Blue wavelengths of light are damaging to many forms of life, and glare from unshielded light compromises road safety and infiltrates bedrooms, suppressing melatonin production, undermining sleep quality and duration, and exacerbating susceptibility to many kinds of illness...
An astronomical year for me ….When I was in the third grade I suddenly became very interested in everything astronomical – especially the planets of our local solar system. That same year we studied the Solar System in public school, and that only added to my excitement over the topic. I began badgering my parents to buy me a telescope...
Fast Radio Bursts are flashes of radio emission lasting for several milliseconds. The time of arrival of signals depends on the radio frequency, called the dispersion measure (DM), which depends on the environment through which the signals travel, specifically the number of free electrons in their path. Very few FRBs have matches with sources observed at other wavelengths (Wikipedia - Fast Radio Burst).
By now, you have probably read or heard that our polluting ways have reached a critical point, where Earth is rapidly approaching total failure as a planet. Perhaps you have wondered how we humans could have managed to do so much damage in so little time.
Permanent settlements in space will require forms of localized government that are likely to differ from contemporary models of political order. This article thus asks a provocative question associated with the empirical record of human colonization and settlement in prior eras: What sort of authoritarian governance is most likely to form in human space settlements during the medium term?
The formula for collisional excitation of the atoms responsible for auroral emission can explain why green auroras from excited oxygen atoms can occur at relatively low altitudes, but red auroras from these same atoms are constrained to higher altitudes of lower density. The same formula also suggests much lower electron velocities (~100 km/s) than are required to excite the oxygen atoms to the required metastable levels for subsequent emission (~1000 km/s).
Astronomy encompasses the fields of Planetary Science (including Earth as a planet), Heliophysics, Astrophysics, Astrochemistry, Astrobiology, Cosmology, and Cosmogony – the study of cosmic origins. Astronomy, in turn, is informed by the core sciences of Physics, Chemistry, and Biology. It both depends upon and helps to advance technological innovation...