On the physical basis of cosmic time - Philsci
... In this paper we shall motivate and discuss the suggestion that a physical condition for making the t ↔ time interpretation in cosmology is the (at least possible) existence of a physical process which can function as what we call the ‘core’ of a clock. In particular, we suggest that in order to mak ...
... In this paper we shall motivate and discuss the suggestion that a physical condition for making the t ↔ time interpretation in cosmology is the (at least possible) existence of a physical process which can function as what we call the ‘core’ of a clock. In particular, we suggest that in order to mak ...
Early Star-Forming Galaxies and the Reionisation of the Universe
... internally by gas heated by young stars. The observability of Lyman α emission is sensitive to the ionisation state of the IGM, as the observed line strength can be attenuated by intervening neutral hydrogen. The challenge in utilising this technique to chart the end of reionisation lies in isolatin ...
... internally by gas heated by young stars. The observability of Lyman α emission is sensitive to the ionisation state of the IGM, as the observed line strength can be attenuated by intervening neutral hydrogen. The challenge in utilising this technique to chart the end of reionisation lies in isolatin ...
Distribution of density along magnetospheric field lines
... ion species is difficult, owing to the difficulty in measuring cold ions and the strong dependence of density across field lines; nevertheless, Gallagher et al. [2000] found that the sum of the H+ and He+ densities was roughly constant along field lines within the plasmasphere in the range LTRE = 3– ...
... ion species is difficult, owing to the difficulty in measuring cold ions and the strong dependence of density across field lines; nevertheless, Gallagher et al. [2000] found that the sum of the H+ and He+ densities was roughly constant along field lines within the plasmasphere in the range LTRE = 3– ...
l47 estimating the column density in molecular clouds with far
... maps. 4.4. Comparison with Observations In real molecular clouds, the best estimate of column density often comes from the measured near-infrared (NIR) colors of background stars and is calculated from the reddening done by the intervening dust. Column density maps made this way have a fundamental u ...
... maps. 4.4. Comparison with Observations In real molecular clouds, the best estimate of column density often comes from the measured near-infrared (NIR) colors of background stars and is calculated from the reddening done by the intervening dust. Column density maps made this way have a fundamental u ...
Dahler and Sciven 1963
... Mathematically rigorous formalizations of continuum mechanics are still under construction (Noll 1958, 1959). The traditional application of Kewton's linear momentum principle to continua is as follows. I n the usual way we define our system to be the constant inertial mass assigned to the region en ...
... Mathematically rigorous formalizations of continuum mechanics are still under construction (Noll 1958, 1959). The traditional application of Kewton's linear momentum principle to continua is as follows. I n the usual way we define our system to be the constant inertial mass assigned to the region en ...
Metal-Ferroelectric-Metal structures with Schottky contacts: II
... performed and the results are shown in Figs. 2 and 3. As expected, the investigated films have very different ferroelectric properties. The shape of the loops is different from sample to sample. The polarization values are scattered over almost a decade. Typically, ferroelectric properties of epitax ...
... performed and the results are shown in Figs. 2 and 3. As expected, the investigated films have very different ferroelectric properties. The shape of the loops is different from sample to sample. The polarization values are scattered over almost a decade. Typically, ferroelectric properties of epitax ...
Interplay between curvature and Planck
... effort, but it appears likely that this might change in the not-so-distant future. This expectation originates from the fact that many cosmological observations reflect the properties of the Universe at very early times, when the typical energies of particles were significantly closer to the Planck ...
... effort, but it appears likely that this might change in the not-so-distant future. This expectation originates from the fact that many cosmological observations reflect the properties of the Universe at very early times, when the typical energies of particles were significantly closer to the Planck ...
Formation and loss of hierarchical structure in two
... turbulent pressures on stellar scales (e.g., Padoan 1995). This effect of turbulence is most clearly revealed by the systematic decrease in the ratio of the clump mass to the turbulent Jeans mass on decreasing scales in molecular clouds (Bertoldi & McKee 1992; Falgarone, Puget, & Pérault 1992; Vazq ...
... turbulent pressures on stellar scales (e.g., Padoan 1995). This effect of turbulence is most clearly revealed by the systematic decrease in the ratio of the clump mass to the turbulent Jeans mass on decreasing scales in molecular clouds (Bertoldi & McKee 1992; Falgarone, Puget, & Pérault 1992; Vazq ...
Rest of the Universe
... nobody could see. [Does the Universe Have an Edge?] Other pieces of evidence came from gravitational lensing, which happens when the gravity of a large object bends the light waves around that object. Per Albert Einstein's theory of general relativity, gravity bends space (like a sumo wrestler might ...
... nobody could see. [Does the Universe Have an Edge?] Other pieces of evidence came from gravitational lensing, which happens when the gravity of a large object bends the light waves around that object. Per Albert Einstein's theory of general relativity, gravity bends space (like a sumo wrestler might ...
CLUSTER FORMATION IN CONTRACTING MOLECULAR CLOUDS
... relation. Our conclusion, based on this admittedly limited evidence, is that a more realistic model of the internal turbulence has a spatially constant velocity dispersion.2 If we further appropriate the relationship between P and v derived by McKee & Zweibel (1995), we are then positing an isother ...
... relation. Our conclusion, based on this admittedly limited evidence, is that a more realistic model of the internal turbulence has a spatially constant velocity dispersion.2 If we further appropriate the relationship between P and v derived by McKee & Zweibel (1995), we are then positing an isother ...
An Expanded View of the Universe
... material distributed in protoplanetary discs? Are there signs of life on any exoplanet? ...
... material distributed in protoplanetary discs? Are there signs of life on any exoplanet? ...
The False Force - Gravity
... has a universal radius, it is possible that slight charges brought on by the quick movement of electrons could cause gravity in a macroscopic scale. Two interactions would be at work: the attractions of positive and negative charges, and the repulsions of similar charges. A balance between both forc ...
... has a universal radius, it is possible that slight charges brought on by the quick movement of electrons could cause gravity in a macroscopic scale. Two interactions would be at work: the attractions of positive and negative charges, and the repulsions of similar charges. A balance between both forc ...
A new view of galaxy evolution
... son is that the nature of the dark matter particle only with the HST were astronomers able to determines how galaxies will form. Simply put, show that galaxies indeed gain a large fraction if the dark matter particle were moving quickly of their mass through the merger process. at near the speed of ...
... son is that the nature of the dark matter particle only with the HST were astronomers able to determines how galaxies will form. Simply put, show that galaxies indeed gain a large fraction if the dark matter particle were moving quickly of their mass through the merger process. at near the speed of ...
Factors affecting the Cl atom density in a chlorine discharge
... gas into radicals which react to etch (volatilize) the substrate or to deposit a solid film. Recently, remote plasmaenhanced processing (RPEP) has gained popularity for etching sensitive substratesor for depositing films with tailored properties2 In RPEP, a plasma is generated at an upstream locatio ...
... gas into radicals which react to etch (volatilize) the substrate or to deposit a solid film. Recently, remote plasmaenhanced processing (RPEP) has gained popularity for etching sensitive substratesor for depositing films with tailored properties2 In RPEP, a plasma is generated at an upstream locatio ...
Dark Matter: A Brief Review
... wash out too much small-scale structure (see Sec. 4; [19]). In order for lighter gravitinos to be dark matter, one typically must introduce some non-standard cosmology [20]. Heavy gravitinos are, in my opinion, more interesting. If the next-lightest supersymmetric particle (NLSP) is only barely more ...
... wash out too much small-scale structure (see Sec. 4; [19]). In order for lighter gravitinos to be dark matter, one typically must introduce some non-standard cosmology [20]. Heavy gravitinos are, in my opinion, more interesting. If the next-lightest supersymmetric particle (NLSP) is only barely more ...
Planck 2013 results. XXVI. Background geometry and topology of
... European Space Agency (ESA) with instruments provided by two scientific consortia funded by ESA member states (in particular the lead countries France and Italy), with contributions from NASA (USA) and telescope reflectors provided by a collaboration between ESA and a scientific consortium led and f ...
... European Space Agency (ESA) with instruments provided by two scientific consortia funded by ESA member states (in particular the lead countries France and Italy), with contributions from NASA (USA) and telescope reflectors provided by a collaboration between ESA and a scientific consortium led and f ...
G485 Definitions etc A2 G485 Term Definition
... Explain how ultrasound transducers emit and receive high-frequency sound Explain that the standard (hot big bang) model of the universe implies a finite age for the universe Explain that the universe can be ‘open’, ‘flat’ or ‘closed’, depending on its density Explain that the ultimate fate of the un ...
... Explain how ultrasound transducers emit and receive high-frequency sound Explain that the standard (hot big bang) model of the universe implies a finite age for the universe Explain that the universe can be ‘open’, ‘flat’ or ‘closed’, depending on its density Explain that the ultimate fate of the un ...
arXiv:1210.1847v1 [hep-ph] 4 Oct 2012
... the case that the fundamental equations of nature allow on the order of 10500 solutions [28], then perhaps the most profound quest that can be undertaken by a sentient being is the exploration of the landscape through universe simulation. In some weak sense, this exploration is already underway with ...
... the case that the fundamental equations of nature allow on the order of 10500 solutions [28], then perhaps the most profound quest that can be undertaken by a sentient being is the exploration of the landscape through universe simulation. In some weak sense, this exploration is already underway with ...
Suppose you tried to determine where we are in the galaxy by
... a) bluer than expected for their spectral type. b) redder than expected for their spectral type. c) the same as when seen without dust. ...
... a) bluer than expected for their spectral type. b) redder than expected for their spectral type. c) the same as when seen without dust. ...
Conductivity, electric field and electron drift velocity within the
... in a sweep mode (−2.4 to +2.4 V in 0.5 s followed by 1.5 s of fixed bias at +2.4 V); later flights used a more or less standardized form with a fixed bias at +4.0 V. The conversion of the probe current to electron density was calibrated using the critical frequency of the E region, f o E, from the i ...
... in a sweep mode (−2.4 to +2.4 V in 0.5 s followed by 1.5 s of fixed bias at +2.4 V); later flights used a more or less standardized form with a fixed bias at +4.0 V. The conversion of the probe current to electron density was calibrated using the critical frequency of the E region, f o E, from the i ...
Current states in superconducting films: Numerical results
... Such a relation is also obviously valid for narrow channels, that makes it reasonable to extend it over the films of arbitrary width. In the resistive vortex state, I > Ic, the quantity Qe holds its critical value Qc, and Eqs. (11) and (12) determine the dependence E0 (I), i.e., the IVC, V(I) ¼ E0 ( ...
... Such a relation is also obviously valid for narrow channels, that makes it reasonable to extend it over the films of arbitrary width. In the resistive vortex state, I > Ic, the quantity Qe holds its critical value Qc, and Eqs. (11) and (12) determine the dependence E0 (I), i.e., the IVC, V(I) ¼ E0 ( ...
Folie 1 - Pi of the Sky
... Probing the high-redshift Universe with Gamma-ray bursts M.I. Andersen ...
... Probing the high-redshift Universe with Gamma-ray bursts M.I. Andersen ...
Emission from dust in galaxies: Metallicity dependence
... region (Osterbrock 1989). Thus, during the resonant scatterings in an H ii region, all the Lyα photons are assumed to be absorbed by grains in IHK00, which this paper is based on. If the dust-to-gas ratio is significantly smaller than the Galactic value, the dust grains might not efficiently absorb ...
... region (Osterbrock 1989). Thus, during the resonant scatterings in an H ii region, all the Lyα photons are assumed to be absorbed by grains in IHK00, which this paper is based on. If the dust-to-gas ratio is significantly smaller than the Galactic value, the dust grains might not efficiently absorb ...
A fully relative theory of gravitation Peter R. Lamb Institute for
... the observers. The requirement that the laws of physics are the same for observers moving at constant velocity then leads to an apparent dependence of mass, length and clock rate on relative motion and the famous E0 mc 2 . In seeking to obtain a theory of gravity, Einstein proposed that physics in ...
... the observers. The requirement that the laws of physics are the same for observers moving at constant velocity then leads to an apparent dependence of mass, length and clock rate on relative motion and the famous E0 mc 2 . In seeking to obtain a theory of gravity, Einstein proposed that physics in ...
Relativity and Gravitation
... parallel to (but not in) the plane of symmetry a lengthy calculation shows this to require a + b — c sin2 0 > (5¾) where the quantities a = 2g2 (g + 3/j)3 {r2 - 2mr) (r - m)2, b = qg2 {m\q + 2h)2 (g + 3h) {g (r2 - 2mr) [3 (r - m) + 2qg] + 3(g+6/0(r-m)3}, (60o) c = 2q2g3 (mjq + 2h)3 [g (r2 - 2mr) + ( ...
... parallel to (but not in) the plane of symmetry a lengthy calculation shows this to require a + b — c sin2 0 > (5¾) where the quantities a = 2g2 (g + 3/j)3 {r2 - 2mr) (r - m)2, b = qg2 {m\q + 2h)2 (g + 3h) {g (r2 - 2mr) [3 (r - m) + 2qg] + 3(g+6/0(r-m)3}, (60o) c = 2q2g3 (mjq + 2h)3 [g (r2 - 2mr) + ( ...
Flatness problem
The flatness problem (also known as the oldness problem) is a cosmological fine-tuning problem within the Big Bang model of the universe. Such problems arise from the observation that some of the initial conditions of the universe appear to be fine-tuned to very 'special' values, and that a small deviation from these values would have had massive effects on the nature of the universe at the current time.In the case of the flatness problem, the parameter which appears fine-tuned is the density of matter and energy in the universe. This value affects the curvature of space-time, with a very specific critical value being required for a flat universe. The current density of the universe is observed to be very close to this critical value. Since the total density departs rapidly from the critical value over cosmic time, the early universe must have had a density even closer to the critical density, departing from it by one part in 1062 or less. This leads cosmologists to question how the initial density came to be so closely fine-tuned to this 'special' value.The problem was first mentioned by Robert Dicke in 1969. The most commonly accepted solution among cosmologists is cosmic inflation, the idea that the universe went through a brief period of extremely rapid expansion in the first fraction of a second after the Big Bang; along with the monopole problem and the horizon problem, the flatness problem is one of the three primary motivations for inflationary theory.