And it turned out to be a that little path next to the Royal Observatory in Greenwich, not the Prime Meridian line. The 0° meridian is what the GPS uses for global navigation, the discrepancy results from the fact that the Prime Meridian was originally measured without taking it into consideration that the Earth isn’t a perfect smooth ball (if the measurements are made inside the UK, as it it was originally done, this does’t lead to as much discrepancy as when vaster areas are included).
Caught Simon’s reaction to Wednesday’s breaking news on video: the first-ever image of a black hole published, made by the Event Horizon Telescope project team. Simon explains why, if you stood next to the black hole, you would be able to see the back of your own head.
Simon loved this video by Veritasium about how the image of the black hole was made (he had watched this one day prior to the actual publication of the black hole image).
Yesterday, wee also watched this beautiful TEDx contribution by Katie Bouman (one of the leading figures behind the algorithm that helped stitch the M87 black hole image data together). The video is from three years ago, when the project was just getting started. Katie is such an inspiration: a computer scientist helping astrophysicists!
Scientists report ‘groundbreaking’ black hole findings from the Event Horizon Telescope: link to the actual press conference.
“The birth of a star is not that interesting. It’s just a stellar nebula turning a protostar. The old age of a star is also not that interesting: it’s either a red giant or a red supergiant. But the death of a star is really interesting. There’re loads of intricate options that can happen!”
An unbelievable experience Friday night, as we were on an Antwerp rooftop prepping to observe Uranus and Orion nebula through a telescope, Simon and I (and one more person next to us) saw an extremely bright meteor, presumably a bolide!! It came swishing over our heads in the direction of The Netherlands (north) and its head looked like a large fireball (a little smaller than a full moon, but brighter), glaring yellow and red. Simon says it was the best star gazing trip ever! All of a sudden we were made aware of the constant bombardment that our fragile atmosphere protects us from. And how close space actually is. Here is Simon’s account, including a video that somebody else made with a car cam:
and here a Belgian weather station Facebook account collecting witness reports.
Simon is interested in space again, since he has gravitated towards Physics and has been learning a lot of astrophysucal concepts. We had times when he didn’t bother to join the night sky observations but now he is enthusiastic again and keeps spitting out the facts about the Moon that fascinate him.
When we got home tonight, he initiated a demo (involving a blanket and balls of different mass) to show me how the balls (symbolizing a planet and its moon) fall towards each other on a blanket (spacetime) stretched over a large chest, but don’t collide if the smaller ball is set in fast motion.
Mom, did you know there’s a density limit? Density is mass divided by size! If an object reaches the density limit it will become a black hole. If you have an object that is not homogeneous it can be more than the density limit in some places and less than the density limit in other places, and then in some places it’ll be a black hole and in others not. And so the object will swallow up itself!
(exactly what we are talking about when the picture was taken)
We were also lucky to have friends with a telescope over at Simon’s grandma’s summer house in Friesland last weekend and saw the Moon a little closer than as shown on these mobile phone pics I took. It was very warm and great to be outside at midnight after many hours in the train on the melting railroad (the train couldn’t move for one and a half hours due to the switches malfunctioning in the heat).
Simon watching Daniel Shiffman’s live stream on Machine Learning outside:
We are very grateful to brother Robert and his awesome colleagues from the Urania observatory for tonight’s adventure. We saw Jupiter and its four main moons, Saturn and Venus. And refreshed the most visible summer stars in our memory.
We drew a line to mark how far the sea has pulled back between 17:30 and 21:00 o’clock. It’s amazing to observe the the Moon in action! We have read about this dance that the Earth and the Moon dance with each other, circling round and round in what is currently our favorite book, Eine kleine Nachtphysik by Wolfgang Rosler: