Egos and intensity in the search for dark matter

Voices in the dark.

In the next few weeks, the world’s most sensitive dark matter detector will begin its operations under Italy’s Gran Sasso mountain. This seems a good time to point out that it is sharing the mountain with a detector that may already have found some. What a shame, then, that what might one day be viewed as a historic result has been mired in petty name-calling.

We’ve been looking for dark matter since 1933, when the astronomer Fritz Zwicky pointed out that clusters of galaxies move in ways that seemingly defy the laws of physics. The movement made sense only if the clusters were experiencing a gravitational pull from some invisible stuff nearby.

For various reasons, mostly to do with other astronomers not liking Zwicky very much, we’ve been searching for dark matter seriously only since the 1970s. During those four decades, there has been a series of pronouncements about its discovery being only a decade away. It might now be time to take those pronouncements a little more seriously: lately, the sensitivity of detectors has been improving tenfold every two years. We must surely be on the verge of finally nailing down the existence of dark matter. If we haven’t already, that is.

Dark matter doesn’t just hold gravity clusters together – it’s everywhere. It’s right here on earth, for instance: billions of dark matter particles fly through your body every second. You won’t feel them and they won’t harm you. They don’t interact much with the stuff of our everyday reality, which is what has made them so hard to detect.

While we don’t have any concrete detections of single particles, we do seem to have a discernible signal from passing through clouds of dark matter. It was first spotted by the DAMA dark matter detector, which is based, like the new DarkSide-50 detector, deep under the mountains at Gran Sasso. The rock covering them protects the instruments from distracting sources of noise.

In 2008, DAMA’s operators announced that they had identified a signal that rose and faded with the seasons. It might have been ignored, except that this is exactly what Katherine Freese predicted for a dark matter signal in 1986. She said that the intensity of dark matter detections should depend on the time of year, because as the earth whirls round the sun and the sun moves through the Milky Way, the amount of dark matter hitting the detectors will ebb and flow. It’s rather like the difference between walking into wind-driven rain, then turning and walking the other way. In June, dark matter hits Planet Earth full in the face; in December, it’s at our back.

So, it was pretty exciting that DAMA’s detector saw this predicted pattern. It was even more exciting when another detector, CoGeNT, based in a deep underground mine in Minnesota, also saw it. It’s a shame that a third detector, Xenon, didn’t.

Xenon is also in the Gran Sasso mine and there is no love lost between the leaders of these two research efforts. CoGeNT’s Juan Collar has called Xenon’s science “pure, weapons-grade balonium”. Not content with antagonising his peers, Collar has also accused the DAMA project of “cheapening the level of our discourse to truly imbecilic levels”.

Finding dark matter is proving to be astonishingly difficult and everyone knows there’s a Nobel prize at stake, so it’s not surprising that the claws are out.

Anyway, welcome to the fray, DarkSide-50; there is definitely room for more players in this competition. Whether there is room for more egos, however, is another matter.

Inside the DarkSide-50 experiment.

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 18 February 2013 issue of the New Statesman, Iraq: ten years on

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Why Twitter is dying, in ten tweets

It's ironic that the most heated discussions of the platform's weaknesses are playing out on the platform itself. 

Twitter has been dying since 2009, and commentators have pre-emptively declared it deceased pretty much every year since. To declare that it's on the downturn has become a bit of a cliché. But that doesn't mean that it isn't also, well, true.

Grumbling among users and commentators has grown to a roar over the past few days, thanks in part to a Buzzfeed report (refuted by Jack Dorsey, Twitter's CEO) claiming the service will move away from a chronological timeline and towards an algorithmic one. Users coined the hashtag #RIPTwitter in response, and, tellingly, many of their complaints spanned beyond the apparently erroneous report. 

They join a clutch of other murmurings, bits of data and suggestions that things are not as they should be in the Twitter aviary. 

Below is one response to the threat of the new timeline, aptly showing that for lots of users, the new feed would have been the straw that broke the tweeters' backs:

Twitter first announced it was considering a new 10,000 character limit in January, but it's yet to be introduced. Reactions so far indicate that no one thinks this is a good idea, as the 140 character limit is so central to Twitter's unique appeal. Other, smaller tweaks – like an edit button – would probably sit much more easily within Twitter's current stable of features, and actually improve user experience: 

While Dorsey completely denied that the change would take place, he then followed up with an ominous suggestion that something would be changing:

"It'll be more real-time than a feed playing out in real time!" probably isn't going to placate users who think the existing feed works just fine. It may be hard to make youself heard on the current timeline, but any kind of wizardry that's going to decide what's "timely" or "live" for you is surely going to discriminate against already alienated users.

I've written before about the common complaint that Twitter is lonely for those with smaller networks. Take this man, who predicts that he'll be even more invisible in Twitter's maelstrom if an algorithm deems him irrelevant: 

What's particularly troubling about Twitter's recent actions is the growing sense that it doesn't "get" its users. This was all but confirmed by a recent string of tweets from Brandon Carpenter, a Twitter employee who tweeted this in response to speculation about new features:

...and then was surprised and shocked when he received abuse from other accounts:

This is particularly ironic because Twitter's approach (or non-approach) to troll accounts and online abusers has made it a target for protest and satire (though last year it did begin to tackle the problem). @TrustySupport, a spoof account, earned hundreds of retweets by mocking Twitter's response to abuse:

Meanwhile, users like Milo Yiannopolous, who regularly incites his followers to abuse and troll individuals (often women and trans people, and most famously as part of G*merg*te), has thrived on Twitter's model and currently enjoys the attentions of almost 160,000 followers. He has boasted about the fact that Twitter could monetise his account to pull itself out of its current financial trough:

The proof of any social media empire's decline, though, is in its number and activity of users. Earlier this month, Business Insider reported that, based on a sample of tweets, tweets per user had fallen by almost 50 per cent since last August. Here's the reporter's tweet about it:

Interestingly, numbers of new users remained roughly the same – which implies not that Twitter can't get new customers, but that it can't keep its current ones engaged and tweeting. 

Most tellingly of all, Twitter has stopped reporting these kinds of numbers publicly, which is why Jim Edwards had to rely on data taken from an API. Another publication followed up Edwards' story with reports that users aren't on the platform enough to generate ad revenue:

The missing piece of the puzzle, and perhaps the one thing keeping Twitter alive, is that its replacement hasn't (yet) surfaced. Commentators obsessed with its declining fortunes still take to Twitter to discuss them, or to share their articles claiming the platform is already dead. It's ironic that the most heated discussions of the platform's weaknesses are playing out on the platform itself. 

For all its faults, and for all they might multiply, Twitter's one advantage is that there's currently no other totally open platform where people can throw their thoughts around in plain, public view. Its greatest threat yet will come not from a new, dodgy feature, but from a new platform – one that can actually compete with it.

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.