These are some of my cosmology posts
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Books from Explaining Science 2023
Update 30 August 2025 I have extensively expanded and rewritten all three “A Short Guide to…” e-books. I will make these books available on Kindle for a competitive price. However, in future I won’t do any deals where I offer free or discounted prices on these books for a limited time period. I believe the books offer…
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Is the Universe curved?
In this post I’ll talk about curvature, what terms such as flat, positive and negative curvature mean and how this applies to the Universe. I won’t use complex mathematical definitions here, but intuitively curvature is a measure of how much a two-dimensional surface deviates from being flat. This concept can be extended to any number…
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Rising use of fossil fuels
I was disturbed to read the recent UN report pointing out that the government plans and projections from the major fossil fuel producers would lead to an increase in global coal production until 2030, and in global oil and gas production until at least 2050. This conflicts with government commitments under the Paris Agreement, and…
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COP26 Two years on
On 30 November 2023 the 28th United Nations Climate Change conference (COP 28) will open at Expo City, Dubai My somewhat pessimistic view is that our chances of significantly reducing carbon dioxide levels in the atmosphere over the next 10-15 years or so don’t look particularly promising – mainly because there is the competing objective…
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September 23 2023 the equinox
In 2023 September 23 is the date of the September equinox and is also the first day of autumn (or the first day of spring if you’re one of my readers in the Southern Hemisphere). In this post I’ll talk about the equinoxes and discus the commonly held, but incorrect, view that they are the…
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A Cyclical Universe
Updated 17 December 2025 In The End of the Universe I remarked on the surprising similarity between conditions in the very early Universe, just after the Big Bang, and the far future of the Universe. In this post I’ll give an overview of Roger Penrose’s model of the Universe in which it passes endlessly through…
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Commercial Space Travel
Although a small number of extremely wealthy space tourists have paid millions of dollars for orbital spaceflight, by their very nature only a handful of people can take part in these spaceflights each year. It looks like Virgin Galactic will start commercial spaceflights aimed a larger audience soon. According to the Virgin Galactic Website Galactic…
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The End of the Universe
In the Universe’s far future, star formation will cease, and it will contain white dwarfs, neutron stars, and black holes. Over immense timescales, stellar remnants will decay, and black holes will evaporate through Hawking radiation. Ultimately, the Universe will consist solely of low-energy photons and dark energy, mirroring its early state.… Continue reading The End…
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The Lyrids 2023
The night of 22/23 April 2023 will be the peak of the Lyrids, one of the most famous prolific meteor showers. Meteors (also known as shooting stars) are bright streaks of light caused by small lumps of rock or metal called meteoroids hitting the Earth’s atmosphere at very high speed. As they pass through the atmosphere they get…
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Roger Penrose – Cycles of Time
Updated 18 December 2025 In another post I talk in more detail about conformal cyclical cosmology (CCC). Roger Penrose’s model of the Universe where it passes endlessly through a possibly infinite number of cycles (or aeons) each of which starts with a big bang and ends with a rapidly expanding empty universe. This fascinating idea…
Explaining Science 