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Cosmology

Alison and Chanda
Physics

Chanda Prescod-Weinstein: ‘Things are hard, but physics is beautiful’

The theoretical physicist and Â鶹´«Ã½ columnist talks to Alison Flood about her new book, The Edge of Space-Time - the September read for the Â鶹´«Ã½ Book Club

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Physics

We’ve long thought that time has only one dimension. What if we’re wrong?

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Space

The cosmic coincidences that made our universe – and us – possible

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Physics

The surprising upsides of living in a reality that repeats for eternity

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NGC 6357: Cosmic 'Winter' Wonderland Although there are no seasons in space, this cosmic vista invokes thoughts of a frosty winter landscape. It is, in fact, a region called NGC 6357 where radiation from hot, young stars is energizing the cooler gas in the cloud that surrounds them. This composite image contains X-ray data from NASA's Chandra X-ray Observatory and the ROSAT telescope (purple), infrared data from NASA's Spitzer Space Telescope (orange), and optical data from the SuperCosmos Sky Survey (blue) made by the United Kingdom Infrared Telescope. Located in our galaxy about 5,500 light years from Earth, NGC 6357 is actually a "cluster of clusters," containing at least three clusters of young stars, including many hot, massive, luminous stars. The X-rays from Chandra and ROSAT reveal hundreds of point sources, which are the young stars in NGC 6357, as well as diffuse X-ray emission from hot gas. There are bubbles, or cavities, that have been created by radiation and material blowing away from the surfaces of massive stars, plus supernova explosions. Astronomers call NGC 6357 and other objects like it "HII" (pronounced "H-two") regions. An HII region is created when the radiation from hot, young stars strips away the electrons from neutral hydrogen atoms in the surrounding gas to form clouds of ionized hydrogen, which is denoted scientifically as "HII". Researchers use Chandra to study NGC 6357 and similar objects because young stars are bright in X-rays. Also, X-rays can penetrate the shrouds of gas and dust surrounding these infant stars, allowing astronomers to see details of star birth that would be otherwise missed. A recent paper on Chandra observations of NGC 6357 by Leisa Townsley of Pennsylvania State University appeared in The Astrophysical Journal Supplement Series and is available online. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.

Space

Why the most central law in cosmology may need to be broken

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Dr Becky Smethurst in front of a milky way reconstruction
Space

We still don’t know how black holes get so big | Becky Smethurst

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Space

This physicist is hunting for the biggest black hole in the universe

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Physics

Sean Carroll: uncovering the mysteries of quantum mechanics

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Space

We may have finally solved cosmology’s chicken-or-the-egg problem

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Colourful smears across the screen slowly form beautiful flowers

Physics

Where did the laws of physics come from? I think I’ve found the answer

The rules governing gravity and other laws of nature seem like eternal truths, but cosmologist João Magueijo has always questioned their origins. Now, he has a bold new proposal

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Space

The problem of cosmic inflation and how to solve it

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Space

The rise, the fall and the rebound of cyclic cosmology

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Physics

A once-fantastical collider could answer physics’ biggest mysteries

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Space

What does it mean if the universe has extra dimensions?

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