Author: Matt Collinge

While most of our attention may understandably be consumed by events taking place here on planet Earth, it’s a good practice to pause occasionally and take in a larger perspective. A fine occasion for such activity presents itself whenever clear skies align with favorable Moon phases.

Each year, International Observe the Moon Night, marked in 2020 on Saturday, September 26th, encourages Earthlings to point our gazes skyward and appreciate our closest celestial neighbor. (NASA organizes a list of events that might allow for an in person experience, as well as ways to participate from home.)

The first quarter lunar phase each month is widely considered to be best for viewing because of its evening visibility and the oblique angle of sunlight that throws its surface details into sharp relief. When looking at the Moon from Earth, we definitely recommend grabbing a pair of binoculars, if available, as any amount of magnification greatly enhances the visibility of surface features such as craters.

And while you’re thinking about gazing skyward, don’t forget to think about other ways to get your astronomy fix, and be sure to check out Sky & Telescope’s Sky at a Glance for more detail about what’s on the celestial menu these days.

While the MDSGC Observatory remains closed for the time being, with a little inspiration and effort we can still admire the night sky above us — and certainly now, as much as ever, we can all benefit from a cosmic perspective!

Here is a recent article by University of Arizona astronomer professor Chris Impey on ways to enjoy astronomy during the pandemic. It’s a must read for would be backyard astronomers. Of special note is the “Sky at a Glance” from Sky & Telescope, a highly useful guide to tracking the Moon, planets, and other noteworthy celestial events.

Another recommended activity that may be appealing is to construct a planisphere: a device that shows the locations of the stars in the sky each night. You can buy one, of course, or use free astronomy software such as Stellarium, but if you happen to live at a latitude not too different from Baltimore, MD (39.29 degrees North) and have access to a printer, you can also make your own using these files: planisphere instructions and planisphere cutouts. The second file has two pages, which need to be printed on separate sheets of paper. You’ll also need a paperclip.

Until we can once again welcome you to visit our Observatory, happy star-gazing!

Watching live coverage of the successful NASA Mars Insight landing yesterday reminded us of some other excellent space videos we’ve seen lately.

Here’s one to mark NASA’s 60th anniversary. Like science fiction, but real:

Also celebrating an anniversary recently, in this case its 20th, was the International Space Station (ISS). A long sequence of Earth from orbit, with some landmarks identified:

As long as we’re on the topic, here’s one more from ISS. An inbound rocket launch:

Hope you enjoy them as much as we did. If you’re curious about the image at the top, click on it to learn more!

Tuesday, October 16, 2018, is the one hundred and seventy-fifth anniversary of the discovery of quaternions, one of the most difficult discoveries ever in the history of mathematical physics.  The discovery was made — in a sudden moment of inspiration following 11 years of studious toil — by Sir William Rowan Hamilton as he was crossing Brougham Bridge, in Ireland, with his wife.  On the spot, or so it is said, he carved his famous equations on the bridge.

Some years later, Hamilton recalled:

They started into life, or light, full grown, on the 16^th of October, 1843, as I was walking with Lady Hamilton to Dublin, and came up to Brougham Bridge.  That is to say, I then and there felt the galvanic circuit of thought closed, and the sparks which fell from it were the fundamental equations between I, J, K; exactly such as I have used them ever since.  I pulled out, on the spot, a notebook, which still exists, and made an entry….

Although Hamilton’s original inscription does not survive, the plaque shown above hangs on the bridge to this day in commemoration both of Hamilton’s discovery and of his sudden inspiration. The plaque reads:

Here as he walked by
on the 16th of October 1843
Sir William Rowan Hamilton
in a flash of genius discovered
the fundamental formula
for quaternion multiplication
i² = j² = k² = i j k = -1
& cut it on a stone of this bridge

Here’s to Hamilton, to quaternions, to bridges, and to inspiration!