READ: Observations and Facts
READ: Observations and Facts
A scientist observed this orange-colored scum on a pond in her neighborhood. She wondered what the scum is and why it was there. She decided to do an investigation to find answers to her questions. Scientific investigations often result when observations like this raise questions.
What Are Observations?
An observation is any information that is gathered with the senses. Our senses include vision, hearing, touch, smell, and taste. We see with our eyes, hear with our ears, touch with our hands, smell with our nose, and taste with our tongue. We can also extend our senses and our ability to make observations by using instruments such as microscopes, telescopes, and thermometers.
Using Observations to Gather Evidence
Besides raising questions for investigation, observations play another role in scientific investigations. They help scientists gather evidence. For example, to investigate whether a chemical change has occurred, a scientist might observe whether certain telltale signs are present. In some chemical changes, for example, a substance turns from one color to another. You can see an example of this in the Figure below. In other chemical changes, an odor is produced or gas bubbles are released. All of these changes can be observed with the senses.
Some of these pennies are shiny and copper colored. That’s how pennies look when they are new. The older pennies are dull and brown. Copper at the surface of these pennies has combined with air to become a different substance with different properties. The change in color shows that a chemical change has occurred.
Facts, Observations, Opinions
Scientists usually begin an investigation with facts. A fact is a bit of information that is true. Facts come from data collected from observations or from experiments that have already been run. Data is factual information that is not subject to opinion or bias.
What is a fact? Look at the following list and identify if the statement is a fact (from observation or prior experiments), an opinion, or a combination.
Can you be sure from the photo that Susan has a cold?
- Susan has long hair.
- Susan is sneezing and has itchy eyes. She is not well. She has a cold.
- Colds are caused by viruses.
- Echinacea is an herb that prevents colds.
- Bill Gates is the smartest man in the United States.
- People born under the astrological sign Leo are fiery, self-assured, and charming.
- Average global temperature has been rising at least since 1960.
An Analysis
The following is an analysis of the statements above:
- This is a fact made from observation.
- The first part is from observations. The second is a fact drawn from the prior observations. The third is an opinion, since she might actually have allergies or the flu. Tests could be done to see what is causing her illness.
- This is a fact. Many, many scientific experiments have shown that colds are caused by viruses.
- While that sounds like a fact, the scientific evidence is mixed. One reputable study published in 2007 showed a decrease of 58%, but several other studies have shown no beneficial effect.
- Bill Gates is the wealthiest man in the United States; that’s a fact. But there’s no evidence that he’s also the smartest man, and chances are he’s not. This is an opinion.
- This sounds like a fact, but it is not. It is easy to test. Gather together a large number of subjects, each with a friend. Have the friends fill out a questionnaire describing the subject. Match the traits against the person’s astrological sign to see if the astrological predictions fit. Are Leos actually more fiery, self assured, and charming? Tests like this have not supported the claims of astrologers, yet astrologers have not modified their opinions.
- This is a fact. The Figure below shows the temperature anomaly since 1880. There’s no doubt that temperature has risen overall since 1880 and especially since the late 1970s.
Global Average Annual Temperatures are Rising. This graph shows temperature anomaly relative to the 1951-1980 average (the average is made to be 0). The green bars show uncertainty.
Summary
- Facts are true. Data, gathered correctly, are facts.
- Some statements that appear to be facts are not.
- All scientific explanations and interpretations are based on facts.
- An observation is any information that is gathered with the senses.
- Observations raise questions that lead to scientific investigations. Observations also help scientists gather evidence in investigations.
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