Spotted: The Largest Black Hole Ever Seen

By Chris Gayomali

Astronomers have identified what's likely to be the largest black hole ever discovered.

Just how massive is it? The superlative-defying behemoth has roughly 17 billion times the mass of our own sun and consumes 59 percent of the centermost bulge of stars in its host galaxy NGC 1277. Typical black holes take up 0.1 percent of their containing galaxies, and the next biggest black hole only takes up 11 percent of its host galaxy's central bulge.

The hole in NGC 1277, located 250 million light-years from Earth in the constellation Perseus, is considered such an outlier that the scientists who discovered it took an extra year to double-check their research before submitting the results for publication.

"The first time I calculated it, I thought I must have done something wrong," lead author Remco van den Bosch tells "We tried it again with the same instrument, then a different instrument. Then I thought, 'Maybe something else is happening.'"

And its unprecedented scale is merely the beginning. Astronomers were perplexed when they realized that the stars surrounding the black hole appear to have been "relatively undisturbed for eons," says Irene Klotz at Discovery News, meaning it wasn't gobbling up nearby stars and planets as black holes tend to do.

In other words, we may have to rethink what we know about the already mysterious relationship between black holes and their host galaxies.

'Lime Disease' Could Give You a Nasty Rash This Summer

A cold Corona or virgin margarita is best enjoyed by the pool, but watch where you’re squeezing those limes. As Slate illustrates in a new video, there’s a lesser-known “lime disease,” and it can give you a nasty skin rash if you’re not careful.

When lime juice comes into contact with your skin and is then exposed to UV rays, it can cause a chemical reaction that results in phytophotodermatitis. It looks a little like a poison ivy reaction or sun poisoning, and some of the symptoms include redness, blistering, and inflammation. It’s the same reaction caused by a corrosive sap on the giant hogweed, an invasive weed that’s spreading throughout the U.S.

"Lime disease" may sound random, but it’s a lot more common than you might think. Dermatologist Barry D. Goldman tells Slate he sees cases of the skin condition almost daily in the summer. Some people have even reported receiving second-degree burns as a result of the citric acid from lime juice. According to the Mayo Clinic, the chemical that causes phytophotodermatitis can also be found in wild parsnip, wild dill, wild parsley, buttercups, and other citrus fruits.

To play it safe, keep your limes confined to the great indoors or wash your hands with soap after handling the fruit. You can learn more about phytophotodermatitis by checking out Slate’s video below.

[h/t Slate]

Why Eating From a Smaller Plate Might Not Be an Effective Dieting Trick 

It might be time to rewrite the diet books. Israeli psychologists have cast doubt on the widespread belief that eating from smaller plates helps you control food portions and feel fuller, Scientific American reports.

Past studies have shown that this mind trick, called the Delboeuf illusion, influences the amount of food that people eat. In one 2012 study, participants who were given larger bowls ended up eating more soup overall than those given smaller bowls.

However, researchers from Ben-Gurion University in Negev, Israel, concluded in a study published in the journal Appetite that the effectiveness of the illusion depends on how empty your stomach is. The team of scientists studied two groups of participants: one that ate three hours before the experiment, and another that ate one hour prior. When participants were shown images of pizzas on serving trays of varying sizes, the group that hadn’t eaten in several hours was more accurate in assessing the size of pizzas. In other words, the hungrier they were, the less likely they were to be fooled by the different trays.

However, both groups were equally tricked by the illusion when they were asked to estimate the size of non-food objects, such as black circles inside of white circles and hubcaps within tires. Researchers say this demonstrates that motivational factors, like appetite, affects how we perceive food. The findings also dovetail with the results of an earlier study, which concluded that overweight people are less likely to fall for the illusion than people of a normal weight.

So go ahead and get a large plate every now and then. At the very least, it may save you a second trip to the buffet table.

[h/t Scientific American]


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