Who are you?  Who are you online?  Are you the same to everyone?  Should you be?

There's been a lot of talk about Google Wave as a new communications paradigm.  I like Wave.  I also think it's retro, harkening back to Nelson and Engelbart's work in the 60s.  Evolutionary rather than revolutionary, as the quote goes.  But even Wave assumes you are a single 'you'.  They need to look at handling multiple personas.

What do you do with a petabyte of data?

The question came up during a lunch today with two NASA computing people, on in IT and the other in supercomputing.  Modern satellites are returning petabytes of data, and there are many satellites.  This is far more than any human can expect to personally look at, and in fact more than they can fit into their local machine.  How do we make these huge amounts of data useful?

We can't ship it to the user's desktop-- there's no room, it'd take forever, and the user doesn't have tools that can browse massive data sets.

My kids asked me if there was enough water in the universe to quench the Sun.  I voted yes, but of course science isn't about voting, but about verifiable facts.  So now the explanation.

The Sun has a mass of around a third of a million Earths.  Stealing a figure from MadSci.org, the mass of water on the Earth is 1/4400 the total mass.  We'll say we need enough water to completely douse every atom in that fusion-burning puppy we call Sol, so we'll need... 4400 * 0.3 * a million Earths. 

This works out neatly to just over a billion Earths, to get enough water to douse the Sun.

The mystery of the solar corona may be resolved.  ScientificBlogging has covered this, as did space.com, Space Fellowship, and other sites.  Two of them couldn't resist the same money quote, too:

"Why is the sun's corona so darned hot?" said study member

James Klimchuk of NASA's Goddard Space Flight Center in Greenbelt, MD.

Why is this useful?