[freescale]

The analysis is silly. By either by car or public transport, it can easily take 45 minutes to travel from Cambridge, MA to Jamaica Plain, MA, even though they are only one mile apart. This is even more pronounced in NYC. In the urban sprawl that is the Midwest, 15 miles can easily be traversed in 45 minutes.

The analysis would have more bite if it were redone with an eye towards mapping 'temporal' density, rather than spatial density. This would better reflect the ease of meeting in person.

[nostrademons]

Cambridge and Jamaica Plain are actually more like 6 miles apart. Hell, it's a mile just to get from Harvard Square to Central Square in Cambridge.

I agree that travel time matters more than distance, though, and it'd be more interesting to see this redone in terms of "smart people per travel-minute". It only takes about 20 minutes (outside of rush hour) to get from Burlington to Needham, MA, despite them being 20 miles apart. Meanwhile, it can take 20 minutes to get from Cambridgeport to Harvard Square, despite them being about 1 mile apart.

There're similar effects in Silicon Valley - it's about 10 minutes to get from Palo Alto to Sunnyvale despite them being 7-10 miles apart, while it can be 10 minutes to get from SOMA to Market St in SF.

[enf]

If it's taking you 45 minutes to go a mile, you should be walking instead.