The Shrinking Moon

Recently, I came across an interesting article about the shrinking Moon. After reading it, here is what I think happened. The Moon, after being hit by many asteroids and other foreign objects from the space, was really hot and as it cooled, it shrank. So, here is what I think may happen when maybe millions and millions or maybe longer years later, when the moon shrinks to nearly nothing:

1)Firstly, the tides here on Earth will be less strong as the gravitational pull of the Moon is gone.However, there will still be tides as there is still the Sun.
2)Secondly, a day will be shorter as without the gravitational pull of the Moon on the Earth, the Earth will rotate faster and thus we will get shorter days.
3)Lastly, there will be no Moon during the Mooncake Festival! :(

Science ace project(2) Parts of an animal cell

Science Ace Project---parts of an animal cell

My ace project(1) on Oobleck

Oobleck -

Separation technique(1)

There are many separation techniques and the one I will be explaining in this post will be evaporation.

Evaporation

Evaporation is a separation technique used when we want the solute and not the solvent, which will we evaporated. We use this technique and not filtration because sometimes, things like salt can dissolve in the water into tiny particles that cannot be filtrated. However, the disadvantage would be that we cannot get the solvent because it is already being dissolved away.

Paper Chromatography

In one of the past science lessons, I learnt about paper chromatography. We used it to seperate the blue colour of a pen to see what colours makes up its colour. We had a dot on a filter paper and put it in a test tube of ethanol. Lastly, we waited. We waited until the colour was broken up and observed the colours present at the end. The further the colour is from the original blue colour, the more loosely attached it is to the filter paper, and thus the closer it is to the blue colour, the more strongly it attaches itself to the filter paper. There are also other forms of chromatography like gas chromatography which separates different gases.

Term 2 sabbatical reflection

For my term 2 sabbatical, I participated in a course called "Science Eureka" which is a course that, by looking at its name you will know, teaches us science. The course was really interesting as we learnt science through many different experiments. We did experiments on making the best parachute, electrolysis and many others. The course ended with a quizz to test us on what we have learnt. On he last day of the course, each group was given a project to present to the whole class. I will be putting my project in another post.

Recent camp

Recently, I went to a science camp at the Republic Polytechnic of Singapore about how Science solve crimes.It was fun,enriching but also a little confusing,maybe because the things taught were a little too difficult for us.We learnt about DNA analysis,fingerprint analysis and some other stuff.It was quite difficult,but I got to use equipments that I never got to use before.I will be posting some stuff about it in the near future because I have to sleep now.Bye!(Most probably tomorrow :D)

Global warming awareness

The earth is sick.Why?We only have ourselves to blame. Human activities have destroyed our planet. The burning of coal, oil and fuels have created so much greenhouse gases the average temperature of the earth has increased drastically. There are many causes to greenhousw gases. Wasting electricity at home contributes to global warming. Whenever we waste electricity,more fuel has to be burned to supply electricity to the appliances. The releases unwanted greenhouse gases. Some other causes are areosol sprays that contain chlorofluorocarbons or CFC which destroys the ozone layer, allowing the radiative rays of the sun to harm us and also heating the earth. Deforestation also contribute a lot as when the people burn down the forest to build buildings, carbon dioxide is produced and it will rise up into the atmosphere and it will trap the heat in the earth, heating it up. To conclude, global warming can affect our lives very much just that we do not feel it now yet so let us save the earth before it is too late.

Why does fire create smoke

If you now toss a piece of wood, or even a sheet of paper, onto this fire, what you will notice is that the new fuel produces a lot of smoke as it heats up. Then, all of a sudden (often with a small pop), it bursts into flame and the smoke disappears. There are four things that you find in any piece of wood:

1.Water - Freshly cut wood contains a lot of water (sometimes more than half of its weight is water). Seasoned wood (wood that has been allowed to sit for a year or two) or kiln-dried wood contains a lot less water, but it still contains some.
2.Volatile organic compounds - When the tree was alive, it contained sap and a wide variety of volatile hydrocarbons in its cells. If you have read How Food Works, you know that cellulose (a chief component of wood) is a carbohydrate, meaning it is made of glucose. A compound is "volatile" if it evaporates when heated. These compounds are all combustible (gasoline and alcohol are, after all, hydrocarbons -- the volatile hydrocarbons in wood burn the same way).
3.Carbon
4.Ash - Ash is the non-burnable minerals in the tree's cells, like calcium, potassium and magnesium.
When you put the fresh piece of wood or paper on a hot fire, the smoke you see is those volatile hydrocarbons evaporating from the wood. They start vaporizing at high temperatures. If the temperature gets high enough, these compounds burst into flame. Once they start burning, there is no smoke because the hydrocarbons are turned into carbon dioxide and water (both invisible) when they burn.
This explains why you see no smoke from a charcoal fire (or a fire that has burned down to embers). Charcoal is created by heating wood to high temperatures in the absence of oxygen.

Diamond vs Graphite

Diamond and Graphite, the most interesting elements. How are they similar?They are both carbons, just of different crystal structures are called polymorphs. Another important physical difference is their hardness. The hardness of minerals is compared using the Mohs Hardness Scale, a relative scale numbered 1 (softest) to 10 (hardest). Graphite is very soft and has a hardness of 1 to 2 on this scale. Diamonds are the hardest known natural substance and have a hardness of 10. No other naturally occurring substance has a hardness of 10. The crystal structure of graphite yields physical properties that permit the use of graphite as a lubricant and as pencil lead. The gem and industrial properties of diamond, physical properties that we cherish and exploit, are also a result of diamond's crystal structure.

Conclusion:
Diamonds and graphites are both carbons, just of different polymorphs, or structures of the atoms.

Why does ice float on water?

Have you ever wondered why does ice float on water?
A substance floats if it is less dense, or has less mass per unit volume, than other components in a mixture. For example, if you toss a handful of rocks into a bucket of water, the rocks, which are dense compared to the water, will sink. The water, which is less dense than the rocks, will float. Basically, the rocks push the water out of the way, or displace it. For an object to be able to float, it has to displace a weight of fluid equal to its own weight.
Water reaches its maximum density at 4°C . As it cools further and freezes into ice, it actually becomes less dense. On the other hand, most substances are most dense in their solid state than in their liquid state.

Why?
I found out that water is different because of hydrogen bonding.A water molecule is made from one oxygen atom and two hydrogen atoms, strongly joined to each other with covalent bonds. Water molecules are also attracted to each other by weaker chemical bonds (hydrogen bonds) between the positively-charged hydrogen atoms and the negatively-charged oxygen atoms of neighboring water molecules. As water cools below 4°C, the hydrogen bonds adjust to hold the negatively charged oxygen atoms apart. This produces a crystal lattice, which is commonly known as 'ice'.

Ice floats because it is about 9% less dense than liquid water. In other words, ice takes up about 9% more space than water, so a litre of ice weighs less than a litre water. The heavier water displaces the lighter ice, so ice floats to the top.

If water floats on ice,that lakes and rivers freeze from top to bottom, allowing fish to survive even when the surface of a lake has frozen over. If ice sank, the water would be displaced to the top and exposed to the colder temperature, forcing rivers and lakes to fill with ice and freeze solid.

Science home learning units research

The interesting unit that I am going to talk about is horsepower. Everytime you see sports cars in newspapers and magazines they would always indicate a "horsepower". It is refering to the power of the car. So, since they are cars, why horsepower and not carpower? Well, that is what I am going to talk about. The word horsepower originally came from the time when steam engines were first invented, replacing the previous horses. People at that time did not know what to compare speed to, and thus compared it to the only form of speed they knew, the horse's speed. They estimated how much power a horse can have and compare it to their new steam engines. The mechanical horsepower of 550 foot-pounds per second is approximately equivalent to 745.7 watts. The unit was not accepted as a SI unit as the definition of the unit varied between geographical regions. Horsepower is useful as the horse is fast, and therefore it is easy to compare with our vehicles now but the disadvantage is that we cannot compare all machineries with the horsepower as even though the horse is fast, our jet planes are far more faster and we therefore cannot compare them. However, it is still useful as it is widely known and can be easily understood by others.

Home learning homework

Question:
Why does the egg float in salt water?
Answer:
Density is equal to mass over volume. The egg is denser than freshwater and floats but when salt was added to the freshwater, the freshwater increased in mass by quite much but not in volume. This results in the density of the now salt water to be greater and the egg. When it is denser, the egg floats.

Use of wrong units in science

The use of wrong units in science can be deadly. An example is the Gimli Glider. It suddenly went out of fuel at 12500m of altitude.Luckily the pilots were skilled and the Glider landed safely. Further investigations have shown that what caused that incident was just a small human error. One part of th team used the new metric system to calculate the amount of fuel given to the Glider while the other used the old imperial system. Such a big mistake was caused by a smal human error--use of different units. Every unit is different,one m cube is equal to 1000000 cm cube. So if you should a plane with 1000m cube of fuel but you calculate it as 1000cm cube, it would have 1000000 times lesser fuel. There are many unit systems in the world, like the imperial units system. However, now the world has adopted a new system widely used, the metric system which has the SI units. M is standard for metres and K is standard for kelvin. Around the world, these units have been used as a base. Imagine one day when you buy your bag of rice it does not say 10kg, but 10 pounds, and you not having heard of pounds before thought it was normal, but you see that the rice bag is smaller and the price is the same. If you only recognise 10, you have been cheated almost half of the bag of rice. However, you will not have any idea what is going on and if you buy the rice twice a month, you will be cheated $5 each time you buy, which is $10 a month and $120 a year. Thus, I conclude that the new units system is to not allow confusion to be made in calculations so that no more such accidents like the Gimli Glider shall occur.

2012

Hi everyone,

Seen the movie 2012?It seems as if it really is happening. More and more disasters are happening these days, the sichuan earthquake not long ago, now the haiti earthquake and if you are aware of the news, there are more and more bushfires, extreme winters and summers occuring these days. Could it have been because of global warming?As you know, when global warming starts, the carbon dioxide rises to outside Earth and forms a large black blanket around Earth. At that time, it will get hotter and hotter on Earth until the light and heat from the Sun is totally blocked out, then the Earth will start getting colder,global cooling, and slowly dies. I read an article about 6 degrees changing the world. If I'm not wrong, by the third degree, Singapore would be underwater. Ahh.....So please start conserving energy to save the Earth, and yourself.