Honey is a food oddity in that it doesn’t spoil. Here’s the chemistry behind why, as well as an explanation of how bees make honey: http://wp.me/p4aPLT-qn
Scientists have discovered the largest black holes yet, and they’re far bigger than researchers expected based on the galaxies in which they were found. The discovery suggests we have much to learn about how monster black holes grow, scientists said.
All large galaxies are thought to harbor super-massive black holes at their hearts that contain millions to billions of times the mass of our sun. Until now, the largest black hole known was a mammoth dwelling in the giant elliptical galaxy Messier 87. This black hole has a mass 6.3 billion times that of the sun.
Now research suggests black holes in two nearby galaxies are even bigger. The scientists used the Gemini and Keck observatories in Hawaii and the McDonald Observatory in Texas to monitor the velocities of stars orbiting around the centers of a pair of galaxies. These velocities reveal the strength of the gravitational pull on those stars, which in turn is linked with the masses of the black holes lurking there.
The new findings suggest that one galaxy, known as NGC 3842, the brightest galaxy in the Leo cluster of galaxies nearly 320 million light years distant, has a central black hole 9.7 billion solar masses large. The other, named NGC 4889, the brightest galaxy in the Coma cluster more than 335 million light years away, has a black hole of comparable or larger mass. Both encompass regions or “event horizons” about five times the distance from the sun to Pluto.
"For comparison, these black holes are 2,500 times as massive as the black hole at the center of the Milky Way galaxy, whose event horizon is one-fifth the orbit of Mercury," said study lead author Nicholas McConnell at the University of California, Berkeley. Astronomers had suspected that black holes more than 10 billion solar masses large exist, based on light from quasars, cosmic objects from the early universe that are no more than a light year or two across but are thousands of times brighter than our entire galaxy.
The light of quasars is thought to come from matter driven to incandescent brightness as it spirals at high speeds into supermassive black holes. This is the first time scientists have detected black holes approaching such theorized giants in size.
"These two new supermassive black holes are similar in mass to young quasars, and may be the missing link between quasars and the supermassive black holes we see today," said study co-author Chung-Pei Ma, an astrophysicist at the University of California, Berkeley.
The geometry of diatoms, desmids and other algae.
It’s time for the most intense nights of Perseid meteor shower (August 10–13; Tuesday night with as many as 100 ‘shooting stars’ per hour), here are some tips:
- Give your eyes 20 minutes to adjust to the dark. Avoid looking at the moon, your phone or any device that shows light – any exposure to bright lights will instantly ruin your eye’s acclimatization to the dark
- If possible go outside the city, or search for good local stargazing places
- For the best chances of spotting a shooting star, scan the whole sky repeatedly
- Be prepared to spend a few hours sitting outside. Meteor showers can be seen as soon as it gets dark, but better viewing begins about 11 pm
- If you have binoculars or a telescope, take them with you. While you’re there, you can also look for constellations, stars, and planets
(Gif: Exploding Perseid Meteor filmed by
if you aren’t hyped about synthetic life and colonizing space then get out of my face
Perseid Meteor Shower
Not as great as last year but still worthy of watching. The Full Moon will compete with the shower this year, lowering the peak-rates to around 40 or 60 meteors per hour at best, even in the darkest of skies. The peak time is Aug 10-13 but you can see meteors for about a week before and after, so start watching now! The earlier you watch, the less the moon will be in the way, so watching a few days before the peak might actually be better if not the same. For more stargazing events this month, see What’s Up for August. Also, Semi-Relevant/Informative post from last year
Memory Relies on Astrocytes, the Brain’s Lesser Known Cells
When you’re expecting something—like the meal you’ve ordered at a restaurant—or when or when something captures your interest, unique electrical rhythms sweep through your brain.
These waves are called gamma oscillations and they reflect a symphony of cells—both excitatory and inhibitory—playing together in an orchestrated way. Though their role has been debated, gamma waves have been associated with higher-level brain function, and disturbances in the patterns have been tied to schizophrenia, Alzheimer’s disease, autism, epilepsy and other disorders.
For decades, flower hat jellyfish managed to keep their early lives a secret.
In adulthood, the jellyfish are striking, with a nest of fluorescent tentacles that look like party streamers, but pack a nasty sting. In infancy, well, scientists didn’t know. Aquarists tried, unsuccessfully, to raise the animals in tanks to understand what happens before the jellyfish are fully grown.
"They just aren’t like other jellies," said Wyatt Patry, senior aquarist at the Monterey Bay Aquarium in California.
Now, Patry and colleagues report they’ve finally raised the jellyfish in captivity. In a new paper, the researchers describe the elusive species’ life cycle, from egg to larva to single-tentacled polyp to juvenile to adult.
Scientists at the aquarium first bought a group of flower hat jellies back from Japan in 2002 for an exhibit on jellyfish. At the time, aquarists tried to mate and culture the species (scientifically named Olindias formosus), but they just couldn’t seem to get the jellies to release any sperm or eggs.
Patry said the researchers tried performing in vitro fertilization and exposing the jellies to stresses that might make them release sex cells. The creatures produced some larvae, but they didn’t grow much larger than that stage. Ultimately, it seemed that the scientists were missing some cue the jellyfish needed for reproduction.
When it came time for another jellyfish show in 2012, the team tried again. They kept groups of flower hat jellies in small tanks with mesh netting to keep the creatures off the bottom, where detritus and rotting pieces of half-eaten fish settled. The scientists don’t exactly know what they did right the second time around, but during routine maintenance, they discovered fluorescent jellyfish polyps attached to the wire mesh and glowing under a blue light.
Jellyfish larvae attach themselves to a solid surface and become stalklike polyps, which then bud into juvenile “medusae” — what jellyfish are called when they reach their most recognizable, umbrella-shaped form. Jellyfish polyps persist for an unknown amount of time. The polyps of flower hat jellies were unusual in that they had a single, highly active tentacle.
"They just look like little sea anemones," Patry told Live Science. "They seem to use the tentacle to sweep around their position to capture food."
Patry hopes the new information might help scientists and wildlife managers look for the species in the wild — and predict when and where “blooms” of the jellyfish could affect beachgoers.
Flower hat jellies kill and eat entire fish, and their venom is powerful enough to inflict a painful rash on humans. The mark looks like a burn, said Patry. (Take it from him. He said he usually gets stung a couple of times a year.) A 2007 review of jellyfish incidents recorded around the world found one death associated with flower hat jellies, in Japan in the 1970s.
The findings on young flower hat jellies were published in June in the Journal of the Marine Biological Association of the United Kingdom.