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David Freeman
David Freeman is the senior science editor of The Huffington Post in New York City and the host of Science Insider, a weekly radio program on an NPR station in Sharon, CT.

Entries by David Freeman

Pluto Has Blue Skies And Red Ice, NASA Says

(0) Comments | Posted October 8, 2015 | 2:10 PM

NASA's New Horizons mission keeps revealing new surprises about Pluto.

The latest: The far-flung dwarf planet has blue skies and small patches of water ice on its surface.

"Who would have expected a blue sky in the Kuiper Belt?" Alan Stern, the mission's principal investigator, said...

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Neil deGrasse Tyson Talks God, Aliens, And Multiverses

(0) Comments | Posted October 5, 2015 | 11:30 AM

EDITOR'S NOTE: An earlier version of this story was published here.  

Things are looking up for Neil deGrasse Tyson--way up. As the director of the Hayden Planetarium and the author of several popular books on space, Tyson is already one of the nation's best-known scientists. And...

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Stunning New Charon Photos Reveal Pluto Moon's Violent Past

(0) Comments | Posted October 1, 2015 | 11:05 PM

NASA has released striking new images of Pluto's largest moon, Charon, and the world they show is very different from what the space agency's scientists had expected.

Many of the scientists had expected Charon to have a monotonous surface covered with craters, the agency said. Instead, the photos--taken by NASA's New Horizons spacecraft on July 14--reveal a landscape dotted with mountains, canyons, and landslides.

The high-resolution photos also show stark variations in Charon's surface color.

“We thought the probability of seeing such interesting features on this satellite of a world at the far edge of our solar system was low, but I couldn't be more delighted with what we see,” Dr. Ross Beyer, an affiliate of the New Horizons team from the SETI Institute and NASA Ames Research Center in Mountain View, California, said in a written statement.

(Story continues below images.)

Perhaps the most dramatic feature is a vast system of canyons that stretches more than 1,000 miles across Charon's face and likely onto the moon's far side. (The video above lets you fly through it.)

In case you're wondering, NASA says that's four times longer than the Grand Canyon and in some places twice as deep. As Dr. John Spencer, a New Horizons scientist affiliated with the Southwest Research Institute in Boulder, Colorado, said in the statement, "It looks like the entire crust of Charon has been split open.”   

The New Horizons spacecraft, now 3.1 billion miles from Earth, is still sending data about Pluto and its moons back to Earth. So, impressive as the new photos are, NASA says even better images are yet to...
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Why Bill Nye Is So Pumped About The Mars Water Discovery

(1) Comments | Posted September 29, 2015 | 4:26 PM

Bill Nye is positively gushing about the recent discovery of liquid water on Mars--not so much about the water itself but about what its presence means for the chances that the red planet harbors life.

"With salty water flowing every Martian year, it is very reasonable that there...

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Watch NASA's 'Mars Mystery Solved' Press Briefing Right Here

(3) Comments | Posted September 26, 2015 | 8:42 PM

NASA will hold a press briefing at 11:30 a.m. EDT on Monday, Sept. 28 to detail what the space agency calls a "major science finding" from its ongoing exploration of Mars. You can watch it here.

What will NASA be reporting? Some have speculated that the space agency might report the discovery of life on Mars. Others think it might report the discovery of liquid water, which is considered a key ingredient for a planet's suitability for life

Whatever it is, we'll just have to wait and see what NASA has up its sleeve.

NASA says members of the public are welcome to pose questions to the participants of the briefing using the hashtag #AskNASA.

The participants include:

  • Jim Green, director of planetary science at NASA headquarters in Washington, D.C.
  • Michael Meyer, lead scientist for the agency's Mars Exploration Program, also at NASA headquarters.
  • Lujendra Ojha, a Ph.D. candidate in planetary science at Georgia Institute of Technology in Atlanta.
  • Mary Beth Wilheim, of NASA's Ames Research Center in Moffett Field, California and Georgia Institute of Technology
  • Alfred McEwen, principal investigator for the High Resolution Imaging Science Experiment (HiRISE) at the University of Arizona in Tucson.


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RECAP: Dramatic Eclipse Photos

(0) Comments | Posted September 25, 2015 | 2:39 PM

After weeks of anticipation, the supermoon lunar eclipse finally arrived.

The long-awaited “blood moon” stunned stargazers on Sunday night. It was visible across the U.S. starting at 9:07 p.m. EDT.  In case you missed it, check out some spectacular new photos of the eclipse, below, taken by skywatchers and professional astronomers.

A photo posted by Todd Carr (@photofox5000) on

A photo posted by Valentine (@valissa7) on

A photo posted by dgold911 (@dgold911) on

A photo posted by Craig (@craigmo71) on

More specific times, courtesy of EarthSky. 

Eastern Daylight Time (Sept. 27, 2015)
Partial umbral eclipse begins: 9:07 p.m. EDT on Sept. 27
Total eclipse begins: 10:11 p.m. EDT
Greatest eclipse: 10:47 p.m. EDT
Total eclipse ends: 11:23 p.m. EDT
Partial eclipse ends: 12:27 a.m. EDT on Sept. 28

Central Daylight Time (Sept. 27, 2015)
Partial umbral eclipse begins: 8:07 p.m. CDT on Sept. 27
Total eclipse begins: 9:11 p.m. CDT
Greatest eclipse: 9:47 p.m. CDT
Total eclipse ends: 10:23 p.m. CDT
Partial eclipse ends: 11:27 p.m. CDT

Mountain Daylight Time (Sept. 27, 2015)
Partial umbral eclipse begins: 7:07 p.m. MDT on Sept. 27
Total eclipse begins: 8:11 p.m. MDT
Greatest eclipse: 8:47 p.m. MDT
Total eclipse ends: 9:23 p.m. MDT
Partial eclipse ends: 10:27 p.m. MDT

Pacific Daylight Time (Sept. 27, 2015)
Partial umbral eclipse begins: 6:07 p.m. PDT on Sept. 27
Total eclipse begins: 7:11 p.m. PDT
Greatest eclipse: 7:47 p.m. PDT
Total eclipse ends: 8:23 p.m. PDT
Partial eclipse ends: 9:27 p.m....

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America Is Throwing Out Way More Garbage Than We Thought

(2) Comments | Posted September 24, 2015 | 2:00 PM

If you worry that Americans produce too much garbage, you won’t get much reassurance from a new study published in the journal Nature Climate Change.

The study shows that landfills across the country are taking in more than twice as much solid waste as the government thought: a whopping 262 million tons of food scraps, paper products, and the like in 2012 rather than the 122 million tons that the EPA had estimated for that year.

In more personal terms, the new estimate suggests that our landfills are taking in roughly five pounds of solid waste per person per day, according to the Associated Press.

(Story continues below map.)

What explains the jarring discrepancy between the new estimate and EPA’s? It’s all about methodology.

The EPA traditionally has based its estimate on reports from businesses, industry associations, the U.S. Census, and other sources, according to a written statement released by Yale University.

Instead, the researchers behind the new study went directly to the operators of more than 1,200 municipal solid waste landfills across the nation, using four years of data through 2013. That makes the new estimate a “superior number,” Jon Powell, a Ph.D. student in Yale’s department of chemical and environmental engineering and the lead author of a paper describing the research, said in the statement.

“I am excited about the possibilities that the quality-assured, measured data we were able to leverage in this study holds in terms of informing our path forward to manage wastes more sustainably,” Powell told The Huffington Post in an email.

The nation isn’t about to run out of landfill space anytime soon. In fact, the new research suggests that the average landfill has enough capacity for another 30 to 40 years of use.

But the landfills that have more space can be far away from the cities that need their services, Dr. Morton Barlaz, head of the department of civil, construction and environmental engineering at North Carolina State University, told LiveScience. Barlaz was not involved in the new study.

And then there’s the fact that landfills give off lots of gas—including methane, which contributes to global warming. In fact, the decomposition of municipal waste in landfills is considered one of the world’s largest sources of human-produced methane emissions, according to the statement.

(Story continues below map.) 

The new study may encourage researchers to develop better ways to curb the release of methane from landfills, according to Science magazine.  

What else can be done to mitigate our garbage problem? According to Powell, "There are many interconnected factors that impact the production of waste--mass of raw materials used, durability of goods, individual behavior, to name a few."

Time to reconsider how much you throw away every...

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12 Fascinating Facts About Your Lips

(0) Comments | Posted September 24, 2015 | 1:34 PM

Lips are, of course, essential for eating and speaking. And whistling. And kissing. And we'd look pretty silly without them. 

But if you think that's all there is to say--and know--about human lips, you're in for a big surprise. Just take a look at our list of 12 fascinating facts...

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No, The 'Blood Moon' Doesn't Mean Doomsday Is Here

(0) Comments | Posted September 23, 2015 | 12:55 PM

Here's some welcome news for anyone who is worried--as some fundamentalists might be--that the upcoming "blood moon" means the world is coming to an end:

It isn't.

Astronomically speaking, "there is no such thing as a 'blood moon,'" Dr. Jay Pasachoff, an astronomer at Williams College in Williamstown, Mass., told The Huffington Post in an email. People who use that term are either "misguided or malicious," he added.

The moon will look reddish for a brief time on the night of Sept. 27-28. But that's only because the moon will be cast into shadow as the Earth passes between it and the sun--in other words, we're set to see a lunar eclipse.

In the U.S., the eclipse will begin at 9:07 p.m. E.T. and will last for more than three hours. What astronomers call "totality"--when the moon is fully enveloped within the Earth's shadow--will begin at 10:11 p.m. and last for 72 minutes.

Fair enough. But why exactly will the moon take on that crimson cast?

In a new video (above) posted on its website, NASA suggests a simple thought experiment can make it all clear:

Using your imagination, fly to the Moon and stand inside a dusty lunar crater. Look up. Overhead hangs Earth, nightside facing you, completely hiding the sun behind it. The eclipse is underway. You might suppose that the Earth overhead would be completely dark. After all, you're looking at the nightside of our planet. Instead, something amazing happens. When the sun is located directly behind Earth, the rim of the planet seems to catch fire! The darkened terrestrial disk is ringed by every sunrise and every sunset in the world, all at once. This light filters into the heart of Earth's shadow, suffusing it with a coppery glow. Back on Earth, the shadowed Moon becomes a great red orb.

In more scientific terms, the moon looks red during a lunar eclipse because of Rayleigh scattering. That's a phenomenon in which sunlight--essentially a mash-up of all the different colors of light--is scattered by Earth's atmosphere. Since blue light is scattered more than red light, it's essentially "filtered out" as it passes through the atmosphere--leaving red light to reach the moon.

You don't need any special equipment to see a lunar eclipse. But watching the action unfold with a telescope or binoculars will add to the fun. As astronomer Phil Plait wrote recently on  Slate, "The moon can take on an odd three-dimensional appearance when you use binoculars during an eclipse, and it's pretty cool to see."

This is the last total lunar eclipse until 2018, according to Sky & Telescope. So enjoy the show!

Correction: A previous version of this story misstated the relative positions of the Earth, moon, and sun that occur during a lunar eclipse.

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15 Of Richard Dawkins' Most Controversial Tweets

(1) Comments | Posted September 21, 2015 | 1:50 PM

For better or worse, Richard Dawkins simply isn't one to bite his tongue.

On Sunday, the outspoken evolutionary biologist and best-selling author took to Twitter to suggest that Ahmed Mohamed, the Texas teen who was arrested last week after showing up at school with a clock...

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If You Like To Blow S*** Up, Check Out These Chemistry GIFs

(0) Comments | Posted September 17, 2015 | 4:24 PM

Chemistry can be a blast--literally.
Just consider what happens when you seal dry ice (solid carbon dioxide) in a bottle and submerge it in hot water. Via a process known as sublimation, the dry ice turns into gaseous carbon dioxide,...
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Dramatic Photos Show ISS Silhouetted Against Sun, Moon

(0) Comments | Posted September 9, 2015 | 6:20 PM

Call it a double helping of celestial inspiration.

Just weeks after releasing a dramatic photo of the International Space Station passing in front of the moon, NASA has offered up an equally eye-popping image of the ISS transiting the sun.

(Story continues below images.)


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Descoberta histórica de ‘ladrilho' dá um chacoalhão no mundo da matemática

(6) Comments | Posted September 3, 2015 | 10:38 AM

Uma equipe de matemáticos surpreendeu o mundo da ciência com a descoberta de um novo tipo de pentágono capaz de “ladrilhar uma superfície” – ou seja, cobrir totalmente uma superfície plana sem que haja sobreposições ou espaços vazios.

Seria somente o 15º pentágono do tipo encontrado, e o...

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Homens produzem mais espermatozoides quando estimulados por 'nova fêmea'

(0) Comments | Posted August 26, 2015 | 2:49 PM

Os homens ejaculam mais rápido e produzem mais espermatozoides e de melhor qualidade quando eles se masturbam com o "estímulo de uma nova fêmea" dizem os cientistas.

Dizem que a variedade é o tempero da vida e novas e provocativas pesquisas de cientistas de Ohio sugerem que isso...

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La découverte d'une "tuile" historique secoue le monde des mathématiques

(0) Comments | Posted August 21, 2015 | 12:14 PM

Une équipe de mathématiciens a bouleversé le monde des maths en découvrant un nouveau type de pentagone capable de "paver un plan", c'est-à-dire que les tuiles peuvent s'assembler sur une surface plane sans qu'elles ne se chevauchent ni ne laissent de trous.

Seuls quinze pentagones de ce type...

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La découverte d'une «tuile» historique secoue le monde des mathématiques

(0) Comments | Posted August 21, 2015 | 10:14 AM

Une équipe de mathématiciens a bouleversé le monde des maths en découvrant un nouveau type de pentagone capable de « paver un plan », c'est-à-dire que les tuiles peuvent s'assembler sur une surface plane sans qu'elles ne se chevauchent ni ne laissent de trous.

Seuls quinze pentagones de ce type...

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Historic 'Tile' Discovery Gives Math World A Big Jolt

(1) Comments | Posted August 18, 2015 | 10:02 PM

A team of mathematicians has wowed the math world with their discovery of a new kind of pentagon capable of "tiling a plane"--that is, fitting together on a flat surface without overlapping or leaving any gaps.

It's said to be only the fifteenth such pentagon ever...

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These Macro Photos Reveal The Awesome Diversity Of Human Eyes

(0) Comments | Posted August 18, 2015 | 2:57 PM

It sees. It cries. It helps us communicate. Yes, the human eye is one outstanding organ. But what do you see when you look into someone’s eyes?

Most of us focus on their color. But give a really close look and you’ll see at once that our...

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Freaky 'Sea Monster' Recovered From Centuries-Old Shipwreck

(0) Comments | Posted August 13, 2015 | 12:52 PM

The fearsome-looking figurehead of a warship that went down in the Baltic Sea more than 500 years...

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21명의 남자들이 과학을 위해 자위를 한 결과는?(연구)

(0) Comments | Posted August 10, 2015 | 6:13 PM

다양함은 삶의 즐거움이라고들 한다. 오하이오의 과학자들이 진행한 도발적인 새 연구에 의하면 인간의 섹스와 번식의 세계에서도 그 말은 진리다.

21명의 남성과 포르노의 도움을 받아, 우스터 대학의 연구자들은 남자들은 ‘새로운 여성 자극’을 보며 자위할 때 더 빨리 사정하고 품질이 우수한 정자를 더 많이 생산한다는 것을 밝혔다.

쉽게 말해, 전에 마주친...

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