Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Universe curvature

On further investigation, Shashidar [20] explains, a remarkable situation was found. In every case, one of the materials had an inherent SmC phase, while the other did not. As there was no observed miscibility gap, in every case there had to be a N-SmA-SMC point at very low temperatures. They also knew from their studies at high pressure [54] as well as their detailed studies on mixtures exhibiting the N-SmA-SmC and the Nre-SmC-SmA point (see Figs. 4 and 12) [16], that the phase diagram has the universal spiral topology where phase boundaries curve as the N-SmA-SmC point is approached. Shashidhar [20] concludes that, as re-entrance in nonpolar compounds results from the universal curvature of the phase boundaries as the N-SmA-SMC point is approached, its origin is the fluctuations associated with the N-SmA-SmC multicritical point. [Pg.436]

The work of Collier at the University of Florida [14] produced the finding that a modified Brunauer type I isotherm, with a more modest degree of curvature to the isotherm, was the theoretical optimum for deep dehydration cycles that were expected to be used in open cycle desiccant cooling cycles. The adsorbent was dubbed a type IM (M for moderate). To understand this designation zeolite type X with its incredible steep isotherm is designated a type IE (E for extreme). [Pg.301]

The pressure applied produces work on the system, and the creation of the bubble leads to the creation of a surface area increase in the fluid. The Laplace equation relates the pressure difference across any curved fluid surface to the curvature, 1/radius and its surface tension y. In those cases where nonspherical curvatures are present, the more universal equation is obtained ... [Pg.15]

Yes. In the foam, adjacent regions of space are continually stealing and giving back energy from one to another. These cause fluctuations in the curvature of space, creating microscopic wormholes. Who knows, someday civilizations might be able to use such wormholes to travel the universe. ... [Pg.66]

You throw one of the balls to Sally. The curvature of our 3-D universe would be in the direction of the fourth dimension. Our straight lines would actually be curved, but in a direction unknown to us. This would be similar to a creature living on the two-space surface of a sphere. Lines that appeared straight to him would actually be curved. Parallel lines could actually intersect, just as longitude lines (which seem parallel at the equator) intersect at the poles. This curvature could be hard to detect if his, or our, universe were large compared to the local curvature. In other words, only if the radius of the hypersphere (whose hypersurface forms our 3-D space) were very small, could we notice it. ... [Pg.84]

Considering the derivations of equation (1), it can be predicted that all molecules having the same value of [rj M would have the same value of Vh, the hydrodynamic volume. Also, if v/, is the parameter that uniquely determines the elution volume, Ve, these molecules should have the same elution volume. The arguments presented by these authors do not predict that the relationship between these parameters should necessarily be linear. Most universal calibration curves shown in the literature that cover 4 to 6 decades of M show a definite upward curvature at high values of M (28). [Pg.92]

It is often necessary to make hardness measurements on curved surfaces, e.g. rollers or O rings. In the first example the product may be large enough for the hardness instrument to rest upon it, whilst in the second it would usually be possible to rest the product on the specimen table. In either case, some form of jig is required to locate the test piece and suitable examples and precautions to be taken are described in ISO 48. Any of the standard methods could be used for curved surfaces except that it is not possible to use a foot on concave surfaces. For large cylindrical surfaces, the hardness tester is either fitted with feet movable in universal joints which rest on the curved surface or the base of the instrument is fitted with two cylindrical rods which rest on the curved surface. The latter method can be used for surfaces with radius of curvature down to 50 mm. For surfaces having double curvature, only the method using movable feet is suitable. For small products and where the radius of curvature is too small to rest the instrument on the surface, the test piece is placed on the base of the instrument as with... [Pg.126]

The term k in this metric is a constant that determines the spacial curvature of the cosmology. For k = 1 the cosmology is a closed spherical universe, for k = 0 the cosmology is flat, and for k - — 1 the cosmology is open. The Einstein field equations give a constraint equation and a dynamical equation for the rate the radius changes with time. If we define a velocity as v = (R/R)H(t)r, where H (t) is the Hubble parameter, a constant locally, the constraint equations is... [Pg.464]

It is apparent that the numbers and masses of the flavor and quark-lepton transforming gauge bosons are larger than those of the SU(5) minimal model. This means that the value of a is lower, and assuming that the duration of the inflationary period is fixed, the scale for the expansion of the universe is reduced. This means that there is the enhanced prospect for deviations from flatness. So one may presume that the universe started as a small 3-sphere with a large curvature, where the inflationary period flattened out the universe, but maybe not completely. This leaves open the prospect that if before inflation that if the universe were open or closed, k = 1, that the universe today still contains this structure on a sufficiently large scale. The closer to flatness the universe is, the tighter are the constraints on the masses of particles in the early universe. [Pg.466]

In a Universe dominated instead by curvature or an accelerating component such as a cosmological constant, the expansion of the universe is more rapid than in a matter dominated universe. In both of these cases, there is no longer a growing mode neither solution to Equation 10.10 grows with time. [Pg.181]

Significant new evidence is the self-similarity of sub-atomic, atomic, biological, planetary and galactic structures, all related to the golden section. The astronomical structures are assumed to trace out the shape of local space. The obvious conclusion is that all of space has a uniform non-zero characteristic curvature, conditioned by the universal constants tt and r. Space, in this sense, is to be interpreted as equivalent to the three-dimensional sub-space of the Robertson-Walker metric [104]. In standard cosmology this sub-space... [Pg.288]

Cosmic structure based on a vacuum interface has been proposed before [49, 7] as a device to rationalize quantum events. To avoid partitioning the universe into regions of opposite chirality the two sides of the interface are joined together with an involution. The one-dimensional analogue is a Mobius strip. Matter on opposite sides of the interface has mutually inverted chirality - matter and anti-matter - but transplantation along the double cover gradually interconverts the two chiral forms. The amounts of matter and anti-matter in such a universe are equal, as required by symmetry, but only one form is observed to predominate in any local environment. Because of the curvature, which is required to close the universe, space itself is chiral, as observed in the structure of the electromagnetic field. This property does not appear in a euclidean Robertson-Walker sub-space. [Pg.290]

Formerly, the beginner was taught to crawl through the underbrush, never lifting his eyes to the trees today he is often made to focus on the curvature of the universe, missing even the earth. [Pg.433]

This space-time model is a conjecture that has been described in detail [28] and will be reconsidered in chapter 7. A new aspect thereof, which derives from number theory, is that the general curvature of this space-time manifold [26, 29] relates to the golden mean. This postulate is required to rationalize the self-similar growth pattern that occurs at many levels throughout the observable universe. [Pg.57]


See other pages where Universe curvature is mentioned: [Pg.235]    [Pg.235]    [Pg.365]    [Pg.255]    [Pg.1311]    [Pg.233]    [Pg.177]    [Pg.147]    [Pg.227]    [Pg.154]    [Pg.221]    [Pg.206]    [Pg.237]    [Pg.12]    [Pg.12]    [Pg.13]    [Pg.224]    [Pg.225]    [Pg.365]    [Pg.94]    [Pg.480]    [Pg.684]    [Pg.519]    [Pg.519]    [Pg.603]    [Pg.69]    [Pg.48]    [Pg.2]    [Pg.101]    [Pg.111]    [Pg.225]    [Pg.248]    [Pg.292]    [Pg.33]    [Pg.114]    [Pg.49]    [Pg.97]   
See also in sourсe #XX -- [ Pg.3 , Pg.9 , Pg.40 ]




SEARCH



Curvatures

© 2024 chempedia.info