One of the most obvious things about looking at stars in the sky is that they're not all the same brightness.
A handful are so bright that you can easily see them even in a big city's washed-out sky, while others are so faint that they're invisible unless you're stargazing on a moonless night from an essentially light-pollution-free locale (if you can find one).
This varying visibility of stars is so obvious you may not have given it much thought.
Astronomers, however, think about it a lot.
And astronomers, being scientists, decided they had to quantify it; in other words, throw math at it.
The first person we know did this was Greek polymath Hipparchus, who created a star map noting the brightness of various stars more than two millennia ago.
A few centuries later, another Greek astronomer, Ptolemy, attempted to classify stars using a six-tier scale, assigning the brightest stars to the first tier and the faintest ones to the sixth.
You're at brunch with friends, and mimosas are on the house.You're tempted, but you also want to go for a run later.What should you do?Will drinking doom your workout?Despite the popularity of boozy athletic events like Craft Brew Races and Bikes and Beers, exercise physiologists and nutrition experts strongly discourage drinking alcohol before, during or after exercise.
Scientists Just Got A Step Closer to The Sci-Fi Reality of Building Solar Power Stations in Space
Hajimiri leads a component of a larger endeavor by Caltech researchers to develop technology that could gather the sun's energy in massive satellites orbiting Earth and beam it down to power the grid.
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Solar panels on Earth only work during the day, and they don't produce much power on cloudy days or when the sun is low in the evening or early morning.
In orbit, however, such panels would produce a constant stream of zero-emission power.
In space, it's always noon on a sunny day, says Hajimiri.
Deep in the ocean, hydrothermal vents can tower up to 200 feet above the seafloor, belching out scalding water warmed by hot magma from underwater volcanoes.
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A recent expedition to locate more of these vents yielded a new find: a group of "black smoker" vents emitting water of 645 degrees Fahrenheit along the Mid-Atlantic Ridge near Puerto Rico.
Most Planets in the Galaxy Orbit Stars You Can’t Even See
When I was younger, I gazed at the stars at night and wondered how many possessed planets like Earth.Being a Star Trek nerd, I couldn't help but imagine a universe where stars were fecund and planets were everywhere.But not knowing was agony.This story has a happy ending, though: Now we do know-the galaxy is filled with planets.
NASA Confirms That Cosmic Object Is so Bright That It Defies Laws of Physics
If you're looking for some of the brightest objects in the cosmos, squint no further than ultra-luminous x-ray sources, or ULXs.
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These loci of overwhelming luminosity have long puzzled astronomers because they at least appear to exceed what's known as the Eddington limit, which restricts how bright an object can be based on its mass, by up to 500 times.
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According to NASA, a marshmallow-sized object hitting such a star would release the energy of a thousand hydrogen bombs.
Newfound Mathematical ‘Einstein’ Shape Creates a Never-Repeating Pattern
Creatively tiling a bathroom floor isn't just a stressful task for DIY home renovators.It is also one of the hardest problems in mathematics.For centuries, experts have been studying the special properties of tile shapes that can cover floors, kitchen backsplashes or infinitely large planes without leaving any gaps.
Ronnie Wood and Paul Costelloe among stars creating artworks for charity
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As part of the Incognito initiative, almost 3,000 pieces of postcard-sized original artwork will be sold in aid of the Jack and Jill Children's Foundation.
Dinosaurs' Air Sacs Evolved Many Times and Let Them Take Over the World
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The researchers were surprised to find that the early dinosaur bones were more similar to those of alligators and deer than to those of the dinosaurs' later descendants."Prior to this study, it looked unlikely to me that invasive air sacs would have evolved three times independently" in separate dinosaur lineages, Aureliano says-but the new results suggest that scenario.
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Instead the study most likely indicates that air sacs invaded the bone multiple times independently, as the reptiles became larger and more diverse.
NASA discovery reveals an intergalactic gamma-ray burst that could be the brightest of all time
In October, astronomers recorded a singular cosmic explosion across the universea pulse of gamma radiation so fantastic that NASA scientists have dubbed it the BOAT, or brightest of all time.
It was astonishing and consequential, and like most faraway whims of space and time whose existence finally make themselves known to our corner of the universeplanet Earthit was also far in the past, long gone from a fleeting moment.
The signal from the gamma-ray burst, now named GRB 221009A, had been racing through space for 1.9 billion years before reaching the fields of our telescopes.
New Heart-Health Study Gives Reason To Drink Multiple Cups Of Coffee Per Day
If you're a one- coffee-per-day drinker, it may be time to up your intake.
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The roughly 12.5-year study, which was published in the European Journal of Preventive Cardiology, explored the impact coffee had on the health of 449,563 adults age 40 to 69 with no history of cardiovascular issues.
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Coffee was found to help heart health and led to a reduced risk of death overall.
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People who drank four to five (not two to three) cups of ground or instant coffee each day saw a reduction in arrhythmias - and there was no reduction for people who drank decaf coffee.
Scientists Reveal How Tardigrades Can Survive Decades Without Water
To shed light on this superpower, researchers led by Akihiro Tanaka, a graduate student in biological sciences at the University of Tokyo, studied structures called cytoplasmic-abundant heat soluble (CAHS) proteins.
The team revealed that these proteins can form protective substances akin to gels that contribute to the exceptional physical stability in a dehydrated state seen in tardigrades, a finding that may have implications for human medical treatments and technologies, according to a study published in the journal PLOS Biology on Tuesday.
Although water is essential to all life we know of, some tardigrades can live without it potentially for decades, said Takekazu Kunieda, an associate professor at the University of Tokyo and the senior author of the study, in a statement.
The pigs had been dead for an hour. Scientists made their hearts beat again.
Hours after pumping synthetic fluids through the bodies of dead pigs, a team of researchers from Yale University observed their hearts beginning to beat faintly.Blood circulation was restored, and some cellular functions were revived in vital organs such as the heart and liver.
Life on Mars: A critical tool in the search for aliens is delayed
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Some 3.8 billion years ago, at the same time as life was emerging on Earth, Mars was habitable too.There is evidence from orbiters and landers of water on the surface then - there would have been clouds, rain, and a thick atmosphere.There was also a global protective magnetic field and volcanos.This means Mars essentially had all the right ingredients for life - carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.If life emerged there as it did on Earth, we were on a track to find it.
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My expectation is that 2028 is most likely for our mission, but it will require hard work.
Solar eruptions, flares could impact Earth, NASA says
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NASA says the sun has been very active, which is what could cause problems on Earth.
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Scientists from NASA have said that more solar activity, flares and eruptions are coming and that the solar cycle is not yet at its peak, but has already surpassed expectations.
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NASA predicts that solar eruptions and flares will continue to increase from now until 2025.
Why Animals Are Less Vulnerable Than Humans to BA.5 and Omicron
But there's good news: other research has found that the highly infectious Omicron variant and its multiple subvariants might hit animals less hard than they hit ustransmitting less easily among them and causing less severe disease.
Blood substitute repairs damaged organs hours after heart stops
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"We have shown that cells don't die as quickly as we assumed they do, which opens up possibilities for intervention.We can persuade cells not to die," says Zvonimir Vrselja at Yale School of Medicine.