Hello all, The next MaPSS talk of this semester will be at 17:00 on Mon 4th Nov in Carslaw 535. It’s a great opportunity to meet fellow postgrads, listen to an interesting talk, and of course get some free pizza! ************************************************************************************** Speaker: Joel Gibson Title: Quaternions, rotations, and Spin groups Abstract: The quaternions are a four-dimensional number system, famously discovered by William Hamilton in 1843 whilst vandalising a bridge in Dublin. Despite their dubious origins, they have become ubiquitous in computer graphics because of their close relationship to 3D rotations. In this talk I will cover different ways to encode 3D rotations, including unit quaternions and their higher-dimensional analogues built from Clifford algebras (the Spin groups), and conclude by comparing the underlying geometry of all of these parameter spaces. The talk will include lots of pictures, discussion of vague questions like "what is an 11-dimensional rotation, really?", and most probably a mislabelled angle in a planar geometry proof. ************************************************************************************** See you there! Details can also be found on the school’s Postgraduate Society website: http://www.maths.usyd.edu.au/u/MaPS/mapss.2019.html Cheers, Eric