If not, the grains are smaller than many theories expected:
Einstein’s General Theory of Relativity describes the properties of gravity and assumes that space is a smooth, continuous fabric. Yet quantum theory suggests that space should be grainy at the smallest scales, like sand on a beach.
...
Some theories suggest that the quantum nature of space should manifest itself at the ‘Planck scale’: the minuscule 10
-35 of a metre, where a millimetre is 10
-3 m.
However, Integral’s observations are about 10 000 times more accurate than any previous and show that any quantum graininess must be at a level of 10
-48 m or smaller.
“This is a very important result in fundamental physics and will rule out some string theories and quantum loop gravity theories,” says Dr Laurent.
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