What I call a lived-in blackboard.Well trying to remember when I started my undergraduate course that blackboards (green) were moderately usual use. Rather less in my final year when we had one formal lecture a day and, the department being under construction, lectures were held in a theatre also used by the faculty of Law. Lecturers had been pressured to minimise use, because the elegant legal gentleman who lectured after them then had to appear in Court and did not appreciate chalkdust on their formal black suits.
After my degree I have been in any number of seminars, lectures, conferences and meetings for decades, and just never came across backboards. It was slides all the time. I was there around the time of the change over when slide displays were a bit clunky, there were still two formats, and presentations involved a collaborating ‘projector’, i.e. a colleague or a technician detailed to work the projector. Talks were always interrupted continually by the call 'Next Slide Please’. If one incorporated this call within the talk with phrases like ‘so then as the next slide shows' then often nothing would happen – the speaker would have to call out loud 'Next Slide Please!’. This went on for some years but after a time remote controls came in which made it more convenient. Transparences came in, which were at least easier to prepare. And you could write on them during the talk, so they were somehow more like a blackboard and more friendly I would say. But a real blackboard in use I never saw for decades whilst I was in research attending conferences and so on and I forgot about them. (I wasn't teaching, but I think the lecturing where I was was largely with slides too).
Then my job changed out of research to something of which a small but the most interesting part involved taking in and reporting back on a wide variety of scientific conferences and training activities over all the sciences. It was still nearly all the same. In all disciplines. Everywhere.
Until one day my scientific butterfly samplings took me to the Newton Institute, Cambridge. Many mathematicians here will no doubt know it, or at least its standing. For others I should say this: if you have read some of the popularisations of modern, last few decades, mathematics you may have the impression that it is just
a different thing from what you know as mathematics. The calculations you do a little of resemble it the same way that your school experiments verifying Hooke's law with weights and springs or something resemble the work at the Large Hadron Collider. You can't do anything on your own just in the study, it seems, unless you can insert yourself into some such large-scale structure. At the Newton they have six-month research binges on some topical theme to which anybody who is anybody in the specialist field tries to get to for a time, perhaps for months, and exchange or collaborate with others, including one or two weeks climax conference where the top people talk (all confirming another impression you may have got reading the pop maths maths books as well as those about abstruse theoretical physics like Theory of Everything and its generalisations, that the lifestyle is rather enviable in comparison with even the most fashionable biologist, who must be tied to his laboratory mainly.)
I reported back that the facilities were
Excellent, or rather, hors categorie. You cannot compare it to any other meetings facility, it is more an intellectual Accelerator”. An Excellerator I should have said, but I only thought of that just now, I expect I'm not the first.
One instrument illustrating the peculiarity of mathematics among the sciences: in the sessions attended they were making heavy use of a visual aid I haven't seen used before – blackboards. (Well now I cast my mind back a not dissimilar device was in use when I was at school – it must be a rediscovery.) There are also overhead projectors but more often than not they remove them as being 'in the way'. This leaves eight blackboards in a lecture room which they cover with formulae, just like you see in those old photos of Einstein etc.
The whole Newton Institute is made from blackboard plus of course glass windows, otherwise it would be too dark to see what is written on them. This is not an exaggeration
At all moments in any discussion anywhere in the place there are several handy where the discussants can write down their ideas and calculations.
Visiting journalists as they find math a bit hard to understand or explain fix the reports rather on the blackboards, also found in the lifts and the toilets where I was told one can see theories evolving collaboratively over a period. Who knows how many mathematical inspirations were in the past lost forever for lack of this means of immediate capture? And how many trees saved by it?
(I don't have any pictures of the wall–and–pillar blackboard-covered general areas, but here from the Institute site is seminar room 1)
For lectures I was told that one of the advantages of blackboards is that they slow lecturers down. (This may be somewhat offset if the calligraphy is impossible to read, as I found in one case, though for the mathematical audience familiar with what the squiggles are about this was not a problem.) They usually use eight at a time, but this is not enough for most lectures, so they use that other schooldays technology the blackboard eraser.
It must have been a wish to not confess my total overawe that induced me to conclude with this overthetop suggestion for an improvement:
The only thing lacking is a complete polygonal (e.g. Euclideanally constructible heptadecanal) or polyhedral auditorium so the audience could appreciate the whole argument in the round but this will come someday somewhere no doubt of it.