These are some of my cosmology posts
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The September equinox
In 2019 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 view that they are the two days in…
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The Goldbach Conjecture
The Goldbach conjecture, posed in 1742, asserts that every even number greater than 2 can be expressed as the sum of two prime numbers. Despite exhaustive verification for even numbers up to four quadrillion, no proof exists for all even integers. A million-dollar prize for a solution remains unclaimed.… Continue reading The Goldbach Conjecture →
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Relaunching My Science Blog: Welcome to Explaining Science

In 2019, the Science Geek blog was relaunched as Explaining Science, featuring a new name, logo, and domain. The blog continues to target a similar audience with accessible articles on astronomy and space. Additionally, a YouTube channel was launched in 2020, offering diverse video content under a Creative Commons license.… Continue reading Relaunching My Science…
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12-13 August 2019 – the Perseids
For revised post containing more tips on how to view the Perseids see The Perseids 2021. 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 a very high speed (in the case of the Perseids around 200,000 km/h). As…
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Apollo 11 lunar landing
20 July 2019 is the fiftieth anniversary of the first manned landing on the Moon. Mission Insignia of Apollo 11- Image from NASA On 21 May 1961 President John F Kennedy made the following address to the United States Congress: ‘I believe that this nation should commit itself to achieving the goal, before this decade…
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Summer twilight
This explains the stages of twilight , and describes how the Sun’s path changes throughout the year in Manchester, England. The phenomenon of “Simmer Dim” in the Shetland Islands is highlighted, characterized by continuous twilight and celebrated with a festival.… Continue reading Summer twilight →
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e-book from Explaining Science on Venus
Updated 7 December 2025 I have now updated my e-book on Venus, the planet closest to the Earth in distance, size and internal composition, and the third brightest natural object in our sky after the Sun and the Moon. Topics include To find out more click on A Short Guide to Venus e-book …
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The Impact of Stellar Aberration on Astronomy

Stellar aberration was discovered by James Bradley in 1727. He observed unexpected star position shifts, confirming the heliocentric theory and enabling light speed measurement. Today, it’s explained by Einstein’s theory of relativity. … Continue reading The Impact of Stellar Aberration on Astronomy →
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Solar energy costs

In a previous post I talked about the advantages of solar electricity compared to other renewable source of electricity. In this post I’ll move away from my normal scientific topics and discuss the costs of small scale solar energy and how it compares with other renewables. Whats is ‘the LCOE’? When comparing the relative costs…
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Advantages of solar energy
As shown in the graph and table below, most renewable electricity is generated by hydroelectric power. Solar energy lies in third place behind wind. Electricity generated from renewable sources. From Our world in data (2018). The ‘Others’ category includes biofuels (e.g. burning wood, animal and agricultural wastes), geothermal energy and wave/tidal power) Despite only being…
