Astronomy, Curent Events, Geography, Physics, Together with sis

Watching Bob and Doug start a new era of space exploration

We watched both on Wednesday, May 27 and Saturday, May 30 when it actually happened: the historic launch of Crew Dragon Demo-2, a commercial state-of-the-art aircraft, marking the start of a whole new era of space exploration for the whole of humankind. And then, 23 minutes after the launch, we rushed towards the balcony to watch them fly over Belgium, only to realize that it was too light outside… But we did get lucky the second time they passed! Exactly at 23:18, we spotted a little bright dot going from West to East, vanishing mid-way. It was a very memorable moment. #LaunchAmerica

Crew Dragon Demo 2’s approximate trajectory over Belgium. Image source link.

Astronomy, Curent Events, live stream, Murderous Maths, Notes on everyday life, Physics, Set the beautiful mind free, Simon's sketch book, Space

More Stephen Wolfram and Brian Greene

What has been your silver lining during this COVID-19 crisis so far, in terms of self-directed learning? Simon is happy that Grant Sanderson, Stephen Wolfram and Brian Greene all have more time now to make frequent streams and tutorials. In fact, he can’t even follow all of them live as they often overlap!

Luckily, years of homeschooling have allowed us to develop a very flexible approach to daily routine, enabling us to embrace learning opportunities from across the Atlantic, that mostly present themselves in the evening hours. Our learning is circular, cyclical, not linear (we learn around the clock and Simon often returns to the topics he has already covered before but at a new level).

Simon delirious watching a Stephen Wolfram livestream
A screenshot from the live chat in Stephen Wolfram’s stream

Brian Greene publishes daily videos called “Your Daily Equations” on the World Science Festival channel, and viewers can “order” which equation they want to discuss next. He also does a weekly live Q&A.

It’s funny how both Wolfram and Greene are Simon’s professors as part of the World Science Scholars program, but he seems to have gotten a better chance to engage with them personally now that we’re all stuck at home (through the live chat and comments) than during the official World Science Scholars sessions!

Every day, Simon feels like he’s sitting right next to Brian Greene in his living room. There’s this atmosphere of informal talk and human warmth, as one of the world’s top flight professors is accessible for questions and gives Simon and other students so much of his precious time to explain all the quantum physics fundamentals. So touching yesterday, as Brian Greene just took off his socks and held them up in the air to visualise spin.
On April 2: there’re equations for relativistic mass and rest mass. The speed of light equation that Brain Greene talks about is with relativistic mass. — Do you know the equation with the rest mass? — No… In fact, let’s derive it right now!
Astronomy, Experiments, Geography, history, Milestones, Notes on everyday life, Physics, Space, Together with sis, Trips

We’ve found the real 0° meridian!

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).

Simon standing with one foot in the Western hemisphere and the other one in the Eastern hemisphere
The GPS determines the longitude of the Prime Meridian as 0.0015° W
Simon tried to use JS to program his exact coordinates, but that took a bit too long so we switched to the standard Google Maps instead
The Prime Meridian from inside the Royal Observatory building
Looking for the real 0° meridian: this is an open field next to the Royal Observatory. At this point, the SatNav reads 0.0004° W.
And we finally found the 0° meridian! Some 100 meters to the East of the Prime Meridian
The 0° meridian turned out to intersect the highest point on the path behind Simon’s back!
Simon and Neva running about in between the measurements of longitude
Astronomer Royal Edmond Halley’s scale at the Royal Observatory
Halley’s scale is inscribed by hand
Astronomy, Milestones, Notes on everyday life, Physics

Black Hole Breakthrough

Simon recorded this video right after the news was announced on April 10

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.

Astronomy, Milestones, Notes on everyday life, Together with sis

A Guest from Space

The Moon through a telescope
Simon and Neva looking at Uranus

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.

Astronomy, Physics

Looking at the Moon and Mars

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.

Astronomy, Milestones, Notes on everyday life, Physics, Simon teaching

No Limit

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)

Astronomy, Coding, Together with sis

Observing the Red Moon during the eclipse last Friday night

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: