RISHI MURUGESAN

a PowerPoint

What is a Scientific Theory

A scientific theory is a theory that explains scientific observations. It must be falsifiable.

What is a Superseded Scientific Theory?

A superseded scientific theory is a theory was once thought to be true but has been proven false.

What is a Superseded Theory that has changed in the last 500 years?

One example is the theory of Spontaneous Generation. Spontaneous generation has been proven wrong.

What is Spontaneous Generation?

Spontaneous means sudden or unplanned

Generation means creation of making of.

Spontaneous Generation means the sudden creation of something.

Why did people believe in Spontaneous Generation?

Back in 343 B.C., there was a scientist named Aristotle. He wrote books on Spontaneous Generation.

What is the History of Animals?

Aristotle wrote it. In it he said that all life forms are created from the air and pneuma or “vital heat.”

Was Aristotle correct?

No. There is no vital heat. He believed vital heat was the breath of life. There isn’t vital heat.

How was the theory of Spontaneous Generation disproven?

In the 19th century, Louis Pasteur’s work with germs. He made an experiment which disproved the theory.

What was his experiment?

It was a small bottle with a long tube. He filled it with broth and experimented.

So Spontaneous Generation is Wrong!?!?

Yes. Since nothing grew in the bottle, the theory doesn’t work. A Theory needs to work every time for it to be true.

What happened?

Since there was no air inside the tube, nothing grew inside of it. Because of this, Spontaneous Generation was wrong.

What are your sources?

Fankhauser and Carter, D. B. and J. Stein. "Spontaneous Generation." Spontaneous Generation. 2 Nov. 2004. 8 Feb. 2009.

"Louis Pasteur." Wikipedia. 7 Feb. 2008. 9 Feb. 2009.

"Pneuma(Stoic)." Wikipedia. 22 Dec. 2008. 9 Feb. 2009.

"Superseded Scientific Theories." Wikipedia. 5 Jan. 2009. 8 Feb. 2009.