Tags: time

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Saturday, June 22nd, 2019

Apollo 11 in Real-time

What a magnificent website! You can watch, read, and listen to the entire Apollo 11 mission! Do it now, or wait until until July 16th when you can follow along in real time …time-shifted by half a century.

Monday, June 17th, 2019

First You Make the Maps

How cartography made early modern global trade possible.

Maps and legends. Beautiful!

Sunday, June 16th, 2019

BBC - Future - How to build something that lasts 10,000 years

As part of the BBC’s ongoing series on deep time, Alexander Rose describes the research he’s been doing for the clock of the long now—materials, locations, ideas …all the pieces that have historically combined to allow artifacts to survive.

Thursday, May 30th, 2019

Decimal Clock

If we had ten hours in a day, instead of 24, and if each of these hours had 100 minutes instead of 60, and if every minute had 100 seconds, our clocks would look like this…

Tuesday, May 28th, 2019

Opinion | It’s 2059, and the Rich Kids Are Still Winning - The New York Times

The New York Times is publishing science-fictional op-eds. The first one is from Ted Chiang on the Gene Equality Project forty years in our future:

White supremacist groups have claimed that its failure shows that certain races are incapable of being improved, given that many — although by no means all — of the beneficiaries of the project were people of color. Conspiracy theorists have accused the participating geneticists of malfeasance, claiming that they pursued a secret agenda to withhold genetic enhancements from the lower classes. But these explanations are unnecessary when one realizes the fundamental mistake underlying the Gene Equality Project: Cognitive enhancements are useful only when you live in a society that rewards ability, and the United States isn’t one.

Wednesday, May 8th, 2019

Timing out

Service workers are great for creating a good user experience when someone is offline. Heck, the book I wrote about service workers is literally called Going Offline.

But in some ways, the offline experience is relatively easy to handle. It’s a binary situation; either you’re online or you’re offline. What’s more challenging—and probably more common—is the situation that Jake calls Lie-Fi. That’s when technically you’ve got a network connection …but it’s a shitty connection, like one bar of mobile signal. In that situation, because there’s technically a connection, the user gets a slow frustrating experience. Whatever code you’ve got in your service worker for handling offline situations will never get triggered. When you’re handling fetch events inside a service worker, there’s no automatic time-out.

But you can make one.

That’s what I’ve done recently here on adactio.com. Before showing you what I added to my service worker script to make that happen, let me walk you through my existing strategy for handling offline situations.

Service worker strategies

Alright, so in my service worker script, I’ve got a block of code for handling requests from fetch events:

addEventListener('fetch', fetchEvent => {
        const request = fetchEvent.request;
    // Do something with this request.
});

I’ve got two strategies in my code. One is for dealing with requests for pages:

if (request.headers.get('Accept').includes('text/html')) {
    // Code for handling page requests.
}

By adding an else clause I can have a different strategy for dealing with requests for anything else—images, style sheets, scripts, and so on:

if (request.headers.get('Accept').includes('text/html')) {
    // Code for handling page requests.
} else {
    // Code for handling everthing else.
}

For page requests, I’m going to try to go the network first:

fetchEvent.respondWith(
    fetch(request)
    .then( responseFromFetch => {
        return responseFromFetch;
    })

My logic is:

When someone requests a page, try to fetch it from the network.

If that doesn’t work, we’re in an offline situation. That triggers the catch clause. That’s where I have my offline strategy: show a custom offline page that I’ve previously cached (during the install event):

.catch( fetchError => {
    return caches.match('/offline');
})

Now my logic has been expanded to this:

When someone requests a page, try to fetch it from the network, but if that doesn’t work, show a custom offline page instead.

So my overall code for dealing with requests for pages looks like this:

if (request.headers.get('Accept').includes('text/html')) {
    fetchEvent.respondWith(
        fetch(request)
        .then( responseFromFetch => {
            return responseFromFetch;
        })
        .catch( fetchError => {
            return caches.match('/offline');
        })
    );
}

Now I can fill in the else statement that handles everything else—images, style sheets, scripts, and so on. Here my strategy is different. I’m looking in my caches first, and I only fetch the file from network if the file can’t be found in any cache:

caches.match(request)
.then( responseFromCache => {
    return responseFromCache || fetch(request);
})

Here’s all that fetch-handling code put together:

addEventListener('fetch', fetchEvent => {
    const request = fetchEvent.request;
    if (request.headers.get('Accept').includes('text/html')) {
        fetchEvent.respondWith(
            fetch(request)
            .then( responseFromFetch => {
                return responseFromFetch;
            })
            .catch( fetchError => {
                return caches.match('/offline');
            })
        );
    } else {
        caches.match(request)
        .then( responseFromCache => {
            return responseFromCache || fetch(request);
        })
    }
});

Good.

Cache as you go

Now I want to introduce an extra step in the part of the code where I deal with requests for pages. Whenever I fetch a page from the network, I’m going to take the opportunity to squirrel it away in a cache. I’m calling that cache “pages”. I’m imaginative like that.

fetchEvent.respondWith(
    fetch(request)
    .then( responseFromFetch => {
        const copy = responseFromFetch.clone();
        try {
            fetchEvent.waitUntil(
                caches.open('pages')
                .then( pagesCache => {
                    return pagesCache.put(request, copy);
                })
            )
        } catch(error) {
            console.error(error);
        }
        return responseFromFetch;
    })

You’ll notice that I can’t put the response itself (responseFromCache) into the cache. That’s a stream that I only get to use once. Instead I need to make a copy:

const copy = responseFromFetch.clone();

That’s what gets put in the pages cache:

fetchEvent.waitUntil(
    caches.open('pages')
    .then( pagesCache => {
        return pagesCache.put(request, copy);
    })
)

Now my logic for page requests has an extra piece to it:

When someone requests a page, try to fetch it from the network and store a copy in a cache, but if that doesn’t work, show a custom offline page instead.

Here’s my updated fetch-handling code:

addEventListener('fetch', fetchEvent => {
    const request = fetchEvent.request;
    if (request.headers.get('Accept').includes('text/html')) {
        fetchEvent.respondWith(
            fetch(request)
            .then( responseFromFetch => {
                const copy = responseFromFetch.clone();
                try {
                    fetchEvent.waitUntil(
                        caches.open('pages')
                        .then( pagesCache => {
                            return pagesCache.put(request, copy);
                        })
                    )
                } catch(error) {
                    console.error(error);
                }
                return responseFromFetch;
            })
            .catch( fetchError => {
                return caches.match('/offline');
            })
        );
    } else {
        caches.match(request)
        .then( responseFromCache => {
            return responseFromCache || fetch(request);
        })
    }
});

I call this the cache-as-you-go pattern. The more pages someone views on my site, the more pages they’ll have cached.

Now that there’s an ever-growing cache of previously visited pages, I can update my offline fallback. Currently, I reach straight for the custom offline page:

.catch( fetchError => {
    return caches.match('/offline');
})

But now I can try looking for a cached copy of the requested page first:

.catch( fetchError => {
    caches.match(request)
    .then( responseFromCache => {
        return responseFromCache || caches.match('/offline');
    })
});

Now my offline logic is expanded:

When someone requests a page, try to fetch it from the network and store a copy in a cache, but if that doesn’t work, first look for an existing copy in a cache, and otherwise show a custom offline page instead.

I can also access this ever-growing cache of pages from my custom offline page to show people which pages they can revisit, even if there’s no internet connection.

So far, so good. Everything I’ve outlined so far is a good robust strategy for handling offline situations. Now I’m going to deal with the lie-fi situation, and it’s that cache-as-you-go strategy that sets me up nicely.

Timing out

I want to throw this addition into my logic:

When someone requests a page, try to fetch it from the network and store a copy in a cache, but if that doesn’t work, first look for an existing copy in a cache, and otherwise show a custom offline page instead (but if the request is taking too long, try to show a cached version of the page).

The first thing I’m going to do is rewrite my code a bit. If the fetch event is for a page, I’m going to respond with a promise:

if (request.headers.get('Accept').includes('text/html')) {
    fetchEvent.respondWith(
        new Promise( resolveWithResponse => {
            // Code for handling page requests.
        })
    );
}

Promises are kind of weird things to get your head around. They’re tailor-made for doing things asynchronously. You can set up two parameters; a success condition and a failure condition. If the success condition is executed, then we say the promise has resolved. If the failure condition is executed, then the promise rejects.

In my re-written code, I’m calling the success condition resolveWithResponse (and I haven’t bothered with a failure condition, tsk, tsk). I’m going to use resolveWithResponse in my promise everywhere that I used to have a return statement:

addEventListener('fetch', fetchEvent => {
    const request = fetchEvent.request;
    if (request.headers.get('Accept').includes('text/html')) {
        fetchEvent.respondWith(
            new Promise( resolveWithResponse => {
                fetch(request)
                .then( responseFromFetch => {
                    const copy = responseFromFetch.clone();
                    try {
                        fetchEvent.waitUntil(
                            caches.open('pages')
                            then( pagesCache => {
                                return pagesCache.put(request, copy);
                            })
                        )
                    } catch(error) {
                        console.error(error);
                    }
                    resolveWithResponse(responseFromFetch);
                })
                .catch( fetchError => {
                    caches.match(request)
                    .then( responseFromCache => {
                        resolveWithResponse(
                            responseFromCache || caches.match('/offline')
                        );
                    })
                })
            })
        );
    } else {
        caches.match(request)
        .then( responseFromCache => {
            return responseFromCache || fetch(request);
        })
    }
});

By itself, rewriting my code as a promise doesn’t change anything. Everything’s working the same as it did before. But now I can introduce the time-out logic. I’m going to put this inside my promise:

const timer = setTimeout( () => {
    caches.match(request)
    .then( responseFromCache => {
        if (responseFromCache) {
            resolveWithResponse(responseFromCache);
        }
    })
}, 3000);

If a request takes three seconds (3000 milliseconds), then that code will execute. At that point, the promise attempts to resolve with a response from the cache instead of waiting for the network. If there is a cached response, that’s what the user now gets. If there isn’t, then the wait continues for the network.

The last thing left for me to do is cancel the countdown to timing out if a network response does return within three seconds. So I put this in the then clause that’s triggered by a successful network response:

clearTimeout(timer);

I also add the clearTimeout statement to the catch clause that handles offline situations. Here’s the final code:

addEventListener('fetch', fetchEvent => {
    const request = fetchEvent.request;
    if (request.headers.get('Accept').includes('text/html')) {
        fetchEvent.respondWith(
            new Promise( resolveWithResponse => {
                const timer = setTimeout( () => {
                    caches.match(request)
                    .then( responseFromCache => {
                        if (responseFromCache) {
                            resolveWithResponse(responseFromCache);
                        }
                    })
                }, 3000);
                fetch(request)
                .then( responseFromFetch => {
                    clearTimeout(timer);
                    const copy = responseFromFetch.clone();
                    try {
                        fetchEvent.waitUntil(
                            caches.open('pages')
                            then( pagesCache => {
                                return pagesCache.put(request, copy);
                            })
                        )
                    } catch(error) {
                        console.error(error);
                    }
                    resolveWithResponse(responseFromFetch);
                })
                .catch( fetchError => {
                    clearTimeout(timer);
                    caches.match(request)
                    .then( responseFromCache => {
                        resolveWithResponse(
                            responseFromCache || caches.match('/offline')
                        );
                    })
                })
            })
        );
    } else {
        caches.match(request)
        .then( responseFromCache => {
            return responseFromCache || fetch(request)
        })
    }
});

That’s the JavaScript translation of this logic:

When someone requests a page, try to fetch it from the network and store a copy in a cache, but if that doesn’t work, first look for an existing copy in a cache, and otherwise show a custom offline page instead (but if the request is taking too long, try to show a cached version of the page).

For everything else, try finding a cached version first, otherwise fetch it from the network.

Pros and cons

As with all service worker enhancements to a website, this strategy will do absolutely nothing for first-time visitors. If you’ve never visited my site before, you’ve got nothing cached. But the more you return to the site, the more your cache is primed for speedy retrieval.

I think that serving up a cached copy of a page when the network connection is flaky is a pretty good strategy …most of the time. If we’re talking about a blog post on this site, then sure, there won’t be much that the reader is missing out on—a fixed typo or ten; maybe some additional webmentions at the end of a post. But if we’re talking about the home page, then a reader with a flaky network connection might think there’s nothing new to read when they’re served up a stale version.

What I’d really like is some way to know—on the client side—whether or not the currently-loaded page came from a cache or from a network. Then I could add some kind of interface element that says, “Hey, this page might be stale—click here if you want to check for a fresher version.” I’d also need some way in the service worker to identify any requests originating from that interface element and make sure they always go out to the network.

I think that should be doable somehow. If you can think of a way to do it, please share it. Write a blog post and send me the link.

But even without the option to over-ride the time-out, I’m glad that I’m at least doing something to handle the lie-fi situation. Perhaps I should write a sequel to Going Offline called Still Online But Only In Theory Because The Connection Sucks.

Monday, March 25th, 2019

WWW:BTB — History (Overview)

This history of the World Wide Web from 1996 is interesting for the way it culminates with …Java. At that time, the language seemed like it would become the programmatic lingua franca for the web. Brendan Eich sure upset that apple cart.

Thursday, February 28th, 2019

A Briefer History of Time

You can read all of Stephen Hawking’s 2008 book online as a web book (kind of like Resilient Web Design).

Sunday, February 17th, 2019

Timelines of the web

Recreating the original WorldWideWeb browser was an exercise in digital archeology. With a working NeXT machine in the room, Kimberly was able to examine the source code for the first every browser and discover a treasure trove within. Like this gem in HTUtils.h:

#define TCP_PORT 80 /* Allocated to http by Jon Postel/ISI 24-Jan-92 */

Sure enough, by June of 1992 port 80 was documented as being officially assigned to the World Wide Web (Gopher got port 70). Jean-François Groff—who worked on the World Wide Web project with Tim Berners-Lee—told us that this was a moment they were very pleased about. It felt like this project of theirs was going places.

Jean-François also told us that the WorldWideWeb browser/editor was kind of like an advanced prototype. The idea was to get something up and running as quickly as possible. Well, the NeXT operating system had a very robust Text Object, so the path of least resistance for Tim Berners-Lee was to take the existing word-processing software and build a hypertext component on top of it. Likewise, instead of creating a brand new format, he used the existing SGML format and added one new piece: linking with A tags.

So the WorldWideWeb application was kind of like a word processor and document viewer mashed up with hypertext. Ted Nelson complains to this day that the original sin of the web was that it borrowed this page-based metaphor. But Nelson’s Project Xanadu, originally proposed in 1974 wouldn’t become a working reality until 2014—a gap of forty years. Whereas Tim Berners-Lee proposed his system in March 1989 and had working code within a year. There’s something to be said for being pragmatic and working with what you’ve got.

The web was also a mashup of ideas. Hypertext existed long before the web—Ted Nelson coined the term in 1963. There were conferences and academic discussions devoted to hypertext and hypermedia. But almost all the existing hypertext systems—including Tim Berners-Lee’s own ENQUIRE system from the early 80s—were confined to a local machine. Meanwhile networked computers were changing everything. First there was the ARPANET, then the internet. Tim Berners-Lee’s ambitious plan was to mash up hypertext with networks.

Going into our recreation of WorldWideWeb at CERN, I knew I wanted to convey this historical context somehow.

The World Wide Web officially celebrates its 30th birthday in March of this year. It’s kind of an arbitrary date: it’s the anniversary of the publication of Information Management: A Proposal. Perhaps a more accurate date would be the day the first website—and first web server—went online. But still. Let’s roll with this date of March 12, 1989. I thought it would be interesting not only to look at what’s happened between 1989 and 2019, but also to look at what happened between 1959 and 1989.

So now I’ve got two time cones that converge in the middle: 1959 – 1989 and 1989 – 2019. For the first time period, I made categories of influences: formats, hypertext, networks, and computing. For the second time period, I catalogued notable results: browsers, servers, and the evolution of HTML.

I did a little bit of sketching and quickly realised that these converging timelines could be represented somewhat like particle collisions. Once I had that idea in my head, I knew how I would be spending my time during the hack week.

Rather than jumping straight into the collider visualisation, I took some time to make a solid foundation to build on. I wanted to be sure that the timeline itself would be understable even if it were, say, viewed in the first ever web browser.

Progressive enhancement. Marking up (and styling) an interactive timeline that looks good in a modern browser and still works in the first ever web browser.

I marked up each timeline as an ordered list of h-events:

<li class="h-event y1968">
  <a href="https://en.wikipedia.org/wiki/NLS_%28computer_system%29" class="u-url">
    <time class="dt-start" datetime="1968-12-09">1968</time>
    <abbr class="p-name" title="oN-Line System">NLS</abbr>
  </a>
</li>

With the markup in place, I could concentrate on making it look halfway decent. For small screens, the layout is very basic—just a series of lists. When the screen gets wide enough, I lay those lists out horzontally one on top of the other. In this view, you can more easily see when events coincide. For example, ENQUIRE, Usenet, and Smalltalk all happen in 1980. But the real beauty comes when the screen is wide enough to display everthing at once. You can see how an explosion of activity in the early 90s. In 1994 alone, we get the release of Netscape Navigator, the creation of HTTPS, and the launch of Amazon.com.

The whole thing is powered by CSS transforms and positioning. Each year on a timeline has its own class that gets moved to the correct chronological point using calc(). I wanted to use translateX() but I couldn’t get the maths to work for that, so I had use plain ol’ left and right:

.y1968 {
  left: calc((1968 - 1959) * (100%/30) - 5em);
}

For events before 1989, it’s the distance of the event from 1959. For events after 1989, it’s the distance of the event from 2019:

.y2014 {
  right: calc((2019 - 2014) * (100%/30) - 5em);
}

(Each h-event has a width of 5em so that’s where the extra bit at the end comes from.)

I had to do some tweaking for legibility: bunches of events happening around the same time period needed to be separated out so that they didn’t overlap too much.

As a finishing touch, I added a few little transitions when the page loaded so that the timeline fans out from its centre point.

Et voilà!

Progressive enhancement. Marking up (and styling) an interactive timeline that looks good in a modern browser and still works in the first ever web browser.

I fiddled with the content a bit after peppering Robert Cailliau with questions over lunch. And I got some very valuable feedback from Jean-François. Some examples he provided:

1971: Unix man pages, one of the first instances of writing documents with a markup language that is interpreted live by a parser before being presented to the user.

1980: Usenet News, because it was THE everyday discussion medium by the time we created the web technology, and the Web first embraced news as a built-in information resource, then various platforms built on the web rendered it obsolete.

1982: Literary Machines, Ted Nelson’s book which was on our desk at all times

I really, really enjoyed building this “collider” timeline. It was a chance for me to smash together my excitement for web history with my enjoyment of using the raw materials of the web; HTML and CSS in this case.

The timeline pales in comparison to the achievement of the rest of the team in recreating the WorldWideWeb application but I was just glad to be able to contribute a little something to the project.

Hello WorldWideWeb.

Is the universe pro-life? The Fermi paradox can help explain — Quartz

Living things are just a better way for nature to dissipate energy and increase the universe’s entropy.

No anthropocentric exceptionalism here; just the laws of thermodynamics.

According to the inevitable life theory, biological systems spontaneously emerge because they more efficiently disperse, or “dissipate” energy, thereby increasing the entropy of the surroundings. In other words, life is thermodynamically favorable.

As a consequence of this fact, something that seems almost magical happens, but there is nothing supernatural about it. When an inanimate system of particles, like a group of atoms, is bombarded with flowing energy (such as concentrated currents of electricity or heat), that system will often self-organize into a more complex configuration—specifically an arrangement that allows the system to more efficiently dissipate the incoming energy, converting it into entropy.

Sunday, January 27th, 2019

10 Year Challenge: How Popular Websites Have Changed

Side by side screenshots of websites, taken ten years apart. The whitespace situation has definitely improved. It would be interesting to compare what the overall page weights were/are though.

Tuesday, January 1st, 2019

Sunday, December 30th, 2018

Very Slow Movie Player on Vimeo

I love this use of e-ink to play a film at 24 frames per day instead of 24 frames per minute.

Wednesday, December 12th, 2018

Is Tech Too Easy to Use? - The New York Times

Seams!

Of all the buzzwords in tech, perhaps none has been deployed with as much philosophical conviction as “frictionless.” Over the past decade or so, eliminating “friction” — the name given to any quality that makes a product more difficult or time-consuming to use — has become an obsession of the tech industry, accepted as gospel by many of the world’s largest companies.

Sunday, December 2nd, 2018

One Time File

Drag and drop a file up to 400MB and share the URL without a log-in (the URLs are using What Three Words).

Friday, November 23rd, 2018

Home - Memory of Mankind

A time capsule for the long now. Laser-etched ceramic tablets in an Austrian salt mine carry memories of our civilisation in three categories: news editorials, scientific works, and personal stories.

You can contribute a personal story, your favorite poem, or newspaper articles which describe our problems, visions or our daily life.

Tokens that mark the location of the site are also being distributed across the planet.

Tuesday, November 13th, 2018

Tweeting for 10,000 Years: An Experiment in Autonomous Software — Brandur Leach

Taking the idea of the Clock of the Long Now and applying it to a twitterbot:

Software may not be as well suited as a finely engineered clock to operate on these sorts of geological scales, but that doesn’t mean we can’t try to put some of the 10,000 year clock’s design principles to work.

The bot will almost certainly fall foul of Twitter’s API changes long before the next tweet-chime is due, but it’s still fascinating to see the clock’s principles applied to software: longevity, maintainability, transparency, evolvability, and scalability.

Software tends to stay in operation longer than we think it will when we first wrote it, and the wearing effects of entropy within it and its ecosystem often take their toll more quickly and more destructively than we could imagine. You don’t need to be thinking on a scale of 10,000 years to make applying these principles a good idea.

Saturday, November 10th, 2018

CSS Frameworks Or CSS Grid: What Should I Use For My Project? — Smashing Magazine

Rachel does some research to find out why people use CSS frameworks like Bootstrap—it can’t just be about grids, right?

It turns out there are plenty of reasons that people give for using frameworks—whether it’s CSS or JavaScript—but Rachel shares some of my misgivings on this:

In our race to get our site built quickly, our desire to make things as good as possible for ourselves as the designers and developers of the site, do we forget who we are doing this for? Do the decisions made by the framework developer match up with the needs of the users of the site you are building?

Not for the first time, I’m reminded of Rachel’s excellent post from a few years ago: Stop solving problems you don’t yet have.

Tuesday, October 2nd, 2018

Countdown Timer – Track your launch or deadline

Cameron made this nifty single-serving site that does one thing—counts down to an important date.