This year, for the majority of the world’s Christians, 4 April is Easter Sunday, one of the most important dates in the calendar. Although because of the current restrictions due to the Covid pandemic, celebrations will be a little limited in many places. Although Easter is the festival celebrating the resurrection of Jesus Christ from the dead,… Continue reading Easter April 4 2021
Author: Steve Hurley
Distances in Cosmology
Discusses the nuances of distance measurement in cosmology., focusing on the cosmic microwave background (CMB) and its proper distance of 46 billion light years from Earth. It clarifies concepts such as light travel distance, proper distance, comoving distance, and various astronomical distance metrics, emphasizing the expansion of the Universe
Advancing the Clocks
On the early hours of Sunday 14 March 2021, most of the United States will put their clocks forward an hour and Daylight Saving Time (DST) will commence. Two weeks later on 28 March most countries in Europe (including the UK) will follow, switching to summer time. In this post I’ll talk about the practice… Continue reading Advancing the Clocks
Solar Sails
Update 21 September 2025 As this is a changing area, I have replaced this post from 2021 with a revised and updated one. This is available at https://explainingscience.org/2025/09/21/solar-sails-fuel-free-space-travel/ I have also created a video which goes into solar sails in much more detail https://youtu.be/PcwASDdNQxk
Human spaceflight in 2021
2021 will be an interesting year for human space flight. Not only is it the sixtieth anniversary of Yuri Gagarin’s historic first manned spaceflight, but it will be the first time that a privately operated spacecraft will arrive at the International Space Station (ISS). This private spacecraft is not just a one-off but will be… Continue reading Human spaceflight in 2021


