What does Google Weigh?

I'm sure I should have better things to be doing today (namely getting two sites live) but, while reading a recent paper about a parallel programming model I got to wondering: what does google weigh?

I'm very happy to report this took about 10 seconds to work out with, yes, Google.

I think many people probably go years without discovering Google Calculator so this is perhaps a good example of how insanely useful (or useless) it can be for helping you with your maths.

Now the article in question states that Google is "searching a multi-terabyte web index for every query with an average response time of less than a quarter of a second".  But what does a terabyte weigh??

Ok.. if a 4GB iPod nano weights 1.74 ounces that means a couple of terrabytes weights around 25Kg and if Google are serving 150 million requests per day that's around 7'000 requests per second  (bear with me!)

... so even a conservative estimate of indexes in the region of 2TB that's about 44 tonnes of data per day ... if there indexes are closer to 100TB that's more like 2000 tonnes.

The paper - which is far more interesting - is here!