Wednesday, October 10, 2012

Nutrition - Nova (Dying to be Thin)

Why do we eat? How do our bodies use the foods we eat? What organ or system in your body may not be getting enough of what it needs? This interactive feature from NOVA "Dying to Be Thin" Web site will fill you in. Just click on a body part or on the name of a nutrient to find out what you need to eat to stay healthy.
NOVA Body Needs
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  • Media Type: Interactive
  • Size: 121.0 KB
  • Level: Grades 3-8

  • Log in to Teachers' Domain to download, share, rate, save, and match to state standards.
Source: NOVA: "Dying to Be Thin" Web site
This resource can be found on the NOVA: "Dying to Be Thin" Web site.

Background

Standards of beauty have changed over the years. In the late 1800s, advertisers regularly used models who would be considered overweight by today's standards. Times have changed dramatically. Most Americans are exposed to thousands of media messages every day -- in magazines and newspapers, on television, on outdoor billboards, and over the Internet. These messages promote bodies that are thin and, in some cases, unrealistically proportioned, and they are creating a culture of young people who are obsessed with losing weight.

As a result of this obsession, many people have sworn off fat. They avoid eating fat in any form and, instead, obtain most of their calories from carbohydrates, like bread and pasta. For decades, doctors and health experts supported this fat-free nutritional strategy. Fat was the enemy, they said; it was the cause of obesity and heart disease. Carbohydrates were your friends and could be consumed, many thought, in mass quantities with few concerns about health consequences. Recent studies, however, have begun to reveal the flaws in this thinking.

A nutritional plan that shuns fat ignores this food's important role in the body. While fat's main purpose is to store energy, it serves many other functions as well. Either in its whole form or broken down into small molecules, fat does the following: provides insulation, builds membranes, aids digestion, promotes proper nervous system function, regulates hormones, keeps the skin healthy, and aids the chemical communication between cells. And these are just a few of the important things that fat does for us. Still, many people continue on a fat-free path.

Somewhat surprisingly, fat-free diets often result in the accumulation of excess body fat. Carbohydrates, including sugars and starchy foods, provide the body's most efficient form of energy. They are broken down quickly into glucose, the sugar that cells need in order to function. This is why energy bars used by athletes are made up primarily of carbohydrates: They are quickly broken down in the stomach, and the resulting sugars are easily transported throughout the body via the bloodstream.

When the body is active at high intensity for long periods of time, carbohydrates must be eaten regularly to provide the cells with the energy they need. Carbohydrates that are consumed when the body is at rest, however, are stored. Relatively small amounts of carbohydrates can be stored in the muscles and the liver as a complex sugar called glycogen. When glycogen stores are full, however, and there is no further demand for sugar, carbohydrates are stored as fat.

Although most doctors and nutritionists still recommend that people get the majority of their calories from carbohydrates, they also suggest that many people would benefit from increasing their fat intake. According to most nutritionists, the ratio of carbohydrate, fat, and protein calories should, in fact, be much closer to equal -- at 40, 30, and 30 percent respectively. They stress that exercising and eating moderately from all of the food groups is the proper path to better health.

Questions for Discussion

  • Could you stay healthy eating three or fewer of the foods shown here? Explain your answer, using information from the site.
  • Why do you think 75 percent of the U.S. population doesn't meet daily recommended dietary needs? What ideas do you have about changing the nutritional habits of people in this country?
SOURCE: http://www.pbs.org/wgbh/nova/education/body/body-needs.html?elq=0937217e29c949998c57be7bcd65db11&elqCampaignId=431

DNA - Nova

NOVA
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DNA. It's what makes you unique. Unless you have an identical twin, your DNA is different from that of every other person in the world. And that’s what makes DNA fingerprinting possible. Experts can use DNA fingerprints for everything from determining a biological mother or father to identifying the suspect of a crime. What, then, is a DNA fingerprint and how is it made? Here, you'll find out by solving a mystery—a crime of sorts. First, you’ll create a DNA fingerprint (we'll supply the lab and all necessary materials). Then you’ll compare this DNA fingerprint to those of all seven suspects to nab the perpetrator. Ready? Let's get to work!

VIEW
  • Media Type: Interactive
  • Size: 283.0 KB
  • Level: Grades 6-12
  • Log in to Teachers' Domain to download, share, rate, save, and match to state standards.
Source: NOVA: "The Killer's Trail" Web site
This feature originally appeared, in a different design, on the site for the NOVA program .

Background

In the last 15 years, DNA has played an increasingly important role in our legal system. Tissue evidence is now routinely collected during criminal investigations in hopes that it will provide genetic clues linking suspected criminals to crimes.

DNA profiles help forensic investigators determine whether two tissue samples -- one from the crime scene and one from a suspect -- came from the same individual. Fortunately, the genetic comparison doesn't require that investigators look at all of the DNA found in the tissue samples. That would take months or even years. Instead, by marking a small number of segments of DNA in one sample and then checking for the presence or absence of those segments in the other sample, investigators can say with some assurance whether the samples are from the same person.

How do they do it? Investigators use chemicals to cut the long strands of DNA into much smaller segments. Each segment has a specific length, but all of them share the same repeating sequence of bases (or nucleotides). The chemicals cut the segments at the beginning and at the end of the repeating string of nucleotides, so one segment might be ATCATCATCATCATC, for example, while another might be ATCATC. (The DNA segments used in forensic investigations are, of course, much longer than this.)

Investigators use a process called gel electrophoresis to separate these repeating segments according to length. Next, they introduce a small set of radioactive "markers" to the sample. These markers are segments of DNA of known length, with bases that complement the code of, and bind to, sample segments of the same length. The sample segment above (ATCATCATCATCATC), for example, would be tagged by a marker with the complementary code TAGTAGTAGTAGTAG.

Markers that do not bind to sample segments are then rinsed away, leaving in place only those markers that bound to complementary sample segments. Photographic film, which darkens when exposed to the radioactive markers, identifies the location of all marked sample segments. This film, then, becomes the DNA "fingerprint" that forensic investigators analyze.

The final step is a relatively simple matter of lining up the sample profiles side by side and comparing them for the presence or absence of segments with particular lengths. The more segments the two samples have in common, the more likely it is that the samples came from the same person.

Questions for Discussion

  • Describe the process of DNA fingerprinting.
  • In what ways is it like actual fingerprinting and in what ways is it different?
  • How conclusive is the evidence of DNA fingerprinting?
  • Where is there possibility for error?

SOURCE: http://www.pbs.org/wgbh/nova/education/body/create-dna-fingerprint.html?elq=0937217e29c949998c57be7bcd65db11&elqCampaignId=431

Thursday, October 4, 2012

BPA Timeline

source: http://www.jsonline.com/watchdog/watchdogreports/34532374.html 
Nov 15, 2008

Watchdog Reports      The history of BPA     TIMELINE


1891: Bisphenol A, or BPA, is developed.

1930s: The chemical is used as a synthetic estrogen.

1960s: Food manufacturers begin to use BPA to make hard, clear plastic for items such as baby bottles and the lining of metal food cans, including liquid baby formula.

1998: Patricia Hunt, a geneticist at Washington State University, notices that control mice had many more defective eggs when stored in polycarbonate cages.

2000-present: More than 1,000 studies are published showing harm to lab animals from BPA, including cancer, obesity, diabetes, reproductive failures and neurological disorders.

2008: Annual sales of BPA exceed $6 billion.
April 2008: Canadian health officials begin steps to declare BPA a toxin and to have it banned from use in baby bottles and tableware for children. Several manufacturers - including Nalgene, Wal-Mart, Toys "R" Us and CVS pharmacies - announce plans to phase out use of the chemical in children's products.

August 2008: The Food and Drug Administration declares BPA to be safe.

September 2008: The National Toxicology Program, an advisory board to the FDA and Environmental Protection Agency, releases its report expressing some concern for how BPA affects the prostate and neural development of fetuses, infants and children. It also expressed concern about the chemical's effect on breast tissue and early puberty.

A study published in the Journal of the American Medical Association in September tied BPA to heart disease in humans. Lawmakers start to call for a ban of the chemical in children's products.

October 2008: The FDA's Science Board finds that the FDA ignored hundreds of studies on BPA and advises the agency to reopen its investigation of the chemical. A study finds that even low levels of BPA can interfere with chemotherapy for breast cancer patients.


Wednesday, September 12, 2012

BIg Chem; Big Harm? (NYT)

Son, this is one reason I have worked so hard to find a place to shop that doesn't have ANY harmful chemicals in their products.  You know my favorite store.  You may also want to click here after reading this article. ;-) This is an important science lesson.The assignment details follow the article.

BIG CHEM; BIG HARM?
by Nicolas Kristof
                                                                  edited by Mom

NEW research is demonstrating that some common chemicals all around us may be even more harmful than previously thought. It seems that they may damage us in ways that are transmitted generation after generation, imperiling not only us but also our descendants.

Yet following the script of Big Tobacco a generation ago, Big Chem has, so far, blocked any serious regulation of these endocrine disruptors, so called because they play havoc with hormones in the body’s endocrine system
One of the most common and alarming is bisphenol-A, better known as BPA. The failure to regulate it means that it is unavoidable. BPA is found in everything from plastics to canned food to A.T.M. receipts. More than 90 percent of Americans have it in their urine

Even before the latest research showing multigeneration effects, studies had linked BPA to breast cancer and diabetes, as well as to hyperactivity, aggression and depression in children.
Maybe it seems surprising to read a newspaper column about chemical safety because this isn’t an issue in the presidential campaign or even firmly on the national agenda. It’s not the kind of thing that we in the news media cover much. 
Yet the evidence is growing that these are significant threats of a kind that Washington continually fails to protect Americans from. The challenge is that they involve complex science and considerable uncertainty, and the chemical companies — like the tobacco companies before them — create financial incentives to encourage politicians to sit on the fence. So nothing happens. 
Yet although industry has, so far, been able to block broad national curbs on BPA, new findings on transgenerational effects may finally put a dent in Big Chem’s lobbying efforts. 
One good sign: In late July, a Senate committee, for the first, time passed the Safe Chemicals Act, landmark legislation sponsored by Senator Frank Lautenberg, a New Jersey Democrat, that would begin to regulate the safety of chemicals. 
Evidence of transgenerational effects of endocrine disruptors has been growing for a half-dozen years, but it mostly involved higher doses than humans would typically encounter.
Now Endocrinology, a peer-reviewed journal, has published a study measuring the impact of low doses of BPA. The study is devastating for the chemical industry.

THE EXPERIMENT:
Pregnant mice were exposed to BPA at dosages analogous to those humans typically receive. 
WHAT HAPPENED:
1) The offspring were less sociable than control mice (using metrics often used to assess an aspect of autism in humans), and various effects were also evident for the next three generations of mice. 
WHY?
The BPA seemed to interfere with the way the animals processed hormones like oxytocin and vasopressin, which affect trust and warm feelings. And while mice are not humans, research on mouse behavior is a standard way to evaluate new drugs or to measure the impact of chemicals. 
CLARIFICATION & COMMENTS by authors of the report
“It’s scary,” said Jennifer T. Wolstenholme, a postdoctoral fellow at the University of Virginia and the lead author of the report. She said that the researchers found behaviors in BPA-exposed mice and their descendants that may parallel autism spectrum disorder or attention deficit disorder in humans. 
Emilie Rissman, a co-author who is professor of biochemistry and molecular genetics at University of Virginia Medical School, noted that BPA doesn’t cause mutations in DNA. Rather, the impact is epigenetic — one of the hot concepts in biology these days — meaning that changes are transmitted not in DNA but by affecting the way genes are turned on and off.  These results at low doses add profoundly to concerns about endocrine disruptors,” said John Peterson Myers, chief scientist at Environmental Health Sciences. “It’s going to be harder than just eliminating exposure to one generation.” 
SCIENCE HISTORY NOTE:  In effect, this (epigenetic impact) is a bit like evolution through transmission of acquired characteristics — the theory of Jean-Baptiste Lamarck, the 19th-century scientist whom high school science classes make fun of as a foil to Charles Darwin. In epigenetics, Lamarck lives. 
The National Institutes of Health is concerned enough that it expects to make transgenerational impacts of endocrine disruptors a priority for research funding, according to a spokeswoman, Robin Mackar.

In his conclusion, the author of this New York Times Article offers his two cents:
Like a lot of Americans, I used to be skeptical of risks from chemicals like endocrine disruptors that are all around us. What could be safer than canned food? I figured that opposition came from tree-hugging Luddites prone to conspiracy theories.
Yet, a few years ago, I began to read the peer-reviewed journal articles, and it became obvious that the opposition to endocrine disruptors is led by toxicologists, endocrinologists, urologists and pediatricians. These are serious scientists, yet they don’t often have the ear of politicians or journalists.
I’m hoping these new studies can help vault the issue onto the national stage. Threats to us need to be addressed, even if they come not from Iranian nuclear weapons, but from things as banal as canned soup and A.T.M. receipts.
ORIGINAL SOURCE:
New York Times Article - Big Chem; Big Harm?
by
Published: August 25, 2012


ASSIGNMENT:  
1) Read this New York Times article. Read a second time and take key word notes
I have edited with notes in red to keep you focused on important points.
2) VOCABULARY: Define and memorize the 20 bolded words or terms.  You already know many of the words and numerous other words can defined contextually.
3) Make sure you understand and memorize the 2 bolded sentences.
4) Become familiar enough with the article that you are ready to discuss it.
5)  Complete a re-write in your own words by Monday.
5) We can discuss this after dinner tonight.  :-)


Also see: http://kristof.blogs.nytimes.com/
 

Monday, September 10, 2012

Scientific Method

Key Info

  • The scientific method is a way to ask and answer scientific questions by making observations and doing experiments.
  • The steps of the scientific method are to:
    • Ask a Question
    • Do Background Research
    • Construct a Hypothesis
    • Test Your Hypothesis by Doing an Experiment
    • Analyze Your Data and Draw a Conclusion
    • Communicate Your Results
  • It is important for your experiment to be a fair test. A "fair test" occurs when you change only one factor (variable) and keep all other conditions the same.
  • While scientists study how nature works, engineers create new things, such as products, websites, environments, and experiences.

    Overview of the Scientific Method

    The scientific method is a process for experimentation that is used to explore observations and answer questions. Scientists use the scientific method to search for cause and effect relationships in nature. In other words, they design an experiment so that changes to one item cause something else to vary in a predictable way.
    Just as it does for a professional scientist, the scientific method will help you to focus your science fair project question, construct a hypothesis, design, execute, and evaluate your experiment.
    Overview of the Scientific Method


    Steps of the Scientific Method Detailed Help for Each Step
    Ask a Question: The scientific method starts when you ask a question about something that you observe: How, What, When, Who, Which, Why, or Where?
    And, in order for the scientific method to answer the question it must be about something that you can measure, preferably with a number.
    Your Question
    Do Background Research: Rather than starting from scratch in putting together a plan for answering your question, you want to be a savvy scientist using library and Internet research to help you find the best way to do things and insure that you don't repeat mistakes from the past. Background Research Plan
    Finding Information
    Bibliography
    Research Paper

    Construct a Hypothesis: A hypothesis is an educated guess about how things work:
    "If _____[I do this] _____, then _____[this]_____ will happen." You must state your hypothesis in a way that you can easily measure, and of course, your hypothesis should be constructed in a way to help you answer your original question.
    Variables
    Variables for Beginners
    Hypothesis

    Test Your Hypothesis by Doing an Experiment: Your experiment tests whether your hypothesis is true or false. It is important for your experiment to be a fair test. You conduct a fair test by making sure that you change only one factor at a time while keeping all other conditions the same. You should also repeat your experiments several times to make sure that the first results weren't just an accident.
    Experimental Procedure
    Materials List
    Conducting an Experiment

    Analyze Your Data and Draw a Conclusion: Once your experiment is complete, you collect your measurements and analyze them to see if your hypothesis is true or false. Scientists often find that their hypothesis was false, and in such cases they will construct a new hypothesis starting the entire process of the scientific method over again. Even if they find that their hypothesis was true, they may want to test it again in a new way.
    Data Analysis & Graphs
    Conclusions

    Communicate Your Results: To complete your science fair project you will communicate your results to others in a final report and/or a display board. Professional scientists do almost exactly the same thing by publishing their final report in a scientific journal or by presenting their results on a poster at a scientific meeting. Final Report
    Abstract
    Display Board
    Science Fair Judging

    Even though we show the scientific method as a series of steps, keep in mind that new information or thinking might cause a scientist to back up and repeat steps at any point during the process. A process like the scientific method that involves such backing up and repeating is called an iterative process.
    Throughout the process of doing your science fair project, you should keep a journal containing all of your important ideas and information. This journal is called a laboratory notebook.

    LINKS:  Steps of the Scientific Method


Wednesday, September 5, 2012

Franklin Bell & Leyden Jar

Franklin bells are an early demonstration of electric charge designed to work with a *Leyden jar. They were invented by Benjamin Franklin in the 18th century during his experimentation with electricity. Franklin bells are only a qualitative indicator of electric charge and were used for simple demonstrations rather than research.

The bells consist of a metal stand with a crossbar, from which hang three bells. The outer two bells hang from conductive metal chains, while the central bell hangs from a nonconductive thread. In the spaces between these bells hang two metal clappers, small pendulums, which hang from nonconductive threads. A short metal chain hangs from the central bell.

The central bell's chain is put in contact with the inner surface of a * Leyden jar, while the outside surface of the jar is put in contact with the metal stand. The central bell takes its charge from the inner surface of the jar, while the outer surface charges the two bells on the conductive chains; this causes the bells to have a potential difference equal to that between the inner and outer surfaces of the jar. The hanging metal clappers will be attracted to one bell, will touch it, pick up its charge, and be repelled; they will then swing across to the other bell, and do the same there. Each time the clappers touch a bell, charge is transferred between the inner and outer surfaces of the *Leyden jar. When the jar is completely discharged, the bells will stop ringing.


Electric Fly Swatter + Coke Can = Franklin's Bell 
http://www.youtube.com/watch?v=jIL0ze6_GIY&feature=related 


What is a Leyden Jar?

A Leyden jar, or Leiden jar, is a device that "stores" static electricity between two electrodes on the inside and outside of a glass jar. It was the original form of the capacitor.

It was invented independently by German cleric Ewald Georg von Kleist on 11 October 1745 and by Dutch scientist Pieter van Musschenbroek of Leiden (Leyden) in 1745–1746.[1] The invention was named for this city.

The Leyden jar was used to conduct many early experiments in electricity, and its discovery was of fundamental importance in the study of electricity. Previously, researchers had to resort to insulated conductors of large dimensions to store a charge. The Leyden jar provided a much more compact alternative.

Wednesday, July 4, 2012

Chemistry Jokes and Riddles


Q: Anyone know any jokes about sodium?
A: Na
Making bad chemistry jokes because all the good ones Argon 


Q: What is the most important rule in chemistry?
A: Never lick the spoon! 

 
Helium walks into a bar,
The bar tender says "We don't serve noble gasses in here."
Helium doesn't react. 


Silver walks up to Gold in a bar and says, "AU, get outta here!" 


Two chemists go into a restaurant.
The first one says "I think I'll have an H2O."
The second one says "I think I'll have an H2O too" -- and he died. 


Q: What did the scientist say when he found 2 isotopes of helium?
A: HeHe 


Q: Why was the mole of oxygen molecules excited when he walked out of the singles bar?
A: He got Avogadro's number! 


A proton and a neutron are walking down the street.
The proton says, "Wait, I dropped an electron help me look for it."
The neutron says "Are you sure?" The proton replies "I'm positive." 


Money has recently been discovered to be a not-yet-identified super heavy element.
The proposed name is: Un-obtainium. 


As an ion chromatography chemist I made this one up:
Anions aren't negative, they're just misunderstood. 


The optimist sees the glass half full.
The pessimist sees the glass half empty.
The chemist see the glass completely full, half in the liquid state and half in the vapor state.
 

Q: What do chemists call a benzene ring with iron atoms replacing the carbon atoms?
A: A ferrous wheel.
 

Q: If H2O is the formula for water, what is the formula for ice?
A: H2O cubed.
 

Q: What did the bartender say when oxygen, hydrogen, sulfur, sodium, and phosphorous walked into his bar?
A: OH SNaP!
A neutron walks into a bar. He asks the bartender, "How much for a beer?" The bartender offers him a warm smile and says, "For you, no charge".
 

Q: What do you do with a dead chemist?
A: Barium
 

Q: What did one ion say to the other?
A: I've got my ion you.
 
Q: Why did the chemist sole and heel his shoes with silicone rubber?
A: To reduce his carbon footprint.
 

Q: What do you call a tooth in a glass of water?
A: One molar solution.
A small piece of sodium that lived in a test tube fell in love with a Bunsen burner. "Oh Bunsen, my flame," the sodium pined. "I melt whenever I see you," The Bunsen burner replied, "It's just a phase you're going through."
 

Q: What do you call a clown who's in jail?
A: A silicon.
 

Q: Why do chemists enjoy working with ammonia?
A: Because it's pretty basic stuff.
 

Q: What emotional disorder does a gas chomatograph suffer from?
A: Separation anxiety.
 

Q: Why does hamburger yield lower energy than steak?
A: Because it's in the ground state.
Florence Flask was getting ready for the opera. All of a sudden, she screamed: "Erlenmeyer, my joules! Somebody has stolen my joules!" The husband replied, "Calm down, honey. We'll find a solution."
 

Q: If H20 is water, what is H204?
A: Drinking, bathing, washing, swimming, etc.
Titanium is a most amorous metal. When it gets hot, it'll combine with anything.
 

Q: What did one titration say to the other?
A: "Let's meet at the endpoint."
 

Q: What did the Mass Spectrometer say to the Gas Chromatograph?
A: Breaking up is hard to do.
Old chemists never die, they just stop reacting.
 

Q: What is "HIJKLMNO"?
A: H2O.
 

Q: When one physicist asks another, "What's new?" what's the typical response?
A:C over lambda.
 

Q: How did the chemist survive the famine?
A: By subsisting on titrations.
 

Q: What happens when spectroscopists are idle?
A: They turn from notating nuclear spins to notating unclear puns.
If you're not part of the solution, you're part of the precipitate.
 

Q: Why can't lawyers do NMR?
A: Bar magnets have poor homogeneity.
 

Q: What element is derived from a Norse god?
A: Thorium.
 

Q: What happened to the man who was stopped for having sodium chloride and a nine-volt in his car?
A: He was booked for a salt and battery.
 

Q: What element is a girl's future best friend?
A: Carbon.
Little Willie was a chemist. Little Willie is no more. What he thought was H2O was H2SO4.
 

Q: What is the name of 007's Eskimo cousin?
A: Polar Bond.

Friday, January 20, 2012

Composite Materials Lesson (level 9-12)

http://www.teachersdomain.org/resource/npe11.sci.engin.design.composites/

In this video segment adapted from NASA 360, learn about composite materials and how they are being used in spacecraft design at NASA. Composites are known primarily for the enhanced strength and stiffness they give to objects, such as airplane wings, while being lighter than conventional materials. Objects made from composites can also hold their shape better and not experience fatigue under heat or pressure. In the video, a NASA engineer explains how and why composites are being used in place of metals in a prototype crew module design.

open Background Essay
While many products we use in our lives are made of a single material like solid wood, cotton, or aluminum, more and more are made of composites. A composite is a combination of different materials, called constituents. Composites offer certain performance advantages because the constituents work together to give the resulting object special properties. Most composites are made from two or more constituent materials: a binder, or matrix, which surrounds a reinforcement. Not all composites are the product of modern advanced technology. One common example is concrete. In concrete, cement (the binder) is combined with gravel (the reinforcement).

In deciding to use one material or composite over another, engineers consider many factors, among them strength, weight, corrosion resistance, and cost. Depending on the application, other factors may also matter. In developing the next-generation space capsule, NASA engineers need materials that are strong and lightweight (or technically, less massive) but also highly shapeable and resistant to extreme temperatures and fatigue. Before settling on a solution, these engineers will have conducted multiple tests to ensure that the composite fulfills all of these needs.

While spacecraft are still largely made of metal, NASA has begun investigating alternative materials that fulfill its safety objectives but offer performance advantages. The next-generation Space Shuttle Program for manned space exploration includes a newly designed mission crew module—the part of the spacecraft the astronauts will occupy. The design being evaluated, called a composite crew module, or CCM, is made of a carbon-graphite epoxy resin composite. This means that layers of carbon fiber—a material that is just as strong or stronger than steel, at about one-fifth the mass—with graphite reinforcement will cover an aluminum honeycomb shape. The “sandwich” structure will be coated in epoxy resin and cured, or hardened, in a kind of pressure oven called an autoclave. The resulting module will possess considerable strength and be much lighter than if it were made entirely of aluminum. It will be shaped to fit into the International Space Station when docking in space, and its heat shield, located at the bottom of the module, will also be able to withstand reentry temperatures of 3000°F (1650°C).

Composite materials feature in designs beyond spacecraft. Among the many industries already using them is the auto industry. As you might expect in an era of rising fuel prices, car companies are looking for ways to combine strength with weight reduction to improve fuel efficiency. As a result, many have begun developing designs that feature a carbon-fiber body in place of the usual steel and fiberglass. Because of its high ratio of strength to weight, carbon fiber is also used in a variety of consumer products besides cars, including tennis rackets, golf clubs, fishing rods, and bicycles.

open Discussion Questions
Before the Video
  • What substances can you think of that are made of two or more things with very different individual properties than the combination they form?
After the Video
  • What is a composite material?
  • Give an example of a composite material and explain its possible advantages and disadvantages.
  • How do you think you could create a composite material yourself?
  • The auto industry has begun to use a carbon fiber composite in place of fiberglass. Knowing what you do about carbon fiber, why do you think it’s doing this?

Texas
Subchapter B. Middle School
§112.22 Knowledge and skills
(6.7) Science concepts. The student knows that substances have physical and chemical properties.
(A) Demonstrate that new substances can be made when two or more substances are chemically combined and compare the properties of the new substances to the original substances
§112.24 Knowledge and skills
(8.5) Scientific processes. The student knows that relationships exist between science and technology.
(B) Design and test a model to solve the problem