Investigating Science

What esperiment did Van Helmont conduct to investigate where plants gather mass from?

Helmont filled a plant pot with 200 pounds of dry soil and watered it with rainwater. He then planted a small willow weighing 5 pounds. He let the plant sit for 5 years, occasionally watering it with rain or distilled water, and the tree had grown to 169 pounds and 3 ounces. Van Helmont then dried the soil from the pot in an oven and discovered the same 200 pounds, however, it was missing appoximately 2 ounces. As a result, Helmont concluded that 164 pounds of wood, bark, and roots grew from being fed only water.

**Identify** at least five variables that might affect Van Helmont’s experiment.

* Measurement technology and accuracy


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Examples of scientific methodologies.

* experimental testing= a scientific procedure undertaken to make a discovery, test a hypothesis, or demonstrate a known fact.


* models= a physical and/or mathematical and/or conceptual representation of a system of ideas, events or processes.
* secondary sources= popular books and journal articles, histories, criticisms, reviews, commentaries, encyclopedias, and textbooks.

Can you name some more examples of scientific methods?

* simulations= imitation of the operation of a real-world process or system over time.
* Conducting surveys= try to find out detailed information about a lot of different people or things, usually by asking people a series of questions.
* fieldwork= the collection of raw data outside a laboratory, library, or workplace setting.