The discovery of dark energy

The is a now an expanded and updated version of this post available at: https://explainingscience.org/2020/12/10/dark-energy-an-unexpected-finding/   The Expansion of the Universe Astronomers have known since the late 1920’s that the Universe is expanding. By this we mean that distances between objects which are not bound together by another force, such as gravity, increase over time.… Continue reading The discovery of dark energy

Daylight Saving Time

As mentioned in my previous post, in the early hours of Sunday 27 October the clocks go back an hour throughout the European Union and daylight saving time comes to an end. Although many Europeans will welcome the extra hour in bed on the night of 26/27 October, I suspect that a lot of people… Continue reading Daylight Saving Time

Jim Peebles winner of the Noble Prize 2019

I was interested to hear that Jim Peebles, at the age of 84,  has won a half share of the 2019 Noble Prize for physics for theoretical discoveries in physical cosmology. Jim Peebles (1935-) Image from Wikimedia commons In the early 1960s Peebles and his colleague Robert Dicke had predicted the existence of the microwave… Continue reading Jim Peebles winner of the Noble Prize 2019

Time and time zones

In this post I’ll talk about the measurement of time and the use of time zones throughout the world. This is particularly topical at this time of year.  In the early hours of Sunday 27 October the clocks go back an hour throughout the EU as Europe switches to winter time. The natural day There… Continue reading Time and time zones

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… Continue reading The September equinox