Don't fear Facebook, pity it. It's a datavore with no data

Facebook can draw inferences from your likes. But who has any likes anymore?

Our very own Helen Lewis has a piece in today's Guardian where she throws cold water on the fears that Facebook's users were giving away more than they meant to by liking pages. She writes:

Dig a little deeper and some of this soul-scrying voodoo becomes slightly less terrifying. One of the TV-show likes that's a predictor of female homosexuality is The L Word – a drama about lesbians. Two of the pages associated with being a gay man are Wicked the Musical (no comment) and the No H8 campaign, which advocates equal marriage. I'm sure you could guess my gender from my self-declared love of Jane Austen and the history of fashion on Facebook. Or you could just look at my name.

But there's a bigger reason why we oughtn't be that concerned: who the hell clicks "like" anymore?

Facebook is designed to be used in a way that corresponds with the actual use patterns of fewer and fewer of its members. Even "active users"—its new preferred metric, since the total number of registered users is now limited by the population of the earth—may not be active the way it likes us to be.

The perfect Facebook user checks in whenever they go somewhere; they like the pages of all their favourite bands, movies, TV shows, and even their dentist; they tell Facebook where they work and went to school; they visit other sites through apps on Facebook; and they never, ever change their privacy settings from the default.

Does that describe you? Does that describe anyone?

The fact is that for an increasing number of people Facebook is basically a glorified webmail service. There's still a lot of money to be made in that—targeted ads served against keywords culled from your messages and events is the reason why Google runs Gmail, for instance—but not enough to justify Facebook's market cap, and certainly not as much as Mark Zuckerberg would like.

The company's been big at giving users new ways to get data out of Facebook, such as redesigning its news feed and introducing Graph Search; but it has yet to touch on any changes which would make people more likely to put data in. As Buzzfeed's John Herrman writes, Facebook "is demanding more and more of a graph that is able to provide less and less."

The real problem we all face isn't that the information we put out on the internet might be used against us. Despite looking like it was going to be ubiquitous, the fad for documenting every aspect of one's life is dying off. Foursquare has pivoted to be about providing data, rather than encouraging check-ins; Instagram, which provides ephemeral, context-free images, was poised to overtake Facebook as the leading photo service on line (until it became Facebook); and when was the last time you "liked" something?

We don't have to worry about what we put out on purpose; the problem is what we put out without knowing. It's not scary if Facebook can tell you're gay because you choose to like certain pages; it's more concerning that Google can tell your age because of your search habits; and it's downright worrying that Target can find out a teenage girl is pregnant before her own father based on what she buys.

If you choose what data to share, you are probably not too concerned about the inferences that can be drawn from it. But very little of what we share is done voluntarily these days; and as Facebook struggles to get us to give it the information it wants, they too may start taking it from us without asking. That's when it gets more concerning, because that's when it gets harder to fight.

Photograph: Getty Images.

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

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Inside Big Ben: why the world’s most famous clock will soon lose its bong

Every now and then, even the most famous of clocks need a bit of care.

London is soon going to lose one of its most familiar sounds when the world-famous Big Ben falls silent for repairs. The “bonging” chimes that have marked the passing of time for Londoners since 1859 will fall silent for months beginning in 2017 as part of a three-year £29m conservation project.

Of course, “Big Ben” is the nickname of the Great Bell and the bell itself is not in bad shape – even though it does have a huge crack in it.

The bell weighs nearly 14 tonnes and it cracked in 1859 when it was first bonged with a hammer that was way too heavy.

The crack was never repaired. Instead the bell was rotated one eighth of a turn and a lighter (200kg) hammer was installed. The cracked bell has a characteristic sound which we have all grown to love.

Big Ben strikes. UK Parliament.

Instead, it is the Elizabeth Tower (1859) and the clock mechanism (1854), designed by Denison and Airy, that need attention.

Any building or machine needs regular maintenance – we paint our doors and windows when they need it and we repair or replace our cars quite routinely. It is convenient to choose a day when we’re out of the house to paint the doors, or when we don’t need the car to repair the brakes. But a clock just doesn’t stop – especially not a clock as iconic as the Great Clock at the Palace of Westminster.

Repairs to the tower are long overdue. There is corrosion damage to the cast iron roof and to the belfry structure which keeps the bells in place. There is water damage to the masonry and condensation problems will be addressed, too. There are plumbing and electrical works to be done for a lift to be installed in one of the ventilation shafts, toilet facilities and the fitting of low-energy lighting.

Marvel of engineering

The clock mechanism itself is remarkable. In its 162-year history it has only had one major breakdown. In 1976 the speed regulator for the chimes broke and the mechanism sped up to destruction. The resulting damage took months to repair.

The weights that drive the clock are, like the bells and hammers, unimaginably huge. The “drive train” that keeps the pendulum swinging and that turns the hands is driven by a weight of about 100kg. Two other weights that ring the bells are each over a tonne. If any of these weights falls out of control (as in the 1976 incident), they could do a lot of damage.

The pendulum suspension spring is especially critical because it holds up the huge pendulum bob which weighs 321kg. The swinging pendulum releases the “escapement” every two seconds which then turns the hands on the clock’s four faces. If you look very closely, you will see that the minute hand doesn’t move smoothly but it sits still most of the time, only moving on each tick by 1.5cm.

The pendulum swings back and forth 21,600 times a day. That’s nearly 8m times a year, bending the pendulum spring. Like any metal, it has the potential to suffer from fatigue. The pendulum needs to be lifted out of the clock so that the spring can be closely inspected.

The clock derives its remarkable accuracy in part from the temperature compensation which is built into the construction of the pendulum. This was yet another of John Harrison’s genius ideas (you probably know him from longitude fame). He came up with the solution of using metals of differing temperature expansion coefficient so that the pendulum doesn’t change in length as the temperature changes with the seasons.

In the Westminster clock, the pendulum shaft is made of concentric tubes of steel and zinc. A similar construction is described for the clock in Trinity College Cambridge and near perfect temperature compensation can be achieved. But zinc is a ductile metal and the tube deforms with time under the heavy load of the 321kg pendulum bob. This “creeping” will cause the temperature compensation to jam up and become less effective.

So stopping the clock will also be a good opportunity to dismantle the pendulum completely and to check that the zinc tube is sliding freely. This in itself is a few days' work.

What makes it tick

But the truly clever bit of this clock is the escapement. All clocks have one - it’s what makes the clock tick, quite literally. Denison developed his new gravity escapement especially for the Westminster clock. It decouples the driving force of the falling weight from the periodic force that maintains the motion of the pendulum. To this day, the best tower clocks in England use the gravity escapement leading to remarkable accuracy – better even than that of your quartz crystal wrist watch.

In Denison’s gravity escapement, the “tick” is the impact of the “legs” of the escapement colliding with hardened steel seats. Each collision causes microscopic damage which, accumulated over millions of collisions per year, causes wear and tear affecting the accuracy of the clock. It is impossible to inspect the escapement without stopping the clock. Part of the maintenance proposed during this stoppage is a thorough overhaul of the escapement and the other workings of the clock.

The Westminster clock is a remarkable icon for London and for England. For more than 150 years it has reminded us of each hour, tirelessly. That’s what I love about clocks – they seem to carry on without a fuss. But every now and then even the most famous of clocks need a bit of care. After this period of pampering, “Big Ben” ought to be set for another 100 or so years of trouble-free running.

The Conversation

Hugh Hunt is a Reader in Engineering Dynamics and Vibration at the University of Cambridge.

This article was originally published on The Conversation. Read the original article.