The ocean looks blue because red, orange and yellow (long wavelength light) are absorbed more strongly by water than is blue (short wavelength light). So when white light from the sun enters the ocean, it is mostly the blue that gets returned. Same reason the sky is blue.
In other words, the color of the ocean and the color of the sky are related but occur independently of each other: in both cases, the preferential absorption of long-wavelength (reddish) light gives rise to the blue. Note that this effect only works if the water is very pure; if the water is full of mud, algae or other impurities, the light scattered off these impurities will overwhelm the water's natural blueness.
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Acid rain is rain consisting of water droplets that are unusually acidic because of atmospheric pollution - most notably the excessive amounts of sulfur and nitrogen released by cars and industrial processes.
Acidity itself is determined based on the pH level of the water droplets. PH is the scale measuring the amount of acid in the water and liquid. The pH scale ranges from 0 to 14 with lower pH being more acidic while a high pH is alkaline; seven is neutral. Normal rain water is slightly acidic and has a pH range of 5.3-6.0. If pH of rain is less than 5.3, then it's acid rain..\
What are the causes?
Acid deposition can occur via natural sources like volcanoes but it is mainly caused by the release of sulfur dioxide and nitrogen oxide during fossil fuel combustion. When these gases are discharged into the atmosphere they react with the water, oxygen, and other gases already present there to form sulfuric acid, ammonium nitrate, and nitric acid. These acids then disperse over large areas because of wind patterns and fall back to the ground as acid rain or other forms of precipitation.
What are its effects?
There are many problems and effects caused by acid rain. Acid rain can cause buildings, statues and bridges to deteriorate faster than usual. Another problem is it harms thousands of lakes, rivers, and streams worldwide. It disrupts lake ecosystems and kill wildlife in affected lakes, rivers and streams. Acid rain also damages soil and the tree roots in it. When soil is acidified, tree roots are damaged, leaving them not able to draw in enough nutrients to support the tree. When acid rain falls on trees, it makes their leaves turn brownish-yellow and the tree can no longer carry out photosynthesis properly. Another problem is it will harm people when they breathe in smog, acid rain in one of its many forms.
What can be done ?
Acid rain can be prevented by reducing emissions that come from the mining industries, burning of fuels for electrical power generation, oil operations, and reducing fuel emissions from cars and trucks. Reduce our use of products that produce chlorofluorocarbons that are released into the atmosphere by actively conserving the use of your air conditioning. Become energy wise by conserving energy through the use of fluorescent lights, closing off rooms you do not use, and use washers, dryers, and dishwashers only when full. Last but not lease please recycle packaging and other disposable products.
Source: about.com, ask.com
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Unlike the Earth, the Moon does not have an atmosphere. Temperatures on the Moon’s surface fluctuate dramatically from blistering heat during the day (100° C) to frigid cold during the night (-173° C). With no atmosphere, there is also no wind. Footprints of the Apollo astronauts and those of future explorers may last for thousands of years!
Image credit and source: NASA
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An ATM (Automated Teller Machine) is a computerized system individuals can use to deposit money into their banking accounts, withdraw money from their accounts, check balances and transfer money from one account to the other. ATMs can either be part of a specific bank (a Suntrust ATM, for example), or an independent entity that has contracts with several banks and credit card companies (a Presto machine, for instance). The former are usually found in stand alone booths or on the outsides of a bank, while the latter are usually found in other public places, such as grocery stores and malls.
Working:
In order to access various accounts, ATM computers are connected to complex interbank networks, which allows customers from many different banks to access their accounts through the machine. There are several of these interbank networks; among them are Cirrus and LINK. In order to provide access to the customer, ATMs rely on authorization from the financial institutions. To cover the costs of operation and the fees that involve belonging and accessing the networks, most independent ATMs charge a fee for each transaction. These fees usually range from 30 to 50 rupees.
The ATM is made up of much more than a computer, however. In order to perform all of its functions, the ATM has many different parts. These include the computer, which includes the interface and the keypad for the customer to use, and a magnetic card reader. The latter allows the machine to read the magnetic strip on the back of a customer's debit or ATM card. The machine will also include a display screen, function buttons (usually placed near the screen and covering the functions of saying "yes," "no," and "cancel"), a printer and a cash drawer. Depending on the ATM, it may also provide envelopes for deposits and security camera...
source: ehow.com
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Normally if you cool a liquid it becomes dense. Same thing happens to water till 4 degrees Celsius. Further cooling below 4 degree Celsius causes water to expand. Water freezes to form ice at 0 degree Celsius, and expands further.
Due to low density of ice compared to the density of water, the ice floats on water.
Due to this nature of water, i.e. it is densest at 4 degrees, the 4 degree water goes to the bottom of lakes. Only the surface gets too cold and freezes. Ice is also a bad conductor of heat, this slows down the freezing of lower layers. This way marine life in water, can remain in water, although the surface freezes to form ice...
Source: answers.com
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In spite of popular misconception, you don't yawn because you're tired.
You yawn because your body has built up too much carbon dioxide and needs to release it.
When you're in an inactive state (sitting in class or something like that) your body does not have much opportunity to expel excess carbon dioxide. Excess carbon dioxide in the bloodstream is dangerous, so your body responds by yawning and expelling more carbon dioxide that you would normally do by breathing.
When exercising, you breathe heavily, so it's easy to expel excess carbon dioxide. It only becomes an issue when you're resting... whether it's because you're tired or because you're bored and sitting still.
Yawning does seem to be contagious, but that seems to be a psychosomatic effect. Basically, you see someone yawn, and you feel compelled to yawn. I don't know that there's much more to that. Some things in biology are just quirky that way, or we just don't understand them well enough yet.
Source: answers.yahoo.com
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