July242013
"The two-spot ladybird (Adalia bipunctata) has up to 16 black or red spots, which can be very variable – in splodges or in a grid pattern. It is the ladybird which most commonly overwinters in buildings”
[SOURCE: A guide to British ladybirds – in pictures]

"The two-spot ladybird (Adalia bipunctata) has up to 16 black or red spots, which can be very variable – in splodges or in a grid pattern. It is the ladybird which most commonly overwinters in buildings”

[SOURCE: A guide to British ladybirds – in pictures]

November262012
A radioactive button like this is inside most smoke detectors. A trace of americium creates charged particles that betray the smoke. Americium is thus the only man-made element available in grocery stores. (via Pictures, stories, and facts about the element Americium in the Periodic Table)

A radioactive button like this is inside most smoke detectors. A trace of americium creates charged particles that betray the smoke. Americium is thus the only man-made element available in grocery stores. (via Pictures, stories, and facts about the element Americium in the Periodic Table)

August292012
ScienceDaily (Aug. 28, 2012) — Coming less than a year after the announcement of the first circumbinary planet, Kepler-16b, NASA’s Kepler mission has discovered multiple transiting planets orbiting two suns for the first time. This system, known as a circumbinary planetary system, is 4,900 light-years from Earth in the constellation Cygnus.
Read more @ NASA’s Kepler discovers multiple planets orbiting a pair of stars

ScienceDaily (Aug. 28, 2012) — Coming less than a year after the announcement of the first circumbinary planet, Kepler-16b, NASA’s Kepler mission has discovered multiple transiting planets orbiting two suns for the first time. This system, known as a circumbinary planetary system, is 4,900 light-years from Earth in the constellation Cygnus.

Read more @ NASA’s Kepler discovers multiple planets orbiting a pair of stars

July282012

quantumaniac:

The Physics of Swimming

With the 2012 Olympics now under way, swimming has been labeled, unsurprisingly, as one of, if not the, most competitive sport this time around. Thus, Quantumaniac wanted to share a scientific approach to swimming to give our readers a clue what to watch for when they see the events. Let’s start from the beginning of a race and go from the push-off to final stretch - scientifically of course: 

The push-off:  Basically, a swimmer wants to reduce drag resistance as much as possible by minimizing their surface area. As the body assumes a streamline position and is forced off the wall, the sleeker the body, the less drag produced. While pushing off the wall, the body should be submerged and facing the bottom of the pool. The swimmer should be flat and streamline in the water, with the feet swept back. The push-off is the same for all the strokes, except the backstroke, in which the body should be facing the ceiling. When the body begins to loose speed and float to the surface, the kick and first stroke is applied. The kick helps propel the body through the water, while the stroke helps pull it.

The stroke: Each stroke and pattern is unique. The physics of each stroke is similar, so let’s discuss Freestyle. Freestyle begins with the catch, a motion which allows the swimmer’s hand to engage the water. As the arm enters the water; first, the body rolls downward to the same side. Second, the shoulder pushes forward from the chest. These two movements mimic a person stretching to reach something beyond grasp. At this point the arm rolls counterclockwise and sweeps outward, using the latissimus muscle. When done correctly, a solid feel of water pressure against the hand is experienced. The power phase of the stroke drives the arm inward and backward to the hip. Finally, the recovery brings the hand back to the catch phase of the pulling pattern. 

The turn:  For freestyle, the second to last stroke ends at the hip and stays there while the body follows the last stroke into a summersault. When the body rotates, a tight ball is used to make the turn quick. Physics tells us that as an object is rotating, velocity is increased as the moment of inertia is decreased (i.e. the smaller the sphere, the faster the velocity of the turn). When the body has rotated 180 degrees, the feet are extended to the wall and the push-off from the wall propels the body into another cycle.                                    

Symmetry plays an important role in swimming. If a body and its motion are not symmetrical, the body tends to move in the direction with greater force. For example, a person who pulls hard on the right side will move in a counterclockwise circle. A good swimmer balances the body, the forces exerted, and the forces produced by the body. An imaginary line that passes down the center of the face and ends between the legs is the most common line of symmetry. 

For freestyle, before the power-phase the arm rotates counterclockwise and then sweeps outward. A common mistake is for the arm to rotate clockwise and them pull, which unfortunately causes the arms to pass the line of symmetry, causing the arms to pull water that is disrupted by the body itself, and leads to a very inefficient stroke. The arms that pull to the outside of the body are pulling water that is not disturbed by the body, leading to a greater force applied. 

Swimmers also get into a rhythm with their kicking and pulling. A swimmer with a set rhythm and lots of practice will use less energy to travel the same distance as a swimmer with no rhythm. If you’ve ever seen an Olympic swimmer, you will notice a set rhythm, however, compare them to a beginner and an obvious difference in the rhythm will be noticed. 

Swimming, like most sports, has evolved by leaps and bounds over time. As the sport evolved, the idea of square movement changed to curved paths. Good swimmers now use sculling actions to utilize lift forces. Sculling is a back-and-forth movement of the hands and forearms that provides almost constant propulsion. This is Bernoulli’s Principle at work. The principle of “foil-like” objects moving through a fluid at high speeds with small angles to the flow and a large lift forces is generated, while the drag forces are minimized. The lift forces are caused by the fluid traveling further and faster around the more curved side than the less curved side. Essentially, the hand acts as a foil.

(http://www.ifkb.nl/B4/indexsw.html)

Bernoulli’s Principle is only one explanation of the kinetics of the lift force. Drag and lift both contribute to the net force produced by the hand. Ideally, the combination of lift and drag forces is such that the resultant force is in the desired direction.

In the aquatic environment, propulsion is generated by accelerating water. The momentum, P, of a mass of water, m, traveling with velocity, v, is P = mv. By forcing water backward with a momentum, the resultant propels the swimmer forward.

(http://www.ifkb.nl/B4/indexsw.html)

The pushed-away mass of water acquires kinetic energy as a result of the work done by the swimmer on the pushed-away mass of water. Part of the total work of the swimmer is converted into kinetic energy of the water, rather than forward speed of the swimmer.

By combining these two ideas, a body is propelled through the water by giving water a momentum in the opposite direction and propelling the body forward. In order to give the water a momentum in the opposite direction, the hand manipulates the water and puts lift on the hand and momentum on the water in the opposite direction. 

We already know that as the body moves through the water, it disrupts the flow of water. As the body moves forward, water is given a momentum backwards and travels until the velocity is 0. The water behind the swimmer follows the motion of the swimmer and creates drag. If two people are swimming in a straight line with one in front of the other, the person in the back is being pulled behind the swimmer in the front by a small drag force. As the swimmer in the back slides their hand into the water for the catch, they are placing their hand into water that already has a momentum. For this reason the person in the back does not have to work as hard to travel the same distance.

The swimming pool has floating lane lines that typically divide the pool into six swimming lanes. Within each lane, the motion of swimming is counterclockwise (i.e. swim down on the right and return on the left). These floating lines keep waves to a minimum by knocking them down. They also minimize the momentum of a body of water after is has been pushed backwards. The water vortex breakup when they come into contact with the lines. 

(via scinerds)

July142012

I’m warning you right now: this is a seriously cool amphibian. It’s called the Marbled Tree Frog (Dendropsophus marmoratus) and it’s pretty hard to pick a side to check out first. I mean, its belly is absolutely wild looking with a cheetah-ish print whereas its top is the side really living up to its name. Look how well its marbled back blends in with its surroundings!

Source:  There Are Two (wild) Sides to Every Frog

July102012

Twinkling in the dimmest of places within the tropical jungles of South America is the Fringe-limbed Tree Frog (Cochranella euknemos)Its name euknemos derives from Greek and means “with beautiful legs,” which refers to the frog’s fringed hind limbs.  

Even cooler, this is a species of glass frog, so you can look through and see its organs!

(Source: thefeaturedcreature.com)

July42012
How does the world’s smallest mammalian diver survive icy waters to catch its prey? A recent study of American water shrews to be presented at the Society for Experimental Biology meeting in Salzburg on 1st July has surprised researchers by showing that the animals rapidly elevate body temperature immediately before diving into cold water.
This behaviour is unexpected because lower body temperatures enable diving mammals to stay underwater for longer, so heating up doesn’t make sense. This is because animals use up oxygen more quickly when they are warmer.

How does the world’s smallest mammalian diver survive icy waters to catch its prey? A recent study of American water shrews to be presented at the Society for Experimental Biology meeting in Salzburg on 1st July has surprised researchers by showing that the animals rapidly elevate body temperature immediately before diving into cold water.

This behaviour is unexpected because lower body temperatures enable diving mammals to stay underwater for longer, so heating up doesn’t make sense. This is because animals use up oxygen more quickly when they are warmer.

July22012

Here’s another outstanding Ball Python morph. This one is dubbed a Paradox Hypo Super Mojave and even with the tongue-twisting name it’s simple to see how cool it is. It looks like someone tried to give it a bath, and in the process some of its patterns washed away! What’s left is just a naked-looking snake. Kinda weird but also kinda great. 

(Source: thefeaturedcreature.com)

June192012
The Voyager 1 space probe has reached the edge of the solar system, extending its record for being the most distant man-made object in space.
According to a statement from NASA’s Jet Propulsion Laboratory in Pasadena, California, the spacecraft is sending back data to Earth showing a sharp increase in charged particles that originate from beyond the solar system.
"Voyager scientists looking at this rapid rise draw closer to an inevitable but historic conclusion - that humanity’s first emissary to interstellar space is on the edge of our solar system," NASA said in the statement.
Voyager 1, along with its sister spacecraft Voyager 2, was launched in 1977 and is now about 18 billion kilometers from the Sun. It is moving at a speed of about 17 km per second and it currently takes 16 hours and 38 minutes for data to reach NASA’s network on Earth. Voyager 2 is about 15 billion kilometers from the Sun.
Between them, the probes have explored all the giant planets of the solar system; Jupiter, Saturn, Uranus, and Neptune, as well as 48 of their moons. (Read more: Voyager space probe reaches edge of solar system)

The Voyager 1 space probe has reached the edge of the solar system, extending its record for being the most distant man-made object in space.

According to a statement from NASA’s Jet Propulsion Laboratory in Pasadena, California, the spacecraft is sending back data to Earth showing a sharp increase in charged particles that originate from beyond the solar system.

"Voyager scientists looking at this rapid rise draw closer to an inevitable but historic conclusion - that humanity’s first emissary to interstellar space is on the edge of our solar system," NASA said in the statement.

Voyager 1, along with its sister spacecraft Voyager 2, was launched in 1977 and is now about 18 billion kilometers from the Sun. It is moving at a speed of about 17 km per second and it currently takes 16 hours and 38 minutes for data to reach NASA’s network on Earth. Voyager 2 is about 15 billion kilometers from the Sun.

Between them, the probes have explored all the giant planets of the solar system; Jupiter, Saturn, Uranus, and Neptune, as well as 48 of their moons. (Read more: Voyager space probe reaches edge of solar system)

March62012
ScienceDaily (Mar. 5, 2012) — A 16-member international team of researchers that includes James Kennett, professor of earth science at UC Santa Barbara, has identified a nearly 13,000-year-old layer of thin, dark sediment buried in the floor of Lake Cuitzeo in central Mexico. The sediment layer contains an exotic assemblage of materials, including nanodiamonds, impact spherules, and more, which, according to the researchers, are the result of a cosmic body impacting Earth. (via New research supports theory of extraterrestrial impact)
This is really neat!

ScienceDaily (Mar. 5, 2012) — A 16-member international team of researchers that includes James Kennett, professor of earth science at UC Santa Barbara, has identified a nearly 13,000-year-old layer of thin, dark sediment buried in the floor of Lake Cuitzeo in central Mexico. The sediment layer contains an exotic assemblage of materials, including nanodiamonds, impact spherules, and more, which, according to the researchers, are the result of a cosmic body impacting Earth. (via New research supports theory of extraterrestrial impact)

This is really neat!

Page 1 of 1