Why does Milk spill over when it Boils?

How many times have you seen milk boil and spill over, and wondered why this happens? To answer this question we have to know a little more about the composition of milk.

Milk and its composition
Unlike water, milk is not a simple liquid. It is a colloid and contains many substances in suspended form. These substances are mainly protein, sugar and fat. When milk is heated slowly, the proteins and fat get separated. Since they are lighter than the milk they collect on the surface in the form of a layer called cream.

water vapour and spilling milk
Milk also has a large quantity of water in it. During heating some water gets converted into water vapour. The water vapour being lighter, rises up.

As the upper layer of the milk is covered with cream, the vapour gets trapped below it. As the milk is heated further, the water vapour expands and thick foam is produced on top.

Finally, the trapped vapour lifts the layer of cream up, quite like a hot air balloon, and finally bursts through this layer. As the vapour escapes, a lot of cream and milk spill out.

Why fish can't breathe air from oxygen?

A fish’s respiratory system is determined primarily by the fact that it spends its entire life in water.Fish have developed gills, on which they rely for the oxygen necessary for a fish’s limited metabolism. The water around the fish produces a tiny amount of oxygen. In order for the fish to be able to stay under the water they need to be able to take in oxygen. The fish's gills do just this. They filter the oxygen in the water and this enables the fish to be able to breathe in water.

If you take a fish out of the water, it will die of suffocation. This is because the oxygen in the air has not been filtered through its gills and the fish can't breathe it in properly.

When you find your goldfish lying dead on the top of its bowl, it has probably suffocated from a lack of oxygen because they oxygen has been used up by some other means such as bacteria. So always make sure you clean Jaws' bowl out regularly!

Why human can't breathe oxygen from water?

One thing about chemicals is that, once they react in certain ways, they form compounds that are nothing like the original elements. For example, if you react carbon, hydrogen and oxygen together one way you get glucose (C6H12O6). If you react them together another way you get vinegar (C2H4O2). If you react them another way you get fat. If you react them another way you get ethanol (C2H5OH). Glucose, fat, ethanol and vinegar are nothing like each other, but they are all made from the same elements.

In the case of hydrogen and oxygen gas, if you react them together one way you get liquid water (H2O). The reason we cannot breathe liquid water is because the oxygen used to make the water is bound to two hydrogen atoms, and we cannot breathe the resulting liquid. The oxygen is useless to our lungs in this form.

The oxygen that fish breathe is not the oxygen in H2O. Instead, the fish are breathing O2 (oxygen gas) that is dissolved in the water. Many different gases dissolve in liquids, and we see an example all the time in carbonated beverages. In these beverages, there is so much carbon dioxide gas dissolved in water that it rushes out in the form of bubbles.

Fish "breathe" the dissolved oxygen out of the water using their gills. It turns out that extracting the oxygen is not very easy -- air has something like 20 times more oxygen in it than the same volume of water. Plus water is a lot heavier and thicker than air, so it takes a lot more work to move it around. The main reason why gills work for fish is the fact that fish are cold-blooded, which reduces their oxygen demands. Warm-blooded animals like whales breath air like people do because it would be hard to extract enough oxygen using gills.

Humans cannot breathe underwater because our lungs do not have enough surface area to absorb enough oxygen from water, and the lining in our lungs is adapted to handle air rather than water. However, there have been experiments with humans breathing other liquids, like fluorocarbons. Fluorocarbons can dissolve enough oxygen and our lungs can draw the oxygen out.

Source: HowStuffWorks

How to Breathe Properly While Jogging

I am jogging for the past one year. Some days while jogging I feel relaxed but on some days felt more tired jogging the same distance during the same time frame.When I did some study understood breathing pattern during jogging is more important to make the jogging a healthy one.Below are the few tips that I was able to pick.Planning to follow these tips from tomorrow.Will share my experience after few days of following them.

1) Breathe in through your nose, and out through your mouth. Many people breathe through their mouth the entire workout. Breathing in through your nose signals your body to take deeper breaths, which helps you relax. Relaxing helps you take deeper breaths, which makes jogging easier.

2) Pace your breathing. Breathing in for three or four steps, then breathing out for three or four steps keeps your breathing focused.

3) Try breathing using your stomach. Instead of just expanding your ribcage when you breathe in, try expanding your ribcage, pushing down your diaphragm and expanding your stomach as well. This will allow you to get more air per breath, and can help you relax more.

4) Check your perceived exertion. Are you breathing hard through your entire workout? Would you say that on a scale of one to 10 you are jogging at an eight or above? You might be working in an anaerobic zone, which causes heavy breathing.

Office Hoteling - Help businesses cut real estate, meeting services, travel, and energy costs.

Hoteling (also called office hoteling) is the practice of providing office space to employees on an as-needed rather than on the traditional, constantly reserved basis. This reduces the amount of physical space that an enterprise needs, lowering overhead cost while (ideally) ensuring that every worker can access office resources when necessary.

Offices generally support three kinds of seating assignment:

* Shift/Workshop - People take a seat for a given time-shift. The seat is then released to another person on the next time-shift.
* Assigned - One and only one person is assigned to one or more workstations. Likewise, the workstations are assigned to be used exclusively by one person.
* Unassigned - A person is not assigned to any particular workstation. Likewise, the workstation is not assigned to any particular person.

Recent studies of knowledge workers, particularly salespeople, customer representatives, and consultants, indicate they spend only 30% of their time in the office. Teleworking also contributes to less frequent presence in the office. So why have a workstation? Companies are also finding that people may need different kinds of workstations at different times for different tasks (e.g. an enclosed office one day and open space the next and a war room the next - all within the same office.) This means that nomadism is not only inter-office (travellers and teleworkers), but intra-office.

Many companies are beginning to rethink whether assigned seating makes the most sense. With the increasing price of commercial real-estate the modern corporation is always looking for ways to maximize office space of an ever growing business. Corporations attempt to divide up their resources in an efficient and effective manner. A new system that companies have begun using is called hotelling. Hotelling is a fairly recent idea which has begun to pop-up in many large corporations with travelling employees. The idea stems from that of a hotel where employees must reserve their spot for a specified period of time.

The Man Who Could Have Been Bill Gates - Gary Arlen Kildall

Gary Arlen Kildall was an American computer scientist and microcomputer entrepreneur who created the CP/M operating system and founded Digital Research, Inc. (DRI).
Kildall was one of the first people to see microprocessors as fully capable computers rather than equipment controllers and to organize a company around this concept.Although his career in computing spanned more than two decades, he is mainly remembered in connection with IBM's unsuccessful attempt in 1980 to license CP/M for the IBM PC.

IBM dealings
IBM approached Digital Research in 1980, at Bill Gates' suggestion, to license a forthcoming version of CP/M called CP/M-86 for the IBM PC. Gary left licensing negotiations to Dorothy, as he usually did, while he and colleague Tom Rolander used Gary's private airplane to deliver software to manufacturer Bill Godbout.Before the IBM representatives could explain the purpose of their visit, they insisted that DRI accept a standard non-disclosure agreement that required it not to reveal anything about the meeting and allowed IBM unfettered use of any information that DRI might disclose. On the advice of DRI attorney Gerry Davis, Dorothy refused to sign the agreement without Gary's approval. Gary returned in the afternoon and tried to move the discussion with IBM forward, but accounts disagree on whether he signed the non-disclosure agreement, as well as whether he met with the IBM representatives or was merely at DRI while discussions were in progress.

Various reasons have been given for the two companies failing to reach an agreement. DRI, which had only a few products, might have been unwilling to license its main product to IBM for a one-time payment rather than its usual royalty-based plan. Dorothy might have believed that the company could not deliver CP/M-86 on IBM's proposed schedule, as the company was busy developing an implementation of the PL/I programming language for Data General. Or, the IBM representatives might have been annoyed that DRI had spent hours on what they considered a routine formality. According to Kildall, the IBM representatives took the same flight to Florida that night that he and Dorothy took for their vacation, and they negotiated further on the flight, reaching a handshake agreement. IBM lead negotiator Jack Sams insisted that he never met Gary, and an IBM colleague recalled that he said so at the time. He accepted that someone else in his group might have been on the same flight, but noted that he flew back to Seattle to talk with Microsoft again.

Sams related the story to Gates, who had already agreed to provide a BASIC interpreter and several other programs for the PC. Gates's impression of the story was that Gary capriciously "went flying," as he would later tell reporters.[10] Sams left Gates with the task of finding a usable operating system, and a few weeks later he proposed using the CP/M clone 86-DOS from Seattle Computer Products (SCP). Paul Allen negotiated a licensing deal with SCP, had 86-DOS adapted for IBM's hardware, and IBM shipped it as PC-DOS.

Kildall obtained a copy of PC-DOS, examined it, and concluded that it infringed on CP/M. When he asked Gerry Davis what legal options were available, Davis told him that intellectual property law for software was not clear enough to sue. Instead Kildall only threatened IBM with legal action, and IBM responded with a proposal to offer CP/M-86 as an option for the PC in return for a release of liability. Kildall accepted, believing that IBM's new system (like its previous personal computers) would not be a significant commercial success. When the IBM PC was introduced, IBM sold its operating system as an unbundled (but necessary) option. One of the operating system options was PC-DOS, priced at US$40. CP/M-86 shipped a few months later at $240, but sold poorly against DOS.

Hazy Memories
What's hard to find is the truth. A dozen interviews by BusinessWeek with people on all sides paint a blurry picture of those crucial days in the summer of 1980. While Kildall claims in his memoir that he met with IBM that first day and reached a handshake agreement, DRI's own lawyer at the time, Gerry Davis, says there was no deal. One of the IBMers who visited DRI that day insists he didn't talk to Kildall, but another, Jack Sams, now retired, says it's possible he was introduced to Kildall, although he doesn't remember it. Sams says faulty memories and self-serving accounts make it nearly impossible to tell exactly what happened during those chaotic weeks. "Back in those days, there was a lot of misinformation that was deliberate," he says, pointing out that IBM originally claimed it had made the PC all by itself. "We spun it, Kildall spun it, and Microsoft spun it."

How birds find their way during migration ?

Birds have excellent vision and rely on visual landmarks for local and long-distance migration. They use key land features such as mountains, rivers, coasts or even large buildings.

There are three types of "compasses" a bird uses to find its way. Birds can use the sun, the stars and the Earth's magnetic field.

1.Birds use the sun as a compass. They use the positions of the sun during the day to navigate. They also can use the setting sun as an indication of due west.

2.Night flyers use celestial navigation, which means they find their way by knowing the patterns of the stars in the sky, and by knowing special stars like the North Star. In their first year of life, birds memorize the position of the constellations in relation to the North Star. These star patterns stay the same even though the Earth moves through space, making the constellations appear to move to different spots in the sky during the year.

3.Birds have tiny grains of a mineral called magnetite just above their nostrils. This mineral may help them to navigate using the Earth's magnetic field, which tells the bird what direction is true north.

Single Photon Emission Computed Tomography (SPECT) scan

A Single Photon Emission Computed Tomography (SPECT) scan is a type of nuclear imaging test that shows how blood flows to tissues and organs.

How does a SPECT scan work?

A SPECT scan integrates two technologies to view your body: computed tomography (CT) and a radioactive material (tracer). The tracer is what allows doctors to see how blood flows to tissues and organs.

Before the SPECT scan, you are injected with a chemical that is radiolabled, meaning it emits gamma rays that can be detected by the scanner. The computer collects the information emitted by the gamma rays and translates them into two-dimensional cross-sections. These cross-sections can be added back together to form a 3D image of your brain.

What does a SPECT scan show?

A SPECT scan is primarily used to view how blood flows through arteries and veins in the brain. Tests have shown that it might be more sensitive to brain injury than either MRI or CT scanning because it can detect reduced blood flow to injured sites.

How do fans make you feel cooler?

Fans actually add heat to a room. One way to think about it is like this: If you have a perfectly insulated room and you put an electric fan in it, then the room will get warmer. All the electricity that is driving the fan turns directly into heat.

So a fan does not cool the room at all. What a fan does is create a wind chill effect.

When weatherpeople talk about wind chill on a cold winter day, what they are referring to is how the wind increases convective heat loss. The windchill factor is the same effect that causes you to blow on hot soup to cool it down. The movement of the air increases the soup's loss of heat by convection, so the soup cools down faster.

By blowing air around, the fan makes it easier for the air to evaporate sweat from your skin, which is how you eliminate body heat. The more evaporation, the cooler you feel.

Why are planets round?

Planets are round because their gravitational field acts as though it originates from the center of the body and pulls everything toward it. With its large body and internal heating from radioactive elements, a planet behaves like a fluid, and over long periods of time succumbs to the gravitational pull from its center of gravity. The only way to get all the mass as close to planet's center of gravity as possible is to form a sphere. The technical name for this process is "isostatic adjustment."

With much smaller bodies, such as the 20-kilometer asteroids we have seen in recent spacecraft images, the gravitational pull is too weak to overcome the asteroid's mechanical strength. As a result, these bodies do not form spheres. Rather they maintain irregular, fragmentary shapes.

WHY DO CLOCKS ROTATE CLOCKWISE?

Have you ever wondered why clocks rotate to the right rather than to the left? This standard for the rotation of clock hands has become an everyday part of our lives as we regularly refer to turning things clockwise and counter-clockwise. The standard evolved about 800 years ago as clock makers imitated the motion of shadows as they moved across traditional sundials. Earth rotates around the sun in an anticlock wise direction (counterclockwise)so the shadow of an object on earth would move in a clockwise direction.Early clock makers hailed from the Northern Hemisphere where shadows on sundials moved from the West to East as the day progressed. Thus when the clock was first created, the hands moved “West to East” through noon (the top of the hour), and that direction eventually became known as ‘clockwise.’

What are Fog Lights? Why are they yellow?

Fog lights are the lights mounted on the front of a car or truck which help visibility in foggy or misty conditions. They come in a variety of colors and intensities, but virtually all vehicles have them, and their assistance can be crucial to navigating poor weather.

Traditionally fog lights are yellow, and the reason why is the subject of some speculation. A common claim is that they need to be a single color light rather than white light, to minimize dispersion as the light hits the water vapor and scatters in different directions. It is often said that though red might be a more ideal color, it already has connotations to drivers —- it is used for both stop lights and brake lights. Yellow, then, would seem to be the next-most-suitable choice, because it has the next longest wavelength of visible light.

The problem with this idea, which sounds plausible scientifically, has to do with the size of the water molecules in fog. The molecules of water vapor are large enough that dispersion does not occur in any meaningful way, making the wavelength of the light irrelevant. It is possible that the first car companies to utilize fog lights were not aware of the impact that the size of water vapor molecules would have on the dispersion, and so believed that by choosing yellow lights they were minimizing the blur the fog lights cast. More likely is that yellow was chosen because of its connotations in the West with caution. Yellow lights and yellow signs are used to indicate that a driver should slow, look for obstacles, generally use increased levels of caution -- precisely the activities one wants other drivers to exercise when driving in heavy fog.

Many modern fog lights are halogen lights, which allows them to burn at much hotter temperatures than traditional lights, while retaining a low burnout rate. Halogen fog lights tend to have a tighter beam than incandescent fog lights, which yields an additional benefit. A special class of fog lights seen on some newer cars are high-intensity discharge lamps. These lights may use a number of different minerals to operate, including mercury, sodium and halide. These fog lights are often distinguished by a purplish hue, rather than the more traditional yellow color.

Official U.S. Military Alphabet

A phonetic alphabet is a list of words used to identify letters in a message transmitted by radio or telephone. Spoken words from an approved list are substituted for letters. For example, the word "Army" would be "Alfa Romeo Mike Yankee" when spelled in the phonetic alphabet. This practice helps to prevent confusion between similar sounding letters, such as "m" and "n", and to clarify communications that may be garbled during transmission.

An early version of the phonetic alphabet appears in the 1913 edition of The Bluejackets’ Manual. Found in the Signals section, it was paired with the Alphabetical Code Flags defined in the International Code. Both the meanings of the flags (the letter which they represent) and their names (which make up the phonetic alphabet) were selected by international agreement. Later editions included the Morse code signal as well.

The words chosen to represent some letters have changed since the phonetic alphabet was introduced. When these changes occur, they are made by international agreement. The current phonetic alphabet was adopted in 1957.

A: Alpha
B: Bravo
C: Charlie
D: Delta
E: Echo
F: Foxtrot
G: Golf
H: Hotel
I: India
J: Juliet
K: Kilo
L: Lima
M: Mike
N: November
O: Oscar
P: Papa
Q: Quebec
R: Romeo
S: Sierra
T: Tango
U: Uniform
V: Victor
W: Whiskey
X: X-Ray
Y: Yankee
Z: Zulu

Websites to download YouTube videos

There are a number of installable applications available which let us enter the URL of a YouTube video and then download it. Some of the programs are really great and even provide us with the ability to convert the file format of the downloaded video.

Using these applications can become difficult if you are working on somebody else’s computer and do not have the privileges to install the video-downloading application. In that situation or if you simply do not want to install an extra program on your computer, you can take advantage of the various websites which provide video downloading features in the same way as the installable programs. Some of these sites even allow downloading the HIGH DEFINITION (HD) YouTube videos and videos from other video hosting websites.

keep-tube and clipnabber are good such sources.

Why Shouldn't Infants Eat Honey?

Although honey is a delicious natural sweeter, it should not be fed to infants under one year of age because of the risk of infant botulism.

Botulinum spores are widely found throughout nature, although honey tends to harbor them more than other foods. In fact, botulinum can appear in other sweeteners, such as maple syrup, as well as corn syrup. Botulinum can even be found in dust, indicating that it is an extremely widespread toxin. As a result, most humans adapt to it and are able to fend off small amounts of the toxin, such as those present in honey.

Infants, however, do not have a completely matured digestive system and are susceptible to botulism food poisoning. While honey does not always contain the spores, it is more likely to contain botulinum than some other food products, and therefore parents are recommended to avoid it unless it is pasteurized. Pasteurized honey is also crystallized, however, due to the heat process, and is therefore rarely available. As a result, parents need to be cautious about processed foods containing honey, which is probably unpasteurized. Ingredient labels should always be carefully inspected.

Parents are also recommended to refrain from feeding their children excessively sweet diets when they are very young, to prevent the development of a taste for sweets. While small amounts of natural sweeteners are a splendid way to brighten the day of a young child, excessive use of sugars should be avoided so that children can live longer, healthier lives.

Infant botulism can be deadly if not recognized early, and because of the widespread nature of the toxin, parents should recognize the signs of botulism, which begins with constipation. An infant suffering from botulism will also exhibit nervous system damage, which manifests as muscle weakness. As a result of the muscle weakness, infants with botulism will cry more weakly, have difficulty feeding, and have a limp and floppy appearance. Infant botulism also results in lethargy.

Time Zones: Their Invention and Implementation

The Earth is divided into 24 time zones so that everyone in the world can be on roughly similar schedules (like noon being roughly when the sun is highest in the sky). The idea to divide the Earth into time zones was proposed by the Canadian railway planner and engineer Sir Sandford Fleming (1827 - 1915) in the late 1870s.

Time zones were first used in 1883 by railroads in order to standardize their schedules. World time zones were determined in 1884, at an international conference in Washington, D.C. Each of the 24 world time zones are about 15 degrees wide and differ by one hour.

Early Time Keeping:
Until about 100 years ago, each city set its clocks to local time -- noon was the time when the Sun was at its highest in the sky, as viewed from that city. Even neighboring cities needed to set their clocks differently to make this happen. For example, when it was 8:00 in New York City, it was 8:12 in Boston (because Boston is about 3 degrees east of New York). Before modern transportation and communication, this difference didn't really matter.

A Need for Synchronized Schedules:
Once railroads were built, this became very awkward. Train schedules needed to be written using common time settings that everybody agreed to, so the U.S. railroad companies adopted the idea of time zones. This was soon extended internationally, with the world being divided into 24 time zones, each one a long strip from North Pole to South Pole, about 15 degrees of longitude wide. All the people in one time zone would set their clock the same way (to the local time in the center of the time zone).

24 Hours in a Day and 24 Time Zones:
Since there are 24 hours in a day, dividing the Earth into 24 time zones meant that everybody was using a time setting very close to their local time -- there's at most about a half-hour difference. So 7:00 am was still in the morning, 12 noon was still in the middle of the day, and 7:00 pm was still in the evening.

But this was much more convenient than the older system of using local time. Most neighboring cities use the same time zone settings. Even if two cities are in different time zones, the time settings always differ by a whole number of hours (1 hour, 2 hours, 3 hours, etc.), making it easy to convert from the time in one time zone to the time in the other.

Today, most countries use this time zone system. (In a few places, clocks are set to be 15 minutes or 30 minutes different from the time according to the standardized time zone system.)

The International Date Line:
The prime meridian (zero-degrees longitude) passes through Greenwich, England. Halfway around the world in the middle of the Pacific Ocean (180 degrees from Greenwich) is the International Date Line (IDL), where the date changes across the boundary of the time zone. The entire world is on the same date only at the instant when it is noon in Greenwich, England, and midnight at the IDL. At all other times, there are different dates on each side of the IDL.

What is RSS? RSS stands for Really Simple Syndication.

RSS (most commonly expanded as "Really Simple Syndication") is a family of web feed formats used to publish frequently updated works—such as blog entries, news headlines, audio, and video—in a standardized format.An RSS document (which is called a "feed", "web feed" or "channel") includes full or summarized text, plus metadata such as publishing dates and authorship. Web feeds benefit publishers by letting them syndicate content automatically. They benefit readers who want to subscribe to timely updates from favored websites or to aggregate feeds from many sites into one place. RSS feeds can be read using software called an "RSS reader", "feed reader", or "aggregator", which can be web-based, desktop-based, or mobile-device-based. A standardized XML file format allows the information to be published once and viewed by many different programs. The user subscribes to a feed by entering into the reader the feed's URI or by clicking an RSS icon in a web browser that initiates the subscription process. The RSS reader checks the user's subscribed feeds regularly for new work, downloads any updates that it finds, and provides a user interface to monitor and read the feeds.

What is Blood Pressure?

Blood is carried from the heart to all parts of your body in vessels called arteries. Blood pressure is the force of the blood pushing against the walls of the arteries. Each time the heart beats (about 60-70 times a minute at rest), it pumps out blood into the arteries. Your blood pressure is at its highest when the heart beats, pumping the blood. This is called systolic pressure. When the heart is at rest, between beats, your blood pressure falls. This is the diastolic pressure.

Blood pressure is always given as these two numbers, the systolic and diastolic pressures. Both are important. Usually they are written one above or before the other, such as 120/80 mmHg. The top number is the systolic and the bottom the diastolic. When the two measurements are written down, the systolic pressure is the first or top number, and the diastolic pressure is the second or bottom number (for example, 120/80). If your blood pressure is 120/80, you say that it is "120 over 80."

Blood pressure changes during the day. It is lowest as you sleep and rises when you get up. It also can rise when you are excited, nervous, or active.

Still, for most of your waking hours, your blood pressure stays pretty much the same when you are sitting or standing still. That level should be lower than 120/80. When the level stays high, 140/90 or higher, you have high blood pressure. With high blood pressure, the heart works harder, your arteries take a beating, and your chances of a stroke, heart attack, and kidney problems are greater.

What causes it?
In many people with high blood pressure, a single specific cause is not known. This is called essential or primary high blood pressure. Research is continuing to find causes.

In some people, high blood pressure is the result of another medical problem or medication. When the cause is known, this is called secondary high blood pressure.