Swiss Review 5/2019

Swiss Review / September 2019 / No.5 5 Mailbag Apollo 11 and the beautiful lunar toy from Berne Congratulations on an exceptionally good and informative May issue. I particularly enjoyed the article about that sheet of foil – the Univer- sity of Berne’s Solar Wind Collector. I remem- ber being allowed to stay up and watch the moon landing on television as a little boy. However, I would have liked to have known what the solar sail helped to clear up with re- gard to the Big Bang. DAN PETER, GOMARINGEN, GERMANY “Swiss Review” in general We do like to read the “Swiss Review”. Our preference is the printed version. This publication is mymain and regular read- ing material to learn what is going on in Switzerland, since I do not subscribe to any newspaper or other form of commu- nication. The “Swiss Review”, in my opinion, is balanced but still critical on challenges facing the country. Also, to read about other US clubs’ activities is fun. I hope this publication will continue to be made available. FRED LINDNER, ST. PAUL, MINNESOTA, USA E-voting encounters a headwind In my view, e-voting is now the only way to vote. Yes, I live in Canada and the post gets delivered relatively quickly, but in what century are we actually living? Inmy opinion, this is not just an issue for Swisswho live abroad – surely the younger gen- eration of voters in Switzerlandmatters too. Will they want to send in their votes by post or turn up to polling stations? I doubt it. My sincere hope is that Switzerland can preserve democracy and give everyone a fair chance to have their say. CHRISTINE MEICHSSNER, VANCOUVER, CANADA Further comments on e-voting at www.ogy.de/no-e-voting Swiss young people are fuelling the climate debate What a very informative article. I amdelighted that young peo- ple are taking such an interest in climate change. However, it is crucial that they don’t lose sight of their objectives. Perhaps then politicians might also start taking serious and concerted action and possibly adopt the legislation that we need. ULRICH MENTZ, GERMANY Taking part in climate strikes is mainly just an excuse not to go to school. They protest against climate change but they aren’t willing to give up anything themselves. Howabout if shops started closing again at normal times? And is there any need for bars and restaurants to stay open all night? We conveniently forget about climate change when it comes to making money. We spray artificial snowon ski slopes tokeepourwinter resorts tick- ing over. And thenwe have overpopulation –what arewe doing about it? The only thing our politicians do is invent new taxes. RENATO BESOMI, JAVEA, SPAIN Editor’s response The story of how the Bernese solar sail gave us a better understanding of the Big Bang is a slightly complicated one. By the mid-1960s, there were two theories on the evolution of the universe competing against each other. Alexander Friedmann, the Russian cosmologist, on the one hand, stipulated an expanding universe (1922) that had commenced with a “Big Bang” – a theory that even Albert Ein- stein himself cast doubt on. On the other hand, the steady-state theory of Fred Hoyle, Thomas Gold and Hermann Bondi (1948) stipulated an ever-expanding uni- verse without a beginning. Mathematically, both theories were valid solutions of Einstein’s equations of general relativity, and both were compatible with Edwin Hubble’s observations of the expanding universe (1926). Eventually, the discovery of cosmic background radiation put the steady- state theory to rest. However, no one had been able to clear up the origin of a number of isotopes. In particular, the prevalence of deuterium (or “heavy hydro- gen”) remained a mystery. The Bernese solar sail solved this puzzle. It showed that deuterium occurs up to one tenth as much in the protosolar cloud than on earth or in meteorites, confirming the hypothesis that deuterium was produced exclusively in the Big Bang. However, to complicate matters a little further, the solar wind samples that were collected from the moon did not contain any deuterium at all. When the protosolar cloud gave rise to the sun, all the deuterium was burned into Helium-3. The solar wind sail therefore measured the total prevalence of Helium-3. Using the same method that applies to meteorites or to Jupiter, you must deduct the original Helium-3 content from this measurement to calculate the prevalence of deuterium in the protosolar cloud. Spatium, the English-language periodical of the International Space Science Institute (ISSI), contains further information about the “Deuterium puzzle”: www.ogy.de/deuterium (see page 15).