Geysers

A geyser (pronounced gy-zuhr) is a geothermal feature. Geysers occur where there is an opening or fracture in the surface of the Earth. The opening contains superheated water that periodically erupts in a shower of water and steam. The word geyser is the only Icelandic word in the English language. It stems from the name of a particular geyser in southwest Iceland, the great Geysir (an Icelandic word meaning to gush or rush forth).


Steamboat Geyser in steam phase on May 2, 2000 at 10:00 AM (5:00 AM eruption); Norris Geyser Basin; NPS photo (Tom Cawley)

 

Geysers are rare. According to Geyser World there are approximately 1000 active geysers in the world, with about 500 of them being in Yellowstone National Park. For a listing of active, dormant and exinct geyser one should visit Johnston's Archive Geyser Resources.

In order for a geyser to form, three conditions must be met:


1. an abundant supply of water

2. a heat source

3. special plumbing

The problem is the special plumbing. Most geysers are found in the volcanic rock rhyolite, a high silica rock. Fields of rhyolite are rare hence geysers are rare. The site, “Geyser World”, goes on to give a readable explanation of what happens before and during an eruption. Geysers and the Earth's Plumbing System also explains what factors are needed for a geyser to exist and how a geyser erupts. Some of the links on this page do not work but it is well worth a visit. A cross-sectional diagram illustrates the three conditions that must be met to get geyser activity - heat, water and a reservoir. There are pictures of six basic type of plumbing systems that a geyser might have. The discussion after that gets more scientific in nature.

I have seen WyoJones' Geyser site referred to as the best geyser site on the web. There is a lot of useful information, most notably a section on the continuing survival of geysers. Geysers are temporary geological features. Many factors (either natural or man made) can alter or destroy them. Here, one can find out what dangers geysers have faced and what the greatest threat to their existence is right now. There is a list of geyser that have been damaged or destroyed. It is really a shame.

Is it possible to visit a geyser online? Sure! And where else would one go but to Yellowstone National Park. This is a great site. The tour starts with a visit to the various basins. A geyser basin is just an area that contains a group of geysers. After having finished strolling around the basins, it continues on stopping at each geyser individually. There are movies showing each geyser erupting. Or, one can visit National Park Service's Yellowstone National Park and take in the online nature tours.


Old Faithful Geyser; Upper Geyser Basin; NPS Photo (Jim Peaco)



The underlying geological feature of Yellowstone National Park is a caldera. For a definition of the word caldera visit USGS’s Photo Glossary of Volcanic Terms . For more information on calderas, not only in Yellowstone Park but around the world, one can visit USGS site Calderas and Caldera Formation.


Yellowstone Caldera map

A great site for kids is Making Better Sense of the Planet Earth and Beyond. Here, one can learn how to make his/her own geyser.

Lastly, the site Inside Old Faithful gives an account of what scientists saw when they lowered a camera down inside. Unfortunately, one thing they did discover was that the hot water was depositing silica on the walls of the vent. Old Faithful will eventually become clogged and will die. Let's hope that fate is a long ways in the future.

Standard Model

What are the smallest constituents or basic building blocks of all matter? Or, in scientific terms, what are the elementary or fundamental particles of matter? The words "elementary" and "fundamental" mean that the particle has no substructure. It cannot be broken down further into its constituent parts. Originally, it was thought that the atom was a fundamental particle, but it was discovered that atoms are made up of electrons and a nucleus. And, the nucleus is made up of protons and neutrons. So is that it? Can protons, electrons and neutrons be broken down further? The electron is still considered an elementary particle. Protons and neutrons were found to have substructure. Presently, there are 12 fundamental particles divided into two classes - leptons and quarks.

Within the lepton class, there are 6 fundamental particles - electron, muon, tau, electron neutrino, muon neutrino, tau neutrino.

Within the quark class, there are 6 fundamental particles - up quark (u), down quark (d), charm (c), strange (s), top quark (t), bottom quark (b).

The Fermilab's site, "Searching for the Building Blocks of Nature", relates how they discovered the top and bottom quark. The site talks about the accelerators and detectors needed, other technologies such as MRI (Magnetic Resonance Imaging) developed as a result of this research and their ongoing search for fundamental particles and forces.


All matter within the world is made up of three of these particles - the electron, up quark and down quark. Electrons, protons (u,u,d quark triplet) and neutrons (d,d,u quark triplet) combine to form atoms and molecules. The siteAtom builder illustrates how electrons, up quarks, and down quarks combine to make an atom, in this case a carbon atom. Building an atom is not easy.


So, what holds it all together? There are four elementary forces or interactions between particles - strong (hold the quarks together to form neutrons and protons), weak (help heavy particles to decay), electromagnetic (holds electrons to atomic nucleus) and gravitational. The particles interact with one another via "force carrying particles" called bosons. There are 4 bosons.

1. Gluons (nuclear force)

2. Photons (electromagnetic force)

3. W and Z bosons (weak force)


This is the "Standard Model of Particle Interaction" (or Standard Model - as it stands) - 6 quarks, 6 leptons and 4 bosons. Particle Physics Timeline (or Timeline ) illustrates the development of ideas from 624 B.C. to the present that led to the Standard Model. But it is not the end of the story. The quest goes on.

Impact craters

An impact crater is a site on a planet (i.e. Earth, Mars) or satellite (i.e. Moon) where a meteorite, comet or asteroid crashed. The following article will be concerned specifically with terrestrial (Earth) impact craters.


Artist's impression of a major impact event. 

Terrestrial Impact Craters , part of the Lunar and Planetary Institute's web site, gives a good overview into the subject. Here, one will find that there are presently about 120 identified impact craters on earth. It is felt that in all probability there are many more but due to erosion, volcanic and tectonic activity, traces of them have been erased. So, how does one identify an impact crater? According to the LPI site, certain shock metamorphism structures have been associated with impact sites:

* an abundance of siderophile elements

* shatter cones

* shocked quartz

* diaplectic glass

* high-pressure mineral phases such as stishovite


Extremely high pressure produces shock effects. (On the site MIAC one will find a picture and an explanation of how shatter cones are formed. The site states that the presence of shatter cones is sure evidence of an impact since the only other way that they can form is by nuclear explosion. Next, there is a picture of the feldspar mineral plagioclase , part of which has been changed to diaplectic glass, which happens at high pressure. There is also a picture of shocked quartz. Quartz does not show cleavage planes ordinarily but under high pressure can form parallel pseudo-cleavage planes, another indication that an impact has occurred.) Stishovite or silicon dioxide (SiO₂) forms at very high pressures but not necessary high temperatures, the exact conditions that would exist at an impact site. Siderophile (having an affinity for metallic iron or iron-like ) elements (iron, cobalt, nickel, gold and palladium) are found most abundantly in the earth's core. (Observed relative abundances of elements gives a brief discussion of how elements separate out in a gravitational field.) It is therefore theorized that a high concentration of siderophile elements at the earth's surface is probably due to an extra-terrestrial source, such as a meteorite.

Now that one know how to identify an impact site, what does an impact crater look like? The site Terrestrial Impact Craters identify two types of crater - simple craters and complex craters. Complex craters are characterized by a central peak, which forms when the crater floor rebounds from the initial impact. Crater Formation shows a possible scenario for the formation of a complex crater.

Another interesting site is Impact Craters, part of the University of Hawaii's web site. Although the site is about impact crater on the moon, one can use this site to learn some "crater" jargon. Terms such as impactor, ejecta, rays and central uplift are defined and illustrated.

Where are these impact craters and approximately when did the impacts take place? Terrestrial Impact Craters , lists 20 terrestrial impact sites with great pictures and short descriptions. The NASA's site Exploration features a map of the earth with the positions of various craters marked. There is a sliding scale at the bottom allowing one to go back approximately 1970 million years then move forward to see the order of impact. Additional information on locating impact craters can be found in the Earth Impact Database . This site hosts a database listing all known terrestrial impact structures.

After having learnt so much about impact craters, a visit to one would seem to be in order. How about Meteor Crater a.k.a. Barringer Meteorite Crater in Arizona? One can read about the history of the crater then take the virtual tour around the rim. After getting back from the tour, one can view the animation of the impact. Anyone wishing to discover more about the Barringer Meteorite Crater can drop by their official site . There is a super article about how it was determined that the Barringer Crater was indeed an impact site.


Barringer Crater in Arizona 


Finally, the site National Geographer's Asteroids-Deadly Impact is worth a visit. One can become an agent and solve the mysterious cases of the extraterrestrial perpetrators :-).

Glaciers

What are glaciers? Where do they occur? Why are they of interest? Want to find out?


The Upper Grindelwald Glacier and the Schreckhorn


First stop is an up-to-date site by the National Snow and Ice Data Center (NSIDC) . What is a glacier? Quoting from the site: "...Glaciers are made up of fallen snow that, over many years, compresses into large, thickened ice masses. Glaciers form when snow remains in one location long enough to transform into ice”…. How do they form or why do they move? You are going to have to visit the site to find out. The pictures on this site are in black and white. But don't let that bother you. Some are historical photos dating back to the 1880's. If you find a glacier-related term that you are unfamiliar with, look it up in the glossary. In a hurry? Take the glacier tour for a quick look at the life of a glacier. Phew! That's a lot for one web site. Hope you are not tired. Are you ready to move on?


Formation of glacier ice.

Glacier Power is a site you will enjoy. Your guides are the ice worms Joe, Lady Loo, Gene the Bean, Nick the Nerd, Little Joe, Dr. Daisy, Grammy Lynn. Ice worms live on glaciers eating a diet of algae and pollen. Glacier Power is a learning site for students aged 5 to 12. The pages center on Miner Ed who accidentally falls into a glacial crevice. Poor Ed. Now, it's up to you to determine if and when Miner Ed will emerge from the terminus of the glacier. How do you do that? Well first, read through the site to learn about glaciers. Then, using this information and Synthetic Aperture Radar (SAR) Satellite Images of glaciers, work out if and when Ed will pop out of the glacier. Good thing they help you read the images, otherwise I would have been stuck. And don't worry, Ed gets out. This site is a great educational resource.


Now that you know something about glaciers, how about visiting one? Let's surf on up to Glacier Bay in Alaska which boasts over 200 separate glaciers. This is an unbelievable site. Of course, all NASA sites are unreal. To enjoy it properly you will need a program that plays QuickTime movies. The tour is a long one, so be prepared to stay awhile. First stop, pictures of the spectacular glaciers of Glacier Bay, maps of the area, historical photographs, and satellite images of various glaciers. Don't linger too long. On to the movies where two features are playing: spectacular fly-bys over glaciers and the special effects theatre. The fly-bys were made using satellite images and computer techniques. The tour then continues on to discuss how satellite data can be combined with historical records to track glacier movement and possibly show how climate change affects glaciers and how glaciers might be able to be used as indicators of climate change.

If you would like to visit a glacier in person, try The Inquisitive Traveler . It provides information about accessible glaciers in North America. Glaciers can be found in Alaska, Western Canada, Montana, Oregon and Washington State. If you want to know about glaciers in other parts of the world, visit the World Glacier Inventory by the University of Colorado. It lists over 67,000 glaciers.

Aspirin

The word "aspirin" is a very familiar word, but what exactly is aspirin? I suppose if one wants to learn more about aspirin, they should consult Bayer, the most well known maker of aspirin. Bayer has a separate aspirin site which provides a bit of history. Felix Hoffman, a chemist who worked for Bayer, first synthesized aspirin (acetylsalicylic acid or ASA) in a chemically pure and stable form in 1897. But according to the site, the story of aspirin actually started 3,500 years before that. The Egyptians used a concoction of dried myrtle leaves to treat pain. One thousand years later, Hippocrates was recommending the juice of the bark willow tree for pain. Both contain salicylic acid, the key component of aspirin. Bayer received the patent for aspirin and trademarked it under the name Aspirin® worldwide in 1899. Bayer lost the patent in 1917 allowing other companies to sell acetylsalicylic acid. Then in 1920, Bayer lost the trademark name "Aspirin". The courts in the US ruled that aspirin was a generic term, so that other manufacturers could sell ASA under the name aspirin. Aspirin is still trademarked in some countries, such as Canada and Germany, today. Where did the word aspirin come from? One story claims that the "a" stands for acetylsalicylic acid, the "spir" stands for spiraea ulmaria (the Latin name for the plant Meadowsweet from which one can extract salicylic acid) and the "in" is a chemical suffix use to indicate a manufactured ingredient.


Aspirin C₉H₈O₄



The site "Molecule of the Month, Aspirin" illustrates the chemistry of aspirin. The web page can be viewed in various ways (JAVA or CHIME-a chemical structure visualization program or plug-in). The chemical equations for making aspirin as well as its structure are given here.
But, is it hard to make aspirin? There are many sites that allow the reader to make their own. Chemistry Experiments is a good place to start. Lab 44 is the preparation of aspirin from salicylic acid and acetic acid (needs Adobe Acrobat Reader (a free download) to see it).



A wonderful site about aspirin that is worth a visit is the Aspirin Adventures . Its view point is different than that of a corporate site. Directed toward students, it goes through the process of discovering aspirin step by step, starting with observations and gathering information, then going on to formulating a hypothesis, testing and drawing conclusions.


Aspirin


Another really great fun site is The Reconstructors. This is one of those glorious interactive sites. It takes place in the future where much of the medical knowledge has been lost. The reader's job to recover it, rediscover aspirin and have fun at the same time. This might just turn out to be an all day job!

Lastly, how does aspirin work to relieve pain? The Howstuffworks web site unravels some of the secrets of the wonder drug aspirin.

Sundogs, Pillars or My!

Have you ever seen a "sundog"? How about a "pillar"? Well, maybe. What are they? Glad you asked. Basically, water droplets and ice crystals in the atmosphere refract and reflect light resulting in amazing optical phenomena. Are you ready to investigate further?


Image of a halo with sundogs.
 

"Sundogs" are also called "mock suns" or "parhelia" (from the Greek meaning with or beside the sun). The University of Illinois web site has a graphic illustrating how one is formed. Hexagonal plate-like ice crystals in the atmosphere, with their flat face horizontally oriented, refract or bend the sunlight 22 degrees leading to the formation of sundogs-bright spots on either side of the sun. The web abounds with pictures of sundogs (i.e. sundogs, January 28, Cool Atmospheric Phenomena and Sundogs over VLA). When light is refracted as it passes from one medium to another, a rainbow effect maybe observed due to dispersion. Therefore, it is not uncommon to see a sundog brightly coloured or all the colours of the rainbow! When sunlight is refracted by ice crystals randomly oriented, 22 degree halos occur. This time, light is refracted twice, once when entering and once when leaving the crystals. On Jan 11th, 1999, approximately 24 halos were observed at the South Pole. Was it a world’s record?

A "sun pillar" (or spectacular sun pillar) is a column or shaft of light reaching above or below the light source. In this case, plate or column shaped ice crystals reflect (or light pillars) the light. Pillars usually occur at sunset or sunrise, when the sun is low on the horizon. The web site reflection of light illustrates what happens when light is reflected. The reflected ray is the same colour as the incident ray. Pillars can be coloured, taking on the same colour as the light being reflected.

The sundogs and pillars do not just result from light refracted or reflected from the sun. One might chance to see a moondog or moon pillar or a Venus pillar (Venus Pillars and Dogs).

Wind Tunnel

What is a wind tunnel? Simply put, a wind tunnel is a tube or tunnel through which air is blown. What are they used for? A wind tunnel is used to simulate flight conditions or to study how air moves around an aircraft or part of an aircraft. This is immensely safer than testing a new design in flight.

The site, Parts of a Wind Tunnel, shows the five major parts of a wind tunnel - the settling chamber, contraction cone, test section, diffuser and drive section. The settling chamber evens out the airflow. The contraction cone reduces the volume of the airflow and increases its speed. The object being tested, whether is be a whole airplane or just a part, is placed in the test section. The diffuser then slows the air down. The drive section, which may simply be a large fan, is the power that drives that air through the tunnel. If the reader would like to make their own wind tunnel, there are many web sites with instructions. Make a simple wind tunnel gives directions for making one from a furnace pipe and egg cartons. Another site for making a wind tunnel is Wind Tunnel , a NASA sites.

The first wind tunnel dates back to the mid-1700. Initially, an apparatus called a "whirling arm" was used. Objects were attached to the end of the arm and then the arm was spun. It wasn't until approximately 1871 that Frank H. Wenham constructed the first wind tunnel. To see how the whirling arm and the wind tunnel figure into the chronicles of flight, take a look at a timeline of the history of flight. Interestingly, the Wright Brothers used a wind tunnel. Their wind tunnel looks quite primitive by today's standards. This can be seen by comparing the Wright Brothers' wind tunnel with the wind tunnels used by NASA. But they were able to use it to obtain the correct aerodynamic data, which enabled them to fly. If one would like to get an idea of what it was like to use the Wright Brothers' tunnel, the site Interactive Wright 1901 Wind Tunnel is an Java applet that simulates its operation. The site Java Virtual Wind Tunnel simulates a modern day wind tunnel.

Blood

He accidentally cut his finger and it bled. Blood. Some people faint at the sight of it. If anyone is feeling queasy, perhaps they should consider moving on to the next blog for blood is the topic of this post.

An excellent and comprehensive site to start learning about blood is PBS's Red Gold, the epic story of blood . One will learn about the basics of blood (what blood is made of; how it's made; its function) and about the history of blood. A blood history timeline tracks scientific development in the understanding and use of blood from approximately 2500 BCE to the present. There is a discussion of blood practices such as bloodletting, using leeches and transfusions and a section on major innovators and pioneers in the field of blood. To round it all out, there are lesson plans suitable to be used in the classroom. The PBS site has a short article on blood groups and blood typing. If anyone is interested in blood types and genetics, a good site to visit is the Blood Type Tutorial by the University of Arizona.


Blood type is determined, in part, by the ABO blood group antigens present on red blood cells


Is anyone looking to have some fun? The site Blood Groups, Blood Typing and Blood Transfusions , part of the Nobel e-museum, is just the ticket. First, one should read through the article (to become familiar with the nomenclature), then proceed onto the game. In the blood typing game*, three patients need transfusions. It is the reader's job to determine their blood type and give them the correct blood. Good luck. (Just as an aside, the Nobel e-museum site is a great site. It is fun and educational with great labs.)

After one's successful stint in ER, perhaps a visit to the The Pfizer Foundation Biochemistry Discovery Lab ** is in order. This interactive lab seeks to discover what molecules are found in scabs. Doing an experiment online is great; no mess; no mistakes and the right result every time. One learns that the fibrinogen molecule in blood react with the thrombin molecule (made after a cut happens) to form fibrin which clump together and form a clot.

The site, Cells Alive! , has a scanning electron micrograph of a blood clot. There is also a scanning electron micrograph of red blood cells. The site hosts an animation that compares the size of a red blood cell to a human hair, dust mite, pollen grain and certain bacteria and viruses. The reader might like to check out Anatomy of a splinter to see white blood cells in action.

I never knew blood was so interesting and fun. And I didn't faint.

*needs flash plug-in

**needs Shockwave plug-in

Bats

Bats are often maligned and feared. But, as we will see, we have nothing to fear from bats. Join us as we learn more about this amazing critter.


Big eared townsend fledermaus bat.

First stop Batworld . This site has many interesting facts about bats. We learn that bats are not blind and are actually mammals. Unfortunately, they are also an endangered species. Are bats useful? Quoting from the site..."Bats are vital to the ecosystem! Fruit bats bring us over 450 commercial products, including 80 medicines. The seed dispersal and pollination activities of fruit and nectar eating bats are vital to the survival of rain forests. Seeds dropped by tropical bats account for up to 95% of forest regrowth on cleared land. Night blooming plants and trees depend on nectar eating bats for pollination. An excellent example is the baobab tree of eastern Africa that is so important to the survival of other kinds of wildlife it is referred to as the "Tree of Life". "Bats in the US eat millions of tons of insects annually"”….. Even their droppings are useful. Bat or bird droppings or feces are called guano. Guano has been used for many years as fertilizer. Scientists are now able to extract enzymes from bacteria, which live only in guano, in order to make laundry detergents and other valuable products. Batworld tells us what to do if we find a bat either indoors or out, how to become a bat rehabilitator and help injured or orphan bats return to the wild and runs a wild sanctuary for bats in Mineral Texas. It is a non-profit organization working to save bats and educate one and all about this beautiful and gentle creature.

Bat Conservation International is a non-profit organization dedicated to the protection of bats and the restoration of bats and their habitat worldwide. This site is everything we want to know about bats and more. It has a bat trivia page as well as a bat FAQ. The species list allows us to identify bats that live in our area. There are beautiful pictures of bats throughout the site. There is an explanation of echolocation or biosonar - how bats see in the dark by emitting a high frequency sound or ultrasound. Here, we can read about rabies in bats and find out if we are in danger. Information is provided for joining the organization and help with their efforts to save the bats.

The site Vampire bats , aimed at kids, has pictures with fun facts. It seems that vampire bats don't drink human blood (they dislike it) but prefer blood from cows, pigs or sheep. There is an anticoagulant in the vampire's saliva which causes the blood to flow without clotting, allowing the bat to lick the blood rather then suck it. The anticoagulant from vampire bats' saliva has been synthesized and is now used in medication for human heart patients (bat saliva potential new treatment for stroke victims). But these bats can carry rabies that can be transmitted to humans.

How can we attract bats to our garden (what plants to grow) (or bats in the garden or gardening for bats)?

Bats for Kids is a great web site to learn about bats. This web site was created for kids with the hope that they…”will like, respect and help protect these endangered species"…. We learn where bats live; what they look like; how they help humans and what they eat-all written in kid friendly language.

A great interactive educational NASA site about bats is aimed at kids in grades 5-8. The site features the adventures of Echo the Bat. Echo learns to fly and becomes separated from his mother. The site challenges kids to use remote sensing (interpretation of satellite images) and biodiversity (a variety of living things in a habitat-a place where a plant or animal naturally or normally lives and grows) to locate Echo as he searches for his mother and other bats.

Lastly, an anecdote about a farmer and how he found out that bats were really his friends.

Bose-Einstein Condensate

In 2001 the Nobel Prize in Physics went to two scientists, Eric Cornell of the National Institute of Standards and Technology and Carl Wieman at Colorado University, who were the first to achieve a Bose-Einstein condensate (BEC) in neutral atoms (The 2001 Nobel Prize in Physics ).

I am definitely not a physics person and Bose-Einstein condensate sounds like something I will never understand. But, believe it or not, there are some very readable sites on the Internet on this topic.

One of those sites is the University of Colorado's BCE Homepage. First off, we learn that the Bose-Einstein condensate is a new state of matter (a fifth state, the other four being gas, liquid, solid and plasma). Wonder how many more states of matter are out there waiting to be discovered. It was predicted in 1924 by A. Einstein and S. Bose but not created until 1995. The condensate requires ultra-cold temperatures to form. Wieman and Cornell first formed the condensate at 200-billionths of a degree Celsius above absolute zero. Interestingly, this page states that the coldest place in nature is the depth of outer space, which has a temperature of three degrees above absolute zero. That is why it is believed that the BEC doesn't occur naturally, since colder temperatures are needed for its formation. The University of Colorado site then goes on to explain what exactly a BEC is and how it was made. The discussion is an entertaining exchange between a student and a professor with helpful and fun animations to help with the understanding of the concept being considered. It is a very readable account.

The Bose-Einstein Condensate is Eric A. Cornell's and Carl E. Wieman's own story of how they went about forming the condensate. It was originally published in Scientific American in 1998.

What uses might the condensate be put to, one wonders? So far, it is too early to tell but remember, it took time before the full potential of the laser was realized. The site Bose-Einstein Condensate states that even if it turns out that the condensates have no important practical applications "...they have an important place in science for its own sake. They offer a clearer window than we have ever had before onto the weird world of quantum statistical mechanics. And quantum statistical mechanics is the deepest theory that present human science possesses: it underlies everything...."

Acid Rain

Look at the above picture. Saigo-san, why are you weeping? It shows a bronze statue of Japanese warrior Takamori Saigo (1827-77) in Tokyo's Ueno Park. It looks as though he is crying. Wonder why?


To understand about acid rain, you have to have a basic understanding of pH. pH is use to denote the concentration of hydrogen ions (H+ ) in solution. The pH factor, is a readable introduction into the topic. pH ranges from 0 (zero) to 14. The lower the pH (the higher the concentration of hydrogen ions), the more acidic the solution. pH Table illustrates the scale with examples of substances and their pH's. Bear in mind that going from pH 2 to pH 1 represents a 10-fold increase in hydrogen ions. A substance with pH 1 has 10 times the amount of hydrogen ions as a substance with pH 2. Another site, which gives essentially the same information is The pH Scale. If you want to delve more deeply into the topic of pH, look at The pH-Acid/Base Tutorial.


Acid rain is a term one hears often, but what exactly is acid rain? British Chemist Robert Angus Smith first used the term "acid rain" in 1872 in a book entitled Acid Rain: The Beginnings of a Chemical Climatology. U.S. Environmental Protection Agency's web site explains that a better term would be acid deposition-the return to earth of acid pollutants in the atmosphere by either wet or dry means. Wet deposition is sometimes termed acid precipitation (rain, hail, fog or snow with a pH value of less than 5.6). Dry deposition is acidic gases and particles falling back to earth.


Origins of acid rain.

So what causes acid rain? Simply put, acid rain is cause by human activity and sulfur and nitrogen are the two elements mainly responsible for the harmful effects. Take a look at the web site acid rain. Unpolluted rainwater is slightly acidic due to the presence of dissolved CO2 (carbon dioxide), NO (nitric oxide), and SO2 (sulfur dioxide), which occur naturally in the atmosphere. However, it is NO and S02 from anthropogenic or human made sources that cause the problem. Car exhaust and the burning of fossil fuels adds greatly to the amount of NO and SO2 in the atmosphere thus decreasing the pH (or increasing the acidity) of rainwater.


Is acid rain a problem? The effects of acid rain can be seen on our lakes and streams (or lake, rivers and streams), forests (or forests), building, monuments, tombstones, bridges and statues and even our health.

Is there anything that you can do to reduce acid rain emissions? Environmental Canada web site has some suggestions.

Rubber Bands

Did you know you could have a lot of fun with a rubber band? If not, read on.

Can you build a catapult using a rubber band? Check out suggestions for a rubber band catapult and see. There is a simple design for constructing a catapult with some suggesting for testing it. See what you can learn from a rubber band catapult.

What about employing a rubber band to compare relative levels of ozone in various locations? This activity uses the high oxidation capacity of ozone, which can cause a rubber band to break down in a short period of time, to estimate the ozone level at the particular site. The experiment consists of placing a rubber band around a jar and putting them in different spots. The rubber band is observed over a period of time for changes, such as cracking or pitting. Then conclusions are drawn regarding the level of ozone in each area.

Sound and a rubber band? Is there a connection here? Yes! Check out Amplifying Sound and make a rubber band-can or harpsichord. Also, look at NASA’s site sound box.

Rubber bands can be used to make a tabletop earthquake generator . What do you want with an earthquake generator, you ask? Well, how about constructing different kinds of buildings then using your earthquake generator to determine which one will best survive a quake?

How about using rubber bands to illustrate Newton's Second Law of Motion ? Newton's Car provides directions for the construction of a slingshot that propels a wooden block resting on top of a car forward thus causing the car to roll backwards. See how increasing the number of rubber bands and the weight of the car affects how far the car travels.

Make your own toys using rubber bands? Sure! The Mechanical Toy Page has several toys that one can make using rubber bands. Check out "Cotton-spool tank", "Mouse trap car" and "rubber band gun".

Can a rubber band help one to understand Edwin Hubble's discovery that all galaxies in the universe are moving away from us and the further away the galaxy is, the faster it is moving? Hubble Constant: The Effect of Distant on Speed is an interesting web site. Check it out and see what you think.

What happens to a rubber band when you heat it?

Have you noticed that if you stretch a rubber band, it does not return to its original shape afterwards? This property of a band is called hysteresis. It can be used to calculate the amount of energy lost by the rubber band.

Mars needs rubber*. Are you up to the task?

This is just a sampling of some of the fun you can have with a rubber band. I am sure you can find more.

*requires Adobe Acrobat Reader, a free download.

Dissection Anyone?

Who hasn't dissected a frog in school? Yuck. The frog had to be pithed (a needle stuck in the back of the frog's head to destroy it central nervous system so it is essentially dead). The instructor usually pithed the frog. I refused to do it. Then the poor thing was dissected. I don't know how I ever did it or why. It seems so cruel. But now, web sites exist which illustrate dissections of various animals providing an alternative to the actual dissection of animals in the classroom.




Frog


If you are learning about the anatomy of a frog, here are two excellent sites. On the first Net Frog , both a pithed and preserved frog are dissected. You get complete instructions, movies, pictures, and frog facts. The major organs are outlined so you can identify them. Also check out the virtual frog dissection kit. A click of the mouse and the skin is removed revealing the skeleton and internal organ. Click the mouse again and the heart is gone.


Skeleton of a frog.

Another excellent site is the Exploratorium. Here you can view the dissection of a cow's eye. That is something I never did in school. It has a cow's eye primer that teaches about the various parts of the eye as well as the dissection. Also on the Exploratorium site is the dissection of a sheep's brain . Learn how the brain interacts to perform cognitive and memory functions. A great educational learning sites for students.

The Thinkquest site, dissects a cat. This is something I wouldn't be able to do at all, even if required. The site states that the company the cat was brought from obtains all their preserved specimens in a responsible manner. Hmmm. Still, if you are a cat lover, approach the site with caution or not at all. It did upset me.

Overall, web sites demonstrating dissections are definitely a kinder way to learn about the anatomy of a given animal and great if you are squeamish. It also cuts down on the number of animals used for research purposes.

If you are interested in other alternate methods to dissection, check out National Anti-Vivisection Society (Vivisection: The act of cutting into or dissecting the body of a living animal, especially for the purpose of scientific research) web site. They will provide free of charge computer programs and models to substitute for the use of once-live animals in classroom dissection exercises.