Thursday, September 18, 2014

Understanding Science

http://undsci.berkeley.edu/article/0_0_0/us101contents_01

To understand what science is, just look around you. What do you see? Perhaps, your hand on the mouse, a computer screen, papers, ballpoint pens, the family cat, the sun shining through the window …. Science is, in one sense, our knowledge of all that — all the stuff that is in the universe: from the tiniest subatomic particles in a single atom of the metal in your computer's circuits, to the nuclear reactions that formed the immense ball of gas that is our sun, to the complex chemical interactions and electrical fluctuations within your own body that allow you to read and understand these words. But just as importantly, science is also a reliable process by which we learn about all that stuff in the universe. However, science is different from many other ways of learning because of the way it is done. Science relies on testing ideas with evidence gathered from the natural world. This website will help you learn more about science as a process of learning about the natural world and access the parts of science that affect your life.

Thursday, September 11, 2014

Misconceptions about science
http://undsci.berkeley.edu/teaching/misconceptions.php#b1
Many students have misconceptions about what science is and how it works. This section explains and corrects some of the most common misconceptions that students are likely have trouble with. If you are interested in common misconceptions about teaching the nature and process of science, visit our page on that topic.

Misinterpretations of the scientific process

Misunderstandings of the limits of science

Misleading stereotypes of scientists

Vocabulary mix-ups

Roadblocks to learning science

The Language of Science

Women and science.

Biographies of Women in Science:http://www.eiu.edu/wism/about_biographies.php

Smithsonian Women Scientists http://www.cfa.harvard.edu/hea/sws/
Smithsonian women scientists are an adventurous group: from hunting meteorites in Antarctica, exploring the farthest reaches of the Universe from remote mountain tops, to measuring mercury levels from the depths of the ocean to the canopy of the rain forest. Their professional honors include election to the National Academy of Sciences and as Fellows or Presidents of their respective professional societies. They serve on numerous advisory boards, have high publication records for professional papers and books and in addition many have outreach programs of broad scope. Below are profiles of a few of these women.

Contributed Profiles of Smithsonian Women Scientists

Women and Science: Scientists are tackling the challenges of sustainable development by spurring innovation and economic growth. But is this sector depriving itself of the potential of women? Although there are encouraging signs, women are under-represented in science and technology, whether in basic research or at higher decisionmaking levels.

The role of the UIS
Through its biennial survey and partnerships with other statistical organizations, the UIS collects cross-nationally comparable, gender-disaggregated statistics on Research and Experimental Development (R&D) -- by sector, area of research and level of education -- for more than 200 countries and territories. These data are used to support national and international policymaking to promote gender equality in science and technology and to expand the role of women in all fields of scientific research.

http://www.uis.unesco.org/_LAYOUTS/UNESCO/women-in-science/#overview!lang=en&region=40500

Exploring soils. Smithsonian Education.

Exploring Soils

Overview
Students will investigate soils and learn about soil texture, soil water-holding capacity, and other properties of soils.
Objectives
Students will be able to:
1. Develop an understanding of how water flows through soils and how the water changes as it goes through.
2. Utilize the scientific method; ie, ask questions, develop and test hypotheses, observe and analyze results, and draw conclusions.
3. Work together in small groups and share findings with classmates.
4. Analyze a soil to determine its texture.

Activity A – Soil Texture

Materials
(per group of 3-4 students)
1. “Soil Texture” Activity Sheet A
2. Soil samples: bring to class 1L samples of different types of soil from around the school grounds or from students’ homes. Possibilities include topsoil, potting soil, sand, soils that are compacted, soils with grass
growing on top, soils with clearly different textures.
3. 1 quart-jar (mason) with lid
4. Water
5. Marking pen
6. White poster board
BackgroundSoils are precious natural resources that affect every part of the ecosystem. Soils hold water and nutrients for plants and ultimately animals. All the food we eat and the natural materials we use, such as paper, wood and clothing, depend on soils. It is important to understand soil and its role in the ecosystem and in agriculture.
The physical properties of soils affect the type and amount of vegetation that can grow in a given location. For example, the amount of water a soil can hold (water holding capacity) is a factor affecting the plants that can survive. Certain plants grow in sandy well-drained desert soils while others grow in heavy clay soil wetlands. Soil temperature, soil pH, soil structure, organic matter content, soil moisture and soil fertility are all variables that affect the organisms that can live in the soil, and which, in turn, impact the entire ecosystem.
Soil texture is the way a soil feels, and refers to the amount of sand, silt and clay particles that are present in a soil. Sand, silt and clay particles are all different sizes. The largest soil particle is sand (2.00-0.05mm in diameter), which feels gritty to the touch. The next smaller particle size is silt (0.05-0.02mm in diameter), which feels smooth or “floury” to the touch. The smallest particle size is clay (<0.02mm), which feels sticky and is hard to squeeze in your hand. Most soils have a mixture of sand, silt, and clay. (See Soil Texture Activity Sheet.)

Activity

1. Each group of 3-4 students should have a soil sample.
2. Have students do the “Soil Texture” activity to determine the texture of their soil.
3. Compare results among all of the different groups, and discuss how soil texture affects the uses of soil.

Activity B – Just Passing Through

Materials
(per group of 3-4 students)
1. “Just Passing Through” Activity Sheet B
2. Clear 2L (soda) bottle
3. Three 500mL beakers or similar size clear containers marked off in cm to pour and catch water
4. Soil samples: bring to class 1L samples of different types of soil from around the school grounds or from students’ homes. Possibilities include topsoil, potting soil, sand, soils that are compacted, soils with grass
growing on top, soils with clearly different textures
5. Fine window screen or other fine mesh that does not absorb or react with water (1mm or less mesh size)
6. Quantity of clean sand
7. Water
8. Clock or timer
9. Red and black marking pens
10. pH Test Kit (Extension option)
NOTE: Smaller containers may be used, if desired, as long as the soil container sits firmly on the water-catching container. Reduce the amounts of soil and water, but have all students begin with the same amounts.
Background
What happens to water when it passes through soil depends on many things such as the size of soil particles (texture and particle size distribution), how the particles are arranged (structure), how tightly they are packed (bulk density), and the chemical attraction between the soil particles and the water. Some types of oil let water flow in quickly, and then hold the water inside the soil like a sponge. This might give plants a better chance of using some of that water.Other types of soil may let the water go completely through in just seconds. Still other soils may keep water from getting in at all. None of these soil types is better than the other; they are simply different.
Activity
1. Hand out “Just Passing Through” Activity Sheet B
2. Remove label and lid and cut off bottom (above curve) of the 2L bottle.
3. Turn the bottle over so it looks like a funnel and place a circle of screen inside the bottle so that it covers the cap opening.
4. Pour 3-4 cm of sand onto the screen. The sand will keep the screen from becoming clogged.
5. Place the bottle, mesh side down, on a beaker or clear container.
6. Pour 1L of soil into the bottle over the sand.
7. Conduct the Class Demonstration and Inquiry.
8. Have students do the Group Investigation.

Class Demonstration and Inquiry

1. Choose a soil for the classroom demonstration (a sandy loam works best) and put some of the soil out on white paper on a table for students to observe.
Have students look closely at the soil and notice the color, presence of plant material or other organic matter, the feel, the shape of the particles and record their observations of the soil on the board.
2. Next, place a 1L soil sample in the cut off 2L bottle inverted over the beaker. Pour 300mL of water into a 500mL beaker or other clear container and mark the level in black. Have students notice the clarity of the water. Ask students what will happen when we pour the water into the soil. Ask follow-up questions that get students to explain why they think the soil and water will behave as they predict. Possible questions may include: Will the water run through the bottom of the bottle? Will it all run out? If not all, how much?
What will the water look like? Clear? Murky? Very dirty? How long will it take for the water to flow through? Record all the student hypotheses on the board. Mark the pouring container with a red line where the students predict how much water will flow through the soil.
3. Pour the water onto the soil and begin timing. Ask students to describe what happens as you pour the water. Is the water staying on top? Where is it going? Do you see air bubbles? Why or why not? Does the water coming out of the soil look the same as the water going in? Record the class observations on the board. Also record the time it took for the water to go through the soil.
4. Ask students to compare their hypotheses with what they observed. Once the water has stopped dripping from the bottom of the bottle, remove the soda bottle and hold up the beaker of water that passed through the soil. Ask students to compare their hypotheses about the water to their observations.
Pour the water back into the pouring container and compare the amount with the starting amount (black line). How much water is missing? How can we measure the missing amount? Compare the amount of water with the amount students predicted would come through the soil (red line). Is there more or less water then the class predicted? What happened to the missing water? Is the water more or less clear than the water that was poured through the soil?
Compare samples.
5. Have students predict what will happen if they poured more water into the soil. Record their hypotheses and try it. Compare the observations with their predictions and ask clarifying questions. Next, have students try the same investigation with other soil samples. NOTE: Wash funnel and screen and add more clean sand before using a new soil sample.
Group Investigations
1. Give each student the “Just Passing Through” Activity Sheet, which is a place to record hypotheses, observations, and conclusions. Have the students, in groups of 3-4, repeat the above investigation with the other soil samples.
2. Have students share their results and conclusions with the whole class. Discuss why there were differences between soil samples. Have students draw conclusions about water holding capacity based on the properties of soils.
3. Compare the results of the group investigations. Discuss the differences in soils. Ask questions about soil properties and uses of soils. Which soil property would you look for if you wanted to plant a garden? …build a driveway or a playground? What would happen if the soil is full of water and a heavy rain falls on it? How can you change the way your soil holds water? What happens to the soil when organic matter is added, when plants are growing on top of it, when it is compacted, or when it is plowed?
Extensions
1. Have students try this activity with soil components such as pure sand or clay and compare the differences. They could also do the activity with other materials such as commercial potting soil, perlite, compost, and vermiculite and make conclusions about the properties of these soil enhancements.
2. Students can experiment with filtering by using very murky water and passing it through clean sand.
3. Using distilled water, have students measure the pH of the water. Predict whether the pH will be different after the water passes through the soil. Pour the water through, and then test the pH again. Have students draw conclusions about the affect of soil on water pH.

Adapted from the GLOBE Program, Global Learning and Observing to Benefit the Environment.

Name _________________________ Activity Sheet A
USDA – Ag in the Classroom-www.agclassroom.org
Exploring Soils – Soil Texture
Soil Texture by Feel
Human hands are sensitive to differences in soil particles, so one way of determining the texture of a soil is by “feel.” The largest soil particle is sand (2.00-0.05mm in diameter), which feels gritty to the touch. The next smaller particle size is silt (0.05-0.02mm in diameter), which feels smooth or “floury” to the touch. The smallest particle size is clay (<0.02mm), which feels sticky and is hard to squeeze in your hand. Most soils have a mixture of sand, silt, and clay.
One way to determine the texture of a soil is by moistening a soil sample and trying to form the ribbon with the sample. By feeling the soil sample and answering questions about its behavior, you can get a rough idea of the soil texture.
Follow the procedure below to determine the texture of a soil:
1. Take a soil sample the size of a small chicken egg (2 Tbs.) and add enough water to moisten it. The soil should form a ball when squeezed. If it crumbles, add some more water, and it gets too wet, just add some more dry soil. If the soil sample will not form into a ball, regardless of the moisture, you have Sand.
2. Place the ball of soil between your thumb and forefinger and gently push the soil forward with your thumb, squeezing it upward into a ribbon. Try to keep the ribbon uniform in thickness and width.
3. Does soil form into a ribbon? If yes, go on to #4. If no, you have Loamy Sand.
4. If soil forms a weak ribbon, less than 1” before breaking, you have Loam.
a. Does soil feel gritty? If yes, you have Sandy Loam
b. Does soil feel equally gritty and smooth? If yes, you have Loam
c. Does soil feel smooth? If yes, you have Silt Loam.
5. If soil forms a medium ribbon, 1-2” before breaking, you have Clay Loam.
a. Does soil feel gritty? If yes, you have Sandy Clay Loam.
b. Does soil feel equally gritty and smooth? If yes, you have Clay Loam.
c. Does soil feel smooth? If yes, you have Silty Clay Loam.
6. If soil forms a strong ribbon, 2” or longer before breaking, you have Clay.
a. Does soil feel gritty? If yes, you have Sandy Clay.
b. Does soil feel equally gritty and smooth? If yes, you have Clay.
c. Does soil feel smooth? If yes, you have Silty Clay.
Scientists use a Soil Texture Triangle to determine the relative amounts of sand, silt and clay and then classify the soil into a texture type. Based on your ribbon test, decide where your soil fits on the Soil Texture Triangle below.*

Soil Texture by Sedimentation
Another way to determine soil texture is by dividing the soil into its component parts using water to separate the particles.
Directions:
1. Fill a large (quart size) jar two-thirds full with water. Add soil until the water level is nearly to the top of the jar.
2. Cover and shake vigorously. Set the jar on a level surface and allow time for the particles to settle. The smallest particles may take overnight or even several days to settle.
3. Hold a piece of white poster board against the jar and mark the different layers on the board. Label these layers, from coarsest to finest (bottom to top), as sand, silt, and clay. Mark the top of the water level as well.
4. By measuring each layer of soil and the overall height of the water, you can calculate the percentage of each component and compare your results to the Soil Texture Triangle to determine the overall soil texture.

Just Passing Through
1. Describe your soil sample (color, texture, feel, shape of particles, size of particles, plant material, etc.)
Hypotheses:
2. What do you think will happen when you pour water through the soil sample?
3. How long do you think it will take for the water to flow through the soil?
4. How much water do you think will pass through the soil sample?
5. What will the water look like? (Circle your prediction.)
Observations:
6. What happened when you poured the water onto the soil?
7. How long did it take for the water to flow through the soil?
8. How much water flowed through the soil?
9. What did it look like? (Circle your observation.)
10. Did your observations match your hypotheses? In what ways?
11. What do you think would happen if you poured more water onto the wet soil?
12. 12.What can you conclude about this soil sample and its capacity to hold water?
13. What might this soil be good for? Explain your answer.

Tuesday, September 9, 2014

Sustainable Agriculture.

http://ncsmallfruitsipm.blogspot.com.es/2011/12/definitions-of-sustainable-agriculture.html

http://environment.nationalgeographic.com/environment/habitats/sustainable-agriculture/

Sustainable agriculture takes many forms, but at its core is a rejection of the industrial approach to food production developed during the 20th century.
This system, with its reliance on monoculture, mechanization, chemical pesticides and fertilizers, biotechnology, and government subsidies, has made food abundant and affordable. However, the ecological and social price has been steep: erosion; depleted and contaminated soil and water resources; loss of biodiversity; deforestation; labor abuses; and the decline of the family farm.
The concept of sustainable agriculture embraces a wide range of techniques, including organic, free-range, low-input, holistic, and biodynamic.
The common thread among these methods is an embrace of farming practices that mimic natural ecological processes. Farmers minimize tilling and water use; encourage healthy soil by planting fields with different crops year after year and integrating croplands with livestock grazing; and avoid pesticide use by nurturing the presence of organisms that control crop-destroying pests.
Beyond growing food, the philosophy of sustainability also espouses broader principles that support the just treatment of farm workers and food pricing that provides the farmer with a livable income.
Critics of sustainable agriculture claim, among other things, that its methods result in lower crop yields and higher land use. They add that a wholesale commitment to its practices will mean inevitable food shortages for a world population expected to exceed 8 billion by the year 2030. There's recent evidence, though, suggesting that over time, sustainably farmed lands can be as productive as conventional industrial farms.

Try going green quiz
http://environment.nationalgeographic.com/environment/global-warming/quiz-going-green/

THE FUTURE OF FOOD:
http://food.nationalgeographic.com/

http://ncsmallfruitsipm.blogspot.com.es/2011/12/definitions-of-sustainable-agriculture.html

Thursday, September 4, 2014

Big History Project: Chapter 1 The Universe.

https://www.bighistoryproject.com/chapters/1#intro

(videos, activities on line)

Where did everything come from? Where are we heading? In the easiest terms possible, Big History tells the story of the Universe starting from the Big Bang, the formation of stars, planets, life on Earth, modern civilization — and what might exist in the future.

Tuesday, September 2, 2014

What did dogs teach humans about diabetes? - Duncan C. Ferguson

Diabetes has a history dating back to Ancient Greece. Our treatment of it, however, is more recent and was originally made possible with the help of man's best friend. Due to physiological traits shared with humans, dogs have saved countless lives through the discovery of insulin. Duncan C. Ferguson shares the story of the canine's great contribution to man -- and how we can all reap the medical benefits.

THINK:
http://ed.ted.com/lessons/what-did-dogs-teach-humans-about-diabetes-duncan-c-ferguson#review

How pandemics spread - Mark Honigsbaum

Prehistory climate change and why it matters today.

If you’re looking for a science activity to help introduce environmental issues, or if you’re looking for fun and challenging real-world math problems, we invite you to take a look at this issue of Smithsonian in Your Classroom. In the lesson plan, the class does the work of a team of paleontologists studying a time of rapid global warming 55 million years ago. By examining fossils of leaves from various tree species, and by incorporating the findings into a mathematical formula, the students are able to tell average annual temperatures during this prehistoric time.

The method they practice is called “leaf-margin analysis,” which begins by determining the percentage of leaves that have smooth edges, as opposed to toothed, or jagged, edges. This number—the percentage—goes into an equation that gives the average temperature in Celsius. The higher the percentage of smooth leaves, the warmer the climate.

The leaf fossils were discovered by a Smithsonian paleontologist in the Bighorn Basin of Wyoming. It was a major find: the leaves were the first record of plant life from the rapid warm-up, called the Paleocene-Eocene Thermal Maximum (PETM). They showed, more clearly than any other fossils, the dramatic changes undergone by living things during a change of climate.

The PETM has taken on a topicality in recent years. It has been established that the warming resulted from releases of carbon dioxide comparable to human-generated releases in our time. Climate scientists have been turning to PETM experts for an understanding of what our own future might hold.

http://www.smithsonianeducation.org/educators/lesson_plans/climate_change/index.html

Online interactive: http://www.smithsonianeducation.org/idealabs/prehistoric_climate_change/index.htm

El Niño's Powerful Reach.

http://www.smithsonianeducation.org/db/search/detail.aspx?contenttype=3&museumid=-1&supplierid=-1&pamphletcategoryid=-1&mediaid=-1&statusid=-1&categoryid=62&gradeid=3&KEYWORD=

El Niño’s Powerful Reach

Background:
The primary signature of an El Niño is the warming of sea surface
temperature in the Pacific Ocean near the west coast of South America.
Scientists at NASA, NOAA, the Smithsonian, and at other scientific
organizations around the globe monitor the sea surface temperature to
better predict El Niño events. They obtain data both from buoys in the
Pacific Ocean and from satellites orbiting our planet overhead. They
compile this data to create sea-surface temperature charts that give
them visual predictors of El Niño.

1. Locate and write down definitions of El Niño on the internet at
the NASA (http://www.nasa.gov) and NOAA (http://www.noaa.
gov).
2. Go to the El Niño exhibit computer interactive and explore
the “What is El Niño” section (http://forces.si.edu/elnino/01_
00.html). Watch the video animation of changing sea surface
temperature. Write down your visual observations of what
changed in the animation.
3. Examine the two figures sea-surface temperature charts below.
Compare the two charts. Which one do you think shows
an El Niño event? What differences and similarities to you see
in the two charts?Visit:
http://www.smithsonianeducation.org/db/search/detail.aspx?contenttype=3&museumid=-1&supplierid=-1&pamphletcategoryid=-1&mediaid=-1&statusid=-1&categoryid=62&gradeid=3&KEYWORD=

ACTIVITY: Derivation of the Planets' Names in our Solar System

PROCEDURE:
1) Short explanation about mythology and the explanation for the natural phenomena centered around the actions of the gods and goddesses. The masses of people knew their names. However, few were literate. Therefore, it was necessary to develop a symbol that all would recognize. The symbol of the god usually related to its power.
2) Divide into nine groups--one for each planet--to research the particular planet and its symbol.
3) The nine planets are listed below. Since eight are named for Roman gods, information about them is listed concisely for whom each planet was named, the symbol it was given, and the use of that symbol today (if applicable).
Planets:

a) MERCURY was named after the messenger for the gods. Mercury wore a winged hat and sandals.

b) VENUS was named for the goddess of love and beauty. Her symbol is the universal scientific symbol for a female.

c) MARS is named for the god of war. His symbol, a skull and crossbones, is used as a warning for poison, and is also found on pirate flags. Another symbol is the universal scientific symbol for a male.
d) JUPITER was named for the king of all gods and goddesses. His symbol is lightning, and is at times emitted from his hand.
e) PLUTO is named for the god of the underground, or the dead. He is shown wearing long black robes and a hood. His figure is the symbol of death.
f) NEPTUNE was named for the god of the sea. His symbol is a trident, the three pronged instrument often shown in drawings of evil.
g) URANUS was named for the earliest Greek supreme god. He was the personification of the sky and heavens. He was eventually replaced by Cronus, and then Zeus. He wore a mantle dotted with stars and his hands always pointed to the sun and the moon.
9) SATURN is named for the god of agriculture--sowing and harvests. He was represented as bearing a sickle.

From http://www.clas.ufl.edu/users/ufhatch/pages/05-SecondaryTeaching/NSF-PLANS/1-1_SOLARSYS.htm

You can visit: http://www.kidsastronomy.com/solar_system.htm

http://sixtysymbols.com/index.html

http://sixtysymbols.com/videos/pluto.htm

SCIENCE TO THE CONTEMPORARY WORLD