Black hole winds stop star formation

Artist’s concept of black hole winds via ESA. Read more about this image.

One of the great revelations of modern astronomy are the supermassive black holes – millions to billions of times more massive than our sun – found at the hearts of most galaxies. Most, like the black hole at the center of our Milky Way galaxy, are quiet, but some are known to be voraciously devouring nearby stars, gas and dust. In this process, some also produce powerful winds and jets. Astronomers have suspected that black hole winds might be responsible for draining galaxies of the interstellar gas from which new stars are born. Now they have an example of at least one galaxy doing precisely that. Astronomers using the European Space Agency’s Herschel space observatory have found that the winds blowing from a huge black hole are sweeping away its host galaxy’s reservoir of raw star-building material. Francesco Tombesi from NASA’s Goddard Space Flight Center and the University of Maryland, USA, who led the research published March 26, 2015 in Nature, said:

This is the first time that we have seen a supermassive black hole in action, blowing away the galaxy’s reservoir of star-making gas.

The astronomers combined infrared observations from ESA’s Herschel space observatory with new data from the Japanese/US Suzaku X-ray satellite to detect black hole winds from the central black hole of a galaxy known as IRAS F11119+3257. They also learned the winds’ role in pushing star-forming gas in this galaxy outward.

In a statement, these astronomers said:

The winds start small and fast, gusting at about 25% the speed of light near the black hole and blowing away about the equivalent of one solar mass of gas every year.

As they progress outwards, the winds slow but sweep up an additional few hundred solar masses of gas molecules per year and push it out of the galaxy.

This is the first solid proof that black-hole winds are stripping their host galaxies of gas by driving large-scale outflows.

The astronomers say that the winds from black holes in the hearts of galaxies could eventually affect a galaxy’s star-forming activity, slowing it down or possibly quenching it entirely.

ESA has more on this story

We’re halfway through our annual fund-raising campaign. Have you donated yet? Help EarthSky keep going.

Artist’s concept of a supermassive black hole at the center of a galaxy, causing winds that blow away the materials needed for star formation. Image via ESA.

Bottom line: Astronomers thought that winds from supermassive black holes at the hearts of some galaxies should be capable of blowing away the interstellar gas needed for star formation. Now they have an example of a galaxy – known as IRAS F11119+3257 – doing exactly that.

from EarthSky http://ift.tt/1EQGqaQ

Artist’s concept of black hole winds via ESA. Read more about this image.

One of the great revelations of modern astronomy are the supermassive black holes – millions to billions of times more massive than our sun – found at the hearts of most galaxies. Most, like the black hole at the center of our Milky Way galaxy, are quiet, but some are known to be voraciously devouring nearby stars, gas and dust. In this process, some also produce powerful winds and jets. Astronomers have suspected that black hole winds might be responsible for draining galaxies of the interstellar gas from which new stars are born. Now they have an example of at least one galaxy doing precisely that. Astronomers using the European Space Agency’s Herschel space observatory have found that the winds blowing from a huge black hole are sweeping away its host galaxy’s reservoir of raw star-building material. Francesco Tombesi from NASA’s Goddard Space Flight Center and the University of Maryland, USA, who led the research published March 26, 2015 in Nature, said:

This is the first time that we have seen a supermassive black hole in action, blowing away the galaxy’s reservoir of star-making gas.

The astronomers combined infrared observations from ESA’s Herschel space observatory with new data from the Japanese/US Suzaku X-ray satellite to detect black hole winds from the central black hole of a galaxy known as IRAS F11119+3257. They also learned the winds’ role in pushing star-forming gas in this galaxy outward.

In a statement, these astronomers said:

The winds start small and fast, gusting at about 25% the speed of light near the black hole and blowing away about the equivalent of one solar mass of gas every year.

As they progress outwards, the winds slow but sweep up an additional few hundred solar masses of gas molecules per year and push it out of the galaxy.

This is the first solid proof that black-hole winds are stripping their host galaxies of gas by driving large-scale outflows.

The astronomers say that the winds from black holes in the hearts of galaxies could eventually affect a galaxy’s star-forming activity, slowing it down or possibly quenching it entirely.

ESA has more on this story

We’re halfway through our annual fund-raising campaign. Have you donated yet? Help EarthSky keep going.

Artist’s concept of a supermassive black hole at the center of a galaxy, causing winds that blow away the materials needed for star formation. Image via ESA.

Bottom line: Astronomers thought that winds from supermassive black holes at the hearts of some galaxies should be capable of blowing away the interstellar gas needed for star formation. Now they have an example of a galaxy – known as IRAS F11119+3257 – doing exactly that.

from EarthSky http://ift.tt/1EQGqaQ

Recent Reading: Unusual Fantasy Settings [Uncertain Principles]

All the way back in 2001, I got started on the whole blog thing by beginning a book log. That’s long since fallen by the wayside, but every now and then, I do read stuff that I feel a need to write something about, and, hey, the tagline up at the top of the page does promise pop culture to go with the physics…

I’ve actually been on a pretty good roll with fantasy novels over the last few months, hitting a bunch of books that I’ve really enjoyed, without any real duds. I was actually pleasantly surprised by the first of these, Django Wexler’s The Thousand Names. This got good reviews, but it’s a fantasy novel with muskets, and I’ve always been a little leery of that. I really enjoyed this, though, and I think it helped me pinpoint the problem I’ve had in the past– most of the books I’ve read in that kind of setting are by people who really like Regency England, and as a result, they’re wayyyy into the manners and social class stuff, and that just makes me itch. Wexler’s world is conscious of social class, but doesn’t revel in it, presenting a much flatter sort of hierarchy, that’s much more congenial to my American tastes.

And when you take out the irritatingly mannered stuff, the military tactics and so on are weirdly fascinating. And while Wexler’s no Steven Erikson, he makes a decent stab at the military banter that’s one of the best features of the Malazan books, so this was good fun. The second book, The Shadow Throne moves back to the capital of Wexler’s imaginary empire, and basically does the French Revolution in a fantasy setting, only with good guys inside the Bastille to keep everything from going quite as horribly wrong. It’s a very different book than the first, but still fun.

The realization that muskets per se weren’t what bothered me, and the third book in Wexler’s series a while off, I picked up the first of Brian McClellan’s Powder Mage trilogy The Promise of Blood (a sale aided in part by McClellan saying smart things about book promotion…). These are more obviously epic than Wexler’s books, but start out in a manner that appeals to my anti-class tendencies, with one of the protagonists staging a coup against a corrupt and dissolute monarch, then guillotining hundreds of aristocrats, declaring an end to the age of kings. This turns out to have some unforseen magical consequences…

The Promise of Blood was a fun read, with lots of twists. The next one’s queued up, and the trilogy is complete, so I know that if it continues to be enjoyable, I can get to the end right away.

In between Wexler and McClellan, I plowed through a whole bunch of Kelly McCullough’s Fallen Blade series, starting with Broken Blade. These are magical-assassin stories, with a cool backstory: the protagonist, Aral Kingslayer, was a member of the Blades of Namara, an order in service to the goddess of justice, who existed as a check against the abuse of power. When a king or another high noble got too far out of line, a Blade would be sent to kill them. But several years before the start of the series, the other gods decided to get rid of Namara, and the few Blades who escaped slaughter were chased into hiding. Except the story is more complicated than that…

Unlike the other two series, which I’ve seen reviewed in Locus and elsewhere, I had never heard anything about these. Which is a little weird, because they’re successful enough to have run to five books, with a sixth due at the end of April. And also because they’re pretty good– the bits where Aral struggles with the drinking problem he developed after the fall of the Blades get a little tedious at times, but McCullough did a nice job setting up a scenario that limits and balances the badassery of his main character, while still allowing for fun ass-kicking when appropriate. I’ve got the fifth one lined up in the near future, and that’s longer than a lot of series last for me these days…

While I’m plugging fantasy series, earlier I read Harry Connolloy’s Great Way series, starting with The Way Into Chaos, which he referred to as “Epic Fantasy With No Dull Parts” on Twitter while writing it. That’s not a bad description, either– they start fast, and really don’t slow down. I wasn’t 100% happy with the ending, but then it’s a rare series that sticks the landing, and getting 80% of the way there is pretty good.

I got those because I backed the series on Kickstarter some time back, which also got me a bonus copy of A Key, an Egg, an Unfortunate Remark, which Connolly calls a “pacifist urban fantasy.” I’m about halfway through that, and at least to this point it’s the opposite of all the other books in this post in everything but pace– it moves along quite briskly and enjoyably without big epic battles. I don’t know yet how it will end, but pulling this off for even half a book is an achievement. Connolly’s a damn fine writer, you should go buy his stuff.

And that’s what I’ve been enjoying reading recently. And for at least a little while into the future, at least to the limited extent I’ll have time to read with the new term starting on Monday…

from ScienceBlogs http://ift.tt/1G51s9v

All the way back in 2001, I got started on the whole blog thing by beginning a book log. That’s long since fallen by the wayside, but every now and then, I do read stuff that I feel a need to write something about, and, hey, the tagline up at the top of the page does promise pop culture to go with the physics…

I’ve actually been on a pretty good roll with fantasy novels over the last few months, hitting a bunch of books that I’ve really enjoyed, without any real duds. I was actually pleasantly surprised by the first of these, Django Wexler’s The Thousand Names. This got good reviews, but it’s a fantasy novel with muskets, and I’ve always been a little leery of that. I really enjoyed this, though, and I think it helped me pinpoint the problem I’ve had in the past– most of the books I’ve read in that kind of setting are by people who really like Regency England, and as a result, they’re wayyyy into the manners and social class stuff, and that just makes me itch. Wexler’s world is conscious of social class, but doesn’t revel in it, presenting a much flatter sort of hierarchy, that’s much more congenial to my American tastes.

And when you take out the irritatingly mannered stuff, the military tactics and so on are weirdly fascinating. And while Wexler’s no Steven Erikson, he makes a decent stab at the military banter that’s one of the best features of the Malazan books, so this was good fun. The second book, The Shadow Throne moves back to the capital of Wexler’s imaginary empire, and basically does the French Revolution in a fantasy setting, only with good guys inside the Bastille to keep everything from going quite as horribly wrong. It’s a very different book than the first, but still fun.

The realization that muskets per se weren’t what bothered me, and the third book in Wexler’s series a while off, I picked up the first of Brian McClellan’s Powder Mage trilogy The Promise of Blood (a sale aided in part by McClellan saying smart things about book promotion…). These are more obviously epic than Wexler’s books, but start out in a manner that appeals to my anti-class tendencies, with one of the protagonists staging a coup against a corrupt and dissolute monarch, then guillotining hundreds of aristocrats, declaring an end to the age of kings. This turns out to have some unforseen magical consequences…

The Promise of Blood was a fun read, with lots of twists. The next one’s queued up, and the trilogy is complete, so I know that if it continues to be enjoyable, I can get to the end right away.

In between Wexler and McClellan, I plowed through a whole bunch of Kelly McCullough’s Fallen Blade series, starting with Broken Blade. These are magical-assassin stories, with a cool backstory: the protagonist, Aral Kingslayer, was a member of the Blades of Namara, an order in service to the goddess of justice, who existed as a check against the abuse of power. When a king or another high noble got too far out of line, a Blade would be sent to kill them. But several years before the start of the series, the other gods decided to get rid of Namara, and the few Blades who escaped slaughter were chased into hiding. Except the story is more complicated than that…

Unlike the other two series, which I’ve seen reviewed in Locus and elsewhere, I had never heard anything about these. Which is a little weird, because they’re successful enough to have run to five books, with a sixth due at the end of April. And also because they’re pretty good– the bits where Aral struggles with the drinking problem he developed after the fall of the Blades get a little tedious at times, but McCullough did a nice job setting up a scenario that limits and balances the badassery of his main character, while still allowing for fun ass-kicking when appropriate. I’ve got the fifth one lined up in the near future, and that’s longer than a lot of series last for me these days…

While I’m plugging fantasy series, earlier I read Harry Connolloy’s Great Way series, starting with The Way Into Chaos, which he referred to as “Epic Fantasy With No Dull Parts” on Twitter while writing it. That’s not a bad description, either– they start fast, and really don’t slow down. I wasn’t 100% happy with the ending, but then it’s a rare series that sticks the landing, and getting 80% of the way there is pretty good.

I got those because I backed the series on Kickstarter some time back, which also got me a bonus copy of A Key, an Egg, an Unfortunate Remark, which Connolly calls a “pacifist urban fantasy.” I’m about halfway through that, and at least to this point it’s the opposite of all the other books in this post in everything but pace– it moves along quite briskly and enjoyably without big epic battles. I don’t know yet how it will end, but pulling this off for even half a book is an achievement. Connolly’s a damn fine writer, you should go buy his stuff.

And that’s what I’ve been enjoying reading recently. And for at least a little while into the future, at least to the limited extent I’ll have time to read with the new term starting on Monday…

from ScienceBlogs http://ift.tt/1G51s9v

Nova Sagittarii observation, March 29, 2015

By Thomas Wildoner at LeisurelyScientist.com

I managed to get an early morning view of the new nova in the constellation Sagittarius this morning, March 29, 2015. According to recent observations, this unusual nova has had an unusual magnitude shift, up and down and now back up again. Grab a blanket and head out to see this bright nova before it is gone!

Nova Sagittarii 2015 No. 2 was discovered by nova hunter John Seach of Chatsworth Island, NSW, Australia.

You can consult the chart below to find the nova location. This chart is for my observing location in Pennsylvania.

View larger. | Finder chart for Nova Sagittarii 2015 No. 2, chart credit to Stellarium, via Tom Wildoner.

Sagittarius is low on the southern horizon from my viewing location, just above tree level, but I did manage to capture it this morning. The nova is the brightest object inside the yellow circle. I used a Canon 6D, Canon 100mm f/2.8L lens mounted on a tripod with no guiding. I placed some reference star magnitudes on the chart for you.

View larger. | Nova Sagittarii 2015 No. 2 photographed by Tom Wildoner on March 29, 2015. Single 5 second exposure at ISO 3200 using a Canon 6D and 100mm lens, unguided.

Based on my photographic observation this morning, I would estimate the magnitude to be approximately 5.6. This was estimated by comparing neighboring star brightness’s to the nova.

Observation point was located at 40.9740663,-75.7677017 (you can paste these coordinates in Google to see where the photo was taken from).

You can click HERE to view a list of recent observations by the American Association of Variable Star Observers.

If you get a photo of this new nova, please share it with us, we would love to see it! Please post it to the Leisurely Scientist Facebook page, you can email your image and details to tom @ leisurelyscientist.com or tweet it to @leisurelysci on Twitter.

from EarthSky http://ift.tt/19fPm0N

By Thomas Wildoner at LeisurelyScientist.com

I managed to get an early morning view of the new nova in the constellation Sagittarius this morning, March 29, 2015. According to recent observations, this unusual nova has had an unusual magnitude shift, up and down and now back up again. Grab a blanket and head out to see this bright nova before it is gone!

Nova Sagittarii 2015 No. 2 was discovered by nova hunter John Seach of Chatsworth Island, NSW, Australia.

You can consult the chart below to find the nova location. This chart is for my observing location in Pennsylvania.

View larger. | Finder chart for Nova Sagittarii 2015 No. 2, chart credit to Stellarium, via Tom Wildoner.

Sagittarius is low on the southern horizon from my viewing location, just above tree level, but I did manage to capture it this morning. The nova is the brightest object inside the yellow circle. I used a Canon 6D, Canon 100mm f/2.8L lens mounted on a tripod with no guiding. I placed some reference star magnitudes on the chart for you.

View larger. | Nova Sagittarii 2015 No. 2 photographed by Tom Wildoner on March 29, 2015. Single 5 second exposure at ISO 3200 using a Canon 6D and 100mm lens, unguided.

Based on my photographic observation this morning, I would estimate the magnitude to be approximately 5.6. This was estimated by comparing neighboring star brightness’s to the nova.

Observation point was located at 40.9740663,-75.7677017 (you can paste these coordinates in Google to see where the photo was taken from).

You can click HERE to view a list of recent observations by the American Association of Variable Star Observers.

If you get a photo of this new nova, please share it with us, we would love to see it! Please post it to the Leisurely Scientist Facebook page, you can email your image and details to tom @ leisurelyscientist.com or tweet it to @leisurelysci on Twitter.

from EarthSky http://ift.tt/19fPm0N

Sunday Chess Problem [EvolutionBlog]

I had originally picked out another Circe problem for your enjoyment this week. However, this particular problem was in the genre of “series” movers, and it occurred to me that I had never shown you one of those before. I didn’t want your first one to be the rather complex affair I had selected. So, instead I picked out a simpler series problem, just to illustrate how the genre works. But after preparing this problem, I then discovered that the Circe series problem I wanted to use turned out to be cooked. Oh well. You’re getting this one anyway!

This problem was composed by George Sphicas in 1992. The stipulation calls for Series Selfmate in 14:

The idea is this: White is going to play fourteen consecutive moves. During that time, black will remain motionless. After white’s fourteenth move, the position on the board will be such that all of black’s legal moves will result in white being checkmated. (That’s what makes this a series selfmate, as opposed to some other genre like a series helpmate). During his series white is allowed to capture all the black pieces he wants. The only restriction is that he must not put black in check, with the possible exception of the last move.

For a series mover to be considered sound, it must be that the moves of the series have to come in an exact order. If even two moves can be switched, then the problem must be discarded as cooked. Part of the fun of series movers is working out the reasons why the moves must come in the order they do.

So let us see what we have. Black is only going to make one move. We must envision what the final position could possibly be that will compel that move to be checkmate. Since the white king is already cornered, you might think the idea is to cover all of his flights, and then compel the black king to move from the back rank, thereby discovering check from the black rook.

Alas, if you spend some time trying to make that work you will find it is a no go. White must work harder. Let’s have a look. The solution begins with 1. Ra2 2. Re2:

The white rook has cleared a line for the white queen, and it will eventually prevent the black king from moving to e7 or e8. But why couldn’t the rook have achieved those ends by moving to e4, e3 or e1 instead? Stay tuned!

The white queen now makes use of her new-found freedom to play the dramatic 3. Qa1 4. Qa8 5. Ra1:

The white queen goes corner to corner, pinning the black rook. The queen had to use this eccentric route, since the only alternatives go through f6 or h6, which would have checked the black king.

As for the Ra1 move, wait and see! We now come to the main point of the problem. As if to complement the white queen’s trek, the white king will also move corner to corner. Since the white king must not cross the g-file, because of the check from the black rook, there is a unique, shortest route for the king to make his trip: 6. Ka7 7. Kb6 8. Kc5:

Get the idea? We continue: 9. Kd4 10. Ke3 11. Kf2:

And now for the dramatic finale. White plays 12. Kg1 13. Kh1 14. Rg1, creating this position:

Black finally gets to move, but he only has one option, which is to play 14. … Rxh8 mate.

Now we see why the first white rook had to choose its destination square so carefully. From e4 or e3, the rook would have interposed on the h-file. From e1 it would have interfered with the other rook’s route to g1.

Very pretty stuff! See you next week.

from ScienceBlogs http://ift.tt/1F5wEnU

I had originally picked out another Circe problem for your enjoyment this week. However, this particular problem was in the genre of “series” movers, and it occurred to me that I had never shown you one of those before. I didn’t want your first one to be the rather complex affair I had selected. So, instead I picked out a simpler series problem, just to illustrate how the genre works. But after preparing this problem, I then discovered that the Circe series problem I wanted to use turned out to be cooked. Oh well. You’re getting this one anyway!

This problem was composed by George Sphicas in 1992. The stipulation calls for Series Selfmate in 14:

The idea is this: White is going to play fourteen consecutive moves. During that time, black will remain motionless. After white’s fourteenth move, the position on the board will be such that all of black’s legal moves will result in white being checkmated. (That’s what makes this a series selfmate, as opposed to some other genre like a series helpmate). During his series white is allowed to capture all the black pieces he wants. The only restriction is that he must not put black in check, with the possible exception of the last move.

For a series mover to be considered sound, it must be that the moves of the series have to come in an exact order. If even two moves can be switched, then the problem must be discarded as cooked. Part of the fun of series movers is working out the reasons why the moves must come in the order they do.

So let us see what we have. Black is only going to make one move. We must envision what the final position could possibly be that will compel that move to be checkmate. Since the white king is already cornered, you might think the idea is to cover all of his flights, and then compel the black king to move from the back rank, thereby discovering check from the black rook.

Alas, if you spend some time trying to make that work you will find it is a no go. White must work harder. Let’s have a look. The solution begins with 1. Ra2 2. Re2:

The white rook has cleared a line for the white queen, and it will eventually prevent the black king from moving to e7 or e8. But why couldn’t the rook have achieved those ends by moving to e4, e3 or e1 instead? Stay tuned!

The white queen now makes use of her new-found freedom to play the dramatic 3. Qa1 4. Qa8 5. Ra1:

The white queen goes corner to corner, pinning the black rook. The queen had to use this eccentric route, since the only alternatives go through f6 or h6, which would have checked the black king.

As for the Ra1 move, wait and see! We now come to the main point of the problem. As if to complement the white queen’s trek, the white king will also move corner to corner. Since the white king must not cross the g-file, because of the check from the black rook, there is a unique, shortest route for the king to make his trip: 6. Ka7 7. Kb6 8. Kc5:

Get the idea? We continue: 9. Kd4 10. Ke3 11. Kf2:

And now for the dramatic finale. White plays 12. Kg1 13. Kh1 14. Rg1, creating this position:

Black finally gets to move, but he only has one option, which is to play 14. … Rxh8 mate.

Now we see why the first white rook had to choose its destination square so carefully. From e4 or e3, the rook would have interposed on the h-file. From e1 it would have interfered with the other rook’s route to g1.

Very pretty stuff! See you next week.

from ScienceBlogs http://ift.tt/1F5wEnU

Moon and Jupiter closest on March 29

Tonight – March 29, 2015 – it’ll be hard to miss the king planet Jupiter as the dazzling starlike object near the moon. The moon and Jupiter – nighttime’s brightest and third-brightest lights in the sky – meet up in front of the constellation Cancer the Crab, not far from the legendary Beehive star cluster.

Of course, Venus ranks as the second-brightest orb of nighttime, after the moon, and you can see Venus, too, tonight, in the western sky at dusk and nightfall. Venus sets by mid-to-late evening, but the moon and Jupiter stay out nearly all night long.

The moon and Jupiter climb highest up for the night around mid-evening, and tonight’s shining couple won’t set in the west until shortly before the first stirrings of morning twilight on March 30.

We’re halfway through our annual fund-raising campaign. Have you donated yet? Help EarthSky keep going.

Our friend Scott MacNeill posted this photo at EarthSky Photos on Google+. It’s Jupiter with the Beehive star cluster to the planet’s upper left. He captured them earlier this month. Thanks, Scott! Binoculars should reveal the Beehive near Jupiter, but wait until the moon moves away!

Jupiter is truly a giant world. It’d take 11 Earths lined up side by side to equal the diameter of Jupiter. However, that’s only the beginning of the story. You have to square the diameter to find out Jupiter’s surface area exceeds that of Earth by around 121 times (11 x 11 = 121). And then you have to cube the diameter to find out that Jupiter’s volume is some 1,300 times greater than Earth’s (11 x 11 x 11 = 1,331).

Jupiter has more than twice the mass of all the other solar system planets, moons and asteroids combined!

Jupiter also boasts of having the largest, third-largest, fourth-largest and sixth-largest moons in the solar system (Ganymede, Callisto, Io and Europa).

Meanwhile, Saturn’s moon, Titan, ranks as the second-largest moon. And Earth’s moon ranks as fifth-largest.

View larger. | Graphic courtesy of the Planetary Society

There are at least 18 moons in the solar system that are massive enough for self-gravity to mold these worlds into sphere-shaped objects. If these rather massive moons directly orbited the sun, instead of their parent planets, these worlds would be classified as planets or dwarf planets.

Because Earth’s closest celestial neighbor, the moon, revolves around Earth, our captured world is considered to be Earth’s moon, not a planet or dwarf planet.

Bottom line: Tonight – March 29, 2015 – watch our moon, the fifth-largest in the solar system, pair up with Jupiter, the king of the planets, on the great dome of the nighttime sky.

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

Donate: Your support means the world to us

from EarthSky http://ift.tt/1GaPUC1

Tonight – March 29, 2015 – it’ll be hard to miss the king planet Jupiter as the dazzling starlike object near the moon. The moon and Jupiter – nighttime’s brightest and third-brightest lights in the sky – meet up in front of the constellation Cancer the Crab, not far from the legendary Beehive star cluster.

Of course, Venus ranks as the second-brightest orb of nighttime, after the moon, and you can see Venus, too, tonight, in the western sky at dusk and nightfall. Venus sets by mid-to-late evening, but the moon and Jupiter stay out nearly all night long.

The moon and Jupiter climb highest up for the night around mid-evening, and tonight’s shining couple won’t set in the west until shortly before the first stirrings of morning twilight on March 30.

We’re halfway through our annual fund-raising campaign. Have you donated yet? Help EarthSky keep going.

Our friend Scott MacNeill posted this photo at EarthSky Photos on Google+. It’s Jupiter with the Beehive star cluster to the planet’s upper left. He captured them earlier this month. Thanks, Scott! Binoculars should reveal the Beehive near Jupiter, but wait until the moon moves away!

Jupiter is truly a giant world. It’d take 11 Earths lined up side by side to equal the diameter of Jupiter. However, that’s only the beginning of the story. You have to square the diameter to find out Jupiter’s surface area exceeds that of Earth by around 121 times (11 x 11 = 121). And then you have to cube the diameter to find out that Jupiter’s volume is some 1,300 times greater than Earth’s (11 x 11 x 11 = 1,331).

Jupiter has more than twice the mass of all the other solar system planets, moons and asteroids combined!

Jupiter also boasts of having the largest, third-largest, fourth-largest and sixth-largest moons in the solar system (Ganymede, Callisto, Io and Europa).

Meanwhile, Saturn’s moon, Titan, ranks as the second-largest moon. And Earth’s moon ranks as fifth-largest.

View larger. | Graphic courtesy of the Planetary Society

There are at least 18 moons in the solar system that are massive enough for self-gravity to mold these worlds into sphere-shaped objects. If these rather massive moons directly orbited the sun, instead of their parent planets, these worlds would be classified as planets or dwarf planets.

Because Earth’s closest celestial neighbor, the moon, revolves around Earth, our captured world is considered to be Earth’s moon, not a planet or dwarf planet.

Bottom line: Tonight – March 29, 2015 – watch our moon, the fifth-largest in the solar system, pair up with Jupiter, the king of the planets, on the great dome of the nighttime sky.

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

Donate: Your support means the world to us

from EarthSky http://ift.tt/1GaPUC1

The Vacuity of “Natural Law” [EvolutionBlog]

In this recent essay at The New York Times, philosopher Gary Gutting argues that the Catholic Church should reconsider its ban on gay sex and its opposition to gay marriage, for explicitly Catholic reasons. He is especially critical of “natural law” arguments against homosexuality.

It’s mostly a sensible essay, I think, but it is not the subject of this post. Instead I shall consider this reply to Gutting, written by John Finnis and Robert George. They were unhappy with Gutting, a philosophy professor at Notre Dame, for being so dismissive of natural law. Sadly, though, their attempted defense is entirely unsuccessful.

As presented by its supporters, the natural law approach to sexual morality is about undertaking a process of ratiocination in which we start with noncontroversial premises about human flourishing, applicable to all people at all times, and then deduce eternal moral truths from them. Not for them the messiness of actual human interactions, or the possibility that “flourishing” might mean different things to different people. No, the correct approach to morality, as they see it, is to sit in your comfy chair, place your feet on the ottoman, steeple your fingers, and then explain to others how they ought to live their lives.

Consequently, Finnis and George are endlessly tossing off abstract principles they evidently take to be axiomatic, but which more sensible people will regard as hard to defend, if not flatly false. Let’s pick up the action in the third paragraph:

The idea is not “heterosexual union,” nor “shared acts directed towards reproduction,” nor any of the other concepts Gutting refers to and associates with “nature.” Instead, it’s the idea–the intrinsic human value–of marriage.

This is introduced as “the idea that grounds and unifies the whole set of sex-morality teachings.” Which is a bit of a problem, since it is very unclear what it means. I am not sure what they mean by “marriage,” and I’m very unsure what they mean by “intrinsic human value.”

I think what they mean by marriage is something like, “a loving union between a man and a woman undertaken with an eye towards raising children. And by “intrinsic human value,” I think they mean that such unions are good for all people at all times. That, at least, seems to be what they need for the rest of their argument to hold any water. Here’s their next paragraph:

Even apart from any question of its legal status, marriage is a natural form of human association, with its own basic structure and value. It is the sort of loving union inherently oriented to family life; it is the sort of living bond that by its nature would be fulfilled—extended and enriched—by the bearing and rearing of children. Children by their nature need such familial, parental nurture, support, and guidance; by their coming to be, they make possible the continuance and flourishing of the wider society whose aid and social capital made feasible the wellbeing of their parents and other forebears.

Do you see what I mean about tossing off abstract principles? If all they mean is that men and women sometimes like to pair up and have children, and that society might have an interest in promoting such unions, then I’m fine with it. But in suggesting that a marriage just is that sort of union, they are trying to win the argument by definition. The only part of this paragraph that does not apply with equal strength to homosexual couples is the part about “bearing” children, by which Finnis and George evidently mean bearing children in the normal, biological way. But gay couples can certainly adopt, among other options, and once that’s recognized I fail to see why we cannot say that loving homosexual unions cannot also be inherently oriented to family life. I fail to see why the capacity to produce new children through sex should be thought to have any moral relevance here. Moreover, plenty of heterosexual marriages are childless, but no one then argues that such unions have no societal value, or fail to promote human flourishing.

In their next paragraph Finnis and George graciously acknowledge some of this, but then simply repeat, over and over again, their assertion that an ability to have children through sex is a fact of great moral significance in thinking about marriage. So let’s skip ahead to this:

Moral reasoning is “of a natural law kind,” whether in St. Paul or Aquinas–or in Plato, Aristotle, Musonius Rufus, and others untouched by Jewish or Christian thought–not because it tries to read premises or conclusions off biological or sociological facts. It doesn’t. Instead, it considers what are the basic forms of human flourishing: conditions or activities that are good for us in themselves: friendship, knowledge, life and health, and the like. The identification of these of course takes into account biological and other cause-and-effect facts. But it is focused not on those but on the intrinsic goodness of the various elements of human fulfillment. We can then reason to the moral goodness and badness of types of choice and act by considering which choices are consistent with love and respect for ourselves and all others in regard to each of these basic dimensions of fulfillment. A choice consistent with love and respect for all the goods in all persons is morally upright; one that isn’t, is immoral.

This is just silly. You can certainly define friendship and knowledge in ways that make them intrinsically good, but then you are not really saying very much. If instead we look to those biological and sociological facts that Finnis and George think we can ignore, you find that the picture is far more complex. Friendship is not always good, as when a teenager falls in with the wrong crowd, or when friendship leads to a misplaced sense of loyalty. Nor is knowledge always a good thing, as I would think would be obvious to anyone who has read Genesis 3.

These sorts of considerations apply with much greater force to marriage. For some people, the decision to get married and have children represents a deeply satisfying and fulfilling commitment that immeasurably enriches their lives. But for many others it is a terrible decision, one that causes tremendous pain and misery. That’s why so many marriages fail, after all. And that’s why it’s just absurd to think you can reason in the abstract about human flourishing, or to put forth non-trivial principles that will apply to all people at all times.

Well, as usually happens with these things, this post has gotten a bit long, and I have not yet come to some of the most asinine parts of the essay. So we’ll pack it in for today and come back to it another time.

from ScienceBlogs http://ift.tt/19eiFRj

In this recent essay at The New York Times, philosopher Gary Gutting argues that the Catholic Church should reconsider its ban on gay sex and its opposition to gay marriage, for explicitly Catholic reasons. He is especially critical of “natural law” arguments against homosexuality.

It’s mostly a sensible essay, I think, but it is not the subject of this post. Instead I shall consider this reply to Gutting, written by John Finnis and Robert George. They were unhappy with Gutting, a philosophy professor at Notre Dame, for being so dismissive of natural law. Sadly, though, their attempted defense is entirely unsuccessful.

As presented by its supporters, the natural law approach to sexual morality is about undertaking a process of ratiocination in which we start with noncontroversial premises about human flourishing, applicable to all people at all times, and then deduce eternal moral truths from them. Not for them the messiness of actual human interactions, or the possibility that “flourishing” might mean different things to different people. No, the correct approach to morality, as they see it, is to sit in your comfy chair, place your feet on the ottoman, steeple your fingers, and then explain to others how they ought to live their lives.

Consequently, Finnis and George are endlessly tossing off abstract principles they evidently take to be axiomatic, but which more sensible people will regard as hard to defend, if not flatly false. Let’s pick up the action in the third paragraph:

The idea is not “heterosexual union,” nor “shared acts directed towards reproduction,” nor any of the other concepts Gutting refers to and associates with “nature.” Instead, it’s the idea–the intrinsic human value–of marriage.

This is introduced as “the idea that grounds and unifies the whole set of sex-morality teachings.” Which is a bit of a problem, since it is very unclear what it means. I am not sure what they mean by “marriage,” and I’m very unsure what they mean by “intrinsic human value.”

I think what they mean by marriage is something like, “a loving union between a man and a woman undertaken with an eye towards raising children. And by “intrinsic human value,” I think they mean that such unions are good for all people at all times. That, at least, seems to be what they need for the rest of their argument to hold any water. Here’s their next paragraph:

Even apart from any question of its legal status, marriage is a natural form of human association, with its own basic structure and value. It is the sort of loving union inherently oriented to family life; it is the sort of living bond that by its nature would be fulfilled—extended and enriched—by the bearing and rearing of children. Children by their nature need such familial, parental nurture, support, and guidance; by their coming to be, they make possible the continuance and flourishing of the wider society whose aid and social capital made feasible the wellbeing of their parents and other forebears.

Do you see what I mean about tossing off abstract principles? If all they mean is that men and women sometimes like to pair up and have children, and that society might have an interest in promoting such unions, then I’m fine with it. But in suggesting that a marriage just is that sort of union, they are trying to win the argument by definition. The only part of this paragraph that does not apply with equal strength to homosexual couples is the part about “bearing” children, by which Finnis and George evidently mean bearing children in the normal, biological way. But gay couples can certainly adopt, among other options, and once that’s recognized I fail to see why we cannot say that loving homosexual unions cannot also be inherently oriented to family life. I fail to see why the capacity to produce new children through sex should be thought to have any moral relevance here. Moreover, plenty of heterosexual marriages are childless, but no one then argues that such unions have no societal value, or fail to promote human flourishing.

In their next paragraph Finnis and George graciously acknowledge some of this, but then simply repeat, over and over again, their assertion that an ability to have children through sex is a fact of great moral significance in thinking about marriage. So let’s skip ahead to this:

Moral reasoning is “of a natural law kind,” whether in St. Paul or Aquinas–or in Plato, Aristotle, Musonius Rufus, and others untouched by Jewish or Christian thought–not because it tries to read premises or conclusions off biological or sociological facts. It doesn’t. Instead, it considers what are the basic forms of human flourishing: conditions or activities that are good for us in themselves: friendship, knowledge, life and health, and the like. The identification of these of course takes into account biological and other cause-and-effect facts. But it is focused not on those but on the intrinsic goodness of the various elements of human fulfillment. We can then reason to the moral goodness and badness of types of choice and act by considering which choices are consistent with love and respect for ourselves and all others in regard to each of these basic dimensions of fulfillment. A choice consistent with love and respect for all the goods in all persons is morally upright; one that isn’t, is immoral.

This is just silly. You can certainly define friendship and knowledge in ways that make them intrinsically good, but then you are not really saying very much. If instead we look to those biological and sociological facts that Finnis and George think we can ignore, you find that the picture is far more complex. Friendship is not always good, as when a teenager falls in with the wrong crowd, or when friendship leads to a misplaced sense of loyalty. Nor is knowledge always a good thing, as I would think would be obvious to anyone who has read Genesis 3.

These sorts of considerations apply with much greater force to marriage. For some people, the decision to get married and have children represents a deeply satisfying and fulfilling commitment that immeasurably enriches their lives. But for many others it is a terrible decision, one that causes tremendous pain and misery. That’s why so many marriages fail, after all. And that’s why it’s just absurd to think you can reason in the abstract about human flourishing, or to put forth non-trivial principles that will apply to all people at all times.

Well, as usually happens with these things, this post has gotten a bit long, and I have not yet come to some of the most asinine parts of the essay. So we’ll pack it in for today and come back to it another time.

from ScienceBlogs http://ift.tt/19eiFRj

Saturday Space Sight: Hawaii from Space Looks Awesome

From the International Space Station, European Space Agency astronaut Samantha Cristoforetti (@AstroSamantha) took this photograph of the island of Hawaii and posted it to social media on Feb. 28, 2015. Cristoforetti wrote, “And suddenly as we flew over the Pacific… the island of #Hawaii with its volcanoes! #HelloEarth”

Crewmembers on the space station photograph the Earth from their unique point of view located 200 miles above the surface as part of the Crew Earth Observations program. Photographs record how the planet is changing over time, from human-caused changes like urban growth and reservoir construction, to natural dynamic events such as hurricanes, floods and volcanic eruptions. Astronauts have used hand-held cameras to photograph the Earth for more than 40 years, beginning with the Mercury missions in the early 1960s. The ISS maintains an altitude between 220 – 286 miles (354 – 460 km) above the Earth, and an orbital inclination of 51.6˚, providing an excellent stage for observing most populated areas of the world.

Story and information provided by NASA; Photo: Samantha Cristoforetti/Released

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Disclaimer: The appearance of hyperlinks does not constitute endorsement by the Department of Defense of this website or the information, products or services contained therein. For other than authorized activities such as military exchanges and Morale, Welfare and Recreation sites, the Department of Defense does not exercise any editorial control over the information you may find at these locations. Such links are provided consistent with the stated purpose of this DOD website.

from Armed with Science http://ift.tt/1MfzRI8

From the International Space Station, European Space Agency astronaut Samantha Cristoforetti (@AstroSamantha) took this photograph of the island of Hawaii and posted it to social media on Feb. 28, 2015. Cristoforetti wrote, “And suddenly as we flew over the Pacific… the island of #Hawaii with its volcanoes! #HelloEarth”

Crewmembers on the space station photograph the Earth from their unique point of view located 200 miles above the surface as part of the Crew Earth Observations program. Photographs record how the planet is changing over time, from human-caused changes like urban growth and reservoir construction, to natural dynamic events such as hurricanes, floods and volcanic eruptions. Astronauts have used hand-held cameras to photograph the Earth for more than 40 years, beginning with the Mercury missions in the early 1960s. The ISS maintains an altitude between 220 – 286 miles (354 – 460 km) above the Earth, and an orbital inclination of 51.6˚, providing an excellent stage for observing most populated areas of the world.

Story and information provided by NASA; Photo: Samantha Cristoforetti/Released

Follow Armed with Science on Facebook and Twitter!

———-

Disclaimer: The appearance of hyperlinks does not constitute endorsement by the Department of Defense of this website or the information, products or services contained therein. For other than authorized activities such as military exchanges and Morale, Welfare and Recreation sites, the Department of Defense does not exercise any editorial control over the information you may find at these locations. Such links are provided consistent with the stated purpose of this DOD website.

from Armed with Science http://ift.tt/1MfzRI8