Showing posts with label social media. Show all posts
Showing posts with label social media. Show all posts

Friday, September 21, 2012

More ESRI and Twitter

A while ago I posted about a map from esri.com that incorporated social media such as Twitter with more traditional sources of fire information.  My conclusion was that the social data was not that helpful.

ESRI has just put out another set of maps, this time on acceptance same-sex marriage.  The first map uses a proprietary demographic model to try to rate how likely a given county is to favor same-sex marriage.  As far as I can tell, this model isn't particularly based on, say, polling data or election results from ballot measures, but more on factors like how urban or rural the county is, how many people have gone to college and so forth.

The second map shows state laws.  It corresponds roughly with the first map.  With the interesting exception of Iowa, the first map shows significant support where same-sex marriage is legal, as one would expect.

The third map is based on Twitter data.  It says there is strong support for same-sex marriage across the country, opposition in five states (including Minnesota, despite significant support in the populous Twin Cities), and very strong opposition in exactly one state: North Carolina.  Idaho, Wyoming and Vermont had insufficient data.

The support map shows North Carolina as fairly similar to neighboring Virginia, which the Twitter data shows as strongly supportive, and as more supportive than neighboring South Carolina and Tennessee. The Twitter data show both of those states as moderately supportive.

Clearly something is out of line here.  Two possible explanations:
  • Concerning the overall map, the Twitterverse is not a representative sample.  Overall, Twitter traffic is much more supportive of same-sex marriage than the country as a whole.  This probably shouldn't come as a surprise.
  • Concerning North Carolina, the Twitter data covers May 9 through June 30, 2012.  As the map explanation notes, North Carolina had voted on May 8 against a proposition supporting same-sex marriage, by a roughly 60-40 margin after a very intense campaign.  It would be interesting to know what portion of the Twitter traffic surveyed is from the immediate aftermath of that election.  My guess would be a large portion.
Along with the fire map I mentioned above and a study on Twitter rumors after the London riots, which was presented in the Guardian as confirming the notion that Twitter is a good, self-correcting source of information but in fact shows anything but, this is the third piece of evidence I've run across suggesting that you should treat any inferences drawn from Twitter traffic with a grain of salt.

Twitter may well be a great way to find out what people, at least those with Twitter accounts, are paying attention to at the moment, but it's risky, to say the least, to draw conclusions about objective facts from that.

Friday, September 7, 2012

Curiosity online

The Curiosity rover, formally the Mars Science Laboratory, landed on Mars late on August 5th (or early on the 6th, depending on your time zone).

This was a major accomplishment.  Mars has a habit of eating space probes.  The majority have failed, sometimes quietly and sometimes spectacularly, at least once due to the kind of basic coding error that would send a regular geek cursing back to the keyboard.  Except when it comes to interplanetary travel there's generally no "next release".

The Curiosity landing was more complex than any Mars landing before it, and parts of it had never been realistically tested, much less the overall sequence.  This was not out of negligence or cut corners but a simple necessity.  Mars's atmosphere is much, much thinner than Earth's.  At its thickest it's equivalent to Earth's atmosphere at about 35 kilometers (about 20 miles, or about four times as high as the summit of Mount Everest).  Mars's gravity is about 40% of Earth's.  There's simply no practical way to re-create those conditions at the necessary scale anywhere near Earth.

This thin atmosphere is a real problem.  There's just enough of it you can't ignore it, but not enough for a parachute to take the lander all the way to the surface safely.  To land Curiosity, which is considerably larger and more massive than the Spirit and Opportunity rovers before it, NASA put together a landing sequence that Rube Goldberg might have appreciated:
  • The probe slams into the atmosphere, protected by a heat shield and pulling upwards of 10g of deceleration, possibly as high as 15g (This is from NASA's press kit from before the landing.  I don't know what the actual numbers were, but clearly it's not going to work with humans aboard.)
  • Once the the probe has slowed enough not to need the heat shield, the heat shield is jettisoned.
  • The probe then deploys a parachute, which slows it to about 300 km/h (about 180 mph).
  • The parachute is then jettisoned and a rocket-powered descent stage takes over, carefully avoiding the parachute and the back shell it's attached to.  If the rockets don't work, the probe will hit the surface, hard, in about 20 more seconds.
  • The descent stage lowers the rover on nylon cords while it slowly descends, since landing completely under rocket power risks kicking up enough dust to damage the rover.
  • While the descent stage is doing this, the rover gets its landing gear into place.
  • When the rover is safely on the ground, the cords are cut loose, using explosives, and the descent stage flies off to crash land some distance away.
What could possibly go wrong?  Mind, this is a simplified description (and any inaccuracies are mine).  The full details include several more maneuvers, through six different configurations in all, with 76 pyrotechnic devices, ballast jettisoned at various points and dozens of people sweating bullets in the control room and elsewhere.

"Seven minutes of terror", they called it.  Damn impressive engineering, I call it.


OK, so now that we've paused to admire NASA/JPL's chops, what does this have to do with the web? 

I'm old enough to sorta kinda remember Apollo and grainy black-and-white TV coverage.  And Tang.  Cool, and, it must be said, more culturally significant than today's missions, but technically not even close to what we have today.  This is true not only of the vehicle itself, but of the communications technology.  In the 70s we had grainy black-and-white video.  For better imagery you had to wait for the astronauts to bring back the film.

Now, using essentially the same technology as a cell phone camera, NASA is able to capture digital images and put them up on its web site for the world to see immediately (as many have pointed out, much more quickly than NBC saw fit to broadcast Olympic events).  The web gallery includes not only the pretty press-release pictures but also the raw frames they were made from, including pictures of Curiosity staring at its feet and other such that didn't make the cut.  There are plenty of other goodies as well.  I particularly like the "white-balanced" images, which have been post-processed to show what the same terrain would look like under sunlight on Earth.

And there are, of course, a Twitter hashtag (#MSL) and (obligatory plug) updates on NASA's Google Plus page.

As inspiring as it may have been to watch thrilling news coverage with Walter Cronkite narrating, there's something much more intimate about being able to visit a web site from time to time and watch the story unfold directly from the source.

Wednesday, June 27, 2012

Where's the fire?

It's been a busy fire season in the Southwest, with hot, dry weather and an abundance of fuel.  While I'm generally skeptical about the world-changing potential of social media (ultimately, of the idea that a new technology is necessarily likely to have a great impact), that doesn't mean social media can't play a role.

One example is this fire map from esri (makers of geographic information systems (GIS) software).  Along with official data such as wind information from NOAA and fire perimeters from USGS, it includes layers for Flickr, Twitter, and YouTube activity.  The YouTube feature for some reason got stuck on the same video until I reloaded the page, at which point it worked fine.

The Twitter layer seems to be tagged by the location of the person tweeting.  For example, someone in Fort Collins tweeting a Denver Post story about the Waldo Canyon fire over a hundred miles away is shown in Fort Collins, not where the fire is.  To be fair, it's a lot easier to locate the person tweeting than to figure out from the contents of the tweet that it's really about something somewhere else.

All in all, esri's map seems useful to me mostly for the official information.  The social layer is interesting, but by no means essential.  Searching for "Colorado fire" on Twitter search turns up many more tweets, at least as relevant as those from the map.  Likewise for a YouTube search.  Neither of these searches directly maps the location of the footage, but this doesn't seem like a great obstacle.  Wildfires are quickly given distinctive names ("High Park fire", "Waldo Canyon fire") and you can easily search on those.

And of course wildfires would quickly be given distinctive names.  People need to tell them apart.  If I live in Colorado Springs, I don't care much about the High Park fire, but I care a lot about the Waldo Canyon fire.  As a side effect, it's easy to search for information about a given fire without consulting a map.

And what does such a search find?  Among other things, quite a few links to, and videos from, local newspapers and TV stations.

In short, what does a social-media-enhanced map and search space look like?  A fair bit like one without social media, at least in the context of events with wide interest where there are well-developed traditional media sources.

But broadcasting was never really supposed to be the strong point of social media anyway.