time

Variability time scales in active galaxiesActive galactic nuclei contain a supermassive black hole (SMBH) surrounded by an accretion disk. As disk material falls toward the SMBH, it heats up enough to emit optical light. Burke et al.…

SummaryEvery time the U.N. Intergovernmental Panel on Climate Change (IPCC) issues a new report surveying the science of global warming, the alarm sounds louder. Now, 8 years after its last report, the message of IPCC's latest assessment,…

Adipose thermogenesis is a conserved response to environmental cold or dietary excess and is classically triggered by ligand-dependent receptor activation. Johansen et al. report that cold regulation of Gs-coupled receptor expression…

The Biden administration's decision to elevate the Director of the White House Office of Science and Technology Policy (OSTP) to a cabinet-level position is a win for science. Eric Lander, confirmed in May by the Senate, is now advising the…

Estimating resilience in complex systemsResilience is an important concept in the study of critical transitions and tipping points in complex systems and is defined by the size of the disturbance that a system can endure before tipping into…

Prethermal time crystalCharacterizing and understanding different phases of matter in equilibrium is usually associated with the process of thermalization, where the system equilibrates. Recent efforts probing nonequilibrium systems have…