Monthly Archives: June, 2022

Want to know how cameras and lenses work?

This is an amazing page by Bartosz Ciechanowski: a tutorial where you can drag things, rotate things and generally be interactive while learning how cameras work.

A great deal of labour must have gone into this, and it’s also a very impressive demo of what web browsers are capable of these days.

But if cameras aren’t your thing, don’t worry – Ciechanowski doesn’t stop there.

How about watches? Or internal combustion engines? Or…

Well, you get the idea! Pretty impressive stuff.

Thanks to Michael Dales for the initial link.

Signalling virtue

Dear Reader,

Can I encourage you to try something today? Go to and get hold of the Signal messaging app, and/or go to your app store and download Signal for your phone. And while it’s downloading, come back here and I’ll tell you why I’ve become so fond of it, and why you might actually want another messaging app.

To put it in a nutshell, Signal is like WhatsApp but without selling your soul. Imagine what a good time Faust would have had without that awkward business with the Devil, and you get the idea. Well, OK… you don’t quite have to sell your soul to Facebook to use WhatsApp, but you do have give away your privacy, your friends’ privacy, endure a lot of advertising, and so forth. (More info in an earlier post.)

For Apple users, Signal is rather like Messages, which I also like and use a lot, but you can use Signal with your non-Apple friends too, on all of your, and all of their, devices.


  • is well-designed and nice to use.
  • runs on iOS, Android, Windows, Mac, Linux, tablets, desktop and mobile.
  • uses proper end-to-end encrypted communications, unlike some alternatives such as Telegram.
  • is Open Source, so if you doubt any aspect of it, you can go and see how it works.
  • is free: supported by grants and donations. No advertisements.
  • allows most of the interactions you expect on a modern messaging service: group chats, sharing files and images, audio and video chat, etc.

Now, of course, it has the problem that all networks initially have: what happens if none of my friends are on it? And yes, that can be an issue, but it’s becoming less so. When I first signed up, I think I knew about three other users. Now, over 100 of my contacts are there, and more arrive every week. When I see them pop up, I send them a quick hello message just to welcome them and let them know I’m here too. It’s a bit like wondering if you’re at the wrong party because you know so few people here, and then over time more and more of your friends walk through the door.

How do you find them? Well, like WhatsApp, Signal works on phone numbers, and when you sign up you have the option to let it scan your contacts list and see if any of them are on Signal too. Unlike Facebook/WhatsApp, however, your contacts’ details aren’t transmitted to the company’s servers and used to build the kind of personal profiles that FB keeps even on people who aren’t members.

Signal instead encrypts (hashes) the phone numbers in your contacts, truncates the encrypted form so it can’t be used to match the full phone number, sends those truncated versions to their servers, and if it finds matches for any truncated other account numbers it sends the encrypted possible matches back to you for your app to check. Security experts will realise that this isn’t perfect either, but it’s so much better than most of the alternatives that you can be much more comfortable doing it. Here’s a page talking about it with a link to more detailed technical descriptions about how they’re trying to make it even more secure. And here’s the source code for all their software in case you don’t trust what they say and want to check it out for yourself.

So in recent months, if I’ve wanted to set up group chat sessions to discuss the care of an elderly relative, or plan a boating holiday with friends, or discuss software development with colleagues in another timezone, I tell people that I disconnected from Facebook a few years back so I don’t do WhatsApp, but have you tried Signal? It’s pretty much the same, with all the bad bits taken out, and works much better on the desktop and on tablets, in my now-rather-dated experience, than WhatsApp ever did.

So give it a try, and if you find that not many friends are there, don’t delete it. Just wait a bit… and tell all your friends about this post, of course!

Encloak Demo

For those interested in the Encloak Hide device that I mentioned a few days ago, you can now see a demo of how it works:

Direct link

I should perhaps emphasise that this is the basic version; the Encloak Connect and Encloak Pro versions in the pipeline will do rather more.

Just for the avoidance of doubt: I have no commercial relationship with the company; they’re just old friends whose work I respect.

Brunch with Brent

Amongst the tech podcasts I enjoy while driving, dog-walking, etc are the ones from Jupiter Broadcasting.

The Self-Hosted show, in particular, discusses topic and news of interest to those who like to run some of their own IT infrastructure rather than outsourcing it all to third parties. It covers areas like backups, VPNs, media servers, and home automation (one of my current hobbies)!

Linux Unplugged keeps me in touch with Linux news. Even though I’ve been a heavy user of Linux since the days when it was first released as two floppy disk images, and I run and manage a large number of Linux servers, both personally and professionally, I haven’t really used it as my desktop operating system since Apple’s release of MacOS X gave me a Unix-based alternative, so this helps keep me in touch with developments there as well as on the back-end.

Anyway, I recommend these if you’re interested in such geeky topics; I think they’re nicely produced.

And then there’s Jupiter Extras, a feed with a range of interviews and other stuff that doesn’t really fit into any of the other streams. One of the Jupiter hosts, Brent Gervais, has a set of periodic interviews labelled ‘Brunch with Brent’, and I was delighted to be invited to join him for one of these a little while ago (published yesterday), in which he let me ramble on about everything from scuba diving to the patent system, from QWERTY keyboards to self-driving cars.

The full discussion can be found on Episode 86, and there’s a shorter extract in the middle of the latest Linux Unplugged episode too.

Playing fast and loose…

Subjects like the Northern Ireland Protocol, and Boris Johnson’s plans to disregard the bits he find awkward, are not the kind of thing I’d normally cover in this blog.

But a good friend, Prof. Mark Elliott, has just made a nice video explaining the situation on the University’s YouTube channel. Worth 9 minutes of your time if you want to avoid the banter and bluster from other sources.

Direct link.

Low-tech Wordle

Rose and I have taken to doing collaborative Wordle after dinner. As we finish off our glasses of wine, we pass the iPad to and fro, taking turns to fill out the next line.

The only trouble is that this enjoyable activity is rather short-lived; once you’ve done today’s puzzle, there isn’t another one, and you don’t end up with very many lines each!

So yesterday we got out some paper and took it in turns to pick a word for the other person to solve, which I can recommend as a fun variation.

Of course, I later remembered that my friend Richard was experimenting with this some months ago.

Note: in the original version of this post, I had accidentally spelled it as ‘Worldle’, which explains some of the comments below!

The Christmas Lights Fallacy

Just twenty years ago, there was a popular factoid doing the rounds:

Half of the world’s population have never used a telephone.

I was working on technology for the developing world at the time, and this came up occasionally at conferences and other discussions. It was repeated by Kofi Annan, Al Gore, Belinda Gates, Newt Gingrich…. It was one of those facts that was shocking enough to be interesting, but believable enough to make you think of the implications. You may think you’re in the midst of the dot-com boom, but remember that half the world has never even made a phone call…

But, as I blogged at the time, Clay Shirky went and did some research, and found that, actually, the statistic was first used in 1994, and, even if it had been true then, it certainly wasn’t by the time everyone was quoting it in the early 2000s. Seven years, it turned out, was a very long time in technology.

I was thinking of this today as I read Charles Arthur’s nice analysis of another recent assertion: that Bitcoin may use a lot of energy, but not as much as everybody’s Christmas lights! It’s a fun fact to surprise your friends with at the pub, perhaps, but, as Charles found out, it’s not quite grounded in reality. Take a look.

Sometimes it’s very good to have proper journalists around.

Keep it secret! Keep it safe!

Some very smart friends of mine have created a rather neat device called EnCloak. It looks and acts just like a normal USB drive, but it can encrypt and decrypt files in cunning ways as you save and retrieve them.

“So what?”, you may say, “There are lots of encrypted storage devices on the market.”

Yes, but this one has some particularly smart attributes, most notably that the hardware just uses standard USB file storage operations, so you don’t need any software or drivers on the machine to make use of it. And if you drop it in the car park and somebody picks it up and plugs it in, they’ll just see a small standard flash drive and won’t even know there are also secret files on it without having the appropriate credentials, let alone be able to read them.

Need to take those super-secret exam questions to the publishing company without wanting to trust any intervening networks? Or keep a backup copy of the things you normally store in your password manager, which you could get at anywhere in future without access to that bit of software? This might be the thing for you.

There are lots of other ways to get encrypted data from place to place, so you may not need this. But hey, the printing company may not know about your GPG keys, and the examination board may not want to install your decryption software, and you know the Feds will get at anything you have in the cloud. If they don’t, Facebook will. Besides, gadgets are fun!

Anyway, they’ve been working on this for quite a while; and I saw an early prototype over two years ago, so I can vouch that it worked even back then. Now they’ve just launched a Kickstarter project to fund the initial production run, so you can now sign up for one — either for yourself, or to get your Christmas presents sorted out nice and early for your geeky friends!

If a picture is worth a thousand words, what about an animation?

I’ve often joked that there are lies, damned lies, statistics and web statistics!

You’d have thought that when a web browser connects to a web server, you’d be able to count simple things like the number of visitors to your site with some accuracy, but it turns out to be rather complicated by caches at both ends, by search engines and other automated systems checking your site, by proxies and firewalls and VPNs and pre-loading and… well, you get the idea.

And it can get more difficult when you try to make generalisations about the web as a whole. Take the question of which web browser is the most popular. The browser generally tells the server, so you can come up with some numbers. But which servers’ numbers should you use? Those visited mostly by teenagers? By tech enthusiasts? By business people, or by mobile users? You’ll get very different numbers.

I use Safari for most things, and at the time of writing, these summary tables on Wikipedia will tell you that it has a share of about 3%, if you’re looking at desktop browsers as reported by NetMarketShare, somewhere around 40% if you’re looking at tablet-based browsers reported by StatCounter, and between 14% and 24% if you’re looking at browser usage overall, depending on whom you believe. So this figure is one to be taken with an even bigger pinch of salt than most.

Having said all that…

I do like this animation of web browser usage stats by James Eagle. For young people, it’s a history lesson, and for those of us who have lived through it and been intimately involved with it, this simple graphic encapsulates three decades of development and progress, of nostalgia and relief, of corporate battles and legal battles, of innovation and frustration, and of careers and companies born, thriving and expiring. Nicely done.

Here’s a link to James’s original tweet.


Looking back

Ah, nostalgia! I’ve been looking back at the first messages I sent right back in 2004 using the latest hot new web phenomenon: a beta version of the recently-announced GMail. (I had a friend who had a friend in Google, so got an invitation fairly early.)

They are mostly examples of literary brilliance such as:

Subject: Quick Test of Gmail

Let’s see how it works.

But later that day I had settled down a bit. Here’s an extract from a message I sent to John:

It’s a very nice webmail system, with an unusual amount of storage available per person (1G).
My concerns with the current beta are:

(a) I have 0.7G of email already on other systems, so it wouldn’t be a complete solution for long, and

(b) it really is, at present, just a webmail system. It’s the nicest one I’ve used, but it has no IMAP or other access, and hence no way to export your email. Meaning that messages in Gmail can never be moved to another system. (Though there are some scripts out there which connect, parse the web pages etc)

I imagine they’ll have to add this in some form before too long, but I’m also sure they don’t want to make it too easy. In particular, they probably want to keep the browser as the main interface so they can control advertising around the email.

Back then, a free email account was pretty rare, and a free e-mail account that gave you a whole gigabyte of storage was amazing!

In the intervening 18 years, I’ve never used my Gmail address as my main account, but it has been handy as a backup. I forwarded copies of incoming messages there from my main account, for example, until I realised it was probably foolish: I was giving Google access to all of my life history without even making use of the free email service in return! But I am a big fan of some of the other Google services, and a heavy user of YouTube, Google Maps, and to a lesser extent Google Docs, so having a Google account has always been important. I even earn a little bit of pocket money from some of my YouTube videos.

I did like the early versions of Google Docs which actually let you edit the CSS used in rendering your document, so you could make it look just as you wanted! Sadly, that feature went away in 2010. And I’m conscious that Google products and features do have a tendency to vanish rather unexpectedly.

I expect the ones I’ve mentioned above are pretty safe, but this page is a nice reminder that the free product you depend on today may not be here tomorrow. 2022 is the tenth anniversary of the demise of Google Video, for example, and this blog used to have quite a few links to content there. That was probably pretty safe, wasn’t it? It had been around for seven years, after all! My golden rule about making sure you can get your data out of any system in a useful form, before putting too much of it in, is particularly applicable to Google products.

There’s no such thing as a free inbox

Anyway, the good news is that my Gmail messages are still around, and Google now give you 15x as much storage for free as they used to, but that’s not enough for the amount of old email I’ve been storing there. I’ve been paying a modest amount for Google One storage for the last couple of years, and that’s no bad thing: for a service to be sustainable, its true costs do need to be met somehow. Buy my subscription has just come up for renewal, and since I already pay for cloud storage in a couple of other places that don’t also use my data for other purposes, I’ve decided to thin down the amount of stuff I’ve been keeping on Gmail. My account isn’t going away, but it’ll just be a temporary space; all the important stuff will be sent elsewhere.

The good news is that Gmail did introduce support for IMAP a few years after my early messages, so moving my 17GB of Gmail messages over to join the 24GB in my main account is much more straightforward than it would otherwise have been! (There will be a lot of duplicates, and if you’re doing anything similar and are happy on the command line, you might find my IMAPdedup script useful to get rid of them.)

Lastly, even though I recognise and appreciate the innovation and usefulness of some of them, I’m very glad that I didn’t invest any serious time in any Gmail-specific features!
You may have seen my article a few months ago about why I, and a significant number of my colleagues, will no longer keep important data in our Cambridge University email accounts, for similar reasons.

Anyway, I’m trying to develop Quentin’s Golden Rules of Data Storage. Here’s an early draft of the first two:

  • The more important your data, the more open its storage format should be.

  • The amount of data you put into any proprietary system should be proportional to the ease of extracting it in a usable non-proprietary form.

P.S. You can use these nuggets of wisdom for free at the moment, but I don’t have a sustainable business model for them yet, so I may need to charge you gradually-increasing amounts for them in the future.

A Good Breeze

We had fun on Rutland Water on Friday.

Fixing the NHS problem

My parents live about 13 minutes’ drive from the nearest hospital. There’s also a more substantial one 20 mins away. Over the last few years, they have on several occasions needed to call an ambulance after falls and other serious issues, and the waiting time is always measured in hours; on a couple of occasions, more than eight hours.

This shocks me, but it shocks my American wife even more. When they had to call an ambulance for her mother in Michigan — a fairly regular occurrence in her later life — they would worry that something was wrong if it hadn’t arrived in twenty minutes, because normally it was there in about ten. For all the outrageous costs and several other failings of the American health system, there are some things it does do rather well.

The simplistic public response to the NHS problem is to blame under-funding. “It’s because of Tory cuts!” Here’s a graph that was popular on Twitter last year, for example, and looks pretty damning:

But let’s be clear about what this graph shows: this is expenditure growth, above the rate of inflation. In other words, since its foundation, every government has given the NHS significantly more money in real terms every year. Some have increased it faster than others, but there have never been any ‘cuts’, from Tories or anybody else. So, while more money is desirable, that’s not the primary problem.

(As an aside, we all love the story of Captain Tom Moore who so caught the public imagination by his sponsored walks around his garden between his 99th and 100th birthday that he raised a whopping £33M for the NHS, earning him a knighthood, an honorary doctorate and an RAF flypast on his 100th birthday. It was a great feel-good story during the pandemic, and I don’t want to take anything away from his achievement by pointing out that he, and all his millions of sponsors, funded the NHS for a total of about an hour and a half. The world would be a much better place with more Captain Toms in it, but a whole battalion of Toms are unlikely to make a significant difference to the NHS.)

Now, I’ve written before about some NHS experiences that have convinced me that serious administrative incompetence is the source of many of its issues. And, to the extent that proper funding is also needed, I pointed out, it simply requires us all to vote in a government that is going to charge us about £1000 more per family member per year, and earmark that exclusively for the NHS. The UK public has only very occasionally been given the option to do something like that, even on a more modest scale, and they have never voted for it.

So I was intrigued by John Burn Murdoch’s analysis in yesterday’s FT. (The page itself is probably behind a subscriber paywall.) He provides the usual worrying statistics about A&E and ambulance waiting times, but points out:

While the pandemic has undoubtedly created a shock in the UK’s publicly funded health system, the NHS’s underlying issues are chronic. Waiting lists for elective treatment have been lengthening for 10 years, and the target of keeping 95 per cent of A&E waits under 4 hours missed for just as long.

It would be easy to blame underfunding, but in 2019 the UK spent just over 10 per cent of GDP on healthcare, placing it among other wealthy western European countries. The trend over the past two decades has also aligned with comparable nations, according to the OECD.

The key problems, he suggests, are also not simply with staff shortages:

While the number of fully qualified permanent GPs in England has fallen by 8 per cent since 2009, that of hospital doctors has grown by a third, outpacing the growth of the elderly population that accounts for an outsized portion of hospital demand. Nurse numbers continue to grow despite more departures this year.

In other words,

… ever growing resources are being used to treat ever more sick people, but ever fewer are being used to prevent them from getting sick in the first place.

The UK ranks among the highest for admissions to hospital for some conditions which would, in other countries, be largely treated within primary healthcare. (I am reminded of my wife’s surprise that GP practices in the UK don’t generally have X-Ray machines: you have to go to hospital for a check on a minor fracture!)

Anyway, the first part of his proposed solution is that we need to rethink the balance between primary care and hospital care; this is more of an issue than overall funding levels.

And the second is that it’s easy to blame staff shortages, but studies have shown that A&E delays, for example, are primarily about physical capacity — especially bed capacity — in the rest of the hospital, and are not significantly affected by staffing levels.

In summary, he says,

Much like any chronic illness, the NHS’s afflictions will not be cured with a sticking plaster. The road to recovery is paved with long-term investment to upgrade the physical capacity of the system, and to gradually shift the balance from treatment in hospitals to primary and preventive medicine.

A nicely-written article, and one of the many reasons I would pay for an FT subscription if the university wasn’t kind enough to do so for me.

Update, about six months later: There’s a very interesting page at the BMA providing an overview of current health spending in the UK and how it compares to other countries, and to the past history of the NHS.

© Copyright Quentin Stafford-Fraser