Manuals and instructions for everything

 why do we breathe oxygen and not nitrogen

why do we breathe oxygen and not nitrogen

There are two parts to this answer, and several answers have addressed one or both aspects but I figured I'd put it all in one place. 1) We use oxygen for a purpose that nitrogen is chemically useless for 2) While there is a different purpose we might want to use nitrogen for, it is something that is difficult to evolve (only bacteria have done it) and we can manage without. 1) We use oxygen because our metabolism uses it for energy. Our metabolism derives chemical energy from the breakdown of complex carbon molecules; this doesn't happen on its own and you need very reactive molecules to interact with those complex carbon molecules and break them down. All organisms do this step-by-step, using successive "electron acceptors" to basically strip electrons off of simpler-and-simpler

 why do things dissolve quicker in hot water

why do things dissolve quicker in hot water

Hot water has a higher amount of kinetic energy. The increased amount of kinetic energy is what causes the molecules to move faster. A solvent (the item that the solute is dissolved into) dissolves the solute by breaking up both its molecular bonds and the solute's molecular bonds. The molecular bonds in both substances have to be broken so that new molecular bonds can form between the solute and solvent. Once the solvent and solute are combined with molecular bonds, it is known as a solution. The amount of energy required to dissolve a solute into a solvent depends on what substance the solute is. Solutes with strong molecular bonds require more energy for the bonds to be broken. Weak solutes can dissolve at a lower temperature than strong solutes. Solutes that do not dissolve in water

 why is a switch better than a hub

why is a switch better than a hub

What is the difference between a hub and a switch? January 1, 1999 Hubs and switches are different types of network equipment that connect devices. They differ in the way that they pass on the network traffic that they receive. The term вhubв is sometimes used to refer to any piece of network equipment that connects PCs together, but it actually refers to a multi-port repeater. This type of device simply passes on (repeats) all the information it receives, so that all devices connected to its ports receive that information. Hubs repeat everything they receive and can be used to extend the network. However, this can result in a lot of unnecessary traffic being sent to all devices on the network. Hubs pass on traffic to the network regardless of the intended destination; the PCs to which

 why do protestants wear orange on st patty day

why do protestants wear orange on st patty day

Regarding the wearing of orange by Protestants in Ireland, Wikipedia has this to say: William III (14 November 1650 Б 8 March 1702) was a Prince of Orange by birth. From 1672 onwards, he governed as Stadtholder William III of Orange over Holland, Zeeland, Utrecht, Guelders, and Overijssel of the Dutch Republic. In addition, from 1689 onwards, he reigned as King William III over England and Ireland, and as King William II over Scotland. He is informally known in Northern Ireland and Scotland as БKing BillyБ. A member of the House of Orange-Nassau, William won the English, Scottish and Irish crowns following the Glorious Revolution, in which his uncle and father-in-law, James II, was deposed. ...

 why do we park on driveways and drive on parkways

why do we park on driveways and drive on parkways

English is full of seeming contradictions: ravel means both "to knit up" and "to unknit," inflammable refers to something that's flammable, and so on. George Carlin, the late comedian, often poked fun at English, and in doing so, highlighted another one of these contradictions: why do we park on the driveway but drive on the parkway? First, a defining of terms. A driveway is "a private road giving access from a public way to a building on abutting grounds," and in America, we tend to park our cars in the driveway since driveways typically come right alongside one's house. A parkway, on the other hand, is "a broad, landscaped highway. " The origins of each of these words seems pretty clearв drive + way, and park + way вbut if that's the case, when why don't the verbs that are the

 why do we see the color black

why do we see the color black

Roses are red and violets are blue, but we only know that thanks to specialized cells in our eyes called cones. When light hits an object say, a banana the object absorbs some of the light and reflects the rest of it. Which wavelengths are reflected or absorbed depends on the properties of the object. For a ripe banana, wavelengths of about 570 to 580 nanometers bounce back. These are the wavelengths of yellow light. When you look at a banana, the wavelengths of reflected light determine what color you see. The light waves reflect off the banana s peel and hit the light-sensitive retina at the back of your eye. That s where cones come in. Cones are one type of photoreceptor, the tiny cells in the retina that respond to light. Most of us have 6 to 7 million cones, and almost all of them

 why do people drink so much alcohol

why do people drink so much alcohol

Why do people start drinking alcohol? Top 10 reasons Why do people drink? People drink alcohol for many reasons. But why do they start drinking at all? Here we examine the top 10 reasons why people start drinking, and ask that you leave your own reasons or responses below. If you think that you might have a problem with drinking, check out ourВ evaluation questions so that you can gauge what is normal. 1. For the effect Many people drink alcohol for the effect that alcohol has on the central nervous system. It is both a depressant and a stimulant, and drinking can result in feelings of euphoria, disorientation or a pleasurable release of tension. 2. Out of curiosity People may drink simply to experiment with alcohol and judge whether or not drinking is for them. 3. As a reaction to the

 why do you make it hard to love you

why do you make it hard to love you

When someone says they love you, is your first impulse to argue that they can't? One night when I was 21, a man with curly copper-penny hair told me: I love you. Under the streetlight, in his tan nylon shirt, he sounded so confident. I said: I love you too. But even as I said it, I felt conflicted and sneaky and deceptiveвlike a liar. But I wasn't lying. Really. He was sweet and smart and thus difficult not to cherish. My problem was that I hated myself almost more than I loved him. The old clichГ that says you can't love others if you can't love yourself: Well, it's almost true. You can love others if you cannot love or even like yourselfвjust not wholeheartedly. Loving someone without loving or liking yourself is like trying to sew while blindfolded, or eat spaghetti with a golf ball

 why do pills get stuck in esophagus

why do pills get stuck in esophagus

A doctor explains why it seems your pills get stuck in your esophagus. Sometimes you may be convinced beyond doubt that the pills you just swallowed are sitting in your esophagus, not moving, just stuck there. For this article I consulted with Akram Alashari, MD, abdominal surgeon and critical care physician, Department of Surgery, College of Medicine, University of Florida. Sensation of Pill Stuck in Esophagus Has Multiple Possible Causes Dr. Alashari first explains, БWhile eating, food does not actually slide down the esophagus after swallowing. The esophagus undergoes peristalsis, which are coordinated contractions to help propel the food toward the stomach. Б He speaks of food at this point, since the way the Бfood pipeБ works with food is the same as it works with pills (the

 why do people hate the mormon church

why do people hate the mormon church

I m going to make another post detailing what the Mormons are. This one (unlike the top post) will be aimed at being pedantically accurate so that an active member would agree with it too. The LDS church is a restorationist church started by a self-proclaimed prophet named Joseph Smith during the 2nd great awakening in the early 19th century. They believe that God s true religion has been introduced among mortals on several occasions, generally ending in apostasy, unbelief, and sin. According to their doctrine, Jesus introduced his true church and atoned for our sins during his mortal life. Shortly after the death of the original apostles, the truth was lost again. After ~1800 years, it was reintroduced by direct revelations to Smith. The restoration included introducing new scripture

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