Quantum vacuum: Less than zero energy

According to quantum physics, energy can be 'borrowed' — at least for some time. Energies lower than zero are possible, much like a bank account that can be overdrawn. There are, however, certain restrictions to that. Scientists have now shown that these restrictions are very fundamental properties of our universe and must be true for various possible quantum theories.

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Black holes and their host galaxies, growing old together

The 'special relationship' between supermassive black holes (SMBHs) and their hosts — something astronomers and physicists have observed for quite a while — can now be understood as a bond that begins early in a galaxy's formation and has a say in how both the galaxy and the SMBH at its center grow over time, according to a new study.

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Oldest galaxy protocluster forms 'queen's court'

Astronomers have discovered a collection of 12 galaxies which existed about 13.0 billion years ago. One of the 12 galaxies is a giant object, known as Himiko, which was named for a mythological queen in ancient Japan. This discovery suggests that large structures such as protoclusters already existed when the Universe was only about 800 million years old, 6% of its present age.

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