetrate.

However, other evidence seemed to indicate that the cometary fragments had not reached the water layer, and the waves were instead propagating within the stratosphere.

However, this appears not to be so except perhaps locally in jet stream regions in the stratosphere.

However, it will dissolve in hydrochloric and sulfuric acid, especially when fluorine is present.

For example fluorine is required for the formation of bones and enamel on teeth. However, when taken in more quantities due to its excessive content in ground water by people in some areas causes a disease called " Fluorosis ', in which bone deformations and yellowing of teeth are seen.

However, it is a very slow process to eliminate the fluorine from the body completely.

However, when in an excited state ( induced by an electrical discharge or high-energy electron beams, which produce high energy pulses ), they can form temporarily-bound molecules with themselves ( dimers ) or with halogens ( complexes ) such as fluorine and chlorine.

However, the possible absence of a center of symmetry not only moves the hydrogen atom off Af, but also allows the oxygen atoms to become nonequivalent, with Af at Af and Af at Af ( space group Af ), where Af represents the oxygens on one side of the Af layers and Af those on the other side.

However, if the steel is cooled quickly the carbon atoms will not have time to precipitate.

However, this did not explain similarities between different atoms, as expressed by the periodic table, such as the fact that helium ( 2 electrons ), neon ( 10 electrons ), and argon ( 18 electrons ) exhibit similar chemical behavior.

However, the atomic mass in u of pure isotope atoms is quite close ( always within 1 %) to its simple mass number.

However, metallic bonds are more collective in nature than other types, and so they allow metal crystals to more easily deform, because they are composed of atoms attracted to each other, but not in any particularly-oriented ways.

However, once the applied electric field approaches the breakdown value, free electrons become sufficiently accelerated by the electric field to create additional free electrons by colliding, and ionizing, neutral gas atoms or molecules in a process called avalanche breakdown.

However, the wavelength of visible light ( about 4000 to 7000 angstroms ) is three orders of magnitude longer than the length of typical atomic bonds and atoms themselves ( about 1 to 2 angstroms ).

However, there is another possible location for the third layer, such that its atoms are not above the first layer.

However, since hydrogen is necessary for the reactions listed above, the fuel selected must contain hydrogen atoms.

However, this is a specific property of hydrogen and is no longer true for more complicated atoms which have a ( effective ) potential differing from the form 1 / r ( due to the presence of the inner electrons shielding the nucleus potential ).

However, according to quantum physics, individual molecules ( and atoms, electrons, protons etc.

However, many of the physical properties of water and ice are controlled by the formation of hydrogen bonds between adjacent oxygen and hydrogen atoms.

However, the archetypal channel pore is just one or two atoms wide at its narrowest point and is selective for specific species of ion, such as sodium or potassium.

However, the popular description of light being " stopped " in these experiments refers only to light being stored in the excited states of atoms, then re-emitted at an arbitrary later time, as stimulated by a second laser pulse.

However, empirical proof and the universal acceptance of the existence of atoms didn ’ t occur until the early 20th century.

However, NMR experiments are able to provide information from which a subset of distances between pairs of atoms can be estimated, and the final possible conformations for a protein are determined by solving a distance geometry problem.

However, some photons cause stimulated emission in excited-state atoms, releasing another coherent photon.

However, X-Pro peptide groups tend to have a roughly 3: 1 ratio, presumably because the symmetry between the and atoms of proline makes the cis and trans isomers nearly equal in energy ( See figure, below ).

However, proteins can become cross-linked, most commonly by disulfide bonds, and the primary structure also requires specifying the cross-linking atoms, e. g., specifying the cysteines involved in the protein's disulfide bonds.

However, on smaller length-scales, matter is observed to form " clumps ", i. e., to cluster hierarchically ; many atoms are condensed into stars, most stars into galaxies, most galaxies into clusters, superclusters and, finally, the largest-scale structures such as the Great Wall of galaxies.

An atomic mass unit is, for roughly 40 atoms per cubic meter .</ ref > However, even if every single atom and particle could be removed from a volume, it would still not be " empty " due to vacuum fluctuations, dark energy, and other phenomena in quantum physics.

However, as computational and experimental methods improved over the next decades, it became feasible to deduce reliable atomic positions for more complicated two-and three-dimensional arrangements of atoms in the unit-cell.

However, considering the mass of the source of the photons, e. g., atoms undergoing nuclear fission, brings the specific impulse down to 300 km / s ( c / 1000 ) or less ; considering the infrastructure for a reactor ( some of which also scales with the amount of fuel ) reduces the value further.

However, they are expected to be extremely ( and perhaps prohibitively ) expensive due to current production abilities being only able to produce small numbers of atoms, a scale approximately 10 < sup > 23 </ sup > times smaller than needed for a 10-gram trip to mars.

However, a study of Dalton's own laboratory notebooks, discovered in the rooms of the Lit & Phil, concluded that so far from Dalton being led by his search for an explanation of the law of multiple proportions to the idea that chemical combination consists in the interaction of atoms of definite and characteristic weight, the idea of atoms arose in his mind as a purely physical concept, forced upon him by study of the physical properties of the atmosphere and other gases.