Big Bang

The Standard Model of Cosmology is wrong on multiple counts

The Standard Model of Cosmology is also called the Concordance model, which means the currently accepted model. Another name for it is the Lambda-CDM model, where Lambda is the cosmological constant, and CDM is an acronym for cold dark matter. In a nutshell, the Standard Model of Cosmology says the universe started with the Big Bang, which was followed by a very rapid expansion called inflation. After this came the formation of photons and leptons plus other particles, then hydrogen and helium, then stars and galaxies…

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The James Webb Space Telescope and the massive early galaxies

As I was saying last time, there was a interesting news article recently. I saw it in The Telegraph myself. It concerned observations of massive early galaxies by the James Webb Space Telescope (JWST). Written by Joe Pinkstone, the article was dated 26th August 2024, and was called How scientists used black holes to solve mystery of earliest galaxies. Pinkstone told us that early galaxies had long been thought to contain relatively few stars, and so wouldn’t be particularly big or bright. However when the JWST…

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The gamma bomb

I’ve always been interested in antigravity. It started when I was when I was six, when Fireball XL5 was on TV. Of course, the spaceship itself was a rail-launched rocket with wings. But Steve Zodiac and crew had a "gravity activator" for artificial gravity inside the ship, plus hover bikes. Hover bikes were a recurring feature in Gerry and Silvia Anderson’s futuristic programmes. I think it was because they were cool, and because it wasn’t easy to make those marionettes walk. Gravity generators or compensators were also…

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Misconceptions skewered

I was surfing the web the other day, and I came across Sean Carroll’s Preposterous Universe blog. There's a post on there called True Facts About Cosmology (or, Misconceptions Skewered). I thought it looked interesting, because that’s my kind of thing. I do so dislike all the popscience and the lies to children, and it pleases me to see somebody else trying to put the record straight. But has he? I thought I’d take a look and give my opinion. Carroll leads in with something about…

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The fate of the universe

One of the things cosmologists like to talk about is the fate of the universe. Some say it all depends on the density parameter omega: Ω. This started life as the average matter density of the universe divided by a “critical” matter density for the Friedmann universe: Based on the Friedmann universes public domain image by BenRG, see Wikipedia Commons and Wikipedia Nowadays when we talk about omega we don’t restrict ourselves to matter alone. That’s because energy doesn’t necessarily take the form of matter, and…

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The edge of the universe

When you dig into the history of cosmology, some things catch your eye. Things like the “boundary conditions” in Einstein’s 1917 cosmological considerations in the general theory of relativity. Or something Willem de Sitter said in his 1917 paper On the relativity of inertia. Remarks concerning Einstein's latest hypothesis. He said this: “if the gμν at infinity are zero of a sufficiently high order, then the universe is finite in natural measure”. There’s also something Paul Steinhardt said in his 1982 Natural Inflation paper. He said this:…

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Inflation

The theory of cosmic or cosmological inflation is related to Big Bang theory. It’s been around now for the thick end of forty years. Or more. By 1980 a lot of cosmologists were happy that the universe was expanding, and that it wasn’t a steady-state universe. A lot of cosmologists also thought of the initial expansion of the universe as something fairly steady. However inflation introduced the idea that the initial expansion was very rapid: Image from Rod Nave’s hyperphysics As for how it all began,…

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The Big Bang

Big Bang cosmology arguably started in 1917. Vesto Slipher had measured 21 galactic redshifts by 1917. That’s when Albert Einstein wrote his cosmological considerations paper and Willem de Sitter came up with the de Sitter universe. The next year in 1918 Erwin Schrödinger came up with his cosmic pressure. In 1922 Alexander Friedmann came up with a non-static universe. In 1924 he came up with negative and positive curvature, and Knut Lundmark came up with an expansion rate within 1% of measurements today. In 1927 Georges…

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A compressed prehistory of dark energy

In the Wikipedia dark energy article you can read how the term "dark energy" was coined by Michael Turner in 1998. This was in a paper co-authored with Dragan Huterer called prospects for probing the dark energy via supernova distance measurements. It referred to the type 1a supernovae observations made by the Supernova Cosmology Project and by the High-Z Supernova Search Team. Their observations indicated that the expansion of the universe is accelerating, which was contrary to expectations and led to Nobel prizes in 2011: Expanding…

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