This year marks 65 years since Yuri Gagarin became the first person to fly into space. He was 27 years old and the flight lasted 108 minutes. To celebrate the anniversary, the Institute of Physics (FZU) and the science outreach community Pátečníci put together an afternoon of talks at Dvořák Hall on 12 April.
Following radiation and civilisations
The afternoon opened with astrophysicist Patrik Čechvala, who spoke about Cherenkov radiation, a phenomenon that occurs when a charged particle moves through a medium faster than light travels through the same medium. The result is a brief flash, something like an optical version of a sonic boom. New telescopes at Ondřejov use this effect to detect traces that high-energy particles from space leave behind in the atmosphere.
Astrobiologist Tomáš Petrásek then took on the Fermi Paradox, one of the most famous unsolved puzzles in science. In 1950, physicist Enrico Fermi asked his colleagues a simple question: "Where is everybody?" He was talking about extraterrestrial civilisations, ones that, by his logic, we should have run into by now. The universe is over 13 billion years old, and the Milky Way is full of stars with their own planets. And yet we have never encountered anyone.
Numbers, hopes, and mistakes
Evolutionary biologist Jan Toman followed with a talk on the Drake Equation, which tries to estimate how many civilisations in the universe might be able and willing to communicate with us. The idea is straightforward: multiply a series of estimates (e.g. how many stars form each year, how many have planets, and on how many of those could life exist) and you arrive at a number of civilisations in the Galaxy. The problem is that most of the variables are deeply uncertain, and the estimates we choose tend to say as much about our hopes as about the universe itself. Even Frank Drake himself considered the equation to be more of a thought experiment, and thanks to its nature, it can reveal a lot about our expectations and assumptions.
Halfway through the programme, Julie Nekola Nováková ran a quiz on the search for life in the cosmos. What experiments and telescopes do scientists use? How many times in history have we thought we had finally found extraterrestrial life, only to find out we were wrong? The answer: more times than we would like to admit.
From Jupiter to history
Physicist David Píša presented the JUICE mission, a European Space Agency probe on its way to Jupiter, and more specifically to three of its icy moons: Ganymede, Callisto and Europa. Scientists believe that beneath their frozen surfaces lie deep saltwater oceans, which is precisely what makes them so interesting for astrobiologists: where there is liquid water and energy, life may be possible. The probe launched in 2023 and will arrive at Jupiter in 2031.
Píša also talked about the Czech contribution to the mission. Scientists at the Institute of Atmospheric Physics of the Czech Academy of Sciences built a wave analyser that is travelling on board the probe. It measures electromagnetic waves around Jupiter, which can tell us a great deal about the environment around the planet and what might be happening beneath the icy surfaces of its moons. The talk was part of the Vesmír pro lidstvo (Space for Humanity) project, of which the Institute of Physics of the Czech Academy of Sciences is an active partner.
The programme ended with Petr Tomek and a talk on women in spaceflight. Valentina Tereshkova flew in 1963 as the first woman in space, but her mission was mainly the idea of Nikita Khrushchev, the Soviet leader at the time, who wanted to beat the Americans. Once that moment was over, the Soviet programme stopped sending women into space. In the United States, women were not allowed into the programme at all, even though tests showed they were just as capable as men.
Luckily, we have moved on since then, and we are making strides in space research in general, too. Our institute as well as other institutes of the Czech Academy of Sciences are actively collaborating on multiple European Space Agency (ESA) missions, as well as on ground-based telescopes, so we’re likely to hear about new discoveries soon.
