Ancient engineers used various methods, including weighted strings, to measure surface angles.

FORBES: No. 18 The Level

The gradients seem less marked over the oceans where a lot of gravity field information has already been determined by spacecraft that measure sea-surface topography.

BBC: Europe's Goce satellite probes Earth's gravity

But by the Berkeley team's analysis, the global temperature correlates more closely with the state of the Atlantic Multidecadal Oscillation (AMO) index - a measure of sea surface temperature in the north Atlantic.

BBC: Global warming 'confirmed' by independent study

The buoys, which measure movement on the surface, are linked to sensors, placed on the ocean floor to detect sea activity.

CNN: story.bouy.jpg

The initial estimates that were done used overhead photography to measure the amount of oil on the surface, right?

WHITEHOUSE: Press Briefing

The analogy that somebody used to me was it is -- we are trying to measure, 5, 000 feet below the surface, the amount of material that is coming up if you were to shake a Coke can.

WHITEHOUSE: Daily Press Briefing

"We are able to measure activities that originate deeper in the brain from the surface without penetrating the brain, " said materials engineer George Malliaras at the Microelectronics Center of Provence in France, who led the research team.

WSJ: Brain Science: Mysterious Neural Circuitry Becomes Viewable

The pictures also cover Sony's plans to add a lightweight keyboard to its next tablet, similar to Microsoft's Surface plans, but with some Smart Cover-esque kickstand skills thrown in for good measure.

ENGADGET: Sony Xperia Tablet leaked from internal slides: Surface-style keyboard and tentative $450 price tag

Estimates that it could smack into the Moon caused great excitement, since previous planned impacts of rocket parts allowed Nasa to measure the shockwaves passing through the Moon and find out more about what lies beneath the surface.

BBC: NEWS | UK | Magazine | One giant (scrap)heap for mankind?