These are some of my cosmology posts
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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…
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Easter – 21 April 2019
In 2019 , for the majority of people 21 April was Easter Sunday, one of the most important dates in the Christian calendar. Although Easter is a is a festival celebrating the resurrection of Jesus Christ from the dead, it is also widely marked by non-Christians in the UK, particularly as there are two very welcome public holidays on…
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An amazing discovery
For those who missed my post on 1 April 2016 here is a re-blog of the amazing discovery of the first intelligent alien life. —Original post below News is just reaching us of the most amazing astronomical discovery which I am ever likely to experience in my lifetime, one which I never thought I would see. As regular…
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Solar energy
15 December 2025 This orginal post has been revised and updated. However, a new version is at Opportunities for solar energy In this post I’ll talk about some of the science behind this interesting fact and I’ll also discuss how solar energy is likely to become more important to us in the future. The facts…
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American crewed spaceflight in 2019
Since the retirement of the Space Shuttle in July 2011, America has been unable to put any astronauts into orbit around the Earth. Instead, it has been in the difficult situation of having to rely on the Russian Soyuz spacecraft to ferry astronauts to and from the International Space Station (ISS). This situation may change…
Explaining Science 