Two Unexpected Results
First: According to the European Space Agency (seen via Next Big Future):
It's well known that quantum mechanics and the General Theory of Relativity are incompatible at the smallest conceivable scales. Until now, it seemed clear that quantum mechanics must hold and GTR become an approximation. Now it looks like quantum mechanics must give. This has implications for, among other things, the many-worlds interpretation of quantum mechanics. MWI is based on a literal interpretation of the formalism of quantum mechanics. There might or might not be any room for it in the more complete theory.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.
GRB 041219A took place on 19 December 2004 and was immediately recognised as being in the top 1% of GRBs for brightness. It was so bright that Integral was able to measure the polarisation of its gamma rays accurately.
Dr Laurent and colleagues searched for differences in the polarisation at different energies, but found none to the accuracy limits of the data.
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.
Second: According to Eureka Alert:
In other words, the Earth is giving off more than can be expected from the neutrino count. One conclusion is that my back of the envelope calculation of the amount of fissionable material on Earth was off. Another conclusion is that there might be an energy source down there we don't know about. Maybe the theory in “The Demon Under Hawaii” by Geoffrey Landis (Analog, July 1992)—that an alien spacecraft is buried on Earth, still giving off heat from its dilithium crystals—is actually true.What spreads the sea floors and moves the continents? What melts iron in the outer core and enables the Earth's magnetic field? Heat. Geologists have used temperature measurements from more than 20,000 boreholes around the world to estimate that some 44 terawatts (44 trillion watts) of heat continually flow from Earth's interior into space. Where does it come from?
………
KamLAND detected 841 candidate antineutrino events between March of 2002 and November of 2009, of which about 730 were reactor events or other background. The rest, about 111, were from radioactive decays of uranium and thorium in the Earth. These results were combined with data from the Borexino experiment at Gran Sasso in Italy to calculate the contribution of uranium and thorium to Earth's heat production. The answer was about 20 terawatts; based on models, another three terawatts were estimated to come from other isotope decays.
2 Comments:
The reporting on Dr Laurent's finding was terrible--what was actually ruled out was not quantum graininess at the Planck scale, but rather certain theories which predict a violation of relativity's Lorentz-invariance, see Laurent's actual paper. Most forms of string theory and loop quantum gravity assume Lorentz-invariance is preserved (see this page of a textbook on string theory, and this paper on loop quantum gravity), so this finding isn't a problem for them.
Science journalism sometimes looks quite a bit like the comics.
"If you can't believe what you read in the funnies, what can you believe?" --- Bullwinkle
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