There are plenty of things that can go through glass without breaking it – from the sun’s rays to our own shadows. But what about something a little more everyday, like a cat?
Sure, cats have claws that could potentially break glass, but they also have a natural ability to land on their feet. So it’s not surprising that they can often be found perched atop windowsills or leaping through glass doors.
But how do they do it?
1. What is glass?
Glass is a material that is Liquid at high temperatures and solidifies to a rigid state when cooled. Glass is made from sand (silicon dioxide), lime (calcium oxide) and soda (sodium carbonate). 2. How does glass break?
The most common type of breakage of glass is due to thermal stress. Thermal stress occurs when different parts of the glass are at different temperatures. The outer surface cools first, and contracts more than the inner surface which is still hot. This stresses the outer surface, making it more likely to fracture. 3. What can go through glass without breaking it?
Acharged particle beam, such as an electron beam or ion beam, can be used to drill through glass without breaking it. The charged particles are attracted to the glass by electrostatic forces, and they melt their way through the glass as they travel.
2. The history of glass
Humans have been making glass for over 5,000 years. The first glass was made by the Phoenicians, who used a technique called “casting” to make small decorative pieces. In this process, a lump of glass is placed in a mold and heated until it is soft enough to take on the shape of the mold. Once it cools and hardens, the piece of glass is removed from the mold.
The Phoenicians also invented “blown” glass, which is still used today. In this process, a glob of molten glass is placed on the end of a long rod and then “blown” into a bubble. Once it cools and hardens, the bubble is cut open to form a hollow sphere.
The Romans improved upon both of these techniques and began mass-producing glass objects. One of their most famous innovations was stained glass, which they used to create beautiful windows for their homes and churches.
In the Middle Ages, European glassmakers began using lead oxide to make “lead crystal.” This type of glass has a higher percentage of lead than other types of glass, which gives it a distinctive sparkle. Lead crystal glasses are still used today for special occasions.
Modern glassmaking techniques were developed in the 19th century, and mass production of affordableglassware became possible for the first time. Today, there are many different types of glass that are used for everything from building windows to making optical lenses.
3. How is glass made?
The primary raw materials used to make glass are sand, soda ash, limestone, and other minerals. To make clear glass, a special sand called silica sand is used. This fine white sand is needed because it is very pure and does not contain other unwanted chemicals. Glass production also uses limestone, soda ash and cullet (recycled glass).
The manufacturing process for making glass is very similar worldwide. First, silica sand, limestone, soda ash, and cullet are placed into a large furnace known as a batch house. The batch house holds these raw materials in stockpiles and feeds them into the furnace as needed. In the furnace, at temperatures around 2600 degrees Fahrenheit, the raw materials melt and combine to form a new substance called molten glass.
4. Properties of glass
Glass is an amorphous solid material, which means that its atoms are not arranged in a crystalline structure1. It is a non-crystalline, or “brittle” material2, with a characteristic fracture3.
4.2 Physical properties of glass
The physical properties of glass can be summarized as follows:
- Glass is hard and brittle.
- It has a high degree of transparency to visible light, but Wood’s metal4 can obscure it.
- It has good electrical insulation properties.
- All common glasses have a coefficient of thermal expansion5 that lies between about 3 × 10−6/°C and 9 × 10−6/°C.
4Density: 2.23 g/cm3 (at 20 °C) 5Thermal expansion: 73 × 10−7/°C (at 25 °C)
5. Types of glass
There are several different types of glass that have been developed for different purposes. The most common type of glass is annealed glass. This is the standard type of glass that is used in windows and drinking glasses. It is made by cooling the molten form of silica gradually so that it becomes very hard and strong. However, it is also very brittle and can easily break if hit with a hard object.
Another type of glass is tempered glass. This is a special kind of glass that has been heat treated to make it much harder and more resistant to breakage. It is often used in car windows and in some kinds of cookware because it is less likely to shatter if dropped or hit.
A third type of glass is laminated glass. This is two or more layers of glass bonded together with a plastic interlayer. It is often used in car windshields because it will not break into large shards if hit by an object.
Finally, there is bullet-resistant glass. This is a very strong type of laminated glass that has been designed to stop bullets from penetrating it. It is often used in government buildings and other places where security is a concern.
6. Uses of glass
-Lighting: include: household lamps and outdoor lanterns, flashbulbs in cameras
-Bottles and containers: most perfume bottles, cosmetics bottles, many medications and vitamins are bottled in glass
-Windows and windshields
-Glass bake ware
- Drinking glasses, tumblers, tea cups
- Decorative dishware
-Several types of tubing
7. How to recycle glass
Glass Recycling Facts
Glass is infinitely recyclable and can be reused endlessly without any loss in quality or purity.
Glass is made from all-natural, sustainable raw materials, such as sand, soda ash, limestone and “cullet,” the industry term for furnace-ready recycled glass.
More than 80 percent of the energy saved by recycling glass is from using cullet instead of raw materials.
Every metric ton (1,000 kilograms) of waste glass recycled into new products saves 315 kilograms of carbon dioxide from being released into the atmosphere during the manufacturing process. Stats like this one led the Carbon Trust to label glass “the Greenest Packaging Material” in 2009.
8. Facts about glass
- Facts about glass
-You can recycle glass infinitely without it losing quality
-Glass is made from sand, soda ash and limestone
-The first known glass was made in Mesopotamia in 3,500 BC
-The Romans used glass to make mosaics and windows
-Glass is brittle and will break if hit with a hammer
-The melting point of glass is 1,000 degrees Celsius
-Glass is transparent, but you can add colour to it by adding minerals
-Glass is used in making optical fibre