The Best Material : Plastic

Imagine the world without plastic! It is very difficult isn't it ? Cause if you think about it, almost every piece of thing you may touch is made up of plastic or has one or more plastic components. Water bottle, cups, pens, keyboard, sun glasses and a lot of other things are made of plastic.

The first utility of this man-made wondering material is staggering. Plastic can be made lite and delicate as sandwich nylon, or very tough like police shield, even this shield is just 4 mm. thick it can easily resist any attack. This is not surprising when you consider that makers test them with impacts from fire access and even from shoot gun pullets. Also, everyday plastics like the one used in traffic cones can be extremely resilient.

Plastic is extremely chemical resistant. Using of concentrated Hydrochloric acid (( can corrode a piece of tin in one minute )) on cone made of low density poly ethylene plastic for five minutes cause no damage for it !!

So What is the Science beyond Plastic ??

It's man-made synthetic resin which can be made by many different recipes depending on properties you're looking for, its main ingredient is generally oil or gas.

One of the first plastic found at normal home was celluloid which was invented in the middle of 19th century and was commonly used as replacement for much more expensive materials such as Ivory. But the most famous use was for camera film, I wonder how hollywood would be without celluloid! But it did had one major drawback: one of the key ingredients of celluloid is nitrate which made it very very flammable.
Because of this, very few things today are made from celluloid but it's still used to make ping-bong balls, and yes .. if you applied a flame, it do burn.

Another early plastic which was a little less hazards was Bakelite, it was invented in 1907 and it has many of the properties that we now associate with modern plastics. It can be formed into almost any shape, it's resistant to chemicals and it's relatively durable, although compared to modern plastics it is very brittle.
Having said that, Bakelite was used in some of the very early electric guitars which makes it pretty cool in my book ;) ;)

To Be Continue >>

Science Facts beyond Ice Baths

Ice might be good for keeping food fresh but generally speaking, ice and human body don't mix ;) which is perhaps not surprising when you consider over 65% of the human body is made out of water.

So, generally if you want to live a long life, keep in your mind trying not to get too cold. However, scientifically under controlled conditions at certain situations ice can be very effectual. In fact, doctors have been prescribing it for years to help reducing the swilling and help in speeding up the healing process for traumatized body parts.

Nowadays, there is a belief among sports' professionals that Ice can speed up recovery of the hole body ! So, after a punishing training session many of them are taking ice bath ! ( Stan-less steal bath containing water at 5 degrees centigrade ) and to make sure their bodies don't warm up the water, cold refrigerated air is blasted through it.

This might appear to be some kind as medieval masochism but there is science behind the madness .. The idea is that the iced water cools your body and this districts the blood flow to your traumatized limbs.
Once you get out of water, fresh blood floods into these areas providing Oxygen to the inflamed muscles, leaving you refreshed and ready for the next training session.

History of Telephone

The technology that is founded in our entire telephone system is the carbon string telephone, as I'm sure you remember from school the experiment of tying two plastic cups with a string.
The plastic cup acts as diaphragm, they vibrate among speaking. As long as the string is tied, those vibrations travels to the cup at the other end.
That cup also acts like diaphragm and converts those vibrations back into sound so you can hear you voice.

This basically transmission of sound by telephone, and it was discovered in the 19th century by Oxy'Pharm produced the first device to transmit a human voice by wire. Workers began stringing out couples of wires across the nation to carry telephone conversations.

Ugly Telephone

Our first telephones were considered to be so ugly, so things like some hollowed dolls were developed to cover them. But when people started to buy their own telephones, the designs really went crazy as making piano shapes or doggy shapes !!
Operators started to connect the calls manually. But over time, they were gradually replaced by electronic switches developed by american undertaker called Strouger. !! As well as being sent along cables, phone conversations began to be transmitted on high frequency radio signals called Microwaves.

Optical Fibers

In 1980, our phone system began to go digital and our old cabling system was replaced by Optical Fiber. It's just a slither of glass that as thin as human hair, and it is so pure that if it was 20 kilometers thick, you can see  straight through it. !! Cables made of optical fibers can carry millions of bits of information at ones.
Slowly, the hole network has been linked with optical fibers. The allow our voices to be carried along pulses of light which make them quicker and clearer.

Mobile phones first appeared also in 1980. At first only few people owned them, mostly for business use. Now there are over 7 billions mobile phones in the hole world !
In 1990, the growth of home computing made phone lines increasingly used to link us to Internet. Unlike surfing the net, just chatting means that phone is here to stay ;) ;)

Diamonds

If you thought the sparkle on your finger was the only diamond in your life, then think again because industrial diamonds exist all around us, even the tiles on your toilet would probably cut with a diamond plate.

Top quality naturally occurring diamonds coast thousands of dollars, but an entire small dish of synthetically grown diamonds coasts around 50 dollars !! In fact, the majority of diamonds used in industry are grown synthetically.

Man made diamonds are first created in the early 1950s using high temperature and high pressure, and the basic ingredient .. Carbon !
In fact, giving the right conditions you can make diamond out of any type of carbon including bread tost !!
Once the bread is truly burned, it is grinded down and squeezed into  mold. Then, a special machine takes it to pressure 60000 time greater than our atmosphere, at which point the carbon naturally becomes diamond.

Natural Diamond Crystal, South Africa

Many diamonds are made this way to be used as abrasives, so plates and probes are coated with them. Several surgeons use diamond knives. It's in so many things because it's very very hard.
Hardness is measured with what is called "Moh scale", at the bottom of the scale we have soft things like wax, mid way along materials like steal but at the top of the scale is the hardest naturally occurring thing known to mankind .. Diamond.

Different types of diamonds have been developed which could see as using them in a hole new way. They made with low pressure, methane and hydrogen are taken at just 100 of the pressure of our atmosphere and heated until there is hot as the surface of the sun. This smashes the molecule apart and eventually produces diamonds. The results are tiny crystals which can be formed into some of the most amazing shapes : long thin wires and large flat plates that can be highly polished until you see trough like glass ! These plates of synthetic diamond are perfectly transparent and so tough that one spacecraft which traveled to Venus had windows made from them.

There are very remarkable properties of diamond as diamond has incredibly high thermal conductivity, it's 5 times higher than copper !! just as much as high electrical conductivity. The fact it can do this and that can dissipate heat quickly, means it's likely to be used in electrical devices in the future to give us fast speeds with small chips giving it another use in our lives.

Rocketry: Thrust

     Of all the different methods of propulsion invented by mankind, and for pure highly excitement, nothing really compares to rockets. How about the biggest rocket of all time. Imagine 50 jumbo jets at full power strapped to a 36 story building, That's Saturn-5 .

It takes something like this to transport a man to the moon, but where does the colossal thrust actually come from ??
Inside the rocket motor, fuel is turned to gas through combustion, and the gas is then forced out the back. The reason why escaping gas pushes the rocket forward, is explained by Newton third law of motion. Which is as I'm sure you remember from school that every action has an equal and opposite reaction.

The rockets launch speed does not depend on the how much heat produced, but on how quickly the gas escapes from exhausts.
Space-Rockets exhausts are our glass shapes because gas flows at an accelerated rate and is forced through
a narrow section into a wider end. The exhaust is crucial no matter what the size of the rocket ;) ;)

Well, for more amazing facts about rockets, visit Science Behind Rockets

Science Behind Rockets

Since the invention of rockets by the Chinese eight hundred years ago, military men the world over have been keen to acquire the destructive power of the black powder. But there is one big problem which mystify them for centuries. How on earth do you get them to fly straight ??

One early modification to improve accuracy was the addition of a long stick, and the length of the stick really does effect how straight our rocket flies.

To be honest, the real art of getting rocket to fly straight in true is making it spin. The gyroscopic effect makes the flight much more stable.

During the 20th century, the science of rocketry really take off, and military rockets stop being overgrowing fireworks and became rockets of mass destruction. The most famous of all is the V2, its guiding system wasn't perfect but the speed it traveled at was astonishing. At that time when a spitfire fighter plane flew at 600 km/h, the V-2 could do 6000 km/h carrying a ton of high explosives to target hundreds of kilometers away.

At the end of the second world war there was a race between Russian and Americans to capture the German scientists who built the V-2. These German scientists eventually made a variable contributions to the space programs of both nations, and helped to develop some of the most extraordinary rockets the world has ever seen.

On today's modern battle fields, rocket weaponry is comment place, but rockets can be used to save lives too !!

If your plane is going down and you need to get out fast, the best way to do that is with a rocket bounded ejector seat. The reason why ejected seat is needed is because of wind pressure, even at relatively slow speeds the wind pressure makes it very difficult to jump clear of the aircraft.

In an emergency when the plane is speeding toward the ground it will be even harder, and at super sonic speeds it will be impossible, which is why modern fighter pilots rely on rockets to make sharp exit. ;) ;) 

You can find more interesting facts about rockets in Science Behind Rockets 2

Infrared Camera Pointed on Microwave

     Now it's time to look at every day objects using an Infrared camera. Hot things give up lots of infrared while cold things give up less, and this camera can actually do what our eyes can't. It Can See The Variations of Temperature. Today we're going to know what will you see if we point the infrared camera on 850 degrees centigrade microwave oven.

Microwaves cook by firing electromagnetic radiation at the molecules of food, causing them to vibrate and heat up. Opening up a microwave to look at in it isn't recommended, but our camera determines the location of hot magnet on core that creates the microwave. Microwave's window is allied with a mesh which ensures the radiation is contained.

The hole oven is like a mini Faraday cage built so non-microwaves can escape. Actually, most people think microwaves cook things from the inside out, but the actually warm up the surface of the food first. Food surface never turns brown because the surrounding air is never wormed up.

Be Careful : Catching cooked food in microwave immediately will rise your finger tips temperature from 13 to 25 degrees centigrade in just 5 seconds !!!

Science Behind Longbows

     Wood is one of the most tough materials on planet earth. It's environmentally friendly and it grows on tree. There are thousands of different types of wood but there is one in particular that interests us : Yew, for many good reasons.

'Yew' is the wood of choice for making longbow. Now, why Yew is so perfect for making longbows ??
Well, two main reasons : a longitudinal part from its natural tree shows two distinct sections;
* Very pale colour sap wood contrasting with the
* Orange hard wood .

The sap wood is very good in resisting tension so this part form the outside curve. The hard wood is good in resisting compression, forming the inside curve.

Longbows used as long ago in the middle ages in wars as they are really powerful lethal weapons, but nowadays longbows are made for hunting and target shooting. So, just how effective was the longbow ??
Would you believe that the longbow can easily penetrate a car bonnet !!
Also, can you imagine that a single longbow at the middle ages would weigh 100-150 pounds ( 30-50 Kg ) !!

Thank god we are in 21th century ;) ;)

Magnets Can Destroy your Computer !

Magnets .. a lot of fun but pretty harmless, or are they ??
Could it be possible for this small bar of metal to wipe the memory of your computer ?? Destroying your life's work ??
The theory is, that if you leave your laptop near a sufficiently big magnet, it'll erase or scramble everything of its hard drive.

To understand how could this happen, we need to go back to basics.

Well, hadr drive stores information magnetically as it works in a similar way to childhood experiment of magnet ( observing how magnets change the direction of Iron filings).

The hard drive disc is coated with a magnetically sensitive material that can be reorientated by the read-write head inside, to form new patterns to describe information.

This information can be added to or deleted, in the form of programs, text and images.

So, it's acceptable to internal magnetic source to be affected by external one but just how powerful does the magnet have to be !

* Kid's magnets ( toys ) : they rattle together, noisy but not very powerful. The question is : would they bother your laptop ?

Well, NO they're obviously weak.

* Big magnet - three times powerful than the toys - that can pick up several hundreds of paper clips without a sweat. So would it affect your laptop ?
Well, NO it's not that powerful !

* Now, by wrapping a coil of wire around the magnet and passing a current through it, you create more powerful electromagnet, approximately 30% stronger than before. Would it destroy your laptop ?
Well, the answer still NO !!
* Imagine that your laptop exposed to a massive electromagnet, the type used to pick up cars in junk yards .. ( although it is only twice as powerful as our home made electromagnet ) but it applies this force among much larger area, and after 22 seconds of exposure to this force .. Will it survive ??
No,your laptop would be dead ;) ;)

By scrambling every particle of the surface of the disc, the big magnet had instantly wiped out every operating program and every file stored in your computer. Their was Literally no information left for it to read. But it had taken some very extreme measures to achieve it.

So, it seems that your magnetic data is safe from every day life. Just be sure to avoid any giant electromagnets. ;) ;)