CMB tagged posts

When it comes to measuring how fast the Universe is expanding, the result depends on which side of the Universe you start from. A recent study has calibrated the best cosmic yardsticks to unprecedented accuracy, shedding new light on what’s known as the Hubble tension.

The Universe is expanding — but how fast exactly? The answer appears to depend on whether you estimate the cosmic expansion rate — referred to as the Hubble’s constant, or H0 — based on the echo of the Big Bang (the cosmic microwave background, or CMB) or you measure H0 directly based on today’s stars and galaxies. This problem, known as the Hubble tension, has puzzled astrophysicists and cosmologists around the world.

A study carrie...

Using known distances of 50 galaxies from Earth to refine calculations in Hubble’s constant, a research team led by a University of Oregon astronomer estimates the age of the universe at 12.6 billion years.

Approaches to date the Big Bang, which gave birth to the universe, rely on mathematics and computational modeling, using distance estimates of the oldest stars, the behavior of galaxies and the rate of the universe’s expansion. The idea is to compute how long it would take all objects to return to the beginning.

A key calculation for dating is the Hubble’s constant, named after Edwin Hubble who first calculated the universe’s expansion rate in 1929...

The map of the cosmic microwave background (CMB) sky produced by the Planck satellite. Red represents slightly warmer regions, and blue slightly cooler regions. The Cold Spot is shown in the inset, with coordinates on the x- and y-axes, and the temperature difference in millionths of a degree in the scale at the bottom. Credit: ESA and Durham University. Click for a full size image

A supervoid is unlikely to explain a ‘Cold Spot’ in the cosmic microwave background, according to the results of a new survey, leaving room for exotic explanations like a collision between universes. The cosmic microwave background (CMB), a relic of the Big Bang, covers the whole sky. At 2.73 degrees above 0K, the CMB has some anomalies, including the Cold Spot. This feature, about 0...

LSU Department of Physics & Astronomy Assistant Professor Ivan Agullo’s new research advances knowledge of a classical theory of electromagnetism. Credit: LSU

Discovery may impact the study of the birth of the universe. Radio waves, microwaves and even light itself are all made of electric and magnetic fields. The classical theory of electromagnetism was completed in the 1860s by James Clerk Maxwell. At the time, Maxwell’s theory was revolutionary, and provided a unified framework to understand electricity, magnetism and optics. Now, new research led by LSU Dept of Physics & Astronomy Assistant Prof. Ivan Agullo, with colleagues from Universidad de Valencia advances knowledge of this theory.

Maxwell’s theory displays a remarkable feature: it remains unaltered under the interchange of the e...