Why did Chemistry Become a Science?. Three Primary Factors Based on needs and wants Needs –Shelter from the elements –Food and water –Protection Wants.
Presentation on theme: "Why did Chemistry Become a Science?. Three Primary Factors Based on needs and wants Needs –Shelter from the elements –Food and water –Protection Wants."— Presentation transcript:
Three Primary Factors Based on needs and wants Needs –Shelter from the elements –Food and water –Protection Wants –A mate –Improved self-image (status, beauty) –Entertainment Needs –Shelter from the elements –Food and water –Protection Wants –A mate –Improved self-image (status, beauty) –Entertainment
–Shelter from the elements –Food and water –Protection –Shelter from the elements –Food and water –Protection
Near volcanoes, if the melted rock is mostly silica, it can form a natural glass called obsidian. It can be worked into very sharp tools. Even today some surgeons use obsidian knives in eye surgery.
Stone tools technology Amazingly, stone tools can be sharper than the surgical knives used today. Knives used for cutting meat, cutting hides, cutting fibrous materials. Axes used for chopping trees. Arrowheads for killing animals at distance. All could be used for self-protection
Fire was a huge advance in learning the chemistry of nature and improving chances of survival.
If you want fire, you had to hope for a lightning strike to start it. Then you had to keep it burning.
Learning that fire had important uses. –Warmth –Softens food and makes it easier to digest –Makes food safer to eat. –Scares away predators. –It causes changes in materials that are placed in the fire.
Creation of Fire Figuring out how to start a fire without lightning was another huge step in chemistry. Friction- spinning a suitable stick on a suitable surface with suitable fuel. Learning which of these work best meant the mastering of fire.
Dirt became a solution with fires help Once you had fire where ever you wanted, primitive man would naturally try throwing things into the fire. Sometimes unexpected things happened. Sometimes certain dirt that normally would turn to mud when it got wet, would no longer turn to mud, if it had gotten subjected to fire. Dirt that could do this was pretty easy to recognize. After rains, and after the ground dried. This special dirt had cracks in it. Also, this special dirt could be shaped when it got wet. It was great for making figurines of animals and of beings that possessed special powers. But most important was that it could be molded into pots to store and protect food and water.
Firing of Clay This special dirt is know as clay. Clay can be molded into a bowl and dried; but if you added water to the bowl, it would become soft and weak and the water would leak out. However, if it gets subjected to fire, something very useful happens. It is no longer vulnerable to water and will hold its shape.
Cooking Sterilizes Dries Drying (dehydration) Accelerated evaporation with air and sun Absorption of water with salt Controlled fermentation Wine (alcohol content prevents bacterial growth) Distillation to increase alcohol concentration Beer Cheese Separation of oils, which last longer when separated Add ingredients that prevent bacteria growth. Now we can freeze, refrigerate, freeze dry, & irradiate.
The bacterium, Acetobacter, converts alcohol to acetic acid (vinegar). Oxygen encourages its growth, highlighting the importance of excluding oxygen during the wine making process. Mother of Vinegar: A slimy, gummy substance made up of various bacteria specifically mycoderma aceti that causes fermentation in wine and turns it into vinegar.
Even in Middle-Age Europe, it was well- known that spices provide important preservation qualities. The most effective antimicrobial spices include garlic, onion, cinnamon, cloves, thyme and sage. Cloves, which have a high essential oil content, contain eugenol also present in sage and cinnamon. Allicin, present in garlic, also acts as an antimicrobial agent, as does the allyl isothiocyanate present in mustard. Thymol, present in thyme, oregano and sage, is also noted for its antimicrobial properties. Research at Kansas State University, Manhattan, has shown that cloves have a high antimicrobial effect against E. coli in ground meat. Cinnamon, garlic, oregano and sage were also shown to be effective. CH 2 =CH-CH 2 -N=C=S