Quarter moon, Earth at perihelion and neap tide

The moon reaches its last quarter phase and swings out to lunar apogee – its most distant point from Earth in its orbit – on January 2, 2016. In addition, the Earth sweeps to perihelion – its closest point to the sun in its orbit – on this same date: January 2, 2016. The combination of the last quarter moon at lunar apogee, and Earth at perihelion, should usher in a relatively even-keeled neap tide over the next few days.

At neap tide, the variation between high tide and low tide is at a bare minimum. High tide doesn’t climb all that high and low tide doesn’t fall all that low. At quarter moon, the sun and moon make a 90^o angle in Earth’s sky, so the tidal influence of the sun partially cancels out the tidal influence of the moon. Therefore, the range between high and low tides is quite subdued.

Around each first quarter moon and last quarter moon – when the sun and moon are at a right angle to Earth – the range between high and low tides is least. These are called neap tides. Image via physicalgeography.net

On the other hand, at new moon or full moon the tidal influence of the sun and moon combine to create wide-ranging spring tides. The high tide soars way up high whereas the low tide sinks way down low.

Around each new moon and full moon – when the sun, Earth, and moon are located more or less on a line in space – the range between high and low tides is greatest. These are called spring tides. Image via physicalgeography.net

The moon’s tidal force is about two times greater than that of the sun. Yet, with the quarter moon closely aligning with apogee on January 2, 2016, the moon’s tide-generating force is less than average. Also, the sun comes closest to Earth for the year on January 2, 2016, so the sun’s tide-generating force is at its greatest at this time of year. Unless a storm surge throws a monkey-wrench into things, the ocean coastlines should display little change between high and low tide during the next few days.

Two years from now – in early January 2018 – the full moon will closely align with lunar perigee – the moon’s closest point to Earth in its orbit. And, as always, Earth will be at perihelion in early January. At that time, we should expect a wide-ranging perigean spring tide, as the extra-close full moon teams up with the extra-close sun to produce a maximum variation in high and low tide in early January 2018.

In the meantime, enjoy the relatively level waters that accompany the early January 2016 neap tide!

from EarthSky http://ift.tt/1O1cvBN

The moon reaches its last quarter phase and swings out to lunar apogee – its most distant point from Earth in its orbit – on January 2, 2016. In addition, the Earth sweeps to perihelion – its closest point to the sun in its orbit – on this same date: January 2, 2016. The combination of the last quarter moon at lunar apogee, and Earth at perihelion, should usher in a relatively even-keeled neap tide over the next few days.

At neap tide, the variation between high tide and low tide is at a bare minimum. High tide doesn’t climb all that high and low tide doesn’t fall all that low. At quarter moon, the sun and moon make a 90^o angle in Earth’s sky, so the tidal influence of the sun partially cancels out the tidal influence of the moon. Therefore, the range between high and low tides is quite subdued.

Around each first quarter moon and last quarter moon – when the sun and moon are at a right angle to Earth – the range between high and low tides is least. These are called neap tides. Image via physicalgeography.net

On the other hand, at new moon or full moon the tidal influence of the sun and moon combine to create wide-ranging spring tides. The high tide soars way up high whereas the low tide sinks way down low.

Around each new moon and full moon – when the sun, Earth, and moon are located more or less on a line in space – the range between high and low tides is greatest. These are called spring tides. Image via physicalgeography.net

The moon’s tidal force is about two times greater than that of the sun. Yet, with the quarter moon closely aligning with apogee on January 2, 2016, the moon’s tide-generating force is less than average. Also, the sun comes closest to Earth for the year on January 2, 2016, so the sun’s tide-generating force is at its greatest at this time of year. Unless a storm surge throws a monkey-wrench into things, the ocean coastlines should display little change between high and low tide during the next few days.

Two years from now – in early January 2018 – the full moon will closely align with lunar perigee – the moon’s closest point to Earth in its orbit. And, as always, Earth will be at perihelion in early January. At that time, we should expect a wide-ranging perigean spring tide, as the extra-close full moon teams up with the extra-close sun to produce a maximum variation in high and low tide in early January 2018.

In the meantime, enjoy the relatively level waters that accompany the early January 2016 neap tide!

from EarthSky http://ift.tt/1O1cvBN

Earth closest to sun on January 2

Are you an early riser? Use the waning moon to locate the planet Mars and star Spica before sunrise.

Cartoon above via Sara Zimmerman at Unearthed Comics.

On January 2, 2016, our planet Earth reaches its closest point to the sun for this year at 22:49 Universal Time (5:49 p.m. EST). This is Earth’s perihelion. The word perihelion is from Greek roots peri meaning near, and helios meaning sun.

Earth is closest to the sun every year in early January, when it’s winter for the Northern Hemisphere. We’re farthest away from the sun in early July, during our Northern Hemisphere summer.

Earth is about 5 million kilometers – or 3 million miles – closer to the sun in early January than it is in early July. That’s not a huge change in distance. It’s not enough of a change to cause the seasons on Earth.

This year, on January 2, 2016, the Earth at its closest point swings to within 147,100,176 kilometers (91,403,812 miles) of the sun. That’s in contrast to six months from now, when the Earth reaches aphelion – its most distant point – on July 4, 2016: 152,103,776 km (94,512,904 miles).

Despite what many may think, Earth’s distance from the sun isn’t what causes the seasons. On Earth, because our orbit is so close to being circular, it’s mostly the tilt of our world’s axis that creates winter and summer. In winter, your part of Earth is tilted away from the sun. In summer, your part of Earth is tilted toward the sun. The day of maximum tilt toward or away from the sun is the December or June solstice.

Earth at perihelion and aphelion: 2001 to 2100

Image credit: NASA

Though not responsible for the seasons, Earth’s closest and farthest points to the sun do affect seasonal lengths. When the Earth comes closest to the sun for the year, as around now, our world is moving fastest in orbit around the sun. Earth is rushing along now at 30.3 kilometers per second (almost 19 miles per second) – moving about a kilometer per second faster than when Earth is farthest from the sun in early July. Thus the Northern Hemisphere winter (Southern Hemisphere summer) is the shortest season as Earth rushes from the solstice in December to the equinox in March.

In the Northern Hemisphere, the summer season (June solstice to September equinox) lasts nearly 5 days longer than our winter season. And, of course, the corresponding seasons in the Southern Hemisphere are opposite. Southern Hemisphere winter is nearly 5 days longer than Southern Hemisphere summer.

It’s all due to the shape of Earth’s orbit. The shape is an ellipse, like a circle someone sat down on and squashed. The elliptical shape of Earth’s orbit causes the variation in the length of the seasons – and brings us closest to the sun in January.

Image Credit: Dna-webmaster

Bottom line: In 2016, Earth’s closest point to the sun – called its perihelion – comes on January 2 at 22:49 UTC (5:49 p.m. EST).

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky Planisphere today!

Are the December solstice and January perihelion related?

from EarthSky http://ift.tt/S3BOw5

Are you an early riser? Use the waning moon to locate the planet Mars and star Spica before sunrise.

Cartoon above via Sara Zimmerman at Unearthed Comics.

On January 2, 2016, our planet Earth reaches its closest point to the sun for this year at 22:49 Universal Time (5:49 p.m. EST). This is Earth’s perihelion. The word perihelion is from Greek roots peri meaning near, and helios meaning sun.

Earth is closest to the sun every year in early January, when it’s winter for the Northern Hemisphere. We’re farthest away from the sun in early July, during our Northern Hemisphere summer.

Earth is about 5 million kilometers – or 3 million miles – closer to the sun in early January than it is in early July. That’s not a huge change in distance. It’s not enough of a change to cause the seasons on Earth.

This year, on January 2, 2016, the Earth at its closest point swings to within 147,100,176 kilometers (91,403,812 miles) of the sun. That’s in contrast to six months from now, when the Earth reaches aphelion – its most distant point – on July 4, 2016: 152,103,776 km (94,512,904 miles).

Despite what many may think, Earth’s distance from the sun isn’t what causes the seasons. On Earth, because our orbit is so close to being circular, it’s mostly the tilt of our world’s axis that creates winter and summer. In winter, your part of Earth is tilted away from the sun. In summer, your part of Earth is tilted toward the sun. The day of maximum tilt toward or away from the sun is the December or June solstice.

Earth at perihelion and aphelion: 2001 to 2100

Image credit: NASA

Though not responsible for the seasons, Earth’s closest and farthest points to the sun do affect seasonal lengths. When the Earth comes closest to the sun for the year, as around now, our world is moving fastest in orbit around the sun. Earth is rushing along now at 30.3 kilometers per second (almost 19 miles per second) – moving about a kilometer per second faster than when Earth is farthest from the sun in early July. Thus the Northern Hemisphere winter (Southern Hemisphere summer) is the shortest season as Earth rushes from the solstice in December to the equinox in March.

In the Northern Hemisphere, the summer season (June solstice to September equinox) lasts nearly 5 days longer than our winter season. And, of course, the corresponding seasons in the Southern Hemisphere are opposite. Southern Hemisphere winter is nearly 5 days longer than Southern Hemisphere summer.

It’s all due to the shape of Earth’s orbit. The shape is an ellipse, like a circle someone sat down on and squashed. The elliptical shape of Earth’s orbit causes the variation in the length of the seasons – and brings us closest to the sun in January.

Image Credit: Dna-webmaster

Bottom line: In 2016, Earth’s closest point to the sun – called its perihelion – comes on January 2 at 22:49 UTC (5:49 p.m. EST).

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky Planisphere today!

Are the December solstice and January perihelion related?

from EarthSky http://ift.tt/S3BOw5

Best Science Books 2015: NBC News 12 Notable Tech and Science Books of 2015 [Confessions of a Science Librarian]

As you all have no doubt noticed over the years, I love highlighting the best science books every year via the various end of year lists that newspapers, web sites, etc. publish. I’ve done it so far in 2008, 2009, 2010, 2011, 2012, 2013 and 2014.

And here we are in 2015!

As in previous years, my definition of “science books” is pretty inclusive, including books on technology, engineering, nature, the environment, science policy, history & philosophy of science, geek culture and whatever else seems to be relevant in my opinion.

Today’s list is NBC News 12 Notable Tech and Science Books of 2015.

• On the Move: A Life by Oliver Sacks
• The Man Who Wasn’t There: Investigations into the Strange New Science of the Self by Anil Ananthaswam
• Domesticated: Evolution in a Man-Made World by Richard C. Francis
• Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe by Lisa Randal
• The Invention of Science: A New History of the Scientific Revolution by David Wootton
• The Hunt for Vulcan: . . . And How Albert Einstein Destroyed a Planet, Discovered Relativity, and Deciphered the Universe by Thomas Levenson
• Elon Musk: Tesla, SpaceX, and the Quest for a Fantastic Future by Ashlee Vance
• Rise of the Robots: Technology and the Threat of a Jobless Future by Martin Ford
• The Master Algorithm: How the Quest for the Ultimate Learning Machine Will Remake Our World by Pedro Domingos
• Big Science: Ernest Lawrence and the Invention that Launched the Military-Industrial Complex by Michael Hiltzik
• Leaving Orbit: Notes from the Last Days of American Spaceflight by Margaret Lazarus Dean
• Future Crimes: Everything Is Connected, Everyone Is Vulnerable and What We Can Do About It by Marc Goodman

And check out my previous 2015 lists here!

Many of the lists I use are sourced via the Largehearted Boy master list.

(Astute readers will notice that I kind of petered out on this project a couple of years ago and never got around to the end of year summary since then. Before loosing steam, I ended up featuring dozens and dozens of lists, virtually every list I could find that had science books on it. While it was kind of cool to be so comprehensive, not to mention that it gave the summary posts a certain statistical weight, it was also way more work than I had really envisioned way back in 2008 or so when I started doing this. As a result, I’m only going to highlight particularly large or noteworthy lists this year and forgo any kind of end of year summary. Basically, all the fun but not so much of the drudgery.)

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

As you all have no doubt noticed over the years, I love highlighting the best science books every year via the various end of year lists that newspapers, web sites, etc. publish. I’ve done it so far in 2008, 2009, 2010, 2011, 2012, 2013 and 2014.

And here we are in 2015!

As in previous years, my definition of “science books” is pretty inclusive, including books on technology, engineering, nature, the environment, science policy, history & philosophy of science, geek culture and whatever else seems to be relevant in my opinion.

Today’s list is NBC News 12 Notable Tech and Science Books of 2015.

• On the Move: A Life by Oliver Sacks
• The Man Who Wasn’t There: Investigations into the Strange New Science of the Self by Anil Ananthaswam
• Domesticated: Evolution in a Man-Made World by Richard C. Francis
• Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe by Lisa Randal
• The Invention of Science: A New History of the Scientific Revolution by David Wootton
• The Hunt for Vulcan: . . . And How Albert Einstein Destroyed a Planet, Discovered Relativity, and Deciphered the Universe by Thomas Levenson
• Elon Musk: Tesla, SpaceX, and the Quest for a Fantastic Future by Ashlee Vance
• Rise of the Robots: Technology and the Threat of a Jobless Future by Martin Ford
• The Master Algorithm: How the Quest for the Ultimate Learning Machine Will Remake Our World by Pedro Domingos
• Big Science: Ernest Lawrence and the Invention that Launched the Military-Industrial Complex by Michael Hiltzik
• Leaving Orbit: Notes from the Last Days of American Spaceflight by Margaret Lazarus Dean
• Future Crimes: Everything Is Connected, Everyone Is Vulnerable and What We Can Do About It by Marc Goodman

And check out my previous 2015 lists here!

Many of the lists I use are sourced via the Largehearted Boy master list.

(Astute readers will notice that I kind of petered out on this project a couple of years ago and never got around to the end of year summary since then. Before loosing steam, I ended up featuring dozens and dozens of lists, virtually every list I could find that had science books on it. While it was kind of cool to be so comprehensive, not to mention that it gave the summary posts a certain statistical weight, it was also way more work than I had really envisioned way back in 2008 or so when I started doing this. As a result, I’m only going to highlight particularly large or noteworthy lists this year and forgo any kind of end of year summary. Basically, all the fun but not so much of the drudgery.)

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

The ten greatest steps of the last ten decades (Synopsis) [Starts With A Bang]

“Gamow was fantastic in his ideas. He was right, he was wrong. More often wrong than right. Always interesting; … and when his idea was not wrong it was not only right, it was new.” -Edward Teller

Considering what we know about our Universe today, it’s hard to believe that just a century ago, Einstein’s General Relativity was very much untested and uncertain, and we hadn’t even realized that anything at all lie outside our own Milky Way. But over the past ten decades, ten great discoveries have taken place to give us the Universe we understand today.

Image credit: Adam Block/Mount Lemmon SkyCenter/University of Arizona.

Complete with the Big Bang, dark matter, dark energy, cosmic inflation and so much more, one can’t help but wonder what the current decade — or even the coming decades — might hold to open up our understanding of the Universe even further.

Image credit: Bock et al. (2006, astro-ph/0604101); modifications by me.

Go read the whole story over at Forbes, and ring in 2016 in the most spectacular way possible: with science!

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

“Gamow was fantastic in his ideas. He was right, he was wrong. More often wrong than right. Always interesting; … and when his idea was not wrong it was not only right, it was new.” -Edward Teller

Considering what we know about our Universe today, it’s hard to believe that just a century ago, Einstein’s General Relativity was very much untested and uncertain, and we hadn’t even realized that anything at all lie outside our own Milky Way. But over the past ten decades, ten great discoveries have taken place to give us the Universe we understand today.

Image credit: Adam Block/Mount Lemmon SkyCenter/University of Arizona.

Complete with the Big Bang, dark matter, dark energy, cosmic inflation and so much more, one can’t help but wonder what the current decade — or even the coming decades — might hold to open up our understanding of the Universe even further.

Image credit: Bock et al. (2006, astro-ph/0604101); modifications by me.

Go read the whole story over at Forbes, and ring in 2016 in the most spectacular way possible: with science!

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

Another day, another creationist [Pharyngula]

My conversation with Perry Marshall about “evolution 2.0” is now online on the radio show Unbelievable.

Marshall is sales and marketing guy who has written a book titled Evolution 2.0: Breaking the Deadlock Between Darwin and Design, in which he claims to have worked out a reconciliation between science and religion based on arguments he had with his missionary/theologian brother, that hints at the quality of the science you’ll find in it. He has a superficial view of a few biological processes, like DNA error repair and transposition, and has shoehorned them into his religious belief that these are the tools used by some kind of engineering force that makes them purposeful.

He has a challenge with a $100,000 prize. All you have to do is show an example of Information that doesn’t come from a mind. Basically he’s making the clueless argument that there are no processes in genetics that produce novel information. I think Jeffrey Shallit ought to step up and claim it. Actually, he might have to fight through a mob of information theorists to get his money (if it exists, and if the judging wasn’t rigged).

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

My conversation with Perry Marshall about “evolution 2.0” is now online on the radio show Unbelievable.

Marshall is sales and marketing guy who has written a book titled Evolution 2.0: Breaking the Deadlock Between Darwin and Design, in which he claims to have worked out a reconciliation between science and religion based on arguments he had with his missionary/theologian brother, that hints at the quality of the science you’ll find in it. He has a superficial view of a few biological processes, like DNA error repair and transposition, and has shoehorned them into his religious belief that these are the tools used by some kind of engineering force that makes them purposeful.

He has a challenge with a $100,000 prize. All you have to do is show an example of Information that doesn’t come from a mind. Basically he’s making the clueless argument that there are no processes in genetics that produce novel information. I think Jeffrey Shallit ought to step up and claim it. Actually, he might have to fight through a mob of information theorists to get his money (if it exists, and if the judging wasn’t rigged).

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

Michael Mann on El Niño, COP15, Future Climate Change [Greg Laden's Blog]

Despite the devastating storms across the country the last few weeks, NASA is forecasting the worst is yet to come. Michael Mann, author of “Dire Predictions: Understanding Climate Change” joins to discuss.

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

Despite the devastating storms across the country the last few weeks, NASA is forecasting the worst is yet to come. Michael Mann, author of “Dire Predictions: Understanding Climate Change” joins to discuss.

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

Learn Python Using Minecraft [Greg Laden's Blog]

Minecraft is a gaming world. Or, if you like, a “sandbox.” This is a three dimensional world in which characters do things, all sorts of things. The context for the world of Minecraft is very open ended. The player builds things, moves things, gets things, does things, in a way that makes any one gamer’s game potentially very different from any other gamer’s game.

You can buy Minecraft in various forms such as an XBox 360 version. It comes in Lego form (for example, this), and you can get a Minecraft cloud server version at Minecraft.net.

If you install Minecraft from Minecraft.net (about 30 bucks) and have Python 3, Java, the Minceraft Python API, and a Spigot Minecraft Server, you can program your own versions of the game using Python programming/scripting language.

But how? How do you do that?

Well, you can get Learn to Program with Minecraft: Transform Your World with the Power of Python. This book is intended to teach programming, in the Minecraft setting. The book is designed for kids 10 years and older, though I’m sure some younger kids can use it. Also, it must be admitted that a learning to program book like this may be most valuable for adults who are not coders but want to learn some coding, and happen to be gamers and like Minecraft.

The book, new on the market, provides excellent instructions for setting up all that stuff mentioned above. Everything should work on a Windows machine, on Mac OS X, and Linux.

The programming you do with this book is pretty sophisticated. You learn to create palaces, pyramids, to teleoport players around, to stack blocks, interact with Minecraft’s chat feature, blow stuff up, cast spells, and replicate sections of the Minecraft countryside.

Here is what is interesting about this approach. Python programming is pretty basic, and pretty useful, but one has to do a lot of work to develop something slick and fancy and highly functional (counting working video games or interfaces as highly functional). But working with the existing Minecraft system, via the API, allows some relatively simple programming to produce impressive results. This is “Hello World” on steroids, at the very least.

Of all the diverse No Starch Press programming guides, this one may turn out to be the most effective, as a teaching tools, for that special case where a person is already interested in Minecraft and wants to learn Python.

Here is the Table of Contents:

Introduction
Chapter 1: Setting Up for Your Adventure
Chapter 2: Teleporting with Variables
Chapter 3: Building Quickly and Traveling Far with Math
Chapter 4: Chatting with Strings
Chapter 5: Figuring Out What’s True and False with Booleans
Chapter 6: Making Mini-Games with if Statements
Chapter 7: Dance Parties and Flower Parades with while Loops
Chapter 8: Functions Give You Superpowers
Chapter 9: Hitting Things with Lists and Dictionaries
Chapter 10: Minecraft Magic with for Loops
Chapter 11: Saving and Loading Buildings with Files and Modules
Chapter 12: Getting Classy with Object-Oriented Programming
Afterword
Block ID Cheat Sheet

The author, Craig Richardson, is a eacher of Python, former high school computing science teacher, and has been involved with the Raspberry Pi Foundation.

from ScienceBlogs http://ift.tt/1NZno7d

Minecraft is a gaming world. Or, if you like, a “sandbox.” This is a three dimensional world in which characters do things, all sorts of things. The context for the world of Minecraft is very open ended. The player builds things, moves things, gets things, does things, in a way that makes any one gamer’s game potentially very different from any other gamer’s game.

You can buy Minecraft in various forms such as an XBox 360 version. It comes in Lego form (for example, this), and you can get a Minecraft cloud server version at Minecraft.net.

If you install Minecraft from Minecraft.net (about 30 bucks) and have Python 3, Java, the Minceraft Python API, and a Spigot Minecraft Server, you can program your own versions of the game using Python programming/scripting language.

But how? How do you do that?

Well, you can get Learn to Program with Minecraft: Transform Your World with the Power of Python. This book is intended to teach programming, in the Minecraft setting. The book is designed for kids 10 years and older, though I’m sure some younger kids can use it. Also, it must be admitted that a learning to program book like this may be most valuable for adults who are not coders but want to learn some coding, and happen to be gamers and like Minecraft.

The book, new on the market, provides excellent instructions for setting up all that stuff mentioned above. Everything should work on a Windows machine, on Mac OS X, and Linux.

The programming you do with this book is pretty sophisticated. You learn to create palaces, pyramids, to teleoport players around, to stack blocks, interact with Minecraft’s chat feature, blow stuff up, cast spells, and replicate sections of the Minecraft countryside.

Here is what is interesting about this approach. Python programming is pretty basic, and pretty useful, but one has to do a lot of work to develop something slick and fancy and highly functional (counting working video games or interfaces as highly functional). But working with the existing Minecraft system, via the API, allows some relatively simple programming to produce impressive results. This is “Hello World” on steroids, at the very least.

Of all the diverse No Starch Press programming guides, this one may turn out to be the most effective, as a teaching tools, for that special case where a person is already interested in Minecraft and wants to learn Python.

Here is the Table of Contents:

Introduction
Chapter 1: Setting Up for Your Adventure
Chapter 2: Teleporting with Variables
Chapter 3: Building Quickly and Traveling Far with Math
Chapter 4: Chatting with Strings
Chapter 5: Figuring Out What’s True and False with Booleans
Chapter 6: Making Mini-Games with if Statements
Chapter 7: Dance Parties and Flower Parades with while Loops
Chapter 8: Functions Give You Superpowers
Chapter 9: Hitting Things with Lists and Dictionaries
Chapter 10: Minecraft Magic with for Loops
Chapter 11: Saving and Loading Buildings with Files and Modules
Chapter 12: Getting Classy with Object-Oriented Programming
Afterword
Block ID Cheat Sheet

The author, Craig Richardson, is a eacher of Python, former high school computing science teacher, and has been involved with the Raspberry Pi Foundation.

from ScienceBlogs http://ift.tt/1NZno7d