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Friday, March 18, 2011
Science Jim's Chat with a Physicist #3
Tuesday, March 15, 2011
4 Amazing Stories of Man's Path to Flight
with flight, and earliest attempts to fly. These are some great stories, told in delightful 15 minute episodes the whole family can enjoy! Take advantage of this great resource, and PLEASE
tell some homeschooling friends to check this out!
Details & download links for all four programs are at: http://www.homeschoolradioshows.com
First up, we go on a whirlwind exploration through time to listen in on a bit of the history of man's quest to fly like the birds.
Along the way, we encounter
- ancient myths and legends
- oddball experiments with egg shells and morning dew
- "negative magnetism"
- homebuilt wings
- and other crazy ideas . . . .
A PIECE OF SILK
Next, the fascinating and harrowing story of a man who in 1797 tested his new, untested invention -- a silken parachute!
He tested his new, untested silken parachute by falling 8,000 feet to the ground below!
This is the story of Andre Garnerin, the man who perfected the first parachute.
A great program!
The illustration (to the left) is a contemporary drawing of Garnerin's parachute.
Our next episode of Adventures in Research travels back to the French countryside in 1782 where brothers Joseph & Jacques Montgolfier lie on the grass studying the clouds that drift lazily by above their heads.
Their subsequent experiments lead them to the discovery of the hot air balloon... and man's first ascent into the skies! Another fascinating story!
The illustration (to the right) is a contemporary engraving of the Montgolfier brothers' balloon... note the tiny figures in the basket at the bottom!
This final episode of Adventures in Research shows us how the study of birds led men further toward the actual goal of flight... from the wings of an Albatross to Otto Lilienthal (1848-1896), an engineer from Anklam, Germany, who was one of the first humans to glide through the air. He became a pioneer of unpowered human flight by building and flying the world's first hang gliders.
Lilienthal built several different types of gliders, and made around 5000 flights between 1891-1896. Using his gliders, he flew as high as 984 feet, and would sometimes stay in the air for up to five hours... before he came to a tragic end. The above illustration is a 'magic lantern' slide from the turn of the century depicting Lilienthal's 1895 flight. The photo at the top of this page is Lilienthal ready to take off in one of his gliders.That's it for this time! "Tune in" and enjoy! Best Wishes,
The Erskine Family
Okay, here are the free download links for this week:
The Way of the Eagle
A Piece of Silk
The Birth of the Balloon
Free As A Bird
cross posted @
http://homeschoolingnotebook.blogspot.com/2010/03/four-amazing-stories-of-mans-path-to.html
and on Helpful History Notebook
Monday, March 14, 2011
Saturday, March 12, 2011
Adhesive Investigation - Moo Glue
When we glue things together, sometimes the glue seeps into the tiny openings and hardens, making the materials stick together. Other times, the molecules on the surface of an object mix with the glue molecules, making the objects stick together.
Did you know you can make glue from milk? Try this investigation and the results will “stick” with you for a long time.
Notes:
1) This is a neat investigation. It is not an "experiment."
Experiments are a special type of investigation that requires manipulating variables in a controlled way. Investigations like this do not do so and are not experiments. Not all investigations are experiments.
2) This can get rather odoriferous. You may NOT want to use this as an adhesive on any projects that you plan to keep. :-)
What You Need:
- A tall, clear glass
- Non-fat or skim milk
- White vinegar
- Coffee filters or paper towels
- 2 pieces of paper
What You Do:
1) In a glass, put seven tablespoons of non-fat or skim milk. Make sure to use low-fat milk because whole milk contains more fat, which can change the experiment results.2) Add a tablespoon of white vinegar to the milk; you should see solids begin to form that are suspended in the liquid. The solids will have a grainy appearance.
3) In a about a minute, the mixture will separate and settle toward the bottom of the glass. Then drain the liquid off, using a coffee filter or paper towel.
4) Now, pat the solids with a paper towel to absorb any excess liquid. You can use the resulting slimy substance as glue!
5) Last, coat two pieces of paper with the milk slime, stick them together, and let it dry. How well does your homemade glue work compared to tape or other glues?
plant saps
animal bones and hides
cassava root
bread
fruit and other vegetables
Casein (that protein that is found in milk) was used by ancient Egyptians as a glue for boat building and to weatherproof airplanes during WWII. Casein is what makes the milk adhesive (or, "moo glue") work.
Exact Link Sources:
Ick Stick author: Alicia Danyali
Curds and Whey author:
General source: education.com
WHY DOES THIS WORK? The science behind milk glue.
Milk is a colloid. A colloid is a mixture of substances that do not settle out over time (like a mixture of sand and water would for example).
Unlike a suspension (sand and water or orange juice and pulp) that mixes together when stirred or shaken then settles into separate parts when left at rest, a colloid does not settle because the particles that make it up are extremely tiny.
Looking at a glass of milk, one would not be able to see the particles that make it up, namely the curds (solid casein protein particles) and whey (liquid particles) because they are so small.
So -- remember that the liquids are called whey and the solids are called curds. The curds are full of the protein called casein.
Interestingly, milk appears white even though the particles that make it up are mostly clear, because light is scattered by the tiny particles as it passes through the colloid.
The milk was “curdled” when the acidic vinegar was added and lowered the pH of the milk, causing the casein particles to come out of the solution as solid chunks of curds floating in the liquid whey. Gross - definitely don’t drink!Glue can be made from lots of things like:
plant saps
animal bones and hides
cassava root
bread
fruit and other vegetables
Casein (that protein that is found in milk) was used by ancient Egyptians as a glue for boat building and to weatherproof airplanes during WWII. Casein is what makes the milk adhesive (or, "moo glue") work.
Exact Link Sources:
Ick Stick author: Alicia Danyali
Curds and Whey author:
General source: education.com
Monday, March 7, 2011
Slam Dunk Science
VIDEO HERE
Basketball players looking to rule the court may need more than just skill and endurance to be a top player. A good dribble, some fancy footwork ... It might look good on the court, but when it comes to playing the game, getting the ball through the hoop is what basketball is all about. But it'’s not that easy for every player. Now, physicist and former college ball player, John Fontanella, teaches a few basic principles of science to help players make the basket every time!
Basketball players looking to rule the court may need more than just skill and endurance to be a top player. A good dribble, some fancy footwork ... It might look good on the court, but when it comes to playing the game, getting the ball through the hoop is what basketball is all about.
But it'’s not that easy for every player. Now, physicist and former college ball player, John Fontanella, teaches a few basic principles of science to help players make the basket every time!
One popular move is the jump shot. But many players release the ball too soon and miss the basket.
“"One of the most important things that I found is that the ball really needs to be released right at the top of the jump,"” Fontanella said.
At that moment, the player isn't moving -- his velocity is zero. Releasing the ball at the top gives the player better control of the ball and making it more likely that he will make the shot. Another shot, the lay-up, can be an easy shot to make by hitting the backboard at just the right spot.
“"I found the sweet spot for a right-hand lay-up and the sweet spot for a left-hand lay-up,”" Fontanella said.
The secret is hitting the top corners of the square on the backboard; the angle of the ball is perfect and lands the shot almost every time.
“"A little bit of knowledge of physics helps you play the game better,”" Fontanella said.
The American Association of Physics Teachers contributed to the information contained in the TV portion of this report.
BACKGROUND: Good basketball players develop their skills through endless repetition, hard-wiring the brain with the correct sequence of muscle movements for optimal play (“kinesthetic memory”). However, knowing a little basic physics can still help you improve your game. You can learn why you should put a spin on the ball, get tips on improving your free throws, and discover the secret to Michael Jordan'’s seemingly longer “hang time.”
PUTTING A SPIN ON IT: Once the basketball leaves the shooter’'s hand, it travels in an unchanging parabolic path that can be calculated using Newton’'s laws of motion. But putting a backspin on the ball can help you make more free throws. When a spinning ball bounces, it bounces back in the direction of the spin. If the ball hits the backboard or back of the rim, it will be directed toward into the basket. That’'s because when the ball makes contact with the rim or backboard, the backspin causes a change in velocity opposite to the spin direction, making it more likely that the ball will drop into the net softly.
HANG TIME: Michael Jordan earned the nickname “Air Jordan” because of his seemingly longer “hang time” making jump shots in games, but this is an illusion. How high someone can jump depends on the force used to push on the floor when starting to jump, which in turn depends on the strength and power of the jumper’s leg muscles. The harder and more powerful the jump, the higher and longer the flight. In order to leap four feet into the air, the hang time would be 1.0 seconds. Jordan had a few tricks up his sleeve to make that hang time seem longer. When he dunked, he held onto the ball a bit longer than most players, and actually placed it in the basket on the way down. He also pulled his legs up as the jump progressed so it appeared that he was jumping higher. But it still all happened in less than one second.
Cross Posted @ Homeschooling Notebook (March 7, 2011)
Source: Science Daily.com
original article date: November 1, 2007
Basketball players looking to rule the court may need more than just skill and endurance to be a top player. A good dribble, some fancy footwork ... It might look good on the court, but when it comes to playing the game, getting the ball through the hoop is what basketball is all about. But it'’s not that easy for every player. Now, physicist and former college ball player, John Fontanella, teaches a few basic principles of science to help players make the basket every time!
Basketball players looking to rule the court may need more than just skill and endurance to be a top player. A good dribble, some fancy footwork ... It might look good on the court, but when it comes to playing the game, getting the ball through the hoop is what basketball is all about.
But it'’s not that easy for every player. Now, physicist and former college ball player, John Fontanella, teaches a few basic principles of science to help players make the basket every time!
One popular move is the jump shot. But many players release the ball too soon and miss the basket.
“"One of the most important things that I found is that the ball really needs to be released right at the top of the jump,"” Fontanella said.
At that moment, the player isn't moving -- his velocity is zero. Releasing the ball at the top gives the player better control of the ball and making it more likely that he will make the shot. Another shot, the lay-up, can be an easy shot to make by hitting the backboard at just the right spot.
“"I found the sweet spot for a right-hand lay-up and the sweet spot for a left-hand lay-up,”" Fontanella said.
The secret is hitting the top corners of the square on the backboard; the angle of the ball is perfect and lands the shot almost every time.
“"A little bit of knowledge of physics helps you play the game better,”" Fontanella said.
The American Association of Physics Teachers contributed to the information contained in the TV portion of this report.
BACKGROUND: Good basketball players develop their skills through endless repetition, hard-wiring the brain with the correct sequence of muscle movements for optimal play (“kinesthetic memory”). However, knowing a little basic physics can still help you improve your game. You can learn why you should put a spin on the ball, get tips on improving your free throws, and discover the secret to Michael Jordan'’s seemingly longer “hang time.”
PUTTING A SPIN ON IT: Once the basketball leaves the shooter’'s hand, it travels in an unchanging parabolic path that can be calculated using Newton’'s laws of motion. But putting a backspin on the ball can help you make more free throws. When a spinning ball bounces, it bounces back in the direction of the spin. If the ball hits the backboard or back of the rim, it will be directed toward into the basket. That’'s because when the ball makes contact with the rim or backboard, the backspin causes a change in velocity opposite to the spin direction, making it more likely that the ball will drop into the net softly.
HANG TIME: Michael Jordan earned the nickname “Air Jordan” because of his seemingly longer “hang time” making jump shots in games, but this is an illusion. How high someone can jump depends on the force used to push on the floor when starting to jump, which in turn depends on the strength and power of the jumper’s leg muscles. The harder and more powerful the jump, the higher and longer the flight. In order to leap four feet into the air, the hang time would be 1.0 seconds. Jordan had a few tricks up his sleeve to make that hang time seem longer. When he dunked, he held onto the ball a bit longer than most players, and actually placed it in the basket on the way down. He also pulled his legs up as the jump progressed so it appeared that he was jumping higher. But it still all happened in less than one second.
Cross Posted @ Homeschooling Notebook (March 7, 2011)
Source: Science Daily.com
original article date: November 1, 2007
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