These are some of my cosmology posts
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The Moon e-booklet
Best wishes to all my readers and followers, I hope you enjoyed reading my previous post on dark matter, which is part of my series on cosmology, the study of the origin an evolution of the Universe as a whole. As you may recall in May/Jun last year I wrote series of 5 closely linked posts on the Moon.…
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Dark Matter
Revised and re-written 11 December 2025 This post about dark matter and is part of my series on cosmology, the study of the origin and evolution of the Universe as a whole. As readers of Dark Energy in the Universe will recall, dark matter makes up about 27% per cent of the mass of the Universe. Evidence for…
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12 Feb a special day
February 12, known as Darwin Day, is significant for both Charles Darwin’s and Abraham Lincoln’s birthdays, but it also marks an important astronomical event. On this day in 2026, the solar time is 14 minutes behind clock time, the greatest value of the year, with solar noon occurring shortly after 12:14 PM in London.… Continue…
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Dark Energy Over Time
This post continues the subject of dark energy, which, as discussed in my previous post is a mysterious form of energy which makes up about 68 per cent of the mass of the Universe and is the reason why the Universe is expanding at an ever-faster speed. This post will discuss how the percentage of dark energy changes over time…
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An overview of dark energy
Dark energy, constituting about 68% of the Universe, causes its expansion to accelerate. Discovered in 1998, it contradicted previous beliefs that gravity would slow this expansion. Cosmologists theorize dark energy may be a cosmological constant but are exploring other explanations, as the true nature remains uncertain.… Continue reading An overview of dark energy →
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Happy New Year 2015
Happy new year to all my readers and followers. I hope you have all enjoyed the festive break and that you have some great plans for 2015. I have taken a short break from blogging, although during the break I managed to purchase the domain thesciencegeek.org, which will hopefully make my blog easier to find. I…
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Understanding Christmas Dates: Gregorian vs. Julian Calendar
The celebration of Christmas varies, with most Christians observing it on December 25, while Orthodox Christians celebrate on January 7 due to differences from the Julian to Gregorian calendars. These calendar changes, initiated by Pope Gregory XIII in 1582, addressed drift issues in previous systems, affecting seasonal alignment and date consistency in Christian practices.… Continue…
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The Shortest Day
Updated and revised 11 December 2025 As I write this post, it’s completely dark outside and it’s only 5 o’clock in the afternoon. Today is 4 December, and most people I come across think that it will continue to get dark earlier and earlier in the afternoons until 21 December, the shortest day of the year…
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A Brief History of the Universe
Updated August 2026 This post gives a (brief!) history of the Universe from the Big Bang until the the present day. As I am sure you’ll agree, it’s a big topic; so I’ll only give a outline of some of the key events and when we believed they happened. This post is one of many…
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Philae has landed
Like millions over people I was cheered to see that the probe Philae landed successfully on the 67P/Churyumov-Gerasimenko comet after a 6.4 billion km ten year journey. In a mission this complex there will inevitably be a few hiccups and the biggest one so far has been that the probe has been unable to secure itself to…
Explaining Science 