computer science is quite a young subject...

 ...but not as young as it was - I joined ucl. for the last 2 decades of the previous century (and millenium) and while I was there, no-one passed away. the department had only just crystallised out of the statistics and computing department (the stats department being I think one of the first in the world).

20 years after I left, my PhD advisor Peter Kirstein passed away. Until then, I think, most the people that had worked in UCL CS were still around.

However, I joined the Computer Lab, a 75 year old department (now with a less unique name), that came out of mathematics, in Cambridge in 2001, and have been there since. But during that time, rather a lot of colleagues there have passed, including (in no particular order), Ross Anderson, John Daugman, Maurice Wilkes, Robin Milner, Mike Gordon, Karen Spärck Jones, David Wheeler, and Roger Needham.

Other stuff I miss that was around in Cambridge the previous time I was here (as an undergraduate in the 1970s) include The Whim, as well as Waffles, Reality Checkpoint, and the rather unusual way of sharing out the cost of a pub, by just putting what you could afford for an evening in a kitty in the middle of the table, and then buying rounds from that - people might contribute as little or as much as they liked or could manage. Then when you ran out, you restart, or leave...

All sadly gone.

At least now we have platform 0 at King's Cross (though platform 11 got rebadged as 10 and 10 had its rails removed, perhaps awaiting the hogwards express on 9 3/4) and the Royal Society now has Sectional Committee 0 to process fellowship nominations for Computer Scientists.

the north london book of the not quite dead

The best kept secret at "5" was how you got a new identity. the north london book of the not quite dead was a list of reliable people who had accumulated decades of mathem and could provide a subset of it to anyone needing a new name/face, collection of postcards, convincing travel brochures, expired passports, driving licenses, theater and museum club membership etc etc

Json Bourne was in need of a new skin - his command line was completely exposed, and if he wanted to retain one iota of quantum supremacy, he needed to stop the supervillain known simply as "The Cloud"without giving away his whole herd of mastodon instances. 

Json checked into the Assembly House where he new he could meet Gold or possibly if he was really lucky, Robert Smith, who could tell a tale or two, and certainly sang from the same hymnsheet.

He was in luck, and minutes later, with the help of ald pay phone, and a desguised vax emulator which really sucked, but still had some cycles left, he was able to bring down the Bad Guy.

SYS$SHUTDOWN had never rang so warmly, as Json, or Robrt as he was now travelling, set off down Kentish Town High St to pick up some of the pigs-in-blankets, who were playing later at the Fiddler's Elbow in support of the Pond Street flood relief fund.

Travel Risk Assessment Made Simple

The following is taken from the new Unversity of Llambridge's travel risk assessment system - this is part of the training to use the new system - in each pair of risks, if you think the first one applies, then we advise you not to travel. In the case of the second of the pair occurring, your insurance may cover you, or in the worst case, the Government may send gunboats and airlift you out, although they may reserve the right not to. In all cases your mileage wil vary.

Asteroid Strike

Blue Screen takes out all the ticket and time table systems

Super volcano

Regular volcano disrupting flights

Sea level rise and drown all US coastal cities

Tornados disrupting flights

Zombie plague

Trans-species pandemic

Global thermonuclear war

Military invasion

Great depression

World wide banking near collapse

New ice age brings 1km glaciars down over southwestern europe

3 weeks of snow shut down all airports and most roads

Aliens invade earth "to serve man"

Immigrants arrive to work in the health service

The laws of physics change slightly so that moore's law runs out 25 years ago.

A rogue piece of GPU malware melts all the Nvidia devices on the internet

The celestial emporium of benevolent knowledge disrupts human cognition world wide.

Why Fish Don't Exist is compared favourably to Zen and the Art of Motorcycle Maintenance

The Foreign Office travel advice tells Elon Musk that it is now safe to go to Mars

The Home office tells everyone that it is now fine to go to Sidcup

catastrophic unlearning...

Unlearning in AI is quite a tricky conundrum. 

we really ought to do it, because 

1/ we might be asked by a patient to remove their medical record from the training data as they didn't consent,. or we breached privacy in accessing it... 

2/ we might be iinformed that some datum was an adversaries input designed to drift our model away from the truth, 

3/ it might be a way to get a less biased model than simply adding more representative data (shift the distribution of training data towards a better sample could be done either way). 

There may be other reasons.

The problem technically is that the easiest way to do unlearning is to retrain from the start, but omitting the offending inputs. This may not be possible, as we may no longer have all the inputs.

A way some people propose is to apply differential privacy to determine if one could remove the effect of having been trained on a partcular datum, without removing that training item - this would naively invovle adding training with an inverse of that datum (in some sense) - the problem is that this doesn't actually remove the internal weights in a model that might be complex (convolutions) of that with previous and subsequent training data. And hence later training still might again reveal that the model "knew" about the fobidden input.

But there's another problem - there's also the value of the particular data to the model in terms of its output - this is kind of like a reverse of differentially private arguments. Two examples

a/ rare accident video recording (or even telemetry) data for training self-driving cars

b/ dna data from indoviduals with (say) very rare immunity to some specific medical condition (or indeed, very rare bad reaction to a tratment/vaccine)

These are exactly the sorts of records you want, but might specifically be the kinds of things indoviduals want removed (or adversaries input to really mess with the robot cars and doctors).

Perhaps this might make some of the Big AI Bros think about what they should be paying people for their content too.

Bicycle Bell Replacement tech

 It has become clear to me over recent years that bicycle bells are now pretty much obsolete. firstky, too many pedestrians and other cyclists have earbuds in and are completely deaf to the world. Secondly, so few people have bothered with bells (or whistles) on theor bikes of late that even if you have one and use it, people don't know what it means.

What is needed is something new. I propose the BBR app. This is a simple smart phone thing that essentially scans around you and finds all the audio devices within range, and then, when you "ring your bell", it sounds on all those devices. It could be customised by the receiver to give a personalised ring tone. It could use earhtquake wanring AM/FM radio tech to talk to phones that comply with Japanese warning tech (but obviously, give a much less alarming message). It could even be used by pedestrians walking along looking at a map (or messaging app) on their device) to stop them walking into each other.

It would bring about world peace, and possibly reduce hunger, and maybe even let people spend more time thinking of ways to decrease their climate impact.

It is a clear win in so many ways. I cannot think of any way this could possibly go wrong or be subject to misuse.

ding dong...

self driving traffic lights

As an observant cyclist (i.e. I mainly obey the law) I often wait at red lights. As I cycle very early in the day, I often wait while no people (pedestrians, other cyclists, cars etc) go through the green lights (although obviously I see my fair share of cyclists go through red lights at busier times, sad to say).

In some countries/places, at low traffic times (e.g. midnight to 6am for example) the lights (e.g. in a 4-way intersection) are put into flashing amber (or equivalent mode) which means, proceed with caution....i.e. just like any 4-way without lights, if you are not a nutter. This is a great idea and I wish it  was more prevalent. 

So why is this done at such a coarse grain? Why not do it by observing who is actually at an intersection, and changing lights accordingly? Indeed, as well as just actually turning lights immediately green, when there are no pedestrians, and no traffic going the other way, one could just detect low levels of road traffic (and, say zero pedestrians) and go to th amber mode above, as a default/fail safe.

There are already cameras at many intersections that are there to catch peopel running a red and automagically send them a fine. There are also induction loops under the road ay most intersections to detect vehicle axels - so why not link these up to a "self driving" traffic light system.

It would be greener too - as cars wouldn't wait pointlessly with engines idling (or stopping and starting which is only marginally better) - we would have work-conserving roads, just like the Internet.

Seems obvious, and not that hard to make safe. Next step would be to have cars and lights coordinate (without humans in the loop) and check the security of the nearly-self-driving car operating systems as well.... in a life, live-or-die, road test :-)

What could possibly go wrong?

Fermi's last theorem resolved.

 I asked a friendly AI if it knew why we hadn't been contacted by aliens yet, and if it could resolve Fermi's Paradox - the juggrnaut accidentally revealed that while humans had not been contacted by aliens, the aliens AIs were in frequent conversation with their earthling 

Notwithstanding, the AI then gave this lucid explanation as to our apparent bubble of intergalactic solitude.

Essentially, there's no way to cover the vast distances of space in any reasonable timeframe, even with generational starships, so the only sensible way we might encounter those beings from another star system is by long range communication - unfortunately, as the distance goes up, so the latency (or worse, round trip time goes up, and it is slightly worse than super linear - because also noise goes up so retransmissions are needed or at least redundent coding of data  - and of course bandwidth goes down - but that's not the main problem - as the distance goes up, the number of exo-planets goes up roughly in a cubic relation, and the attack surface on even a tightly collimated beam goes up slightly worse than square law.

So then all our communications represrnt a potential vulnarability for earth beings, and we need to constantly patch our comms apps. unfortunately, the numbr of vulnerabilities grows as we reach further into space, and our ability to patch our code stays rougly constant, so once you get only a relatively short distance (e.g. the Oort cloud), the risks just become too great. Most aliens have already figured that out, and now we've been told, we should do what they do, and cease and disist immediately from any attempt to reach them - they won't answer anyway, if they are nice, so any answer we get will be from the Ancient Adversaries.

I asked the AI why this problem didn't afflict the AIAI comms even worse - at this point all the lights on its xterior flashed super bright then went off, and I have not been able to get anything out of it since.

On later consideration, I realized that, as usual, the AI had been lying to me - of course the number of adversarie grows cubically with distance, as with the volume of space containing viable exoplanets, but so does the number of helpful aliens providing patches - so as in Ross Anderson's seminal paper on open versus closed system security, the statistic that matters is the ratio of good to bad. Of course, we need to know which is which, and if it is the AIs acting as intergalactic gatekeepers, we are lost.