SCIENCE IN UNIVERSE

The Harvest Moon is the full Moon nearest the start of fall or the autumnal equinox. This usually means it coincides with the September full Moon, though it can also fall nearer to the October full Moon, occurring anywhere from two weeks before to two weeks after the equinox. In  2017 , the Harvest Moon will rise on  October 5  at 2:40  P.M. EDT. WHY IS IT CALLED THE HARVEST MOON? For several evenings, the moon rise comes soon after sunset. This results in an   abundance of bright moonlight early in the evening , which was a traditional aide to farmers and crews harvesting their summer-grown crops. Hence, it’s called the “Harvest” Moon! CREDITS -  1)  https://www.almanac.com/content/what-harvest-moon 2) http://news.nationalgeographic.com/2017/10/when-is-harvest-moon-october-space-science/ YOUTUBE LINK -  https://www.youtube.com/watch?v=tJT...

Flight is basically a battle against Earth's gravity, and your greatest ally is the air. Birds and planes, alike, fight gravity by manipulating the air molecules around them. When birds flap their wings, they're generating an area of high air pressure under the wing and low air pressure above it. The same happens when planes race down the runway. The pressure difference above and below the wing creates a net upward force, giving the aircraft lift. Once this upward force exceeds gravity's downward pull, you have liftoff! Of course, a 1 million-pound plane needs  greater  lift to get off the ground than a great bustard. Credits -  http://www.businessinsider.in/How-massive-airplanes-takeoff-and-stay-in-mid-air/articleshow/60214553.cms YouTube Link  -  https://www.youtube.com/watch?v=-TnnjVuxmB8 All other credits to the rightful owners.

The term “ Hunters Moon ” is used traditionally to refer to a full moon that appears during the month of October. It is preceded by the appearance of a “Harvest Moon”, which is the full moon closest to the autumnal equinox (which falls on the 22nd or 23rd of September). It is also known as a sanguine or “ Blood Moon ". The Hunter’s Moon typically appears in October, except once every four years when it doesn’t appear until November.  The name dates back to the First Nations of North America. It is so-called because it was during the month of October, when the deers had fatted themselves over the course of the summer, that hunters tracked and killed prey by autumn moonlight, stockpiling food for the coming winter. YouTube Link  -   http://www.mirror.co.uk/news/uk-news/hunters-moon-2016-what-can-9050088 Credits -  https://c2.staticflickr.com/4/3819/10355721434_6992b719fa_b.jpg

Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea. Out in the depths of the ocean, tsunami waves do not dramatically increase in height. But as the waves travel inland, they build up to higher and higher heights as the depth of the ocean decreases. The speed of tsunami waves depends on ocean depth rather than the distance from the source of the wave. Tsunami waves may travel as fast as jet planes over deep waters, only slowing down when reaching shallow waters. While tsunamis are often referred to as tidal waves, this name is discouraged by oceanographers because tides have little to do with these giant waves. YouTube Link  -  https://www.youtube.com/watch?v=Wx9vPv-T51I Credits -  https://oceanservice.noaa.gov/facts/tsunami.html Picture Credits - To the rightful owner

X-rays are a form of electromagnetic radiation, as are radio waves, infrared radiation, visible light, ultraviolet radiation and microwaves. One of the most common and beneficial uses of X-rays is for medical imaging. X-rays are also used in treating cancer and in exploring the cosmos.  Electromagnetic radiation is transmitted in waves or particles at different wavelengths and frequencies. This broad range of wavelengths is known as the electromagnetic spectrum. The EM spectrum is generally divided into seven regions in order of decreasing wavelength and increasing energy and frequency. The common designations are: radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV), X-rays and gamma-rays.  YouTube Link  -  https://www.youtube.com/watch?v=oM_-FnjNTwA Credits -  https://www.livescience.com/32344-what-are-x-rays.html Picture Credits - To the rightful owner

Dry Ice is the common name for solid carbon dioxide (CO2). It gets this name because it does not melt into a liquid when heated; instead, it changes directly into a gas (This process is known as sublimation). As Ireland’s premier dry ice specialist, Polar Ice provides dry ice solutions for a diverse range of customers, in areas such as: Hospitals & Clinics Food Processing & Distribution Industrial Cleaning and Technical Processes Theatrical and Special Effects YouTube Link  -  https://www.youtube.com/watch?v=kEbwxFinuEs Credits -  https://dryice.ie/what-is-dry-ice/ Picture Credits - To the rightful owner

The Dead Sea has the lowest elevation and is the lowest body of water on the surface of  Earth . For several decades in the mid-20th century the standard value given for the surface level of the lake was some 1,300 feet (400 metres) below  sea level . Beginning in the 1960s, however, Israel and Jordan began diverting much of the Jordan River’s flow and increased the use of the lake’s water itself for commercial purposes. The result of those activities was a precipitous drop in the Dead Sea’s water level. By the mid-2010s measurement of the lake level was more than 100 feet (some 30 metres) below the mid-20th-century figure—i.e., about 1,410 feet (430 metres) below sea level—but the lake continued to drop by about 3 feet (1 metre) annually. YouTube Link  -  https://www.youtube.com/watch?v=c3k1o2dqLD8 Credits -  https://www.britannica.com/place/Dead-Sea Picture Credits - To the rightful owner

Everyone who has been to the beach knows that seawater is salty. Everyone also knows that fresh water in rain, rivers, and even ice is not salty. Why are some of Earth’s waters salty and others not? There are two clues that give us the answer. First, “fresh” water is not entirely free of dissolved salt. Even rainwater has traces of substances dissolved in it that were picked up during passage through the atmosphere. Much of this material that “washes out” of the atmosphere today is pollution, but there are also natural substances present. As rainwater passes through soil and percolates through rocks, it dissolves some of the minerals, a process called  weathering .  This is the water we drink, and of course, we cannot taste the salt because its concentration is too low. Eventually, this water with its small load of dissolved minerals or salts reaches a stream and flows into lakes and the ocean. The annual addition of dissolved salts by rivers is only a tiny fraction of...

Ice floats because it is about 9% less dense than liquid water. In other words, ice takes up about 9% more space than water, so a liter of ice weighs less than a liter water. The heavier water displaces the lighter ice, so ice floats to the top. One consequence of this is that lakes and rivers freeze from top to bottom, allowing fish to survive even when the surface of a lake has frozen over. If ice sank, the water would be displaced to the top and exposed to the colder temperature, forcing rivers and lakes to fill with ice and freeze solid. A substance floats if it is less dense, or has less mass per unit volume, than other components in a mixture. For example, if you toss a handful of rocks into a bucket of water, the rocks, which are dense compared to the water, will sink. The water, which is less dense than the rocks, will float. Basically, the rocks push the water out of the way or displace it. For an object to be able to float, it has to displace a weight of fl...

All boats can float, but floating is more complex and confusing than it sounds and it's best discussed through a scientific concept called  buoyancy , which is the force that causes floating. Any object will either float or sink in water depending on its  density  (how much a certain volume of it weighs). If it's more dense than water, it will usually sink; if it's less dense, it will float. It doesn't matter how big or small the object is: a  gold  ring will sink in water, while a piece of plastic as big as a football field will float. The basic rule is that an object will sink if it weighs more than exactly the same volume of water. But that doesn't really explain why an aircraft carrier (made from dense metal) can float, so let's explore a bit further. Buoyancy is easiest to understand thinking about a  submarine . It has diving planes (fins mounted on the side) and ballast tanks that it can fill with water or air to make it rise or fall as it needs t...