Tuesday, 24 January 2012

What Causes “Eye Floaters”

Today I found out what causes “eye floaters”.

For those who’ve never experienced this phenomenon, eye floaters are little oddly shaped objects that appear in your vision, often when one looks at bright light such as a blue sky. Their shapes vary greatly, but will often appear as spots, cobwebs, or randomly shaped stringy objects. These are not optical illusions, but rather something your eyes are actually perceiving. There are a few different things that can cause this, but in most cases these eye floaters are caused by pieces of the gel-like vitreous breaking off from the back portion of your eye and then floating about in your eye ball.

The vitreous humor, or often just “vitreous”, is a clear gel that fills the gap between your retina and lens, helping maintain the round shape of your eye in the process. This gel is about 99% water and 1% other elements; the latter of which consists mostly of a network of hyaluronic acid and collagen. Hyaluronic acid ends up retaining water molecules. Over time though, this network breaks down which results in the hyaluronic acid releasing its trapped water molecules. When this happens, it forms a watery core in your vitreous body.

As you age then, pieces of the still gel-like collagen/hyaluronic acid network will break off and float around in this watery center. When light passes through this area, it creates a shadow on your retina. This shadow is actually what you are seeing when you see the eye floaters.

Children and teenagers almost never experience these types of eye floaters as there must first be some deterioration of the gel-like substance in their eye, creating the watery core, for these floaters to appear. However, they do still sometimes experience a certain type of eye floater that often appears more like a crystallized web across their vision. These floaters aren’t found in the vitreous humor like the above floaters. Instead, they are found in the Premacular Bursa area, right on top of the retina. These floaters are microscopic in size and only appear as big as they do because of their proximity to the retina. Unfortunately, their microscopic nature makes them almost impossible to treat in most cases.

Bonus Factoids:

Interestingly, if the eye floaters would just stay still instead of floating around, your brain would automatically tune them out and you’d never consciously see them. Your brain does this all the time with things both in and outside of your eyes. One example of this inside your eye are blood vessels in the eye which obstruct light; because they are fixed in location, relative to the retina, your brain tunes them out completely and you don’t consciously perceive them.
The reason you can see floaters better when looking at, for instance, a bright blue sky, is because your pupils contract to a very small size, thus reducing the aperture, which in turn makes floaters more apparent and focused.
Individual floaters often won’t change much throughout your lifetime, typically retaining their basic shape and size.
The perception of eye floaters is known as myodesopsia.
The reason the floating specs never seem to stay still is because floaters, being suspended in the vitreous humor, move when your eye moves. So as you try to look at them, they will appear to drift with your eye movement.
Eye floaters are examples of entoptic phenomena. Entoptic phenomena are things we see where the source is within the eye itself.
If you ever see a ton of floaters appear out of no where, possibly with some light flashes, you should get to an eye doctor immediately. There is a chance (1 in 7) that your retina is about to detach from the back of your eye. If that happens, you have very little time to get it fixed before it effectively dies and you go blind from that eye.
Floaters can damage the retina by tugging on it, sometimes producing a tear. When a tear happens, vitreous can invade the opening in the tear, which will ultimately widen the gap and in 50% of these cases will result in the retina eventually becoming fully detached if not repaired via surgery.
“Light flashes” not caused by actual light, also known as photopsia, will often occur when the photoreceptors in the retina receive stimulation from being touched or from being torn. This produces an electrical impulse to your brain, which your brain more or less interprets as a light flash. This physical stimulation is often caused when traction is being applied while the vitreous detachment is taking place. The flashes should subside when the vitreous finally detaches.
These flashes will also often temporarily occur when you get a sharp blow to the head. The sudden jarring causes pressure on the retina; this in turn creates an electrical impulse to the brain which the brain interprets as a flash.
Yet another potential cause of these flashes is with migraine headaches, usually caused by a spasm of blood vessels in the brain. In this case, you will experience the flashes in both eyes at the same time, often followed by an extreme headache, though this doesn’t necessarily have to follow with a headache. Basically, if you are experiencing these flashes in both eyes at the same time, it is likely caused by either severe head trauma, which resulted in damage to both of your retinas, or more likely by some form of ophthalmic migraine.
Aside: as someone who has had about 12 of these type of migraines, with the extreme headache directly following about 15-ish minutes of flashes where you can barely see in between the flashes, I can say, it’s like getting kicked in the balls continually for about 3 hours or so, only the pain is in your head instead of balls and abdomen. This is all followed by your eyes having a dull ache for a few days. You will also have major pain in your eyes and possible recurrence of the migraine, if you decide to not wear sunglasses at all times during the few days following this event; including wearing the sunglasses inside where people will inevitably think you are a douche for doing so.
About 50% of all people will have a vitreous detachment by the time they turn 80.
If you have had a vitreous detachment and you’ve experienced light flashes with that, you have about a 15% chance of developing a retinal tear. From there, you have about a 50% chance of having your retina eventually become fully detached from the back of your eye.
Nearsighted people have a much higher chance of experiencing vitreous detachments due to their often elongated eye shape.
Surgeries do exist for getting rid of eye floaters, if they seriously hamper your vision. This is typically done by replacing the gel-like substance in your eye with a saline liquid.
When your retina is in the process of detaching, you will often see small dots all over the place. What is happening here is that blood is being leaked into the vitreous and those dots are your visual perception of that blood in your eye.

Fun Link:

Check out this optical illusion for another example of your brain tuning something out based on it being fixed relative to motion; for best affect, once the dots disappear, without looking away, press the stop button; they’ll reappear; press the button again to restart the motion and they’ll disappear instantly.

The Origin of Basketball

Source: http://www.todayifoundout.com/index.php/2012/01/the-origin-of-basketball/

The Origin of Basketball

Today I found out the origin of the sport basketball.

Surprisingly, unlike most sports whose origins are somewhat obscure, often being the combination of other sports and developed gradually through time, basketball has a very precise and fully known origin (the inventor himself wrote an account of it, published after his death; see the “Sources and Further Reading” below). Even the date of the very first game is known, December 21, 1891.

It was all started by Dr. James Naismith, the son of two Scottish immigrants to Canada. By 1891, Dr. Naismith was teaching physical education in Springfield, MA at the YMCA International Training School (which today is Springfield College). While there, he was asked by the director of physical education, Dr. Luther Gulick, to come up with a new game students could play indoors during the winter that would help keep track and field runners in shape and would be relatively safe to play (particularly that it would have a small amount of physical contact so that the players wouldn’t get injured in this game).

Dr. Naismith was given two weeks to come up with such a game. What he came up with was inspired by a game he had played as a child, “Duck on a Rock”, which is a game that has been played since medieval times. In “Duck on a Rock”, a large stone (“duck”) would be placed on top of an even larger rock or tree stump or the like. One unlucky player was then given the job of guarding the rock. All the other players would then have one rock to throw at the “duck” each, in order to knock it off the tree stump or rock it had been placed on. If the “duck” was knocked off before the throwers had all thrown their rocks, the defender will cease defending and pick up the “duck” and go on the offensive. Unfortunately, he does not get to chuck the duck back at the people who were just chucking rocks in his general direction. Rather, after the duck is knocked off, all the players throwing stones must go and retrieve one of the thrown stones and then make it safely back to the throwing line. After the defender picks up the fallen “duck” and places it back on the rock or tree stump, he/she is then allowed to run around and tag any of the players who have not yet made it back to the throwing line. If a player is tagged, they become the new guard.

Rather than using a rock, Dr. Naismith’s decided his game would be played with an association football, also known as a soccer ball (click here to read about the origin of the name “soccer”, which, by the way this name preceded the first known instance of the sport first being called by the singular term “football”). The goal of Dr. Naismith’s game would be to throw a soccer ball into a peach basket, which would be nailed up high on the wall. He chose the soccer ball as he deemed it to be fairly safe to be thrown around and not likely to cause injury. He decided to put the basket high on the wall because he observed most injuries seemed to happen in sports around the goal zone with both defenders and the offensive side becoming very aggressive in these regions. So he felt by putting it up high, it would prevent some of the potential for injury between offenses and defenses.

Interestingly, the original peach baskets did not have their bottoms knocked out, so whenever someone would get the soccer ball in the basket, the game would be temporarily paused while someone climbed a ladder to retrieve the ball. This obviously soon became annoying, so a hole was put in the bottom of the basket. Bizarrely, when they put this hole in the basket, they did not initially think to knock out the entire bottom and instead still had to use a long wooden dowel to poke the soccer ball out of the basket, which was at least less annoying than needing to climb a ladder.

Another major difference from modern day basketball is that there was no dribbling allowed, only passing and the person with the ball had to stay in place, excepting if they were running when they caught the ball, then they were allowed some leeway in which to continue moving while they slowed themselves quickly to a stop. This rule against running with the ball was because Dr. Naismith observed that in most sports, many injuries tended to happen when the player with the ball ran around, particularly with the other team more or less attacking that player. This way, the focus would be more on the ball, rather than the player.

As mentioned, the game was first played on December 21, 1891. This inaugural game was played with nine players on each team and after 30 minutes total of play (two fifteen minute halves) the final score was 1-0, fitting for a game played with a soccer ball. The loan point was scored by William R. Chase, from around 25 feet away from the basket. The thirteen rules used in this original version of basketball were as follows:

The ball may be thrown in any direction with one or both hands.
The ball may be batted in any direction with one or both hands, but never with the fist.
A player cannot run with the ball. The player must throw it from the spot on which he catches it, allowance to be made for a man running at good speed.
The ball must be held in or between the hands. The arms or body must not be used for holding it.
No shouldering, holding, pushing, striking or tripping in any way of an opponent. The first infringement of this rule by any person shall count as a foul; the second shall disqualify him until the next goal is made or, if there was evident intent to injure the person, for the whole of the game. No substitution shall be allowed.
A foul is striking at the ball with the fist, violations of Rules 3 and 4 and such as described in Rule 5.
If either side make three consecutive fouls it shall count as a goal for the opponents (consecutive means without the opponents in the meantime making a foul).
Goal shall be made when the ball is thrown or batted from the ground into the basket and stays there, providing those defending the goal do not touch or disturb the goal. If the ball rests on the edge and the opponents move the basket, it shall count as a goal.
When the ball goes out of bounds, it shall be thrown into the field and played by the first person touching it. In case of dispute the umpire shall throw it straight into the field. The thrower-in is allowed five seconds. If he holds it longer, it shall go to the opponent. If any side persists in delaying the game, the umpire shall call a foul on them.
The umpire shall be judge of the men and shall note the fouls and notify the referee when three consecutive fouls have been made. He shall have the power to disqualify men according to Rule 5.
The referee shall be the judge of the ball and decide when it is in play in bounds, to which side it belongs, and shall keep the time. He shall decide when a goal has been made and keep account of the goals with any other duties that are usually performed by a referee.
The time shall be two 15-minute halves with five minutes’ rest between.
The side making the most goals in that time shall be declared the winners.

This first game was described thus:

When Mr. Stubbins brought up the peach baskets to the gym I secured them on the inside of the railing of the gallery. This was about 10 feet from the floor, one at each end of the gymnasium. I then put the 13 rules on the bulletin board just behind the instructor’s platform, secured a soccer ball and awaited the arrival of the class… The class did not show much enthusiasm but followed my lead… I then explained what they had to do to make goals, tossed the ball up between the two center men & tried to keep them somewhat near the rules. Most of the fouls were called for running with the ball, though tackling the man with the ball was not uncommon… It was the start of the first basketball game and the finish of trouble with that class.

Despite the somewhat underwhelming first game results, which was just one point away from ending in a meaningless tie, the game soon became extremely popular at the YMCA in Springfield and within a year was spreading to other YMCA’s. Within three years, basketball started being accepted as not just a fun game to play indoors, but a legitimate sport in its own right. The rules, of course, began being tweaked nearly from the beginning and the old peach basket was thrown out in favor of iron rims with netting as early as 1893 (though, interestingly, the first netted hoops had a closed bottom, so a long wooden dowel still had to be used to retrieve the ball for around a decade after the net was introduced until someone finally got the bright idea of just using an open ended net, so that the ball would just fall through, no stick required). In addition to that, specialized balls began being made, instead of just using a soccer ball. Fast-forward to today and basketball is considered one of the world’s most popular sports, being played by an estimated 300 million people.

No discussion of the origin of basketball would be complete without addressing the common alternate “conspiracy theory” origin. This theory popped up in the 1950s, claiming that a director of a YMCA in Herkimer, New York, Lambert G. Will, actually invented the game almost a year before Dr. Naismith claimed the first basketball game took place. The primary piece of evidence to support this claim is a photograph of what is apparently a basketball team in Herkimer dated in 1892. Obviously this is after the game illustrated above, but what makes this picture intriguing is that the ball in the picture has 91-92 written on it, implying the team had been formed in 1891, which doesn’t necessarily mean this was before Dr. Naismith’s first game, but possibly. There are a few problems with this, though. First, that Lambert G. Will himself never claimed to have invented the game and further, his grandson, Rick Will claims that his grandfather always implied that Dr. Naismith had invented the game, not himself. Thus even without the mountain of evidence that backs up Dr. Naismith’s claim, while the “91″ on the ball seems curious, if Will himself claimed Dr. Naismith invented it, then one would tend to believe Dr. Naismith’s story of the origin of basketball and the first game.

Now, to be clear, while Will’s descendants don’t claim that Lambert G. Will invented the game, they do claim that he gave Dr. Naismith several suggestions on improving the game as Dr. Naismith had contact him about the new game, asking for suggestions. However, as another of his grandson’s, Lawrence Will, stated, “He came up with some ideas, but I suspect he wasn’t the only one.” What his exact suggestions might have been are unclear, some, like Lawrence Will, indicate that he only made a few suggestions, some of which were adopted, perhaps because of Lawrence Will’s suggestion or perhaps because of another who made the same suggestion (a lot of people in the early days of the sport helped tweak the game). Others go so far as to basically state that Lawrence Will came up with almost every key feature of the game including: passing by hand (these individuals claim Dr. Naismith’s game only included passing by foot with, oddly, a medicine ball, not a soccer ball being used, which obviously makes no sense in the “don’t get people injured” rule for developing the game); introducing a bounceable ball and dribbling; the metal rim; the net (knitted by his wife no less),;standardizing the basketball court; and giving the idea for an open bottom on the net so the ball could fall through. Obviously this seems highly unlikely as it flies in the face of a lot of direct evidence in the Dr. Naismith camp and Will’s descendants on the whole make no such significant claims based on what they know of Lawrence Will’s part in the development of basketball. In the end, it is likely that Will had a part through correspondents with Dr. Naismith in the development of the early game after it was introduced, but it seems pretty clear that he did not invent it, as some basketball conspiracy theorists claim.

Bonus Factoids:

Dr. Naismith became the first coach of the University of Kansas’ basketball team, where he coached nine seasons. Interestingly, to date, he’s the only coach in University of Kansas history to retire with a losing record (55-60). He also held the positions of campus chaplain and physical education director.
Another difference between the first game of basketball and the game we have today was that once the ball was retrieved from the basket following a successful shot, the ball was taken back to center court for a toss up.
Dr. Naismith didn’t believe there was anything to coaching and that it was better just to let the players play. He even tried to instill this in one of his former players, famed coach Forrest “Phog” Allen. When Allen told Dr. Naismith he was going to coach, Dr. Naismith told him, “You can’t coach basketball; you just play it.” Forrest Allen went on to prove Dr. Naismith completely wrong, becoming one of the great coaches in basketball history and today is considered the “father of basketball coaching”.
The Basketball Hall of Fame is named after Naismith: The Naismith Memorial Basketball Hall of Fame. It is located in Springfield, MA, the city where basketball was first invented and played.
Despite eventually becoming highly educated, Dr. Naismith actually dropped out of high school and became a lumberjack for a time. Apparently not finding the world of lumberjacking to be his long term career choice, he went back to school and graduated high school at the age of 21. He followed this by pursuing a degree at the McGill University in Montreal, where he first earned a degree in physical education and then a degree in theology at the Presbyterian College, which was affiliated with McGill University.
While at McGill pursuing a degree in theology, Dr. Naismith became an instructor of physical education and the director of athletics, where he is often credited as being the one who invented the predecessor of the football helmet, though there are several others around this time who also independently chose to wear different types of headgear, such as “helmets” made of moleskin and the like, though it was rare. So whether he was actually the first to introduce this idea is still a matter up for debate.
He eventually left McGill and went to the YMCA Training School in Springfield, MA where he began teaching and subsequently invented basketball there just one year after leaving Canada.
As you might have guessed due to the fact that I keep referring to him as “Dr. Naismith” instead of “Mr. Naismith”, Dr. Naismith graduated from the Colorado Medical School in 1898. At the time, he was the physical education director at the YMCA in Denver and decided to pursue a degree in medicine on the side.
Dr. Naismith was born in Ontario, Canada and was raised by his uncle Peter and grandmother as his parents had died of typhoid when he was nine years old.
Funds were raised by the National Association of Basketball Coaches so that Dr. Naismith could fly to the Berlin Games in 1936, the first Olympics in which basketball was an official participating event (it had previously been a demonstration sport in the Olympics as early as 1904). While there, Dr. Naismith got to be the one to toss the ball up at the start of the first official Olympic basketball game. He also got to present the medals to the winners: U.S. (gold), Canada (silver), and Mexico (bronze). Dr. Naismith was at this point a citizen of two of the former two of those countries. He died just three years later of a brain hemorrhage.
The first official college basketball game was played on January 18, 1896 between the University of Iowa and the University of Chicago. The final score was 15-12, with the visiting Chicago team the victors.
The document Dr. Naismith wrote down the original thirteen rules of basketball on sold in 2010 for $4.3 million. In the year Dr. Naismith made this document, $4.3 million would have been roughly worth about $100 million today in buying power. Makes one wonder what his reaction would have been if someone had told him on the day he created the document that in 119 years, someone would buy that piece of paper for $4.3 million.
The other players in the original basketball game besides William R. Chase, who scored the first basket in basketball history, were, The Winning Team: John J. Thompson, Eugene S. Libby, Edwin P. Ruggles, T. Duncan Patton, Frank Mahan, Finlay G. MacDonald, William H. Davis and Lyman Archibald; The Losing Team: George Weller, Wilbert Carey, Ernest Hildner, Raymond Kaighn, Genzabaro Ishikawa, Benjamin S. French, Franklin Barnes, George Day and Henry Gelan.
Not only did the YMCA have a huge part in spreading basketball around the world, but WWI and the North American soldiers that fought in it are also frequently given credit for spreading the game throughout the world.
The early basketballs were brown. This was later changed to orange to make it easier for spectators to see the ball.

What Causes Arms, Legs, and Feet to “Fall Asleep”

Source: http://www.todayifoundout.com/index.php/2012/01/what-causes-arms-legs-and-feet-to-fall-asleep/

What Causes Arms, Legs, and Feet to “Fall Asleep”

Today I found out what causes limbs to “fall asleep”.

Technically known as “paresthesia”, this syndrome is caused by the compression of specific nerves. When you sit cross-legged, sleep with your arm above your head, or position any limb in such a way to put excess pressure on a nerve, that nerve will stop sending impulses normally. Should the pressure be great, or the duration be long, the nerve will eventually stop sending impulses altogether. Any area the nerve services will essentially then “fall asleep”. Think of a person standing on a garden hose. It’s hard for the water to get to the nozzle when the person’s feet get in the way. If the person’s heavy enough, or she stands on the hose for too long and the hose fully compresses, water will eventually stop flowing entirely. Once this pressure is relieved, your nerve will start to function normally again (hopefully) and you can now move your hand/legs/arms/feet. Nerves, like a well worn hose, may take some time to work properly (expand) and you may feel some tingling, “pins and needles”, during the process.

Nerve cells, for the most part, have their main bodies located in the spinal cord itself. They have what are known as “axons” that branch out to your limbs (and other parts of the body, but we will focus on the limbs) and carry nerve impulses out from the spinal cord. Together with another cellular protrusion known as a dendrite, these projections allow us to feel the world around us.

Nerve impulses require a healthy energy supply, known as the axonal transport system. This well developed micro-vascular distribution method provides the blood flow needed to maintain the cells in good working order. If pressure is put on the correct spot, though, all the tiny arteries, veins and capillaries that supply the nerves’ nutrients become pinched off and the nerve cells begin to function abnormally. If you doubt me, hit the Ulnar nerve (the funny bone) on something and see how sudden, extreme pressure makes you scream!

Studies have shown that it doesn’t take much to cause the axonal transport system go haywire. External pressures of as little as 20 mmHg (about ½ pound per square inch) caused intermittent paresthesia due to the veins supplying the nerve having their blood flow reduced. When you get to around 1 pound per square inch for around 2 minutes, this can cause numbness, impaired dexterity, and result in muscle weakness.

Compression isn’t the only thing that can cause limbs to fall asleep. Excessive vibration will also lead to paresthesia. Operating hand-held vibrating tools is an extremely common cause of this. For example, dirt bike racers who need to grip handlebars tightly, while jumping frequently, experience this and commonly refer to these symptoms as “arm pump”. The process that causes these symptoms in the presence of vibration hasn’t yet been fully clarified, but these pulsations have been shown to injure the entire neuron.

Any discussion of what causes limbs to fall asleep would be remiss without talking about the common misconception that a limb falling asleep is caused by a lack of blood flow to the entire limb involved. While blood flow is blocked to the nerve specifically, if the entire limb were to be cut off from blood, severe life threatening problems would arise every time we sat “crisscross applesauce” in grade-school (see the problems with tourniquet use in the bonus Factoids below).

In medical terms, this is referred to as compartment syndrome. When blood flow is halted or reduced, life sustaining PH balance is in jeopardy. The area affected begins to become extremely acidic and cells begin to break down. Waste products and lethal levels of electrolytes, like potassium, begin to build up. Once the pressure on the limb is released, this “acid blood” is then sent back to the heart with potentially lethal consequences. Ask all those people on death row if excessive potassium is a good thing. They might want to reconsider investing in a portfolio that backs the production of potassium chloride. Cardiac arrest anyone!

Bonus Factoids:

The three most common drugs used in execution by lethal injection are: Sodium Thiopental (causing anesthesia); Pancuronium Bromide (a paralyzer that causes you to stop breathing); and Potassium Chloride (causing cardiac arrest).
The total cost for the drugs involved in lethal injection is about $86.08.
In 2009, the only US supplier of Sodium Thiopental stopped production of the drug forcing several states to postpone some executions because they had to adjust their protocol for putting to death the accused.
One of the most common diagnosis of chronic paresthesia is carpal tunnel syndrome.
The use of tourniquets to stop blood loss in trauma patients was once thought to be a staple life-saving treatment. The resulting induced compartment syndrome, created by their use, has shown the risks of using them far exceed the benefits, in most cases. Once applied, a strict protocol of reperfusion (restoring blood flow) must be followed to ensure fatal metabolites will not be introduced into the bloodstream. After only 60 minutes of use of the tourniquet, the metabolites can cause damage to vital organs; after 2 hours, permanent injury to the limb affected will result; and after 6 hours of tourniquet application, amputation of the limb is the preferred treatment. So next time Timmy the neighbor skins his knee in a bicycle accident, make sure that you instill the nick-name “stubby” before you take off your belt and cinch it around his bloody leg.
The use of tourniquets does have a place in certain situations, though. For instance, the most common use of tourniquets today is in the military. The need for the rapid control of blood loss in a hostile environment has been shown to reduce battlefield deaths, despite the potential risk factor in using a tourniquet. Once the fight has ended, the need for such a method of bleeding control is then reconsidered.
Carpal Tunnel Syndrome occurs more often in women than men and is most common between the ages of 30-60. It usually pops up in people who perform repetitive motion activities like typing, sewing, or playing musical instruments and gets its named from the “tunnel” that provides the pathway for the median nerve being narrowed. This creates a problem when repetitive activities cause minor swelling in the area surrounding the nerve. Pressure is then placed on the nerve and symptoms like numbness tingling and pain are the result.
Prolonged numbness, tingling or loss of motor control, to any limb, should be evaluated by a medical professional. It could be a sign of a more serious problem like a tumor, peripheral neuropathy, or stroke.

One Life. Live It.

Tuesday, 24 January 2012

Life is a Verb

Funny facts

Interesting Animal Facts

Happy Chinese New Year