Balloon in a bottle

Can you empty a ballon without touching it? hummm... thats the challange today.


Suppose the following scenario:
Winter, outside temperatures around 2-3 º C (32-33 F), inside temperatures between 18-20 ° C (64-68 F). Have you noticed that, when you fill a balloon inside the house, and you take it outside it shrinks? Like as if he had lost air? And if you bring it back into the house it recovers the shape? This phenomenon is more visible when the balloon is filled with He.
Physics explain this.
To explain this our young restless minds, let's see this demonstration:


What we need:

• big balloon, for best results blow up the balloon and let the air out once or twice,
• water
• bowl, preferably metal
• ice, enough to fill the bowl
• empty plastic bottle,
• tape
• Flexible measuring tape.

How to:

1. Blow the balloon, enough for it to stand up;
2. Without allowing the air to escape, hold the mouth of the balloon to the neck of the bottle, use the tape if needed;
3. With the tape measure the circumference of the balloon;
4. Fill the bowl with ice and a little water, not much, 3 to 4 fingers high, we want the water to be as cold as possible but the contact surface with the bottle must be the largest possible;
5. Place the bottle in the bowl and wait a few minutes;
6. Re-measure the circumference of the balloon. With luck it will be sucked into the bottle.

Results:
Apparently the balloon will shrink. Sometimes is sucked into the bottle.
 
Why?
As seen in Egg in a bottle, before the bottle is placed on the bowl with ice water, the air inside it- and the balloon- was at same temperature as the air outside. When we place the bottle on ice the air will cool and therefore contracts. At this point the pressure in the bottle is lower then the pressure outside, and the laws of physics kick in pushing the balloon into the bottle. 
This demonstration when done in optimum conditions shows the balloon being sucked into the bottle.

Et Voilá!

Can you blow the balloon again without touching it?

Enjoy!

Tangram legend- Yu and God of Thunder

We can find a lot of legends about Tangram, its impossible to know witch one is true. we found 4 different versions about the origin of this millenary game. The first three are the most common, but the fourth one is the most surprising and interesting. 

The messenger and the Emperor
"Once upon a time 4000 ago, a messenger came to the Emperor Tan with a square mirror, when he dropped to the ground. But he dropped the mirror on the ground and it shattered into seven pieces.
The messenger tried to join the seven pieces in order to reassemble the square. While trying to solve the problem, the messenger has created hundreds of types of people, animals, plants, until finally he made it. "
from here

The disciple and the master
"Once upon a time a young chinese was saying goobye to his master.He was about to take a great trip around the world.
On this occasion, the master handed him a square mirror and said:
-With this mirror, record everything you see on your trip to show me when you get back.
The disciple, surprised, asked:
-But master, how can I show you, with this simple mirror, all I see during the trip?
At this moment the mirror fell from his hands and broke into seven pieces.
Then the Master said:
- Now, with these seven pieces, you can build figures to illustrate your trip. "from here

Mr. Tan and the tile

"Once upon a time, in a land far away, there was a Chinese gentleman named Tan. Mr. Tan lived in a golden palace, with a lake. He loved walk around the lake for hours ... One day while wandered among the reeds, he saw a bright object on the ground. He bent down and found a magnificent silver tile. He took it and admired it, the tile was smooth as the surface of the lake, soft as a feather, bright as his outfit.
Unfortunately, the beautiful tile escaped from his hands and broke into seven pieces on the floor! Mr. Tan, disappointed, tried to reconstitute it. Putting the pieces together, created a form, a little character!, shifted a few more pieces, and to his astonishment, formed a beautiful house!
Mr. Tan returned to the palace so excited to have invented a new game.
He called it TANGRAM and offered one to everyone in his kingdom!"

from here

All this stories share several things: the object geometry, a square tile or a square mirror; the object falls; the object split in seven pieces (Tans); someone try to reconstruct the square and various forms are formed.
As we said earlier, we found a quite a different story, so that caught my attention, the Legend of Yu and the God of Thunder.

Yu and God of Thunder

 "Thousands and thousands of years ago, Yu , the Great Dragon, lived among humans, who venerated him because he was 'yang', good, and was always ready to help them.

One day, the God of Thunder, jealous of the offerings the men had brought to Yu, in a burst of anger, crushed the sky with his hatchet. So, the sky fell on Earth in seven pieces black like coal. Light disappeared taking with it all existing things.

At first Yu felt sad for the world, and then felt nostalgic. So he decided to collect the seven black pieces of the sky and, in memory of the former world, began to reassemble several kinds of shapes: animals, plants and human beings that had disappeared. But after finishing each shape, its shadow left it and wandered the deserted world crying about its misfortune.

These complaints reached the ears of the God of Thunder who was touched and, to remedy the harm he had caused, he pulled from each shadow the body of a living being to repopulate the Earth.

From that time on, our shadow faithfully follows every move we make and with the seven pieces of the sky, called Qi Qiao Ban (literally 'seven boards of cunning'), everything on Earth can still be shaped".

from here

You can read more about Tangram here.

Sources:
http://www.archimedes-lab.org/tangramagicus/Tangram_legend.html
http://peixinhosnosotao.blogspot.com/2009/02/tangram-lenda.html
http://pt.scribd.com/doc/42133445/A-Lenda-Do-Tangram-1
http://www.eb1-setubal-n17-amoreiras.rcts.pt/projectos/fotostangram/a_lenda_do_tangram.htm

Et Voilá!
We found this story so wonderful and so restless that we couldn’t help sharing it
Enjoy!

Christmas tree ornaments

Another Christmas idea.
Let’s do some ornaments to the Christmas tree.

What we need:

• wooden spatulas,
• sand paper,
• nail,
• hammer,
• string,
• felt, with any colors you like,
• black marker,
• transparent glue,
• scissors,
• brush,
• old paper,
• "googly eyes",
• acrylic paint, your favorite colors.

How to:

1. Sand the spatulas, until they are smooth;
2. Draw on the felt the pattern you want to use, you can use your own designs or the ones at the end of this post;
3. Cut your drawings;
4. Use the glue, and with a steady hand, place the felt in place;
5. Let it dry;
6. With the black marker, draw the details;
7. Finally use the brush to paint all the other elements you want to add;
8. Let it dry for 3 or 4 hours;
9. With the hammer and the nail pinch a hole on the top of your spatula;
10. Pass the wire through, and make a knot;
11. Hang your art in your Christmas tree.

Et Voilá!
Another DIY art idea for this Christmas!
Enjoy

Electron microscopy

On March 9, 1931, the german physicist Ernst Ruska and his team, built the first electron microscope, an instrument able to magnify images of organic molecules up to 500,000 times. 
The electron microscope forms the image by emitting electrons.

Due to his amplifying capacity, this instrument produces amazing images of surrounding micro-world.  
Aside the obviouse scientific advances this tool provided, noone is immune to the beauty of the images it produces, finally revealing the symmetry and balance of all forms that we do not see but somehow we know "it's there".
Today we bring you some of these images:

Pollen:

From here

Red Cells:

From here

Spiky Hair:

From here

Suine Flu Virus:

From here

HIV Virus

From here

E. Coli:

From here

Et voilá!
Amazing! the micro is so perfect as the macro!

Enjoy!

Fill balloons with carbone dioxide

Today we will see a different way to blow balloons, maybe isn't the most profitable but its for sure the funniest.

We will need:

• Medium plastic bottle (PET),
• big balloon, blow the balloon a couple of times before you use it,
• 1 teaspoon of sodium bicarbonate, baking soda, a bit more if you want a bigger balloon;
• 3 tablespoons of acetic acid, vinegar, a bit more if you want a bigger balloon.
• tape.

How to:

1. Lay down baking soda in the bottle;
2. Place the vinegar in the balloon, use a funnel if you need to;
3. Secure the open end of the balloon to the neck of the bottle;
4. Use the tape to hold the balloon to the bottle;
5. Lift the balloon so the vinegar falls into the bottle.

Results:
Baking soda starts to bubbling when the vinegar touch it, and the balloon fills up.

Why?
A reaction occurs when vinegar (acetic acid) touches baking soda (Sodium Bicarbonate). In this reaction Carbone dioxide is produced, along with water and sodium acetate, as show is reaction:

NaHCO3 (aq) + CH3COOH (aq) ----> CO2 (g) + H2O (l) + CH3COONa (aq)

Carbone dioxide is a gas, thats why the balloon fills up.

Et Voilá!

Enjoy!

Naked egg

Another science experiment with eggs.
With this demonstration we will be able to see the egg yolk, without break the egg shell.

All the eggs have 2 major parts, the yolk and the white. Both this parts are essential to the egg and protected by a thin membrane. This is a double membrane and is easily observed on the flattened part of the egg, here assumes the form of a air bag.

What we are going to do it's simple, we are going to discard from the equation the egg shell, leaving intact the membrane and everything inside.

This essay takes about one week, all depends on the type of acetic acid we use and on the size of the egg.

We will need:

• vinegar, the flat one, with no flavors will work the best,
• glass jar with lid, big enough "to drawn" the egg inside,
• Raw egg.

How to: 

1. Place the egg in the jar;  
2. Cover the egg with the vinegar;
3. Close the jar, tight, to avoid the vinegar to split and the odor to spreading;
4. Store the jar in a cool and safe place, a kitchen cabinet for example;
5. Wait 24 hours;
6. Replace the vinegar with careful, reject the vinegar inside, and replace it with fresh vinegar;
7. Store it again;
8. Wait 6 more days, replace the vinegar each 2 days, tic tac tic tac;
9. Remove the egg from the inside of the jar very carefully, reject the vinegar;
10. Wash the egg with running water, very carefully, the membrane can burst.

Results:
Tell your restless to record everything he/she see/observe.

You can show him/her the jar every 24h so he can see/register the demonstration evolution. This simple gesture stimulates the observation and helps the child to think and ask.

The egg shell is made of calcium carbonate. The chemical reaction between the acetic acid (vinegar) and the egg shell (calcium carbonate), makes the second disappear, in this process bubbling and carbon dioxide are formed. The raw egg remains intact due to the thin transparent exterior membrane.

Try this, and transform the demonstration in a experiment:

• What happens if you place the naked egg against the light? 
• Drop the naked egg from 2in height... not more... in a smooth surface, what happen?
• On the same day you place the raw egg in vinegar, use other options, in different jars:
• use a boiled egg instead;
• use a boiled egg but with no shell;
• After the 7 days what are the major differences between all eggs?

Et Voilá!
A jumpy naked egg

Enjoy!

Spinning egg, to distinguish between a raw and a boiled egg- Newton First Law

How to distinguish between a raw and a boiled egg?


We will need:

• 2 eggs,
• smooth surface. 

How to:

1. Boil one of the eggs;
2. Let cool;
3. Give both eggs to the restless kid, and ask him/her witch one is boiled; 
4. Ask your child to spin both eggs on the smooth surface. 

What happened?
 One of the eggs spin continuously, the other one oscillates randomly.
The egg spinning continuously is the boiled egg, the other one is the raw.
 
Why?
 The boiled egg is solid, the raw is liquid.When you spin the raw egg the liquid spins inside, but takes a few seconds to overcome the inertia and therefore the movement is not continuous.
The boiled egg is solid  and therefore the inside moves with the shell.

This is Newton First Law of Movement:

 
"All bodies remain in their state of rest or uniform rectilinear motion, unless they are forced to change its state by influence of external forces"
In simpler terms, the Newton's First Law says: "If something is moving or stopped, will remain in motion or stopped unless something disturbs the system."

You can do another test:
Spin the raw egg, when the egg is spinning continuously place your finger on top of it, to stop it, and take it fast. You will see that the raw egg still moving after you stop the shell... why? Because the liquid inside remains in motion.


Et Voilá!

Newton in action!

Enjoy!