Quaternions Turn 175

Plaque on Broom (Brougham) Bridge in Ireland commemorating Hamilton's discovery of quaternions.

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 16th 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!

NASA Express and Science WOW!

Attention, STEM educators, students, and space enthusiasts! Did you know NASA has a weekly service providing information about student and educator opportunities — workshops, scholarships, internships, and more — as well as inspirations for the latest and greatest ideas for science education? If you’re not already registered, head over to the NASA signup page now!

NASA Express Logo

NASA Science Wow banner

MDSGC Students at 231st AAS Meeting

MDSGC proudly supported presentations by several students at the 231st meeting of the American Astronomical Society (AAS), held January 8-12, 2018, in Washington, DC.

Towson Professor James Overduin with students at 231st AAS meeting.

The poster topics included using the 2017 total solar eclipse to repeat Arthur Eddington’s 1919 test of General Relativity; using Towson University’s telescope to study the resolution of Olbers’ Paradox; and using the asteroid Psyche to test the Equivalence Principle. What the projects have in common is their connection to astronomical observations and fundamental physics, a strong emphasis on hands-on student research, and their supervisor: Towson University Professor James Overduin. The three posters presented at the AAS meeting represent collaborations among Towson faculty and students and several local high school students.

The solar eclipse poster generated considerable discussion that kept its authors Keri McClelland and Kelsey Glazer busy answering questions. Professor Overduin explained its popularity: “It seems that we are one of only two or three teams who have tried to do this (replicate Eddington’s test with the 2017 eclipse) and that only one other has been able to do more than us.”

MDSGC congratulates the Towson team on their accomplishments and wishes them success in their future projects! The three student posters are reproduced below.

Poster on students repeating Eddington's test of General Relativity using 2017 solar eclipse.

Olbers paradox poster from 231st AAS meeting.

Psyche poster from 231st AAS meeting.

STEM Extravaganza at Morgan State

The Baltimore MUREP Aerospace Academy (formerly SEMAA) held its yearly STEM Extravaganza on Saturday, September 9th, at Morgan State University.

Photo of MDSGC booth at Baltimore MUREP STEM Extravaganza 2017.

MDSGC was represented by a contingent from Johns Hopkins, along with our partners from Space Telescope Science Institute. Thanks to all our young STEM enthusiasts and parents who stopped by to pay us a visit and learn about scientific ballooning! We hope to see you again soon at one of our upcoming Observatory Open Houses.

August 21st Solar Eclipse

NASA image of partial solar eclipseOn August 21st, 2017, the Moon passed in front of the Sun as seen from much of North America, in an event that was hailed as a Great American Eclipse. (Another contender for that title will occur on April 8, 2024, in case you missed this one!) While a total eclipse was visible from within a narrow band stretching from Oregon to South Carolina, Maryland experienced a partial solar eclipse. In Maryland, approximately 80% of the solar surface was obstructed at the maximum, which occurred at approximately 2:43 pm local time. For any partial solar eclipse, please note: It is not safe to observe a partial solar eclipse without special equipment and/or eye protection — regular sunglasses are not okay!

For information about viewing a solar eclipse safely, please visit NASA’s Eclipse 101 Safety. Key takeaway: if you are trying to observe a partial eclipse, you need special eclipse glasses from a reputable manufacturer. Here is a rundown of information from the American Astronomical Society on solar filters and viewers and how to make sure you get something that is safe to use.

NASA graphic on safely observing phases of a solar eclipse

Baltimore residents had a chance to view the eclipse on “The Beach” at JHU’s Homewood Campus. Here is a news item about that event:

https://hub.jhu.edu/2017/08/22/solar-eclipse-party-johns-hopkins/

For more information about the August 21, 2017 solar eclipse, visit NASA’s Eclipse2017.

To all eclipse watchers, we wish you clear skies!