## Friday, October 12, 2018

### Short items

A few interesting things I've found this past week:

• The connection between particle spin and quantum statistics (fermions = half-integer spin, bosons = integer spin) is subtle, as I've mentioned before.  This week I happened upon a neat set of slides (pdf) by Jonathan Bain on this topic.  He looks at how we should think about why a pretty restrictive result from non-interacting relativistic quantum field theories has such profound, general implications.  He has a book on this, too.
• There is a new book about the impact of condensed matter physics on the world and why it's the comparatively unsung branch of the discipline.   I have a copy on the way; once I read it I'll post a review.
• It's also worth reading about why mathematics as a discipline is viewed the way it is culturally.
• This is a really well-written article about turbulence, and why it's hard even though it's "just $\mathbf{F} = m\mathbf{a}$" for little blobs of fluid.
• Humanoid robots are getting more and more impressive.  I would really like to know the power consumption of one of those, though, given that the old ones used to have either big external power cables or on-board diesel engines.  The robot apocalypse is less scary if they have to recharge every ten minutes of operating time.
• I always wondered if fidget spinners were good for something.

#### 7 comments:

Sherburne said...

Thanks for mentioning my Aeon essay on math! Glad you liked it.

Emil Prodan said...

If anyone wants to see actual video recordings of topological edge modes generated with the fidget spinners, see here

https://arxiv.org/pdf/1803.08781.pdf

(sorry for self-promotion). Anyway, we believe this is the first post on the arxiv with embedded GIFS (see the source code there, to see how it can be done).

Douglas Natelson said...

Sherburne, I hope the Aeon servers can handle the increased load from the flood of traffic I've driven their way :-)

Emil, very cool, but what form of acrobat reader works seamlessly w/ the gifs? I'm on a mac and neither acrobat reader from adobe nor preview seem to be able to do this nicely.

Emil Prodan said...

the microsoft browser as well as google chrome does it automatically

Douglas Natelson said...

Chrome on a mac? Or on a pc? I'm using chrome on a mac, and the pdf viewer that it uses shows "[filename.gif] Media File (image/gif)" in black text on a yellow background when I mouse-over the figures. I can't click on it. In Firefox, it lets me click on the image and then save the gif file, which I can then open. Interesting

Emil Prodan said...

Indeed, Camelia tells me chrome on a mac will not do the job. So mac people need to fix that somehow; PRX accepts now embedded GIFS, which will become the norm in the very near future (PRB told us that, while they are looking into it, for now the GIFS go in supplemental material).

DanM said...

I'm using Chrome on an (older) Dell PC, and getting the same result that Doug described. The videos are not playing automatically. It's a great idea to be able to embed animations and videos in papers, I hope all journals move in that direction. There will inevitably be some bugs, though.