The Voice of Space, Milan Planetarium, 13 November 2020

November 16, 2020

This year is the 150th birthday of my Italian publisher, Hoepli. And Barbara Hoepli, Chairman of the Board, kindly invited me to join the celebrations of this milestone at the Milan Planetarium – which is celebrating its 90th birthday – and give the keynote speech on 11 November. Sadly, despite the heroic efforts of Barbara, Letizia Di Girolamo, Lisa Ceccarelli and others at Hoepli, the Covid-19 pandemic prevented me from travelling from London to Milan. I therefore had to record my talk on “The Voice of Space”, which was broadcast on YouTube after speeches from dignitaries from Milan, Hoepli and the Planetarium. You can see my talk here. It begins at about 40 minutes in.

Barbara Hoepli, Chair of the Board of Hoepli, introduces the 150th birthday celebrations in front of the Planetarium’s Zeiss Projector



Milan Cathedral in the time of Covid

Leonardo Da Vinci’s “Last Supper”





Did you feel queasy on 14 September 2015? If you did, it was probably something you ate (!) because the stretching and squeezing caused by the passage of gravitational waves was TINY.

We have yet to detect the gravitational wave equivalent of a baby crying (You’d have to be there to understand where I was going with that!)

The discovery of gravitational waves earnt the 2017 Nobel Prize for three of the scientists involved

Although the discovery of gravitational waves was deemed worthy of the Nobel Prize, some thought it was worthy of the X-Files. According to one man: “They’re building a time machine”!

One arm of the time machine goes to the future, the other to the past.”! (LIGO is amazing but not THAT amazing)

In an instant, 3 times the mass of the Sun vanished and reappeared as a tsunami of tortured space-time, spreading outwards at the speed of light

For some reason we do not understand, there is a “supermassive” black hole in the heart of EVERY galaxy. The race is on to detect gravitational waves from their mergers.

The skin of a bongos, here played by American physicist, are easy to vibrate. But space-time is a billion billion billion times stiffer than steel. That’s why it’s so hard to vibrate and create gravitational waves.

Wave your hand in the air. You have just created gravitational waves (though they are very weak)

Before they passed through the Earth on 14 September 2015, the gravitational waves had been spreading through space for 1.3 billion years





Back to News & Events