Doran Planetarium - Laurentian University

Adam Shoalts, 'the Canadian Indiana Jones', is speaking at the EcoSummit to 300+ public and high school students. Two of the workshops will take place at the planetarium this afternoon. I plan to show the students how we are made of star dust and how the star dust comes into being.

The sigma standard describes how likely it is that an observed phenomenon is real. A 1-sigma result means there is a 68% chance, 2-sigma at 95%, 3-sigma at 99.7%, 4-sigma at 99.99%. But only a 5-sigma result, corresponding to 99.99994% certainty, is when astrophysicists or astronomers declare a discovery.
Astrophysicists have been burned by seeing 4 sigma results that turn out to be statistical noise, so it has to be 5 sigma or get yourself side-eyed at the next academic conference.
The detection of dimethyl sulfide (DMS), a compound that almost only life can produce, in exoplanet K2-18b by the Webb Telescope is 3 sigma (99.7%). LIGO’s first detection of merging black holes in 2016 was reported at about 5.1 sigma, making it one of the landmark discoveries in astronomy.
5 sigma is roughly 1 in 1.74 million chance of occurring by random noise in a two-tailed test. 5.1 sigma improves this to about 1 in 2.94 million, making false positives ~40% less likely.

The Lyrid meteor shower peaks today (April 22). It is called the Lyrids because the meteors appear to radiate from the constellation Lyra around midnight. In late spring, Lyra rises in the east during the late evening.

Many planetarium visitors have seen diagrams of the flight path of Artemis II and wondered why it is such a big deal. To help them visualize the real challenge, I have created this properly scaled diagram of the Earth and the Moon. Between the Earth’s centre and the Moon’s centre we could fit roughly 30 Earths. Or, more dramatically, if I hold a one‑foot‑long model of the Earth at one end of the planetarium, a visitor holding the Moon (a ball about one third the diameter of the Earth model) will have to stand at the opposite end of the 30‑foot‑long planetarium. Now, imagine shooting a small spacecraft towards the little ball so that the spacecraft will sling back by its gravity.

Photography:
1972, front lighting (the sun is between Apollo and Earth), short exposure, black background, deeper color, seeing no stars and no atmosphere.
2026, back lighting (the sun is behind Earth), long exposure, grey background), colour washout, seeing stars and, most importantly, the fragile, thin layer of Earth's atmosphere.

Physics for Understanding Blackholes (our upcoming Planetarium show): If we move away from the sun on a spacecraft at 17 km/s (roughly the current speed of Voyager 1), we will measure the speed of light passing by us as 299,792.458 km/s. If we accelerate our spacecraft to 99% of the speed of light, we will still measure the speed of light passing by us from the sun as 299,792.458 km/s -- experimentally proven. It is 'strange' because our everyday experience does not feel like that, because Newton and other ancient philosophers are wrong, because there is no universal clock. If we fly into a blackhole, accelerating to the speed of light, we shall think of this poem:

Clocks cannot tell our time of day
For what event to pray
Because we have no time, because
We have no time until
We know what time we fill,
Why time is other than time was.

'We're Late', W. H. Auden
Written in 1930, 25 years after Einstein's Theory of Special Relativity

Photo: NASA

Historian Ivan Malara has identified a 16th-century print of The Almagest containing extensive annotations by Galileo, written around 1590 (notably, the Copernican Revolution had begun in 1543). Though The Almagest is theoretically founded on Ptolemy’s geocentric model, its observational data represented the best available at the time. Building on this data — and the observation from his own telescope — Galileo proved the validity of the heliocentric theory. Interestingly, what drew Malara’s attention at first to the handwriting was Galileo’s reference to Psalm 145, a prayer and praise to God’s greatness. For Galileo, reverence for God was expressed by reference to the hard data for seeking scientific truth.

Reproduced with permission of the National Central Library of Florence

'The novelist seemed to be listening eagerly now, but I wondered what she really thought. Perhaps such a tendency was an asset in my scientific profession, as it kept a person searching for the "truth" of a phenomenon -- the truth being something outside human perception. Or perhaps it was just that interacting with a group of writers.' To Place a Rabbit, Madhur Anand

Two for One, or One for Two?
(1) March 5, 2026, 7:00-8:30, Doran Planetarium
Madhur Anand the writer in conversation with Waubgeshig Rice

(2) March 6, 2026, 2:00-3:00, Doran Planetarium
Science Talk by Madhur Anand: Tipping Points in Coupled Human-Environment Systems