The Science of Snowflakes:

After learning the below eleven big facts about these little crystals, you may never look at a snowflake the same way again.  

1. SNOWFLAKES ARE NOT FROZEN RAINDROPS.

Snowflakes are an aggregation, or cluster, of hundreds of ice crystals that fall from a cloud. Frozen raindrops are actually called sleet.

2. THE TINIEST SNOWFLAKES ARE CALLED "DIAMOND DUST."

The smallest snow crystals are no larger in size than the diameter of a human hair.

Because they're so small and lightweight, they remain suspended in the air and appear like sparkling dust in the sunlight, which is where they get their name. Diamond dust is most often seen in bitterly cold weather when air temperatures dip below 0° F.

3. SNOWFLAKE SIZE AND SHAPE IS DETERMINED BY CLOUD TEMPERATURE AND HUMIDITY.

The reason why snow crystals grow this way is still somewhat of a complicated mystery... but the colder the air surrounding a growing snow crystal is, the more intricate the snowflake will be. More elaborate snowflakes also grow when the humidity is high. If temperatures within the cloud are warmer, or if humidity within the cloud is low, expect the snowflake to be shaped like a simple, smooth hexagonal prism.

4. ACCORDING TO GUINNESS WORLD RECORDS, THE LARGEST AGGREGATE SNOWFLAKE EVER REPORTED FELL IN FORT KEOGH, MONTANA IN JANUARY OF 1887 AND ALLEGEDLY MEASURED 15 INCHES (381 MM) WIDE!

Even for an aggregate (clump of individual snow crystals), this must have been a monster snowflake! Some of the largest non-aggregate (single snow crystal) snowflakes ever observed measure 3 or 4 inches from tip to tip.

On average, snowflakes range in size from the width of a human hair to less than that of a penny.

5. THE AVERAGE SNOWFLAKE FALLS AT A SPEED OF 1 TO 6 FEET PER SECOND.

Snowflakes' lightweight and fairly large surface area (which acts as a parachute slowing their fall) are the primary factors affecting their slow descent through the sky. (In comparison, the average raindrop falls roughly 32 feet per second!). Add to this that snowflakes are often caught in updrafts that slow, halt, or even temporarily lift them back up to higher altitudes and it's easy to see why they fall at such a creeping pace.

6. ALL SNOWFLAKES HAVE SIX-SIDES, OR "ARMS."

Snowflakes have a six-sided structure because ice does. When water freezes into individual ice crystals, its molecules stack together to form a hexagonal lattice. As the ice crystal grows, water can freeze onto its six corners multiple times, causing the snowflake to develop a unique, yet still six-sided shape. 

7. SNOWFLAKE DESIGNS ARE A FAVORITE AMONG MATHEMATICIANS BECAUSE OF THEIR PERFECTLY SYMMETRICAL SHAPES.

In theory, every snowflake nature creates has six, identically shaped arms. This is a result of each of its sides being subjected to the same atmospheric conditions, simultaneously.

However, if you've ever looked at an actual snowflake you know it often appears broken, fragmented, or as a clump of many snow crystals — all battle scars from colliding with or sticking to neighboring crystals during its trek to the ground. 

8. NO TWO SNOWFLAKES ARE EXACTLY ALIKE.

Since every snowflake takes a slightly different path from the sky to the ground, it encounters slightly different atmospheric conditions along the way and will have a slightly different growth rate and shape as a result. Because of this, it is highly unlikely that any two snowflakes will ever be identical. Even when snowflakes are considered to be "identical twin" snowflakes (which has occurred both in natural snowstorms and in the lab where conditions can be carefully controlled), they may look strikingly similar in size and shape to the naked eye, but under more intense examination, small variations become evident.

9. ALTHOUGH SNOW APPEARS WHITE, SNOWFLAKES ARE ACTUALLY CLEAR.

Individual snowflakes actually do appear clear when viewed up close (under a microscope). However, when piled together, snow appears white because the light is reflected by multiple ice crystal surfaces and is scattered back out equally into all of its spectral colors. Since white light is made up of all the colors in the visible spectrum, our eyes see the snowflakes as white.

10. SNOW IS AN EXCELLENT NOISE-REDUCER.

Have you ever gone outside during a fresh snowfall and noticed how silent and still the air is? Snowflakes are responsible for this. As they accumulate on the ground, the air becomes trapped between the individual snow crystals, which reduces vibration. It is thought that snow cover of less than 1 inch (25 mm) is enough to dampen the acoustics across a landscape. As snow ages, however, it becomes hardened and compacted and loses its ability to absorb sounds.

11. SNOWFLAKES COVERED IN ICE ARE CALLED "RIME" SNOWFLAKES.

Snowflakes are made when water vapor freezes onto ice crystal inside of a cloud, but because they grow inside of clouds that also house water droplets whose temperatures are cooled below freezing, the snowflakes sometimes collide with these droplets. If these supercooled droplets of water collect and freeze onto nearby snow crystals, a rimed snowflake is born. Snow crystals can be rime free, have a few rime droplets, or be completely covered with rime. If rimed snowflakes blob together, snow pellets are known as graupel then forms.

Improve Your Memory With This Ancient Loci Technique:

There are many theories and ideas about improving memory, including some that have been around since ancient times. 

Ancient accounts show that early Greek and Roman orators used the "loci" method of remembering long speeches and lists. You may be able to use this method to enhance your memory at test time.

The term loci refer to places or locations. To use the loci system, you will first need to think of a place or route that you can picture in your head very clearly.

It can be your house, your school bus route, or any place that contains clear landmarks or rooms.

For this example, we will use the thirteen original colonies as a list that we want to remember and your house as the method for remembering.

The List of Colonies Includes:

• North Carolina
• South Carolina
• Maryland
• Virginia
• Delaware
• New Hampshire
• New Jersey
• Pennsylvania
• Massachusetts
• Connecticut
• New York
• Rhode Island
• Georgia

Now, picture yourself standing outside your house and begin to make connections with words on your memory list. In this case, you could make a mental note that the front of your house faces north and the back faces south. We have our beginning!

North = North Carolina

South = South Carolina

YOUR TOUR CONTINUES

Imagine that you enter your house and see the coat closet. Open the closet door and note the smell. (It helps to invoke all the senses you can in this method). There you see the coat that Aunt Mary gave your mother (Maryland).

The next room in this imaginary house tour is the kitchen. In this tour, you are suddenly hungry, so you go to the cupboard. All you can find is some virgin olive oil(Virginia). That won't do.

You turn to the refrigerator and look inside. You know your mom just bought some new ham (New Hampshire) from the deli—but where is it?

(Delaware).

You manage to locate the items and assemble a sandwich. You carry it to your bedroom because you want to change into your new football jersey (New Jersey).

You open the closet door and a pen falls on your head from the top shelf (Pennsylvania).

"What's that doing there?" you think. You turn to put the pen in your desk drawer. When you open the drawer, you see a giant mass of paper clips (Massachusetts).

You grab a handful, sit down on your bed, and begin to connect them together to form a long chain (Connecticut).

You realize you're still hungry. You decide you are ready for some dessert. You go back to the kitchen and look in the refrigerator again. You know you'll find some leftover New York cheesecake from yesterday (New York).

It's gone! Your little brother must have finished it off! (Note the shock and anger.)

You turn to the freezer.

There are two types of ice cream. Rocky Road (Rhode Island) or Georgia Peach(Georgia). You eat both.

Now look over the list of states again, and think about the place association for each one. It won't be long before you can recite the list of states easily.

This method can be used for remembering a list of objects or a list of events. All you need is keywords and associations for them.

It may help you to come up with funny things that occur along your path. Emotion and sensory experiences will reinforce the information and enhance the exercise.

That's Cute..!!

Learn to Code: Harvard's Free Online Computer Science Course

Harvard’s “Introduction to Computer Science” course is widely regarded as the best computer science course online and serves as a rigorous starting point for thousands of online students every year. Plus, the course is flexible: there’s an option for you whether you just want to look around, are dedicated to completing every assignment, or want to earn transferable college credit.

Here’s some straight talk: “Introduction to Computer Science” is hard.

It’s designed for students without previous computer programming experience, but it’s no walk in the park. If you enroll, you can expect to spend 10-20 hours on each of the nine project sets in addition to completing a complex final project. But, if you can dedicate the effort required, you’ll gain tangible skills, have a much more in-depth understanding of computer science and develop a better sense of whether or not this is a field you want to pursue.  

INTRODUCING YOUR PROFESSOR, DAVID MALAN

The course is taught by David Malan, an instructor at Harvard University. Before creating the course and teaching at Harvard, David was the Chief Information Officer for Mindset Media. All of David’s Harvard courses are offered as OpenCourseWare – at no cost to the interested public. The primary instruction in “Introduction to Computer Science” is delivered through David’s videos, which are professionally filmed and often use screens and animation to get the point across.

Fortunately, David is both concise and charismatic, making the videos an easy watch for students. (No dry, 2-hours-behind-a-podium lectures here).

WHAT YOU’LL LEARN

As an introductory course, you’ll learn a little bit of everything. The curriculum is broken down into twelve weeks of intense learning.

Each weekly lesson includes an informational video from David Malan (generally filmed with a live student audience). There are also walkthrough videos, in which David directly demonstrates coding processes. Study session review videos are available for students that may be less comfortable with the material and need additional instruction in order to complete the problem sets. Videos and transcripts of videos can be downloaded and watched at your convenience.

Lessons introduce students to: binary, algorithms, Boolean expressions, arrays, threads, Linux, C, cryptography, debugging, security, dynamic memory allocation, compiling, assembling, File I/O, hash tables, trees, HTTP, HTML, CSS, PHP, SQL, JavaScript, Ajax, and dozens of other topics. You won’t finish the course as a fluent programmer, but you’ll have a solid understanding of how programming languages work.

WHAT YOU’LL DO

One of the reasons “Introduction to Computer Science” has been so successful is that it gives students the opportunity to apply what they’re learning while they’re learning it. In order to complete the course, students must successfully finish 9 problem sets. Students begin creating simple programs from the very first week.

The instructions for completing the problem sets are extremely detailed and even feature extra help videos from past students (proudly wearing their black “I took CS50” t-shirts for solidarity with the currently-struggling).

The final requirement is a self-guided project. Students can choose to create any type of software using the skills and programming languages they’ve learned throughout the course. Enrolled students submit their final project to an online fair – after the class is over, projects are shared through a website for peers to see what everyone else has been up to.

Students needing extra assistance can work with Harvard tutors online for $50 an hour.

DID YOU WANT A CERTIFICATE WITH THAT?

Whether you just want to take a peek at the course or want to earn college credit, “Introduction to Computer Science” has an option to help you get started coding.

EdX is the easiest way to access course materials at your own pace. You can sign up for free to audit the course, with full access to videos, instructions, etc. You can also opt to donate $90 or more for a Verified Certificate of Achievement upon completion of all coursework. This can be listed on a resume or used in a portfolio, but will not give you college credit.

You can also view course materials on CS50.tv, YouTube, or iTunes U.

Alternatively, you can take the same online course through Harvard Extension School for about $2050. Through this more traditional online program, you will enroll with a cohort of students during the Spring or Fall semester, meet deadlines, and earn transferable college credit upon completion of the course.

4 Senses Animals Have That Humans Don't:

Radar guns, magnetic compasses, and infrared detectors are all man-made inventions that enable humans to stretch beyond our five natural senses of sight, taste, smell, feel and hear. But these gadgets are far from original: evolution equipped some animals with these "extra" senses millions of years before humans had even evolved. 

ECHOLOCATION

Toothed whales (a family of marine mammals that includes dolphins), bats, and some ground- and tree-dwelling shrews use echolocation to navigate their surroundings.

These animals emit high-frequency sound pulses, either very high-pitched to human ears or completely inaudible, and then detect the echoes produced by those sounds. Special ear and brain adaptations enable the animals to build three-dimensional pictures of their surroundings. Bats, for example, have enlarged ear flaps that gather and direct sound toward their thin, super-sensitive eardrums.

INFRARED AND ULTRAVIOLET VISION

Rattlesnakes and other pit vipers use their eyes to see during the day, like most other vertebrate animals. But at night, these reptiles employ infrared sensory organs to detect and hunt warm-blooded prey that would otherwise be completely invisible. These infrared "eyes" are cup-like structures that form crude images as infrared radiation hits a heat-sensitive retina. Some animals, including eagles, hedgehogs, and shrimp, can also see into the lower reaches of the ultraviolet spectrum.

(On their own, human beings are unable to see either infrared or ultraviolet light.)

ELECTRIC SENSE

The omnipresent electric fields produced by animals often feature in animal senses. Electric eels and some species of rays have modified muscle cells that produce electric charges strong enough to shock and sometimes kill their prey.

Other fish (including many sharks) use weaker electric fields to help them navigate murky waters, home in on prey, or monitor their surroundings. For instance, bony fish (and some frogs) possess "lateral lines" on either side of their bodies, a row of sensory pores in the skin that detects electrical currents in the water.

MAGNETIC SENSE

The flow of molten material in the earth's core and the flow of ions in the earth's atmosphere generate a magnetic field that surrounds our planet. Just as compasses help us navigate toward magnetic north, animals possessing a magnetic sense can orient themselves in specific directions and navigate long distances. Behavioral studies have revealed that animals as diverse as honey bees, sharks, sea turtles, rays, homing pigeons, migratory birds, tuna, and salmon all have magnetic senses. Unfortunately, the details about how these animals actually sense the earth's magnetic field is not yet known. One clue may be small deposits of magnetite in these animals' nervous systems; these magnet-like crystals align themselves with the earth's magnetic fields and may act like microscopic compass needles.  

Interesting Facts About Batteries:

Smoke Detectors mostly chirp in the dead of night because the chemical reaction in batteries slows down when the air get’s colder thus tripping the detectors low battery detector.

There is a battery-powered bell at Oxford University that has been continuously ringing for over 175 years. No one knows what the battery is composed of and no one wants to take the device apart in order to figure it out.

Once the Tesla Gigafactory is operating at 100% capacity, it will churn out more lithium-ion batteries in one year than were produced worldwide in 2013. 

LES1, a satellite that had been abandoned in 1967, recently started transmitting again, after its batteries decayed, shorting the solar panels straight to the electronics.

Disposable electronic cigarettes contain perfectly good rechargeable lithium-ion batteries.

 It is optimal for your lithium-ion smartphone battery to top it off and keep its charge between 40-80%, rather than let it drain 0% and charge it all the way up.

Petroleum companies bought rights to battery patents and sued anyone who used them (with gag orders).

The Germans invented an infrared scope during WWII. A 13-kilogram battery pack was worn on the back, and the scope could be used for 15 minutes at a time. It was codenamed Vampir.

It is possible to make a battery that will last centuries using nuclear waste and artificial diamonds.

If all new cars produced were powered by lithium batteries, the world would run out of lithium in ~30 years.

The 9-volt battery was introduced for improved portable transistorized radios that had lower voltage requirements than the originals.

The iconic Nokia 3310s battery capacity is 3 – 4 times less than an average smartphone today.

The city of Fairbanks, Alaska holds the world’s largest rechargeable battery, which powers the whole city during outages.

Old batteries are recycled into fertilizer to help grow corn.

During the early hours of the Fukushima, nuclear disaster plant employees scavenged car batteries to power essential monitoring equipment in the plant.

Did you know?