Objective(s) Differentiate between science & psuedoscience. - PowerPoint Presentation

Slide1

Objective(s)

Differentiate between science & psuedoscience.

Slide2

What is Environmental Science??

What is Science??

Slide3

The Nature of Science

Intuition leads to the flat Earth society and bloodletting;

experiments lead men to the moon and microsurgery.

- Seth Mnookin

Slide4

The First Vaccination

Up through the 20

th

century, one of the most serious diseases of mankind was smallpox.

One of out every 10 children born in France and Sweden died of smallpox.

The only known “cure” was to contract the disease and recover.

Some inoculated themselves

with fluid and pus from the sick,

hoping to contract a mild caseand survive.

Slide5

The First Vaccination

A British physician named Edward Jenner observed that dairymaids living in his hometown often contracted cowpox, a nonlethal disease with similar symptoms to smallpox.

He decided to intentionally infect a young boy with cowpox, then expose him to smallpox.

Immunity was successfully conferred to the boy.

5

Edward Jenner vaccinating a child with cowpox from a dairymaid. Source: Bettman Archive / Corbis.

Slide6

A different virus was eventually discovered for use in smallpox vaccinations.

Produced much milder symptoms.

Smallpox was declared eradicated by the World Health Organization in 1980.

The same basic technique has been used to develop vaccines for other illnesses, such as measles, tetanus, chickenpox, whooping cough, and others.

6

Eradication

A monument dedicated to smallpox eradication at the WHO headquarters in Geneva. Source: Wikimedia.

Slide7

7

Basic Rules of Science

Science assumes that everything in the universe can be explained, given enough data and experimentation.

All ideas in science are constantly being tested, evaluated, and re-considered.

Hypothesis:

Testable prediction based on prior knowledge and observation.

Can be supported or rejected based on an experiment.

Theory:

Broad explanation based on many experiments and high amounts of data.

Examples: Evolution, Plate Tectonics, Big Bang

Discoveries must be

reproducible

-- designed and recorded such that the results can be repeated by other researchers.

Slide8

Pseudoscience

Complete Planet X Journal Entry

Must provide evidence of research (links on the bottom of handout) in your entry

Get out

Principles of Science

packet

Slide9

Pseudoscience

A far different idea is

pseudoscience

, which appears or claims to be science, but does not follow scientific principles.

9

Slide10

The theory that life arose spontaneously from non-living matter persisted from ancient times through the 19

th

century.

One recipe for life called for dirty garments and husks of wheat to be added to a jar.

Wait 21 days, and mice appear!

This belief was based in falsescience.

Could it be replicated

consistently?

Were any other possible explanations tested?

10

Spontaneous Generation

Slide11

The primary goal of alchemists during the middle ages was to discover a way to transform materials of little value (such as lead) to gold.

A chemist named Hennig Brand in 1669 was studying urine, observing that it had a color similar to gold.

He accidentally discovered phosphorus; an element that glowed.

Hennig, like other alchemists, kept his discoveries secret. The study of chemistry advanced little during this time.

11

Alchemy

The Alchemist in Search of the Philosophers Stone

(1771) by Joseph Wright.

Slide12

Astrology is

another example of pseudoscience

.

A “new” zodiac chart was created by the Minnesota Planetarium Society to reflect the change in the Earth’s rotation.

12

Astrology

Slide13

Objective(s)

Explain

each of the steps of the

scientific method

.

Slide14

14

Scientific Method

All scientific studies, regardless of complexity, follow the same series of steps, called the

scientific method

.

Slide15

The first step is making an

observation

.

Information gathered by noticing specific details of a phenomenon.

Dr. Edward Jenner observed that dairymaids who contracted cowpox seemed to be protected from the more deadly smallpox.

15

Scientific Method

The Dairy Maid

, 1650s, by Aelbert Cuyp.

Slide16

The goal is to be able to explain the observation.

A

hypothesis

, or testable explanation, will be made based on the scientist’s prior experience and research.

Hypotheses are preliminary explanations – they can and are often proven false.

Dr. Jenner’s hypothesis was that exposure to cowpox would grant immunity to smallpox.The hypothesis must be tested.

16

Scientific Method

Slide17

The

experiment

tests the hypothesis under controlled conditions.

A controlled experiment attempts to test a

single variable

, while keeping all others constant.The experimental group receives the variable, while the

control group

does not.

Dr. Jenner’s experiment was to inoculate the 8 year-old son of his gardener with fluid from a cowpox pustule, allow the infection to pass, then repeat with a smallpox pustule.The boy (experimental group) survived 20 inoculations without succumbing to smallpox! The conclusion

states whether or not the hypothesis is supported by the results of the experiment.

17

Scientific Method

Slide18

Scientific Method

The final step is

communication

, where the results are published and reviewed by others to check for errors, bias, or other issues.

Dr. Jenner submitted his study to the Royal Society for Medicine, but was told he needed more proof.

18

“The Cow-Pock—or—the Wonderful Effects of the New Inoculation!—vide. the Publications of ye Anti-Vaccine Society.”

- Satirical cartoon, 1802.

Slide19

19

The Power

Braclet

Slide20

20

Other Factors Affecting Experiments

Accounting for every single variable in a scientific study is nearly impossible. There are many factors that can cause error.

That is where

probability

comes in. This is the likeliness that a result occurred simply due to random chance.

This can be countered by increasing

sample size

, or the number of observations used in an experiment or study.

Dr. Jenner was able to locate several other parents who were willing to volunteer their children. He even included his own 11 month-old son in the study.

The results were finally published. Jenner called his technique vaccination after the Latin word for cow “vacca”.

Slide21

What’s your question?

Write your hypothesis.

Design a procedure to test

What data will you collect?

How will your data be used to evaluate your hypothesis?

Apply Scientific Method to your question.

Slide22

22

What is the hypothesis you are trying to test?

What data will you collect?

How will you represent your data? Draw an example.

What other variables might you need to control for?

Solutions?

How will your sample size limit you experiment?

How might you minimize bias in your experiment?

Slide23

Controlled experiments aren’t always possible or ideal.

Natural experiments

are conducted in the field under normal circumstances.

The advantage is that these experiments take place in a more accurate, realistic environment.

The disadvantage is that natural phenomena are often very difficult to find.

Slide24

24

Combating Bias

Another significant problem in science is

bias

; the preference for an experiment to

turn out in a certain way

.

Bias is not always intentional, but must be controlled by the experimental design.

A

blind experiment

is conducted so the experimental subjects do not know which is the control and which is the experimental group.

Eliminates the “placebo effect”

A double-blind experiment

also

prevents the actual scientists

from knowing which is the control or experimental group.

Slide25

Scientific Fraud

There are many examples of published studies or report that have been later found biased, flawed, or outright fraudulent.

These are always detected, eventually, due to the

scientific method

and

peer review

.

The net effect is loss of time, resources, and public mistrust.

In 1998, Dr. Andrew Wakefield published a study in the British journal The Lancet documenting a link between the MMR vaccine and autism in children.

In the following year, over a thousand articles were written about the possible link, very few by actual experts in the field.

Vaccine rates dropped from 92% to 85% in the U.K., with similar results in other countries.

25

Slide26

Autism / MMR Retraction

Wakefield’s conclusions were found out to be fraudulent and that he had manipulated the data.

Several outbreaks of measles and mumps occurred across the world from 2002-2008.

The United States has seen a similar effect, with vaccination rates below CDC recommendations in several schools.

26

According to a Time Magazine survey, 24% of adults place “some trust” in celebrities’ opinions on vaccines.

Slide27

Background: Case Study of Beriberi Disease It is 1897 and people are dying in Java, an island in Indonesia or the Dutch East Indies. They all seemed to share the same hideous symptoms beginning with overall muscle weakness, loss of appetite, and eventually they suffered paralysis and eventually death by heart failure. This disease was called beriberi by the indigenous people. This was a word from their native language that meant “I cannot, I cannot.” Scientists thought the disease might be caused by bacteria. (After all, since the discovery of bacteria, almost all previously unknown diseases were attributed to a bacterial infection.) They decided to prove that a bacterium was the culprit by conducting an experiment. They used chickens as their trial subject. They injected a group of chickens with the blood from a patient who had beriberi and then to prove that the blood carried the “bacterium that caused the disease” they injected another group of chickens with saline or simple salt solution. Well, both groups got beriberi! So back to the starting board they went.

Slide28

If a chicken is infected with the blood from a person sick with beriberi then the chicken will contract beriberi

Other people being sick due to bacteria

Exposure to beriberi “bacteria”

Becoming sick with beriberi

Slide29

Experimental: Chickens exposed to beriberi blood

Control: Chickens not exposed to beriberi blood

Chickens exposed to beriberi blood became sick. They would have incorrectly concluded that caused the illness

NO!!! – It showed that their hypothesis was incorrect but that is important to learn in order to pursue the correct cause

Slide30

One of the scientists who had been sent to work on this mystery was a Dutch physician and pathologist named Dr. Christiaan Eijkman. One day, as he walked around the hospital compound he observed his surroundings. He noticed that the cook fed every one of the patients the staple diet of the nation polished or white rice. Polished rice is wild, brown rice with the husk or outer layer rubbed off so that its color is white. It was the rice of choice of the middle class of the Indonesian people. He also noticed that the hospital staff fed the chickens (that would eventually be the chicken soup for the patients) wild rice. White rice was more expensive than brown rice, so the chickens were usually fed brown rice. Dr. Eijkman realized that this was an important observation and thought that maybe the wild rice contained something that the white rice did not. So he conducted another experiment. He divided the chickens once again into two separate groups. He fed one group of chickens only white rice and the other group only wild rice. Then he watched and waited.

It turned out that the chickens that had been fed wild rice did not get sick at all, but the chickens that had been fed the polished or white rice became weak, lost their appetite and eventually died from beriberi. Eureka, the case was solved!

Slide31

As Dr. Eijkman and others continued to research this interesting case, they found that polished rice lacked thiamine, a vitamin necessary for good health. This was actually the first "vital amine" or vitamin to be discovered. It is also called vitamin B1. We've now known for more than a hundred years that brown rice is more nutritious than white rice. But most Asian cultures associate eating white rice with prosperity and eating brown rice with bad luck. Most rice is still milled or polished, both in Asia and elsewhere.

In Europe and America both white rice and brown rice are consumed, but mostly white. In fact, some white rice is chemically fortified to add back the B vitamins. In 1929, Eijkman and Hopkins were awarded the Nobel Prize for Physiology or Medicine for this discovery.

Slide32

Both groups of chickens became sick

Polished rice vs. unprocessed rice

Control group – chickens fed unprocessed rice

Experimental group – chickens fed polished rice

Get his experiment and results published.

Slide33

Slide34

Missions:

Complete material in study guide.

Study Guide (Classes: X)

PowerPoint (Classes: X)

Review material in study guide

Old school, “grab a partner & quiz ‘em”

Quizlet (make your own)

Create an instructional video using Powtoons

34