Earth Prepares To Snap First-Ever Image Of A Black Hole’s Event Horizon (Synopsis) [Starts With A Bang]

“Never look down to test the ground before taking your next step; only he who keeps his eye fixed on the far horizon will find the right road.” -Dag Hammarskjold

One of relativity’s oddest predictions is the existence of black holes, objects so dense and massive that nothing, not event light can escape from them. But that lack-of-escaping is limited to a certain volume of space: that within the black hole’s event horizon. Although black holes have been detected and identified, an event horizon has never yet been imaged. That, however, is likely about to change when the Event Horizon Telescope comes online.

The Atacama Large Millimeter submillimeter Array (ALMA) are some of the most powerful radio telescopes on Earth. They are only one small part of the array forming the Event Horizon Telescope. Image credit: ESO/C. Malin.

Given the general relativistic prediction of the size of the supermassive black hole at the center of our galaxy — 37 microarcseconds — and the resolution of the EHT that spans the diameter of Earth, its event horizon should be visible. Speculations about black holes date back to 1783, and just a few decades after the first black hole candidate was identified, we’re now prepared to directly image one.

Simulations of how the black hole at the center of the Milky Way may appear to the Event Horizon Telescope, depending on its orientation relative to us. These simulations assume the event horizon exists. Image credit: Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole, S. Doeleman et al.

Are event horizons real? Get ready, humanity. We’re about to find out!

from ScienceBlogs http://ift.tt/2nADBtz

“Never look down to test the ground before taking your next step; only he who keeps his eye fixed on the far horizon will find the right road.” -Dag Hammarskjold

One of relativity’s oddest predictions is the existence of black holes, objects so dense and massive that nothing, not event light can escape from them. But that lack-of-escaping is limited to a certain volume of space: that within the black hole’s event horizon. Although black holes have been detected and identified, an event horizon has never yet been imaged. That, however, is likely about to change when the Event Horizon Telescope comes online.

The Atacama Large Millimeter submillimeter Array (ALMA) are some of the most powerful radio telescopes on Earth. They are only one small part of the array forming the Event Horizon Telescope. Image credit: ESO/C. Malin.

Given the general relativistic prediction of the size of the supermassive black hole at the center of our galaxy — 37 microarcseconds — and the resolution of the EHT that spans the diameter of Earth, its event horizon should be visible. Speculations about black holes date back to 1783, and just a few decades after the first black hole candidate was identified, we’re now prepared to directly image one.

Simulations of how the black hole at the center of the Milky Way may appear to the Event Horizon Telescope, depending on its orientation relative to us. These simulations assume the event horizon exists. Image credit: Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole, S. Doeleman et al.

Are event horizons real? Get ready, humanity. We’re about to find out!

from ScienceBlogs http://ift.tt/2nADBtz

Physics Blogging Round-Up: March [Uncertain Principles]

Another month, another batch of blog posts at Forbes:

— In Physics, Infinity Is Easy But Ten Is Hard: Some thoughts on the odd fact that powerful math tricks make it easy to deal uncountably many interacting particles, while a smaller number would be a Really Hard Problem.

— New Experiment Explores The Origin Of Probabilities In Quantum Physics: A write-up of an experiment using a multi-path interferometer to look for departures from the Born rule for calculating probabilities from wavefunctions.

— The Most Important Science To Fund Is The Hardest To Explain: In light of the awful budget proposal put forth by the Trump administration, some thoughts on the importance of government funding for the most basic kinds of research.

— Popular Science Writing And Our Fascination With Speculation: Prompted by the new book from Jorge Cham and Daniel Whiteson, a look at why so many pop-science books focus on what we don’t know.

— Can You Make A Quantum Superposition Of Cause And Effect?: A write-up of a new paper where they put a single photon into a superposition of A-then-B and B-then-A, which kind of makes my head hurt.

I’m pretty happy with these, though I would’ve expected more pageviews for the cause-and-effect thing. My teaching schedule is slightly lighter this Spring term, so I may be able to do a little more in-depth blogging than in recent months. Or maybe not. Come back in May to find out…

from ScienceBlogs http://ift.tt/2nATJeC

Another month, another batch of blog posts at Forbes:

— In Physics, Infinity Is Easy But Ten Is Hard: Some thoughts on the odd fact that powerful math tricks make it easy to deal uncountably many interacting particles, while a smaller number would be a Really Hard Problem.

— New Experiment Explores The Origin Of Probabilities In Quantum Physics: A write-up of an experiment using a multi-path interferometer to look for departures from the Born rule for calculating probabilities from wavefunctions.

— The Most Important Science To Fund Is The Hardest To Explain: In light of the awful budget proposal put forth by the Trump administration, some thoughts on the importance of government funding for the most basic kinds of research.

— Popular Science Writing And Our Fascination With Speculation: Prompted by the new book from Jorge Cham and Daniel Whiteson, a look at why so many pop-science books focus on what we don’t know.

— Can You Make A Quantum Superposition Of Cause And Effect?: A write-up of a new paper where they put a single photon into a superposition of A-then-B and B-then-A, which kind of makes my head hurt.

I’m pretty happy with these, though I would’ve expected more pageviews for the cause-and-effect thing. My teaching schedule is slightly lighter this Spring term, so I may be able to do a little more in-depth blogging than in recent months. Or maybe not. Come back in May to find out…

from ScienceBlogs http://ift.tt/2nATJeC

Male Emperor penguins are good dads

Male emperor penguin incubating an egg just prior to hatching in mid-July. Photo via Robyn Mundy/ Australian Antarctic Division.

During the summer in the southern hemisphere – from about December to February – Emperor Penguins in Antarctica are at sea fattening up on squid, fish, and krill. As autumn approaches in March, the Emperors leave the water and begin a long trek to one of several breeding colonies. The breeding cycle begins around now – the month of April, autumn in Antarctica – when penguins mate on the reforming sea ice. Each female produces a single egg. She transfers the egg to her mate, then leaves to spend winter in the open ocean.

During Antarctica’s winter – a frigid night four months long – male Emperor Penguins huddle by the hundreds in the snow. The male penguins guard the eggs and keep them warm. Each male penguin puts his egg on his feet. He covers it with a fold of skin. In this way, he keeps it warm at about 100 degrees Fahrenheit (38 degrees Celsius) while the outside temperatures can drop well below -30 degrees F (?35 degrees C).

For 65 days, each bird incubates an egg, huddled in large colonies with only feathers, fat, and each other to stay warm. The eggs may begin to hatch in July, but the male penguins’ winter vigil won’t end until around August when the sun peeks over the horizon.

By the time the female returns, sleek and full of food, the male may have lost 45% of his body weight. Ravenously hungry, he leaves to feed at sea. The offspring grow rapidly in summer when food at sea is plentiful. By December, the chicks are on their own.

Five years from now, if they survive in their ocean home, the young penguins will return to become parents themselves.

Read more: Emperor penguin breeding cycle

Emperor penguin chick. Photo via Gary Miller/ Australian Antarctic Division.

Bottom line: The story of male Emperor penguins, who sit for a long winter on their eggs.

from EarthSky http://ift.tt/2o224eu

Male emperor penguin incubating an egg just prior to hatching in mid-July. Photo via Robyn Mundy/ Australian Antarctic Division.

During the summer in the southern hemisphere – from about December to February – Emperor Penguins in Antarctica are at sea fattening up on squid, fish, and krill. As autumn approaches in March, the Emperors leave the water and begin a long trek to one of several breeding colonies. The breeding cycle begins around now – the month of April, autumn in Antarctica – when penguins mate on the reforming sea ice. Each female produces a single egg. She transfers the egg to her mate, then leaves to spend winter in the open ocean.

During Antarctica’s winter – a frigid night four months long – male Emperor Penguins huddle by the hundreds in the snow. The male penguins guard the eggs and keep them warm. Each male penguin puts his egg on his feet. He covers it with a fold of skin. In this way, he keeps it warm at about 100 degrees Fahrenheit (38 degrees Celsius) while the outside temperatures can drop well below -30 degrees F (?35 degrees C).

For 65 days, each bird incubates an egg, huddled in large colonies with only feathers, fat, and each other to stay warm. The eggs may begin to hatch in July, but the male penguins’ winter vigil won’t end until around August when the sun peeks over the horizon.

By the time the female returns, sleek and full of food, the male may have lost 45% of his body weight. Ravenously hungry, he leaves to feed at sea. The offspring grow rapidly in summer when food at sea is plentiful. By December, the chicks are on their own.

Five years from now, if they survive in their ocean home, the young penguins will return to become parents themselves.

Read more: Emperor penguin breeding cycle

Emperor penguin chick. Photo via Gary Miller/ Australian Antarctic Division.

Bottom line: The story of male Emperor penguins, who sit for a long winter on their eggs.

from EarthSky http://ift.tt/2o224eu

What is Lunar X?

Lunar X via Raven Yu, January 19, 2013

Lunar X is a famous optical feature on the moon, visible through telescopes. When the terminator – or line between light and dark on the moon – is located in just the right place, it appears as the letter X on the moon’s surface. A sign of an alien visitation? No. Lunar X is a great example of how lighting and topography can combine on a planet or moon to produce a pattern that seems familiar to the human eye.

In reality, the illusion of Lunar X is created by sunlight falling on the rims/ridges between the craters La Caille, Blanchinus, and Purbach.

Help EarthSky stay an independent voice! Donate here.

Ron Bee photo of Lunar X from 2007.

In the case of Lunar X, the pattern repeats at each cycle of the moon, but only for a short time. The X is observable for about 4 hours around the first quarter moon phase.

Aniruddha Bhat in Maryland caught this Lunar X on January 16, 2016.

Bottom line: Lunar X is an optical feature on the moon, an apparent X on the moon’s surface, visible through telescopes. It’s caused by sunlight falling on the rims/ridges between the craters La Caille, Blanchinus, and Purbach.

from EarthSky http://ift.tt/2oQglrU

Lunar X via Raven Yu, January 19, 2013

Lunar X is a famous optical feature on the moon, visible through telescopes. When the terminator – or line between light and dark on the moon – is located in just the right place, it appears as the letter X on the moon’s surface. A sign of an alien visitation? No. Lunar X is a great example of how lighting and topography can combine on a planet or moon to produce a pattern that seems familiar to the human eye.

In reality, the illusion of Lunar X is created by sunlight falling on the rims/ridges between the craters La Caille, Blanchinus, and Purbach.

Help EarthSky stay an independent voice! Donate here.

Ron Bee photo of Lunar X from 2007.

In the case of Lunar X, the pattern repeats at each cycle of the moon, but only for a short time. The X is observable for about 4 hours around the first quarter moon phase.

Aniruddha Bhat in Maryland caught this Lunar X on January 16, 2016.

Bottom line: Lunar X is an optical feature on the moon, an apparent X on the moon’s surface, visible through telescopes. It’s caused by sunlight falling on the rims/ridges between the craters La Caille, Blanchinus, and Purbach.

from EarthSky http://ift.tt/2oQglrU

April 3 is John Burroughs’ birthday

John Burroughs. Image via Wikimedia Commons/Library of Congress

April 3, 1837. John Burroughs – born on today’s date in 1837 – was one of the first naturalists who focused on communicating his love of nature through the written word. You might think you haven’t heard of Burroughs, but you’ve probably heard of some of the things he said. For example:

I go to nature to be soothed and healed, and to have my senses put in order.

He was one of the first to say in print:

If you think you can do it, you can.

And he said:

To me – old age is always 10 years older than I am.

Burroughs was born on a family farm in the Catskill Mountains, in New York state. He was said to be captivated by the return of the birds each spring and other wildlife around the farm, including frogs and bumblebees. In his later years, he credited his life as a farm boy for his subsequent love of nature and feeling of kinship with all rural things.

Later in life, Burroughs often moonlighted as a writer while holding other jobs, which ranged from a teacher, to a farmer, to an employee of the U.S. Treasury Department. His prominent magazine publications included Atlantic Monthly. You can access some of his Atlantic Monthly articles here: http://ift.tt/1GnZfWU

Or you can find many of his writings available free online at Project Gutenberg. Access them here: http://ift.tt/1CjA7KN

From his youth, Burroughs was an avid fly fisherman. This photo is from his 1906 book Camping and Tramping with Roosevelt.

John Burroughs died in 1921. President Theodore Roosevelt, in dedicating one of his books to Burroughs wrote of him:

It is a good thing for our people that you have lived, and surely no man can wish to have more said of him.

Meanwhile, Burroughs said of himself:

Joy in the universe, and keen curiosity about it all – that has been my religion.

Bottom line: April 3, 1837 is the birthday of John Burroughs, one of the first naturalists who focused on communicating his love of nature through the written word.

from EarthSky http://ift.tt/1GnZe5n

John Burroughs. Image via Wikimedia Commons/Library of Congress

April 3, 1837. John Burroughs – born on today’s date in 1837 – was one of the first naturalists who focused on communicating his love of nature through the written word. You might think you haven’t heard of Burroughs, but you’ve probably heard of some of the things he said. For example:

I go to nature to be soothed and healed, and to have my senses put in order.

He was one of the first to say in print:

If you think you can do it, you can.

And he said:

To me – old age is always 10 years older than I am.

Burroughs was born on a family farm in the Catskill Mountains, in New York state. He was said to be captivated by the return of the birds each spring and other wildlife around the farm, including frogs and bumblebees. In his later years, he credited his life as a farm boy for his subsequent love of nature and feeling of kinship with all rural things.

Later in life, Burroughs often moonlighted as a writer while holding other jobs, which ranged from a teacher, to a farmer, to an employee of the U.S. Treasury Department. His prominent magazine publications included Atlantic Monthly. You can access some of his Atlantic Monthly articles here: http://ift.tt/1GnZfWU

Or you can find many of his writings available free online at Project Gutenberg. Access them here: http://ift.tt/1CjA7KN

From his youth, Burroughs was an avid fly fisherman. This photo is from his 1906 book Camping and Tramping with Roosevelt.

John Burroughs died in 1921. President Theodore Roosevelt, in dedicating one of his books to Burroughs wrote of him:

It is a good thing for our people that you have lived, and surely no man can wish to have more said of him.

Meanwhile, Burroughs said of himself:

Joy in the universe, and keen curiosity about it all – that has been my religion.

Bottom line: April 3, 1837 is the birthday of John Burroughs, one of the first naturalists who focused on communicating his love of nature through the written word.

from EarthSky http://ift.tt/1GnZe5n

[Aardvarchaeology]

I like this illustration. Note the spirals in the woman’s hair, repeated in the clouds. Also the hint of post-nookie intimacy suggested by this being *breakfast* tea.

• Been helping Jrette study French for a test. Love making up absurd sentences for her to translate. “On my right is Charlemagne. He is wearing Father’s pink beret. If you take Father’s beret he will not be very nice. But Charlemagne gets to borrow it.”
• Finally got it. The name of the crowdfunding site IndieGogo references indigo.
• Listening to Tubular Bells. Can’t get over that Oldfield was 19 when he recorded it.
• Updated Facebook Messenger and suddenly got access to this enormous backlog of messages from strangers who have tried to contact me for years, most of them quite legitimately, yet which have been automatically muted. /-:
• Planning some fieldwork, I just got schooled in documentation by a metal detectorist. He politely told me we should collect much more accurate information about where each detectorist goes on the site, and offered to organise it.
• 30 March was my tenth anniversary as a daily Linux user. I’ve never really had to learn the command line interface. I still don’t know how to compile source code. It just works. I particularly like that Linux installations don’t spontaneously get slower with time, and that updates don’t noticeably demand more processing power.
• Jrette showed me some male celebs whom she finds handsome. They looked like me with hair and smaller noses. Then she asked me to show her a male celeb whose looks I like. I showed her Mattias Bärjed 15 years ago. Who, I realised, looked like me with hair.
• Don’t write “Not to scale” in captions when you illustrate small finds. All images are to some scale even if it’s unknown to you. The only exception is if the image is funhouse mirrored so that the object is deformed.
• It’s kind of nice to think that Swedish has no equivalents of the verbs sneer and frown. Instead we have to say “to derision-smile” and “to wrinkle the eyebrows”.

Check out the hammer marks on the copper dome / lid that Ola Lindgren excavated inside the kastal tower at Stensö in 2015! 15-20 cm diam. No fancy finial, sadly. X-ray photo by Carola Bohm.

Domed sheet copper lid, inside view, Stensö Castle

Here’s my paternal grandpa Kurt Rundkvist (1911-51). He was a cheerful sort who enjoyed canoeing. I wish he’d still been around when I grew up. Luckily I did get to see a lot of my maternal grandpa Ingemar.

from ScienceBlogs http://ift.tt/2ot50lx

I like this illustration. Note the spirals in the woman’s hair, repeated in the clouds. Also the hint of post-nookie intimacy suggested by this being *breakfast* tea.

• Been helping Jrette study French for a test. Love making up absurd sentences for her to translate. “On my right is Charlemagne. He is wearing Father’s pink beret. If you take Father’s beret he will not be very nice. But Charlemagne gets to borrow it.”
• Finally got it. The name of the crowdfunding site IndieGogo references indigo.
• Listening to Tubular Bells. Can’t get over that Oldfield was 19 when he recorded it.
• Updated Facebook Messenger and suddenly got access to this enormous backlog of messages from strangers who have tried to contact me for years, most of them quite legitimately, yet which have been automatically muted. /-:
• Planning some fieldwork, I just got schooled in documentation by a metal detectorist. He politely told me we should collect much more accurate information about where each detectorist goes on the site, and offered to organise it.
• 30 March was my tenth anniversary as a daily Linux user. I’ve never really had to learn the command line interface. I still don’t know how to compile source code. It just works. I particularly like that Linux installations don’t spontaneously get slower with time, and that updates don’t noticeably demand more processing power.
• Jrette showed me some male celebs whom she finds handsome. They looked like me with hair and smaller noses. Then she asked me to show her a male celeb whose looks I like. I showed her Mattias Bärjed 15 years ago. Who, I realised, looked like me with hair.
• Don’t write “Not to scale” in captions when you illustrate small finds. All images are to some scale even if it’s unknown to you. The only exception is if the image is funhouse mirrored so that the object is deformed.
• It’s kind of nice to think that Swedish has no equivalents of the verbs sneer and frown. Instead we have to say “to derision-smile” and “to wrinkle the eyebrows”.

Check out the hammer marks on the copper dome / lid that Ola Lindgren excavated inside the kastal tower at Stensö in 2015! 15-20 cm diam. No fancy finial, sadly. X-ray photo by Carola Bohm.

Domed sheet copper lid, inside view, Stensö Castle

Here’s my paternal grandpa Kurt Rundkvist (1911-51). He was a cheerful sort who enjoyed canoeing. I wish he’d still been around when I grew up. Luckily I did get to see a lot of my maternal grandpa Ingemar.

from ScienceBlogs http://ift.tt/2ot50lx

Army Engineers Tackle Dirty Job of Soil Testing

Before the U.S. Army Corps of Engineers can dredge an area, proper sediment testing must take place. This video explains that process.
Read More

from Armed with Science http://ift.tt/2nRGQiQ

Before the U.S. Army Corps of Engineers can dredge an area, proper sediment testing must take place. This video explains that process.
Read More

from Armed with Science http://ift.tt/2nRGQiQ