To open our 2021-22 season of public lectures, Cork Astronomy Club welcomed Dr Robin Catchpole of the Cambridge Institute of Astronomy. He talked to us via Zoom.
The title of his lecture was “Taking the Measure of Our Universe”. Two thousand years after the ancient Greeks thought of the idea, we measured the distance to the nearest star. Less than two hundred years later we are measuring the distance to a 1000 million stars almost a million times more accurately, opening a new era of discovery in astronomy. Soon we will measure the position of 3000 million galaxies in the hope that they might reveal the nature of the mysterious dark energy. Robin explained how this is being done and what more we know about our universe.
One member commented: “Robin was an amazing lecturer and had me spellbound.”
Now an astronomer at the Institute of Astronomy, Cambridge, Dr Catchpole has held posts at various observatories around the world including Senior Astronomer at the Royal Observatory Greenwich.
He has authored and co-authored over 120 research papers and articles and used a number of telescopes including the Hubble Space Telescope. Research interests include the composition of stars, exploding stars, the structure of our Galaxy and galaxies with black holes at their centres. His current research interest is in the structure of the Bulge of our Milky Way Galaxy.
For our final lockdown lecture of the current season, Cork Astronomy Club welcomed Society for the History of Astronomy Chairman Gerard Gilligan to tell us about William Lassell, the Liverpool brewer and amateur astronomer who in 1846, using his own self built telescope, discovered Neptune’s largest moon, Triton, just 17 days after the discovery of Neptune itself.
Amanda Bauer, Head of Education and Public Outreach at Vera C Rubin Observatory, joined us by Zoom from Tucson Arizona to tell us about a sizeable telescope due to commence operations in Chile at the end of 2022 which will open a bigger window on the universe and allow citizen scientists to download an app and contribute to analysing data.
The Vera C. Rubin Observatory will conduct the 10-year Legacy Survey of Space and Time (LSST) starting in late 2023. It will survey the southern sky every 4 nights and record every change – what dims, what brightens, what moves or disappears. We’ll see the universe in action! Citizen scientists can join in. One comment was “if the rest of the team are even half as enthusiastic, it’ll be finished ahead of time!”
LSST will deliver a 500 petabyte set of images and data products that will address some of the most pressing questions about the structure and evolution of the universe and the objects in it. Rubin Observatory has an outreach team designing and building an innovative, modern, and inclusive program. Amanda demonstrated a prototype online astronomy investigation and highlighted citizen science opportunities with LSST data.
Calendars, clocks, and how the measurement of time links to the Earth and the solar system were Prof Malone’s theme when he joined us by Zoom from Maynooth University. He called his talk “How to tell the time” and time was the one thing lacking, the question session lasting 25 minutes after the meeting was meant to close. David Malone is a mathematician on the staff of Maynooth University’s Hamilton Institute
A little nugget of information was that the word “minute” comes from the Latin pars minuta prima, meaning “first small part”. This division of the hour can be further refined with a “second small part” (Latin: pars minuta secunda), and this is where the word “second” comes from.
British cosmologist and astrophysicist Martin Rees sees space as the realm of robotic exploration, not human colonisation. A handful of privately funded thrill seeking adventurers will probably settle on Mars but the idea of mass emigration there, proposed by some as the solution to Earth’s problems, he views as a dangerous delusion.
Martin speculated the universe might be beyond the capacity of the human brain, as Euclid is beyond an ape’s.
Life might be unique to Earth or if there are other spacefarers, then as Seth Shostak suggested in his December 2020 lecture, we are more likely to encounter other civilizations’ machines than their biological forbears ─ Martin derives comfort from this as the machines, he thinks, would be more benign than biological entities. (One questioner raised the danger of robots having aggression programmed into them.)
Whilst we may be constrained by the laws of physics to remain within the galaxy, our electronic descendants could live millions of years, Martin thought.
Cork Astronomy Club was immensely honoured that Martin Rees agreed to give our January lockdown lecture. He is currently writing a book on “When we don’t need astronauts”, and looks forward to the day, perhaps 10 years from now, when the European Southern Observatory’s ELT telescope will get spectra of some exoplanets that would indicate the presence of a biosphere (chlorophyll, oxygen, etc).
Launched in 1977 the twin Voyager 1 and 2 spacecraft are exploring where nothing from Earth has flown before. Each is three times farther away from the Earth and Sun than Pluto is, and travelling at 10 miles a second. In 2012, Voyager 1 made the historic entry into interstellar space, the region between stars. Incredibly, these spacecraft are still communicating with NASA and sending usable data.
Prof Bunce is current President of the Royal Astronomical Society, and head of Physics and Astronomy at the University of Leicester, from where she joined us by Zoom to give this lockdown lecture.
It was 31 years ago, in 1989, that Voyager 2 made a close flyby of Neptune, giving humanity its first close-up of our solar system’s eighth planet. No other spacecraft has visited Neptune since. Prof Bunce hopes this will change. A teenager when Voyager’s Neptune fly-by occurred, Emma credits this event with first sparking her interest in astronomy. Today she is a leading expert on the solar system’s gas giants.
Senior Astronomer at the SETI Institute Seth Shostak joined us by Zoom from California to discuss the failure so far to detect extra-terrestrial intelligence by searching the sky for artificial radio signals, and new initiatives being developed or under consideration. We are likely to encounter alien robots before alien biology, he thinks. Seth spends much energy on outreach activities, publishing numerous popular articles on science, giving talks to lay audiences, and hosting the SETI Institute’s weekly science radio show, “Big Picture Science.”
Vatican astronomer Bro Guy Consolmagno, Director of the Vatican Observatory – Specola Vaticana, joined us by Zoom from Tucson, Arizona to talk on the harmonious relationship between science and religion.
Bro Guy argued that logic and reason must always start with assumptions, and the assumptions behind science are, at their root, religious assumptions. Our core beliefs not only determine how we expect the universe to work; they supply the motivation for the science we do, and determine why we choose to look at the stars. How we understand this relationship has changed radically from the time of Galileo, when science was still being invented; and that change continues to this day, as can be seen in the way Pope Francis has blended science and faith in his recent encyclical Laudato Si‘
Modern science required three fundamental shifts which were just beginning in Galileo’s day: > discard the Golden age mentality (the ancients knew more than us, knowledge has faded) > use of instruments in discovery > abandon attempt to seek deductive proof of scientific facts, instead accept probable cause, to be improved on by scientists of the future .
Bro Guy was a most attentive host when Cork Astronomy Club members visited the Vatican Observatory at Castel Gandolfo in 2019. He has family connections in Cork and we look forward to welcoming him back here in what we hope will be the not too distant future.
To coincide with the Mars opposition Kevin Nolan gave a talk on past, present and near-term future Mars exploration. What have we learnt, what can we hope to learn? Looked at the present and continuing unmanned program for Mars which commenced in 1996 with Pathfinder and will continue into the future at least until a sample return mission in 2031 – and surely beyond. Kevin’s passion for the subject and the ease with which he presented so much technical information drew widespread praise from the 90 people in this Zoom call.
Opening our new season of public online lectures, Frances McCarthy and Danielle Wilcox of Blackrock Castle Observatory’s outreach team talked about observing and photographing the night sky’s largest and most changeable object, the Moon.
We learnt that the word “moon” is connected with words for to measure, reflecting the fact that from earliest times the Moon’s phases have been used as a calendar. The moon illusion when the moon is near the horizon is well known, and it seems that it’s perceived especially by children. We heard about the startling difference between the near and far sides of the Moon and possible reasons for this, as well as a hypothesis that the Moon’s tidal lock, which dictates that we always see the same side, may have occurred not over millions of years, but in the course of a single year.