An astrophysicist's attempt to measure quantum "fuzziness" to
find out if we're living in a hologram has been headed off at the pass by results suggesting that we're
In October 2010, we reported on Craig Hogan's experiments with two of the world's
most precise clocks, which he was using to try and confirm the
existence of Planck units -- the smallest possible chunks of space,
time, mass and other properties of the universe.
Hogan's interpretation of results from the GEO600 gravitational wave
experiment had shown a quantum fuzziness -- a sort of pixellation
-- at incredibly small scales, suggesting that what was perceive as
the universe might be projected from a two-dimensional shell at its
However, a European
satellite that should be able to measure these small scales
hasn't found any quantum fuzziness at all, contradicting the
interpretation of the GEO600 results and indicating that the
pixellation of spacetime, if it exists, is considerably smaller
By examining the polarisation of gamma-ray bursts as they reach Earth, we should be able to
detect this graininess, as the polarisation of the photons that
arrive here is affected by the spacetime that they travel through.
The grains should twist them, changing the direction in which they
oscillate so that they arrive with the same polarisation. Also,
higher energy gamma rays should be twisted more than lower
However, the satellite detected no such twisting -- there were
no differences in the polarisation between different energies found
to the accuracy limits of the data, which are 10,000 times better
than any previous readings. That means that any quantum grains that exist would have to measure 10^-48 metres
"This is a very important result in fundamental physics and will
rule out some string theories and quantum loop gravity theories,"
says Philippe Laurent, who analysed the data.