Technology for theory: COVID-19 edition

The new coronavirus upended much of society, including our little corner of it. I believe at this point almost all theorists are teaching and doing research at home, and I thought it would be good to share some of the tools we use for doing so. Below I will describe my setup, but I hope other people share theirs too.

Teaching and virtual whiteboards

I am teaching using Zoom and using an iPad pro with a pencil to simulate a whiteboard. I use a laptop to connect to Zoom and for the camera, laptop, and chat window, and then join the iPad.There are several ways to connect an iPad to a Zoom session:

  1. Join the session from the iPad separately using the iPad Zoom app. (To do so you might need to logout of your other account.)
  2. Within the Zoom program on your computer you can choose “share screen” and then one of the option is to join an iPad connected to the same wireless network as the laptop/desktop and use “screen mirroring” on the iPad. (You can find the screen mirroring option on the iPad by swiping from the top right corner in a diagonal motion.)
  3. Another variant of this is to use a third party app such as Reflector 3. Reflector 3 sets up an airplay server on your PC so you can mirror the iPad screen to it. You can then share the Reflector 3 window from Zoom (see screen shorts below). If you do use Reflector 3, you can remove its annoying iPad like frame.
  4. You can use a wired connection, which is either by just connecting through USB (in a Mac) or a complex combination of combining an adapter to take an HDMI signal out of an iPad with an HDMI capture card to stream this signal to the computer.

I use either option 2 or 3. (Might have used 4 if I had a Mac.) The main reason I prefer these to option 1 is because the application I use for a whiteboard – GoodNotes – has a presentation mode that behaves differently when you are connected to an external display or use AirPlay (which is what options 2 and 3 do). In this presentation mode the students don’t see your interface, and so you can Zoom, go to the page selector and more without it disturbing what they see. GoodNotes also has a great “laser pointer”. I set the pages at a landscape orientation, and pre-write a good chunk of what I plan to present before the lecture. I also use the ability to “duplicate pages” to achieve the PowerPoint like effect of gradual reveal.

It is not perfect – I’ve discovered that the screen share sometimes stops refreshing and I need to leave GoodNotes and return to it for it to go back (this seems to works better in Reflector 3 so far for me).

Monitoring the chat window and raised hands in Zoom is non-trivial. It helps a lot that I have a teaching assistant that participates in lecture and notices if I missed something.

Some people say that a “matte screen protector” such as PaperLike makes the iPad more comfortable to write on – haven’t yet tried it. (Update 4/1/2020: I now tried PaperLike and can vouch for it – it greatly improves my handwriting! shipping from the UK did take some time though.)

I have a good Webcam (Logitech Brio) but at the moment I’m not using it since it seems too taxing on my laptop and so I went back to the native webcam. I have a very nice wireless headset/mic combo (Jabra Evolve 75) that I am constantly using and have been very happy with. I particularly like the feature of being able to unmute and mute yourself by raising and lowering the mike.

Using Screen share from Zoom to either share an iPad or the Reflector 3 window
Choose which source to mirror the screen to on your iPad screen
You can reach the screen mirroring options by swiping from the top right corner of the iPad.


For research Slack continues to extremely useful. For working jointly on a paper Overleaf is of course great, but for maintaining a shared document it sometimes useful to use simpler platform that are not full fledged LaTeX. Some options include:

Google JamBoard is an interactive whiteboard, also with an iPad app. I haven’t tried it yet but it seems promising.

Keeping children busy

For many people I imagine childcare is one of the most challenging aspects. At the moment at least the Cambridge Public Schools are not keeping my kids too busy. While probably most of their time is spent in non educational pursuits, we try to also encourage (i.e., bribe/extort/threaten/beg) them to do some learning. If your kids are interested in math, I highly recommend the courses offered by the Art of Problem Solving (they also have a theory connection: one of their books was co-authored by theorist Ravi Boppana). For younger kids you can also try their Beast Academy.

The AOPS program is not free but over the years my kids (especially my 13 year old daughter Alma) have also spent a lot of time on the free and amazing Khan Academy. In fact, last year she was inspired enough by Khan’s JavaScript course to write the following poem which (for obvious reasons) moved me very much:

Tending / Alma Barak

My mind is a desert
of boredom
of blankness
of leaning-back-in-your-chairness
and of simply-staring-at-the-ceilingness
I kick at a crumpled
deserted baby-blonde post-it
with my spotted socked feet
waiting for Aba to come.

We dive when he comes
into the seas of Khan
free-styling our way
into the lakes of Java
we pass codes we already
while loops
for loops
reminding me of what I’d learned

We frog-kick to an
lagoon of code I don’t know
sometimes I get swept away by currents
of confusion
but my aba, my dad
grabs my hand
and shows me the way through
teaching me
tending to me
washing away the sands of boredom with the sea of Khan.

7 thoughts on “Technology for theory: COVID-19 edition

  1. I recently gave a talk using a similar iPad set up, but using Notability instead of GoodNotes. I wrote by hand in real time and the experience was similar to a blackboard lecture. I was generally quite positive about the experience.

    I had my notes sync to Dropbox and then shared the Dropbox link with the participants, so that they can scroll back to previous pages if they want to go back to view pages that are no longer on screen. Many people liked this feature. Although the auto-sync is not fully automatic–it required me to go back to the main Notability screen every time I wanted to force a Dropbox sync.

    1. Thanks! I think notability can be easier for writing on blank space while Goodnotes is easier if you want to annotate pre-written text. I liked GoodNotes for its ability to set different paper sizes (e.g., landscape vs portrait) and use each as a separate “slide” but perhaps the infinite scroll of Notability can also be good. Good tip about dropbox sync! I think GoodNotes also has dropbox sync but haven’t tried it live.

  2. You can be logged onto Zoom on both the laptop and iPad simultaneously (and your two avatars are co-hosts by default). I use Option 1 with this setup, sharing the screen on Zoom and running Goodnotes from iPad, and using the laptop for camera, chat, and recording. I’d prefer your Option 2 but haven’t gotten the Airplay to work. I have an older iPad (not Pro) – not sure if this matters.

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