January 19, 2014 at 16:55Results of the past year: Dark energy has become even more confusing
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New dimensions of light from distant exploding stars were supposed to tell more about the dark energy that pushes objects in space from each other. Instead, the fate of the universe has become even more confused.
Dark energy was first discussed in 1998, when scientists discovered that light from distant supernovae was weaker than expected. This meant that the universe was expanding at an ever-accelerating pace. To explain this acceleration, scientists have suggested the existence of dark energy that pushes space. Most physicists suspected that dark energy was a form of vacuum energy, known as the "cosmological constant" because its strength never changed. If so, then a number called w, which is equal to the ratio of the force that pushes space to the density of dark energy, should be -1.
But this year, scientists, using a new powerful telescope in Hawaii, came to a different value for w. By combining supernova data with previously obtained results from other studies, the researchers calculated that w should be -1.186.
This value, if confirmed, will force cosmologists to develop more complex theories in which the power of dark energy increases over time. If so, the universe may ultimately be torn apart according to the Big Break theory .
However, so far no one has abandoned the cosmological constant. Researchers say that they and other groups should first try to find the sources of measurement error - starting with the telescopes they use to study the far parts of the universe. Even slight differences in how telescopes collect the light of stars that have passed billions of light years can make a large error in the measurement results.
Two years later, when cosmologists more accurately calibrate their tools and analyze more data, they will be able to say whether it is time to revise the cosmological constant. Currently, shared Armin Rest, head of the research team at the Space Telescope Science Institute in Baltimore, “I suspect w is -1.”
Dark energy was first discussed in 1998, when scientists discovered that light from distant supernovae was weaker than expected. This meant that the universe was expanding at an ever-accelerating pace. To explain this acceleration, scientists have suggested the existence of dark energy that pushes space. Most physicists suspected that dark energy was a form of vacuum energy, known as the "cosmological constant" because its strength never changed. If so, then a number called w, which is equal to the ratio of the force that pushes space to the density of dark energy, should be -1.
But this year, scientists, using a new powerful telescope in Hawaii, came to a different value for w. By combining supernova data with previously obtained results from other studies, the researchers calculated that w should be -1.186.
This value, if confirmed, will force cosmologists to develop more complex theories in which the power of dark energy increases over time. If so, the universe may ultimately be torn apart according to the Big Break theory .
However, so far no one has abandoned the cosmological constant. Researchers say that they and other groups should first try to find the sources of measurement error - starting with the telescopes they use to study the far parts of the universe. Even slight differences in how telescopes collect the light of stars that have passed billions of light years can make a large error in the measurement results.
Two years later, when cosmologists more accurately calibrate their tools and analyze more data, they will be able to say whether it is time to revise the cosmological constant. Currently, shared Armin Rest, head of the research team at the Space Telescope Science Institute in Baltimore, “I suspect w is -1.”