January 4 – Happy Newtonmas!

Today’s factismal: Isaac Newton was born on January 4, 1643.

About a week ago, you may have seen texts fling about from various folks, telling the tale of a baby who was born on Christmas and would go on to change the world – a baby by the name of Isaac Newton. The only problem is that the texts are wrong (sort of). You see, by our calendar, Isaac Newton was born on January 4, not December 25. And therein lies a tale.

Isaac Newton, the man who changed science even if he couldn't get his birthday right (Image courtesy Barrington Bramley)

Isaac Newton, the man who changed science even if he couldn’t get his birthday right
(Image courtesy Barrington Bramley)

You see, calendars are tricky things.  Until the time of Julius Caesar (yes, that Julius Caesar), the Roman calendar was a mess. The original Romulan (no, not those Romulans!) calendar had just ten months and covered just 304 days of the year – the period between December and March were just considered to be one long, cold, winter of despair. Obviously, this wasn’t a very good way of keeping track of time. So Numa, the second king of Rome, changed it.

Numa, the Roman who created the first

Numa, the Roman who created the first “good” calendar
(Image courtesy User Hedning on sv.wikipedia)

Numa added two more months between December and March, and brought the length of the year up to 355 days. But, as every schoolkid knows today, the year is actually closer to 365.25 days long. As a result, the calendar slowly slipped ahead of the actual year, with the embarrassing result of the equinox being declared several weeks before it actually happened! In order to fix this, the chief priest (called the Pontifex Maximus or “Chief Bridge Builder”) would slip in after February an intercalendary month known as a Mensis Intercalaris every so often. Because of the extreme difference between the length of the calendar and the length of the actual year, this had to be done roughly every other year.

But then Roman politics came into play. You see, the Pontifex Maximus was usually also the person who was in charge or one of his friends. As a result, the Pontifex Maximus could add in a Mensis Intercalaris or two when his party was in power (thus making the year and their term in power longer) or withhold them when the other guys were (thus making the year shorter). The worst offender for this was, you guessed it, Julius Caesar who made the year of his third consulship 445 days long!

Julius Caesar conquered the Gauls and the calendar (Image courtesy H. F. Helmolt )

Julius Caesar conquered the Gauls and the calendar
(Image courtesy H. F. Helmolt )

This move offended just about everyone. In order to push it through, Caesar had to promise to reform the calendar so that nobody else could play that sort of trick again. (For a more modern example of this sort of political shenanigans, consider FDR’s four presidential terms.) He did it by making the year 365 days long and adding in an intercalendary day at the end of February every four years, starting with the year 46 BCE.

Now this would have been the end of the story, other than the various maneuverings over the names of months, except for one important fact: the year is not 365.25 days long. Instead, it is 365 days, 5 hours 49 minutes, and 12 seconds long, or a difference of 10 minutes and 48 seconds. Though the difference might not seem like much, it added up over the course of a few centuries. By 1582 CE, the calendar was nearly eleven days behind, throwing everything out of whack.

A comparison of the three calendars. The Gregorian comes closest to our modern year.

A comparison of the three calendars. Pope Gregory’s calendar comes closest to matching our modern year.

So it was up to the new Pontifex Maximus, Pope Gregory XIII, to fix the mess. He did it by jumping the calendar forward ten days and by changing the number of leap years. Under Gregory, every fourth year would be a leap year unless it fell on a century (i.e., 1000, 1200); only every fourth century year (i.e., those divisible by 400) would be leap years. That neatly fixed the lagging calendar and patched the problem so that another intercalendary day wouldn’t be needed until the year 10,000.

But Europe in 1582 CE isn’t the same as Rome in 46 BCE, and though the Pope might call himself the Pontifex Maximus, he didn’t have complete control over the world’s calendars. As a result, many countries didn’t adopt the new calendar until much later. Italy, of course, adopted it immediately. France took up the new calendar less than a year later. But it wasn’t until 1752 that England finally adopted the new calendar. And that is why, though Isaac Newton was born on Christmas day in England, he was really born on January 4 by our calendar. So Happy Newtonmas!

And if you’d like to celebrate, why not do so by lending some of your computer time to LHC@Home? They’ll use your spare computer time to help solve mysteries such as “What is Dark Matter?” and “What would happen if π were exactly 3?” To learn more, page over to:

January 2 – Anemia Pint!

Today’s factismal: The human body creates two million red blood cells every second.

On a typical day, some 41,000 units of blood will be needed in the US alone. But no day is average; there are good days and bad days. And most of the bad blood days happen in January when there are more accidents and fewer people donating blood. As a result, blood banks are always critically short of blood during the long winter months. And that is why January is National Blood Donor Month.


Which blood type are you?

When you donate blood to the Red Cross, they use it specifically for saving lives through transfusions. But your one pint of blood may be used for as many as three different transfusions! They can do that because blood consists of plasma (55%), red blood cells (40%), white blood cells (3%), and platelets (2%). After you donate, your blood is tested for communicable diseases as a precautionary measure. Next it is separated into red blood cells (which carry oxygen), platelets (which cause the blood to clot), and plasma (which holds the other two). By using the red blood cells on one person, the platelets for a second, and giving the plasma to a third, your one donation can save three lives!

bloodOf the three components, red blood cells are the most important. That’s because the red blood cells are covered with proteins that can form clots if they don’t match the proteins in the serum. Fortunately, back in 1901, Karl Landsteiner discovered that most people have red blood cells that are covered with one of three different sets of proteins. He called them “groups A, B, and C”; this was changed into A, B, and O by later workers. And just six years later, in 1907 the first successful blood transfusion took place in New York. Thanks to his work, there are now more than 30 million successful blood donations every year in the US alone!

Blood Type Rh Factor How many have it?
O + 1 person in 3
O 1 person in 15
A + 1 person in 3
A 1 person in 16
B + 1 person in 12
B 1 person in 67
AB + 1 person in 29
AB 1 person in 167

If you’d like to be one of the 15 million people who donate blood every year, then why not contact the Red Cross? Every drop of blood that they get is used specifically for transfusions and they are always need more than they have, especially in January. So go give!


December 16 – Carb-gone 14

Today’s fasctismal: The oldest age that carbon-14 can give is 114,600 years; the youngest is 570 years.

If you have ever cleaned up a teenager’s room, then you have probably discovered one of the most fundamental tools of archeology: relative dating. (You’ve also discovered what it feels like to excavate a midden pile.) As you dug down through the layers of trash, petrified food, and old homework assignments, you probably noticed that the older stuff was on the bottom and the newer stuff was on the top. But what might surprise you more than the Wall Street Journal hidden under your child’s bed is the fact that until 1949, relative dating was about the only method that archeologists had for dating really old artifacts.

A household in Pompeii (My camera)

A household in Pompeii; we know how old this is thanks to records the Romans kept
(My camera)

That’s because very few artifacts come with a date on them. And even those that do come with an identifying mark, such as coins, only give you an approximate range of dates; for example, a coin with Julius Caesar’s face on it was probably minted sometime between 50 BCE (when he conquered Gaul) and 44 BCE (when his political opponents put a permanent end to his ambitions). And the older something is, the less likely it is to have any sort of identifying mark; an empty, twelve hundred year old clam shell from the Spiro Mound looks an awful lot like an empty, fifteen thousand year old clam shell from Siberia.

This coin provides an approximate date (Image courtesy Australian Centre for Ancient Numismatic Studies)

This coin provides an approximate date
(Image courtesy Australian Centre for Ancient Numismatic Studies)

Archeologists have come up with several methods for working around this problem (e.g., by counting tree rings), but they fail more often than not (after all, how many tree rings are there in a clay pot?). They needed something more. They needed a method that would work on almost everything and that could be easily verified. And, in 1949, a chemist by the name of Willard Libby gave it to them. He realized that by comparing the amount of carbon-14 that was in an object to the amount of carbon-12, he could tell how old something was. But, because carbon-14 had a half-life of 5,730 years, it could only be used to measure things that were between 0.1 and 20 half lives; that is, things that were no younger than 570 years old and no older than 114,600 years old.

But how does carbon dating work? I’ll give you an experiment that you can do at home to understand this basic concept (Teachers: This works really well in a large class if you ad up everyone’s numbers.). To do the experiment, you’ll need 84 pennies, 16 nickles, and 16 dimes. We’ll pretend that the pennies are atoms of carbon-12; because carbon-12 is stable, it doesn’t decay. A carbon-12 atom today will still be a carbon-12 atom 100,000 years from now. And we’ll pretend that the dimes are carbon-14 atoms. Carbon-14 is unstable; in 5,730 years, half of the carbon-14 that is present today will decay into nitrogen-14. (We never run out of carbon-14 because it is always being created by cosmic rays hitting nitrogen-14 in the atmosphere and turning it into carbon-14.)

When a critter dies, the ratio of carbon14 to carbon-12 is fixed

When a critter dies, the ratio of carbon14 to carbon-12 is fixed

Now a living thing will take in carbon-12 and carbon-14, so the proportion of the two atoms will be roughly the same as is in the atmosphere. But once it dies, it stops adding new carbon. As a result, when the carbon-14 decays it changes the ratio of the carbon atoms. To see that, we need to do our experiment. Start by placing the pennies in a pile and lining up the dimes, all heads up. (If you want, you can draw a dead critter around the money.) This is what the ratio of carbon-14 to carbon-12 looked like right after the critter died. There were 84 pennies/carbon-12 atoms and 16 dimes/carbon-14 atoms. (This was a very small critter.)

After one half-life about half of the carbon-14 has turned into nitrogen-14

After one half-life about half of the carbon-14 has turned into nitrogen-14

Since we don’t want to wait 5,730 years for the atoms to decay naturally, we’ll flip the dimes, one by one. If the dime comes up heads, put it back in the critter because it didn’t decay. But if it comes tails, the carbon-14 atom decayed and turned into nitrogen-14 (aka, a nickle). You’ll probably have about eight of the dimes decay, so your new ratio will be 86 pennies/carbon-12 atoms to 8 dimes/carbon-14 atoms. Now flip the dimes again, once more replacing those that come up tails with nickles. Odds are that you’ll lose about 4 dimes this time and your ratio will be 86 pennies/carbon-12 atoms to 4 dimes/carbon-14 atoms. Do it again and you’ll get something close to 86 pennies/carbon-12 atoms to 2 dimes/carbon-14 atoms.

After two half-lives half of the remaining carbon-14 has turned into nitrogen-14

After two half-lives half of the remaining carbon-14 has turned into nitrogen-14

As you can see from the experiment, the ratio can tell you when a critter, such as a possum or a palm tree, died. And if that critter was then used to make something else, such as a shoe or a house, then we know about when the something else was made. So all you have to do to find out how old something is is measure the ratio of the carbon-14 to the carbon-12 in it. Pretty nifty, huh?

After three half-lives half of the remaining carbon-14 has again turned into nitrogen-14

After three half-lives half of the remaining carbon-14 has again turned into nitrogen-14

But I’m willing to bet that your ratios didn’t exactly match mine. That’s because we only used a very few atoms; in most living things, there are quadrillions of carbon atoms instead of just 100. But there are still some variances in the ratios because radioactive decay happens randomly. As a result, most carbon-14 ages have an error of about 3-5% (i.e., a 570-year old sample is probably somewhere between 540 and 600 years old).

So that’s our experiment on carbon dating. And now that you are a fully-qualified archeologist on par with Indiana Jones, why not start doing some real archeology by becoming a Digital Volunteer at the Smithsonian? You’ll look at old documents, type what you see, and help preserve historical records dating back hundreds of years! To learn more, flip over to:

December 13 – Point It Out

Today’s factismal: The poinsettia and the Chinese tallow tree come from the same plant family.

For some folks, nothing says Christmas like a big, leafy poinsettia plant. These red and green bush has been a symbol of the season almost since the day that Joel Poinsett brought the first one back from his stay as ambassador to Mexico in 1825. Though the ones sold at the stores are typically only about a foot tall, under the right conditions (warm, fertile soil, plenty of sun and rain) they can grow to be more than 13 feet high! Interestingly, the bright red showy part of the plant isn’t the actual flower; they are leaves that respond to longer nights by turning color. The real flowers are the tiny yellow cyathia located in the center of the red leaves. They share this adaptation with the other members of their plant family, the Euphorbia (named after a Greek physician who described the laxative properties of the family back in 12 BCE). Though many in the family have bright colors and showy leaves like the poinsettia, others appear dull and drab.

The poinsettia, a non-invasive member of the family (Image courtesy USDA)

The poinsettia, a non-invasive member of the family
(Image courtesy USDA)

And, as is true in many families, the showiest ones are the least interesting and the most intriguing are the ones that don’t make a big entrance. For example, though the poinsettia is beautiful and popular across the world at this time of the year, the Chinese tallow plant may be both more valuable and more troublesome. That’s because the Chinese tallow plant acts as a valuable source of nectar for honeybees and other pollinating insects; in addition, the leaves and nuts of the plant are so rich in oil that they are used to make candles and soap. Some people are even exploring turning the Chinese tallow plant into biodiesel. However, the plant is also an aggressive invasive throughout much of America’s South. It is currently against state law to buy, sell, transport, or plant one in Texas, Georgia, and Florida. Despite this, some nurseries in the Northern United States still sell it as an ornamental plant!

The Chinese tallow is found across the South (Image courtesy USDA)

The Chinese tallow is found across the South
(Image courtesy USDA)

The Chinese tallow isn't pretty, but it is pretty obnoxious (Image courtesy USDA)

The Chinese tallow isn’t pretty, but it is pretty obnoxious
(Image courtesy USDA)

If you come across a Chinese tallow plant (or any other invasive plant), please report it to your state agricultural office. And if you’d like to do more to help keep invasives from ruining our beautiful land, then why not join the US Fish and Wildlife Service’s Volunteers against invasives program? For more details, go to:

December 12 – Catch The Wave

Today’s factismal: You can see meteor tracks using radio waves.

If you are a radio history buff, today is a triple jackpot. It starts at the dawn of radio, back in 1896, when Marconi showed a rapt audience in East London how pressing a key could transmit a signal without wires. While his assistant carried a small battery-powered box around the room, showing that it was not connected by wires to anything, Marconi repeatedly pressed a telegraph key to trigger a spark-gap transmitter similar to the one that Tesla had invented just a few years earlier. That would create a signal that would then cause a bell to ring in the box. Wireless telegraphy (as it was called) had arrived.

Marconi would continue to work on wireless telegraphy even as Tesla abandoned it to work on inventing the rest of the modern world. And in just five years, Marconi had built a radio powerful enough to send a signal from Cornwall to New Foundland; on December 12, 1901, he became the first person to send a transatlantic radio message. Of course, given the primitive nature of the equipment, it wasn’t much of a signal – just the Morse code signal for “S” (dot-dot-dot) repeated over and over. Nevertheless, it spurred enough interest in his company that Marconi soon became rich and wireless telegraphy became commonplace.

Sixty years later, radio would make the news one more time as NASA launched the first privately constructed satellite in the world. On December 12, 1961, the OSCAR-1 (Orbiting Satellite Carrying Amateur Radio) hitch-hiked into orbit as a passenger on a military satellite launch. OSCAR-1 was designed and built by students at Foothill College in Los Altos Hills, California, with the help of the TRW Radio Club. The satellite worked flawlessly even though it had been built less than four years after Sputnik and was the world’s first piggy-pack satellite launch as well as the world’s first privately built satellite. For 22 days, OSCAR-1 circled the globe, streaming out a constant “HI HI” to everyone who tuned in.

The OSCAR-1 satellite (Image courtesy Smithsonian)

The OSCAR-1 satellite
(Image courtesy Smithsonian)

Today the OSCAR program continues to excite and inspire. And citizen scientists like Marconi and the students who built OSCAR-1 continue to help make new discoveries in science. For example, did you know that meteors sometimes reflect radio waves when they fall? Thanks to the pressure of their fall, they create a wake of ionized plasma; by bouncing radio waves off of the ionized air, we can learn how many meteorites fall and how they move. To get involved in tracking meteors, scream over to:

November 30 – Map Quest

Today’s factismal: The first map of the Moon was made 407 years ago today.

Back in the 1600’s, there were only two things that everyone was sure of: death and the fact that things in the heavens were perfect. The first was kind of obvious thanks to smallpox, war, famine, and straight party ticket voting, and the second had to be true because Aristotle said it and the Roman Catholic Church believed it. At the time, it was thought that anything on Earth was corrupt thanks to Adam’s sin while anything in the skies was part of Heaven and therefore incorruptible. So you can imagine the furor when Galileo took the telescope he invented and turned it to the Moon – and then told everyone what he saw.

Galileo's telescope revolutionized our view of the Universe - literally!

Galileo’s telescope revolutionized our view of the Universe – literally!

And what he saw was revolutionary. Instead of being a perfect, smooth sphere, the Moon was covered with pockmarks and scars – what we know now to be impact craters and lava flows. While today all of the attention is given to Galileo’s proofs that the Earth was not the center of the Universe, it was his demonstration that the heavens were imperfect that struck the most direct blow at the Roman Catholic Church’s philosophy. As a result, even though anyone could verify the truth of Galileo’s work by simply looking, many preferred not to do so lest they also fall into heresy.

Galileo's map of the Moon (Image courtesy Galileo)

Galileo’s map of the Moon
(Image courtesy Galileo)

If you aren’t afraid of heresy then go out to look a the Moon tonight and take a long gander at the big black splotch that’s looking back at you. That’s Oceanus Procelarum, or the Ocean of Storms. It was named in 1655 (46 years after Galileo published his map) by Giovanni Riccioli, a Catholic priest who liked Galileo’s results but not his methods. To “punish” Galileo and his friends for disproving Church doctrine, he used the names of those who supported the heliocentric universe for the craters nearest Oceanus Procellarum which turns out to be one of the largest outflows of lava anywhere in the Solar System. That big white blotch on the eastern side of the stormy ocean? That’s Copernicus Crater, named for the chief heliocentricist and all-around troublemaker; those long white streaks are bits of lunar rock and dust that were thrown out when the asteroid slammed into the Moon and formed the crater.

A modern view of the Moon (Image courtesy NASA)

A modern view of the Moon
(Image courtesy NASA)

And while you may not believe it, we are still naming things on the Moon today! Even after four centuries of discoveries, there are still new features to see on the Moon and new things to identify. By mapping every crater and every lava flow and every mountain, we can get a better idea of how the Moon has changed over time and learn more about how the Solar System formed. And the best part is that you can help! Just head over to Cosmo Quest and start clicking on the Moon pictures to tell them what you see. For more information, land at:

November 16 – Home Phone E.T.

Today’s factismal: The first interstellar message was sent on November 16, 1974. It will arrive in 25,000 years.

Quick! What’s big enough to hold 10,000 gallons of guacamole, deep enough to put a submarine in, precise enough to see supernovae 44 million light years away, and sent the first message to the stars? It is the Arecibo National Astronomy and Ionosphere Center (the Arecibo Observatory, or just Arecibo, for short).

Words (My camera)

The Arecibo “dish”, big enough for a submarine to hide in (My camera)

Back in the late 1950s, scientists were just learning about the ionosphere and wanted to develop a tool that would allow them to probe its secrets. And other scientists were learning about radio emissions from planets and stars, and wanted a tool to learn about those. And when the first group of wonks met the second group of wonks, a new telescope was born.

The idea was simple: because the same energy (radio waves) that is used to probe the ionosphere is also used to learn more about distant planets and stars, instead of building two small instruments, why not build one huge one? They would get better resolution (thanks to the size of the reflecting dish), more power (thanks to the size of the transmitter/receiver), and more funding (thanks to the size of the project). And so they started looking for a place to build what would be the world’s biggest single aperture telescope, a title it would hold until 2016 when the Chinese opened their Five-hundred-meter Aperture Spherical Telescope.

The remains of the very first supernova ever recorded (Image courtesy NASA)

The remains of the very first supernova ever recorded
(Image courtesy NASA)

They had quite a few requirements on the location. It had to be in the US (thanks to the Cold War). It had to be near the equator (so it could see the planets). It had to be in an area with eroded limestone features called karst (so that it would be easy to build). And the spot that best fit was a little place called Arecibo on the island of Puerto Rico. So that’s where they built it and, on November 1, 1963, they started getting signals.

An image of the Crab Nebula at radio frequencies (Image courtesy NASA)

An image of the Crab Nebula at radio frequencies (Image courtesy NASA)

And what amazing things they saw! At the end of six months, they had discovered that Mercury wasn’t tidally-locked to the Sun like the Moon is to Earth; instead, it had a funny 3:2 rotation so that the day on Mercury appears to take two years! Soon they proved the existence of neutron stars, and mapped asteroids, and found complex molecules in outer space. But they weren’t limited to discovering things; they could also help things discover us. On November 16, 1974, Carl Sagan and friends took over Arecibo and used it to send a message to globular cluster M13, letting ET know where to phone.

Globular cluster M13, target of our first message (Image courtesy NASA)

Globular cluster M13, target of our first message
(Image courtesy NASA)

Unfortunately, Sagan was a better showman than he was an astronomer. In sending the message, he forgot about “proper motion” and sent the message to where the cluster appears to be in the sky. Because M13 is some 25,000 light years away, where it appears to be tonight is actually not where it is now – or where it will be when the message arrives! Imagine that you are walking along and tossing out pebbles every so often. The pebbles take a second to so to hit the ground so that you are in a different place when they land than you were when they were thrown. The same thing is happening here; the light from M13 left 25,000 years ago when the globular cluster was in a different place and it will have moved yet more in the 25,000 years it will take for the message to arrive.  As a result, our message will miss M13 almost entirely and instead head out into deep space.


Arecibo continues its mission of discovery today. One of its most important missions today is the search for black holes – and they need your help! Just go to Radio Galaxy Zoo and help match radio telescope pictures to infrared telescope images. Fun, easy, and really, really cool!