Friday, 8 June 2018

Solve the right problem – dustless chalk

Here is a lesson on how not to do new tech. Make sure you know first what problem you are solving.

Chalk was the greatest educational technology ever. You can write anything with it, draw, do arbitrary mathematical notation, correct as you go.

The only real problem is that it makes a lot of dust when you erase.

So: we need dustless chalk.

Instead, they gave us whiteboards. Slightly less erasing dust, true. But walk into a room with a chalkboard and you can see instantly if you have all the equipment you need. Chalk missing? Walk next door and grab some. The whiteboard introduces a new problem: a line of pens that look inviting but all are dry.

We needed dustless chalk – that didn’t do it. So what do we get next?

The overhead projector. Works well – you can pre-make slides or write as you go (even with erasable pens). But it introduces a new problem: the burnt out bulb.

All we wanted was dustless chalk.

Next: computer presentation. No dust at all. Very pretty slideshows with animations possible. But now we have multiple points of failure – projector bulb dies, computer won’t talk to projector, slides turn out to be the wrong size for the equipment, you brought the wrong adapter … and worst of all, not even a whiteboard as a backup plan in many lecture rooms.

All we wanted was dustless chalk!

Then after all this, one day, I was giving a talk and started thinking: “If only someone would invent a presentation tool where you could edit as you were going.”

Read my paper “Teaching without technology” to see where this went. No, I didn’t mention dustless chalk. But I should have.

Remember always when designing new tech: keep your eye on the problem you’re solving.

Sunday, 24 December 2017

iPhone slowdown: class action against predatory lawyers?

Some people are threatening a class action lawsuit against Apple after the company admitted slowing iPhones down to protect them against sudden shutdown when the battery is weak.

Apple’s biggest mistake was failing to announce this feature to users. For those who want speed at all costs and don’t mind the risk of the phone suddenly shutting down, maybe Apple could provide an off switch for the feature.

The threatened lawsuit is idiotic, notwithstanding Apple’s poor PR.


Because Apple didn’t pour go-slower gunk into your phone ruining it permanently. It is a software fix and a software fix can be turned off.

What actual damage have plaintiffs suffered? Their phone sometimes runs slower instead of shutting off without warning when the battery is below par. That is not actual damage. It is the sort of design trade-off engineers make as a matter of routine.

If there is a case for a class action lawsuit, it is one by Apple shareholders who stand to lose from any gratuitous drop in Apple’s share price arising from an idiotic class action like this.

See the first class action filing here.

Monday, 27 June 2016

How Brexit Broke Britain

There has been a lot of analysis of the Brexit vote; this article is one of the best.

What is missing is the peculiar dynamics by which the position of a party that scored less than 13% of the vote in the 2015 general election and only won one seat was able to secure over 50% of the vote in a referendum on the position they were advocating.

The Tories won about 37% of the vote in 2015 so even if every Tory voter was actually opposed to the EU, this still does not add up to the 52% Brexit vote. Take away the pro-Euro Tories and a substantial fraction of voters for parties who are pro-EU voted the opposite way to the party line. Some blame Jeremy Corbyn for not taking a strong pro-EU line in the referendum campaign. But his position – that the EU was flawed but it was better being in to fix it than out – is not much different from David Cameron’s and the only real difference is that Corbyn stated that view honestly rather than pushing hard to a yes vote, implying that he was more strongly in favour of the EU than he really is.

Even so, it is not usual that party supporters break ranks like this. Most parties can rely on their core base to vote for them no matter what – for example through the sort of change when Blair reverse much of Labour’s traditional policy position or when the US Democrats effectively switched sides with the Republicans on many major positions. With the Republican-Democrat switch, there was a switch in where the parties drew support: the Democrats used to be the party of the South. But this switch in support based took a long time and some very dramatic events like the Civil Rights movement (and even through that, some deeply racist Democrats did not switch sides: George Wallace of Alabama remained a Democrat despite a run for president as an Independent Party candidate, and only saw the error of his ways much later in life, when he ended his political career as an opponent of racism).

So let us study the dynamics of the thing – how Cameron got himself into such a mess.

With Europscepticism a major force among the Tories, he was able to secure his leadership as well as shore up votes in the marginals by promising a referendum. His calculation: not many people really wanted to break with Europe so by pandering to them, he could retain the leadership of his party and shift enough anti-EU voters his way in marginal seats to prevent UKIP from winning and to tilt such seats away from Labour.

The problem is that when the referendum came up, it was at a time when there was mood for shucking off the establishment – the same mood that gave Jeremy Corbyn Labour leadership, that made Bernie Sanders unexpectedly successful and that has kept Trump not only in the race but has made him the Republican candidate (presumptive but in reality, it would be pretty hard to change that now).

What is weird about all this is that the “anti-establishment” mood crystallizes around such different positions.

Trump and Sanders stand for completely opposed values yet a substantial fraction of Sanders voters are more willing to voter for Trump than Clinton.

Meanwhile, parliamentary Labour is revolting against Jeremy Corbyn, as if he is solely responsible for the Brexit vote. Labour MPs, listen up. The public voted Corbyn in because they found you revolting. Labour has failed to tap into the anti-establishment mood since Corbyn’s election not because of him but because of the rank and file who desperately hoped he would go away and they could return to the failed world of Blair and Brown.

The point of the anti-establishment mood is that people are tired of business as usual. That creates a need that can be fulfilled by sane politicians offering real alternatives – like Corbyn and Sanders. But of course their sort of alternative is not very palatable to the plutocrats behind the scenes so when politics as usual fails, they back unpleasant, irrational alternatives like the Tea Party in the US and UKIP in the UK. Out of this, Trump is something of an anomaly as he is not so much a representative of plutocrats as a representative of plutocracy: he does not stand for class interests but rather for himself.

The EU was in many ways a flawed creation – but one that blurred inessential differences and encouraged a rights-based view of difference. Splitting off the UK risks further splits – the Scottish independence movement is revitalized for example. If that goes ahead, it adds impetus for other separatist movements. The end result could be a Europe of much smaller countries and with no unifying framework. That takes us back to the 19th century.

If you really are opposed to the establishment – good. It needs shaking up. But do not be conned by voices of bigotry and hatred. This is not shaking up the establishment. It is about destroying the values that have made a world-wide civilization possible – one that respects difference but does not demand shallow capitulation to imposed values and identities.

Such a civilization does not exist yet, but there is a possibility of one – and the EU hinted at what was possible. The alternative in a world with advanced technology is mini-states hostile to difference and belligerent to those less fortunate than themselves; not an attractive prospect.

Saturday, 25 June 2016

Vegetarian Panna Cotta

The secret to good panna cotta is powdered agar-agar. Agar-agar is a gelling agent derived from algae (usually seaweed). You can also use gelatin, though gelatin is made from animal parts and can also be tricky to work with.

Here is my formula; scale it down if you want a smaller quantity. Some recipes substitute milk for some of the cream.
  • 1 litre milk
  • 300–400ml sugar, depending how sweet you like your dessert
  • 5ml (level teaspoon) agar-agar powder (you can use flakes but the quantity is much harder to measure)
  • half a vanilla bean
Split and scrape the half vanilla bean into the sugar in a saucepan and add the agar-agar. Mix thoroughly so the agar-agar is evenly distributed and won’t form lumps. Mix in the cream and heat to boiling. Reduce the heat and simmer for 2–3 minutes.

Panna Cotta Moulds – I ordered a set like this
and will update the article to review them.
Leave to cool, then remove the vanilla bean pod and decant into 6–8 moulds. Chill for at least 2 hours to set.

If you can find a mould with a removable end (see picture) so the panna cotta can be pushed out from the smaller end of the mould, it should be easy to unmould.

Applying heat to loosen it from the mould is tricky – you can easily end up unsetting the contents; if you are less concerned with being fancy, set it in the serving bowl.