The supermassive black holes found at the centers of galaxies are known for their extreme X-ray emission. This emission is associated with the massive hot disks of gas and debris that circle these monstrous black holes before it is consumed.
However, X-ray observations of distant galaxies have also uncovered additional luminous X-ray sources that aren’t associated with the galactic centers (where supermassive black holes are found). These are ULXs, or ultraluminous X-ray sources. ULXs hav ...read more
By Kaitlin Vortherms
When smog is so thick that it clouds our vision, we can see and acknowledge that air pollution is a problem. In December of last year, China issued its second ever red alert, their highest rating for air pollution, and last month, London broke modern air pollution records.
But on days when the haze has lifted, we tend to forget air pollution is still there. More to the point, we forget about how air pollution affects our health and the environment. It’s out of sight, a ...read more
Pueblo Bonito taken from the northern rim of Chaco Canyon, New Mexico. (Credit: Douglas Kennett, Penn State University)
Before they disappeared in 1130, the Chacoans of New Mexico were a society on par with the Mayans.
Without a writing system to speak of, they maintained complex trade partnerships with nearby populations. They lived in sprawling, complex stone mini-cities called “great houses”—the largest of which, Pueblo Bonito in Chaco Canyon, boasted 650 rooms. They ...read more
(Credit: Shutterstock)
If you have ever been nervous about something that is about to happen, then you may have felt the sensations of nausea and “fluttering”—the recognizable and odd sensation deep in your gut known as having “butterflies in the stomach.”
Perhaps you were about to give a speech to a large audience, were in the waiting room for a big interview, were about to step up and take a key penalty shot or about to meet a potential love interest. Rather tha ...read more
A river of moist air hits Western Europe during Storm Desmond in 2015. (Credit: Wikimedia Commons)
Rivers in the sky may be responsible for up to 75 percent of the largest, most extreme wind and rainfall events that ravage the coasts.
The streams of moisture, called atmospheric rivers, originate in the tropics and often stretch for thousands of miles across the ocean in a thin band. They deliver a deluge of rain that causes major floods, landslides and a rash of insurance c ...read more
Author Vishay SinghPosted on Categories Discover Magazine
