Scientific Models, part 1

August 21, 2015(1.2 in your books)

Meme Moment

Scientist of the Day

Stephen Hawking• Studies space and time• Diagnosed with ALS in college

– thought he’d only live 2 years• When he finally got a

wheelchair, he did a bunch of crazy tricks

• He can’t talk now, so he uses his eye to pick out 15 words/min

• Campaigns for peace, space exploration, and disability rights

Vocabulary

Inference: What you guess based on what you observe, even if you didn’t observe it directly. This is a scientific guess, so it’s not really the same as normal “guessing.” You are explaining or interpreting your observations.

6th grade

Qualitative vs Quantitative

Qualitative: Observations that are subjective. A different person might record something else.

Quantitative: Measurements made with units. No one can argue about the number.

6th and 7th grade

Vocabulary

Objective: Based on evidence. You try to avoid bias.

Subjective: Based on feelings, values, or intuition. There’s often a lot of bias here.

“This shirt is blue.”

“This shirt is ugly.”

“This is a work shirt.”

Vocabulary

Data: Multiple observations collected in a scientific investigation, such as facts, pictures, numbers, etc

Empirical evidence: A good set of data describing objective observations in a scientific way. You can also turn qualitative, slightly subjective observations into empirical evidence by breaking it down further

8th grade

Crow Example• Mask vs hat vs different

mask• “How does the crow react?”

will get a subjective answer...

• But you can add specifics to get empirical evidence

• “How many times is the crow: Looking at you, looking at you and cawing, following you and cawing, no reaction...”

8th grade

http://www.birds.cornell.edu/crows/crowfaq.htm

Real Science vs. Pseudoscience

• Science is based on objective reasoning. We can prove that science is right with data!

• Pseudoscience is based on subjective reasoning or faulty reasoning.

• What are some examples of pseudoscience?

Magnetic Bracelet Example

• This is not true.• Pseudoscience can look like

science on the surface.• Sometimes people look at

bad data and get the wrong conclusion – other times they’re lying!

• Consider the source: is a company trying to sell you something? Be skeptical!

VocabularyPersonal bias: You think one thing, so you think everyone will think that too.

Cultural bias: Everyone around you when you were growing up seemed to think or do something, so you think everyone in the world will think/do that too.

Experimental bias: An experiment doesn’t have a good design, so you’re more likely to get one particular result.

Deductive vs Inductive• Two ways to classify scientific reasoning

• Deductive reasoning starts with other knowledge.

• Inductive reasoning starts with observations.

• Scientists usually like deductive reasoning more, but inductive reasoning is still useful – it just has to be tested afterwards!

Deductive Reasoning

I already know... Observation Conclusion

Inductive Reasoning

Observation I also know... Conclusion

What if you get it wrong?

• Science fixes itself! Even when we get stuff wrong, we often learn more about the problem in the meantime

• It’s especially important to test conclusions from inductive reasoning with new experiments

• On Monday, we’ll talk about designing experiments from scratch and plan our first explosion!

Next Friday

• Make a note!

• 2L bottle of any soda• 1 roll of any Mentos or

similar candy• Optional: poncho

Questions• Any questions about the slides?

• Any new questions?

Questions from Yesterday

• Is there anti-venom for komodo dragons?I’m still not sure. One source said yes, another no.

• What type of oryx was reintroduced? Arabian oryx (Oryx leucoryx) into Oman, Bahrain, Saudi Arabia, Qatar, Jordan, Israel

• Are daddy longlegs the most poisonous type of spider?

No. And spiders usually aren’t poisonous. Poisonous is if you eat it. Venomous is if it stings or bites and injects venom that way.

http://spiders.ucr.edu/daddylonglegs.html

Questions from Yesterday

• Are daddy longlegs a type of spider?It depends. 3 different types of bugs are called “daddy longlegs”

insect – crane fly arachnid, but not a spider arachnid, cellar spider

Questions from Yesterday

• Are bush babies and lemurs types of monkey?

No, bush babies, aye-ayes, and lemurs are “prosimians” (actually in different suborders)