1,432 research outputs found
JWST early Universe observations and {\Lambda}CDM cosmology
Deep space observations of the James Webb Space Telescope (JWST) have
revealed that the structure and masses of very early Universe galaxies at high
redshifts (z~15), existing at ~0.3 Gyr after the BigBang, maybe as evolved as
the galaxies in existence for ~10 Gyr. The JWST findings are thus in strong
tension with the CDM cosmological model. While tired light (TL)
models have been shown to comply with the JWST angular galaxy size data, they
cannot satisfactorily explain isotropy of the cosmic microwave background (CMB)
observations or fit the supernovae distance modulus vs. redshift data well. We
have developed hybrid models that include the tired light concept in the
expanding universe. The hybrid CDM model fits the supernovae type 1a
data well but not the JWST observations. We present a model with covarying
coupling constants (CCC), starting from the modified FLRW metric and resulting
Einstein and Friedmann equations, and a CCC+TL hybrid model. They fit the
Pantheon+ data admirably, and the CCC+TL model is compliant with the JWST
observations. It stretches the age of the universe to 26.7 Gyr with 5.8 Gyr at
z=10 and 3.5 Gyr at z=20, giving enough time to form massive galaxies. It thus
resolves the 'impossible early galaxy' problem without requiring the existence
of primordial black hole seeds or modified power spectrum, rapid formation of
massive population III stars, and super Eddington accretion rates. One could
infer the CCC model as an extension of the CDM model with a dynamic
cosmological constant.Comment: 16 pages, 7 figures. Published in MNRAS 524, 3385-3395 (2023
Measuring inertial mass with Kibble balance
A Kibble balance measures the mass (weight) of a test mass
with extreme precision by balancing the gravitational pull on the test mass
against the electromagnetic lift force. The uncertainty in such mass
measurement is currently ~. We show how the same Kibble
balance can be used to measure the mass of a test mass, that too
with potentially 50% better measurement uncertainty, i.e., ~.
For measuring the inertial mass, the weight of the test mass and the assembly
holding it is precisely balanced by a counterweight. The application of the
known electromagnetic force accelerates the test mass. Measuring the velocity
after a controlled elapsed time provides the acceleration and consequently the
inertial mass of the accelerated assembly comprising the Kibble balance coil
and the mass holding pan. Repeating the measurement with the test mass added to
the assembly and taking the difference between the two measurements yields the
inertial mass of the test mass. Thus, the extreme precision inertial and
gravitational mass measurement of a test mass with a Kibble balance could
provide a test of the equivalence principle. We discuss how the two masses are
related to the Planck constant and other coupling constants and how the Kibble
balance could be used to test the dynamic constants theories in Dirac
cosmology.Comment: 6 pages, 1 figure. Corrections and additions. Prepared for readers'
comments before submitting to a journa
Varying Coupling Constants and Their Interdependence
Since Dirac predicted in 1937 possible variation of gravitational constant
and other coupling constants from his large number hypothesis, efforts continue
to determine such variation without success. Such efforts focus on the
variation of one constant while assuming all others pegged to their currently
measured values. We show that the variations of the speed of light , the
gravitational constant , the Planck constant , and the Boltzmann constant
are interrelated: . Thus,
constraining any one of the constants leads to inadvertently constraining all
the others. It may not be possible to determine the variation of a constant
without concurrently considering the variation of others. We discuss several
astrophysical observations that have been explained recently with the
concomitant variation of two or more constants. We also analyze the reported
and unexplained 35 micro-gram decrease of 1 Kg Pt-Ir working standards over 22
years of measurements and show that they can be accounted for by allowing ,
, and to vary as predicted, provided such mass decrease can be confirmed
with a Kibble balance used for determining the Planck constant and weighing
test-masses with extreme precision.Comment: 6 pages. This version has been accepted by Mod. Phys. Lett.
How might India's public health systems be strengthened ?
The central government’s policies, though well-intentioned, have inadvertently de-emphasized environmental health and other preventive public health services in India since the 1950s, when it was decided to amalgamate the medical and public health services and to focus public health services largely on single-issue programs. This paper discusses how successive policy decisions have diminished the Health Ministry’s capacity for stewardship of the nation’s public health. These decisions have introduced policies and fiscal incentives that have inadvertently enabled states to prioritize medical services and single-issue programs over broader public health services, and diminished the capacity of the public health workforce to deliver public health services. Diseases resulting from poor environmental health conditions continue to impose high costs even among the more affluent, and hinder development. There are many approaches to strengthening the public health system, and the authors suggest one that may require relatively little modification of existing structures and systems. They suggest establishing a focal point in the Health Ministry for public health stewardship, and re-vitalizing the states’ public health managerial cadres as well as the grassroots public health workers. The central government could consider linking its fiscal support to states with phased progress in four areas: (1) the enactment of state Public Health Acts; (2) the establishment by states of separate public health directorates; (3) the re-vitalization of grassroots public health workers; and (4) health department engagement in ensuring municipal public health. The central focal point could provide the needed support, oversight, incentives, and sanctions to ensure that states build robust public health systems. These measures can do much to help governments use public funds more effectively for protecting people’s health.Health Monitoring&Evaluation,Health Systems Development&Reform,Population Policies,Disease Control&Prevention,Health Economics&Finance
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