29 articles
The James Webb Space Telescope has captured a star just before its supernova explosion, offering unprecedented data on stellar death. Meanwhile, new cosmological measurements attempt to resolve the Hubble tension.
The James Webb Space Telescope's advanced capabilities have revealed that the universe likely contains at least two trillion galaxies, a significant increase from previous estimates. This discovery reshapes our understanding of cosmic evolution and the potential for life beyond Earth.
New simulations suggest that direct collapse black holes, a theorized rapid formation pathway, may explain the existence of supermassive black holes in the early universe. Evidence comes from matching JWST spectral data.
The James Webb Space Telescope has discovered enigmatic "platypus galaxies" in the early universe. These objects exhibit unusual spectral properties, challenging current models of galaxy formation and potentially revealing new insights into quasar activity or the birth of the very first galaxies.
Scientists estimate there are at least two trillion galaxies in the observable universe. This staggering number is derived not by direct counting, but by sampling small regions of the sky, extrapolating based on the universe's age and expansion, and accounting for observational limitations.
Our current estimates place the number of galaxies in the observable universe at a staggering two trillion. Counting them individually, even at one per second, would take an immense 62,000 years, highlighting the vastness of space.
The multiverse, a vast ensemble of universes, is explored as a potential explanation for cosmic fine-tuning. While criticized as unfalsifiable, proponents argue it arises naturally from theories like string theory and eternal inflation, and can be indirectly tested.
The universe's seemingly perfect tuning for life, particularly the value of the cosmological constant, might be evidence for a vast multiverse. Steven Weinberg's 1987 paper used anthropic reasoning to estimate this constant, a prediction remarkably close to later observations, suggesting we inhabit a life-permitting universe within a cosmic ensemble.
New observations using the warped light of quasars and supernovae through gravitational lensing are helping to refine measurements of the universe's expansion rate. This technique, time-delay cosmography, is crucial for understanding the accelerating expansion and potentially solving the 'Hubble tension'.
