Galaxies with central black holes can take various forms depending on the angle at which astronomers see them. (Credit: NASA)
Every large galaxy has a supermassive black hole at its center. And some of those black holes are actively ejecting huge amounts of high-energy light out into the cosmos.
Astronomers divide some of these active galaxies, which otherwise look like normal spirals, into two types, so-called Seyfert 1 and Seyfert 2 galaxies. Seyfert 1 galaxies have distinctive light ...read more
Some fish, like the bluefin tune pictured here, are accumulating higher levels of mercury due to human activities. (Credit: Guido Montaldo/Shutterstock)
The USDA recommends Americans eat at least two servings of seafood every week. Most of us turn to tuna – canned or otherwise – and cod. Fish tacos and fish and chips? Yes, please!
But now researchers find mercury levels in these popular seafood options are on the rise thanks to overfishing and climate change. Scientists say the ...read more
Frances "Poppy" Northcutt at work in the Mission Planning and Analysis room at NASA's Mission Control (Houston) during the Apollo program, circa 1968.
The 50th anniversary of Apollo 11 came and went in a blaze of nostalgia for the moment when humans made their first awkward footfall on another world--a moment when (for the true believers, at least) it seemed like humans might keep going and start exploring the whole solar system in person. But Apollo was about much more than Apollo 11, and ...read more
Many older people and their families worry about a diagnosis of Alzheimer’s disease. (Credit: Nadya Chetah/Shutterstock)
Many people who have problems with their memory, especially if they are elderly, worry that they have Alzheimer’s disease, which afflicts at least 5.5 million people in the U.S. and brings tremendous burdens to families as well. This concern is paramount among those who have seen a family member, friend or colleague develop this insidious progressive disease.
...read more
The galaxies are clear to ALMA’s radio vision, but disappear in Hubble’s visible light coverage. (Credit: Image (c) 2019 Wang et al.)
The universe is 13.8 billion years old, but scientists have trouble seeing back to its earliest days. This cosmic dawn has been obscured by time, distance, and the rest of the universe. Part of the problem is that light gets stretched as it travels across the cosmos. The longer the journey, the more stretched out its wavelengths become.
So our e ...read more
Author Vishay SinghPosted on Categories Discover Magazine