What Is the Rainbow Color Order Understanding ROYGBIV

What Is the Rainbow Color Order Understanding ROYGBIV SAT / ACT Prep Online Guides and Tips You’ve more than likely seen a rainbow aftersome rain on a sunny day. But what are the colors of the rainbow in order? And what causes a rainbow to form? We’ll explain everything you need to know about the rainbow color order, including what ROYGBIV means, why rainbows exist, and whether or not the rainbow order will ever change. What Are the Colors of the Rainbow in Order? Officially, therainbow color order is as follows: Red Orange Yellow Green Blue Indigo Violet This means that every rainbow you see will have these seven colors in this order (from the top of the arc of the rainbow to the bottom of the arc). The easiest way to remember therainbow color order is to use the mnemonic device ROYGBIV, in whicheach letter stands for the first letter of the color names (in other words, R is for red, O is for orange, Y is for yellow, etc.). Most people pronounce ROYGBIV in three syllables, making it sound and look more like the name of someone: Roy G. Biv. Occasionally, you might see ROYGBIV written in reverse as VIBGYOR. I'm willing to bet you can readily envision most, if not all, of these seven colors of the rainbow. But many people get confused about the color indigo and how it differs from blue and violet. Typically, indigo is described as being abouthalfway between blue and violet. Most people seem to agree that indigo is closer to a deep or dark blue than it is a more purple or violet color, but there's still debate even about this! What Is a Rainbow? What Causes One to Form? You now know the rainbow color order, but what exactly causes a rainbow to form? And why does a rainbow contain these seven colors in this order specifically? To answer these questions, we'll go all the way back to English scientist and mathematician Isaac Newton. Newton conducted many experiments with light, which are summarized in his 1704 book Opticks, and discovered that when clear white light passes through a prism, it refracts into different colors in a particular order, or what we know as a rainbow. This means that white light is not actually white but is composed of a humongous spectrum of colors! These colors make up the visible (light) spectrum; it's the part of the electromagnetic spectrum that human eyes can see. All colors in the visible light spectrum travel at different wavelengths, with red having the longest wavelength at around 700 nanometers and violet having the shortest at around 380 nanometers. These wavelengths bend at different angles when passing through a prism, and this is what causes the rainbow color order to look the way it does. Newton is the one who decided to interpret the rainbow order in terms of seven unique colors- ROYGBIV- but the truth is that rainbows consist of more than a million colors, many of which are invisible to the human eye! In addition, some colors, such as pink and brown, are indeed visible to the human eye but do not have their own wavelengths and can only be made when combining certain wavelengths. For example, pink is created by combining red, green, and blue wavelengths. So how is a natural rainbow made- you know, those rainbows we see in the sky? Rainbows form naturally when sunlight passes through water droplets in the sky, causing the light to refract and reflect, typically in the form of an arc. Therefore, your chance of seeing a rainbow will be highest on sunny, rainy days. Rainbows always appear opposite the part of the sky the sun is in, so if you’re trying to look for a rainbow, you'll want to make sure that your back is to the sun. Will the Rainbow Color Order Ever Change? When we talk about the rainbow color order,most peoplethink of ROYGBIV. But as I mentioned above, there are actually a lot more than just seven colors in the rainbow. Newton chose to define the rainbow as consisting of seven colorsbecause he believed the number of colors in a rainbowshould be the same as the number of notes in a musical scale. Clearly, this is a pretty arbitrary (and non-scientific way) to look atthe different colors in a rainbow. Indeed, many people still struggle to distinguish indigo from violet and blue! So while the actual rainbow color order (the visible spectrum) will always be the same, the way we talk about the rainbow color order could change over timedepending on how people view and choose to define colors. Many modern portrayals of the rainbow have just six colors- red, orange, yellow, green, blue, and violet- opting to leave out indigo entirely. For example, the LGBT rainbow flag goes directly from blue to violet, without indigo. The LGBT rainbow flag at a gay pride parade. So why do we still include indigo in the rainbow color order, especially if so many people think of it as nothing more than a transitional color between blue and violet? Many believe it is merelydue to the desire towant to stick to tradition. Nevertheless,it's certainly possible that future kindergartners will learn about ROYGBV- minusthe I for indigo! What’s Next? Got other questions about science?Check out our guides on the scientific method (coming soon) and how to convert between nanometers and meters (coming soon). Thinking of taking an AP science exam?Then you'll definitely want to sneak a peek at our expert study guides for AP Biology, AP Environmental Science, and AP Chemistry. Want to know how to say things in other languages? Learn 10 essential Japanese greetings and the different ways you can say, "Hello!" in Italian (coming soon).

Lines of Longitude in Geography

Lines of Longitude in Geography Longitude is the angular distance of any point on Earth measured east or west of a point on Earths surface. Where Is Zero Degrees Longitude? Unlike latitude, there is no easy point of reference such as the equator to be designated as zero degrees in the longitude system. To avoid confusion, the worlds nations have agreed that the Prime Meridian, which passes through the Royal Observatory in Greenwich, England, will serve as that reference point and be designated as zero degrees. Because of this designation, longitude is measured in degrees west or east of the Prime Meridian. For example, 30Â °E, the line passing through eastern Africa, is an angular distance of 30Â ° east of the Prime Meridian. 30Â °W, which is in the middle of the Atlantic Ocean, is an angular distance of 30Â ° west of the Prime Meridian. There are 180 degrees east of the Prime Meridian and coordinates are sometimes given without the designation of E or east. When this is used, a positive value represents coordinates east of the Prime Meridian. There are also 180 degrees west of the Prime Meridian and when W or west is omitted in a coordinate a negative value such as -30Â ° represents coordinates west of the Prime Meridian. The 180Â ° line is neither east nor west and approximates the International Date Line. On a map (diagram), lines of longitude are the vertical lines running from the North Pole to the South Pole and are perpendicular to lines of latitude. Every line of longitude also crosses the equator. Because longitude lines are not parallel, they are known as meridians. Like parallels, meridians name the specific line and indicate the distance east or west of a 0Â ° line. Meridians converge at the poles and are farthest apart at the equator (about 69 miles (111 km) apart). Development and History of Longitude For centuries, mariners and explorers worked to determine their longitude in an effort to make navigation easier. Latitude was determined easily by observing the inclination of the sun or the position of known stars in the sky and calculating the angular distance from the horizon to them. Longitude could not be determined in this way because Earths rotation constantly changes the position of stars and the sun. The first person to offer a method for measuring longitude was the explorer Amerigo Vespucci. In the late 1400s, he began measuring and comparing the positions of the moon and Mars with their predicted positions over several nights at the same time (diagram). In his measurements, Vespucci calculated the angle between his location, the moon, and Mars. By doing this, Vespucci got a rough estimate of longitude. This method did not become widely used however because it relied on a specific astronomical event. Observers also needed to know the specific time and measure the moon and Mars positions on a stable viewing platform- both of which were difficult to do at sea. In the early 1600s, a new idea to measure longitude was developed when Galileo determined that it could be measured with two clocks. He said that any point on Earth took 24 hours to travel the full 360Â ° rotation of Earth. He found that if you divide 360Â ° by 24 hours, you find that a point on Earth travels 15Â ° of longitude every hour. Therefore, with an accurate clock at sea, a comparison of two clocks would determine longitude. One clock would be at the home port and the other on the ship. The clock on the ship would need to be reset to local noon each day. The time difference would then indicate the longitudinal difference traveled as one hour represented a 15Â ° change in longitude. Shortly thereafter, there were several attempts to make a clock that could accurately tell time on the unstable deck of a ship. In 1728, clockmaker John Harrison began working on the problem and in 1760, he produced the first marine chronometer called Number 4. In 1761, the chronometer was tested and determined to be accurate, officially making it possible to measure longitude on land and at sea. Measuring Longitude Today Today, longitude is more accurately measured with atomic clocks and satellites. The Earth is still divided equally into 360Â ° of longitude with 180Â ° being east of the Prime Meridian and 180Â ° west. Longitudinal coordinates are divided into degrees, minutes and seconds with 60 minutes making up a degree and 60 seconds comprising a minute. For example, Beijing, Chinas longitude is 116Â °2330E. The 116Â ° indicates that it lies near the 116th meridian while the minutes and seconds indicate just how close it is to that line. The E indicates that it is that distance east of the Prime Meridian. Although less common, longitude can also be written in decimal degrees. Beijings location in this format is 116.391Â °. In addition to the Prime Meridian, which is the 0Â ° mark in todays longitudinal system, the International Date Line is also an important marker. It is the 180Â ° meridian on the opposite side of the Earth and is where the eastern and western hemispheres meet. It also marks the place where each day officially begins. At the International Date Line, the west side of the line is always one day ahead of the east side, no matter what time of day it is when the line is crossed. This is because the Earth rotates east on its axis. Longitude and Latitude Lines of longitude or meridians are the vertical lines running from the South Pole to the North Pole. Lines of latitude or parallels are the horizontal lines running from the west to the east. The two cross each other at perpendicular angles and when combined as a set of coordinates they are extremely accurate in locating places on the globe. They are so accurate that they can locate cities and even buildings to within inches. For example, the Taj Mahal, located in Agra, India, has a coordinate set of 27Â °1029N, 78Â °232E. To view the longitude and latitude of other places, visit the collection of Locate Places Worldwide resources on this site.