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Why We Do Not Feel the Earth Spin …?

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Why can’t we feel Earth’s spin?

We can’t feel Earth’s rotation or spin because we’re all moving with it, at the same constant speed.

Earth spins on its axis once in every 24-hour day. At Earth’s equator, the speed of Earth’s spin is about 1,000 miles per hour (1,600 kph). The day-night has carried you around in a grand circle under the stars every day of your life, and yet you don’t feel Earth spinning. Why not? It’s because you and everything else – including Earth’s oceans and atmosphere – are spinning along with the Earth at the same constant speed.

Think about riding in a car or flying in a plane. As long as the ride is going smoothly, you can almost convince yourself you’re not moving. A jumbo jet flies at about 500 miles per hour (about 800 km per hour), or about half as fast as the Earth spins at its equator. But, while you’re riding on that jet, if you close your eyes, you don’t feel like you’re moving at all. And when the flight attendant comes by and pours coffee into your cup, the coffee doesn’t fly to the back of the plane. That’s because the coffee, the cup and you are all moving at the same rate as the plane.

Now think about what would happen if the car or plane wasn’t moving at a constant rate, but instead speeding up and slowing down. Then, when the flight attendant poured your coffee … look out!

If you're drinking coffee in a steadily moving car or airplane, no problem. But if the car or plane speeds up or slows down, your coffee sloshes and maybe spills. Likewise, as long as Earth spins steadily, we can't feel it move. Image by H.C. Mayer and R. Krechetnikov, via Science.

If you’re drinking coffee in a steadily moving car or airplane, no problem. But if the car or plane speeds up or slows down, your coffee sloshes and maybe spills. Likewise, as long as Earth spins steadily, we can’t feel it move. Image by H.C. Mayer and R. Krechetnikov, via Science.
Likewise, Earth is moving at a fixed rate, and we’re all moving along with it, and that’s why we don’t feel Earth’s spin. If Earth’s spin were suddenly to speed up or slow down, you would definitely feel it.

The constant spin of the Earth had our ancestors pretty confused about the true nature of the cosmos. They noticed that the stars, and the sun and the moon, all appeared to move above the Earth. Because they couldn’t feel Earth move, they logically interpreted this observation to mean that Earth was stationary and “the heavens” moved above us.

With the notable exception of the early Greek scientist Aristarchus, who first proposed a heliocentric (sun-centered) model of the universe hundreds of years B.C.E., the world’s great thinkers upheld the geocentric (Earth-centered) idea of the cosmos for many centuries.

It wasn’t until the 16th Century that the heliocentric model of Copernicus began to be discussed and understood. While not without errors, Copernicus’ model eventually convinced the world that Earth spun on its axis beneath the stars … and also moved in orbit around the sun.

Sky wheeling around Polaris, the North Star.

Sky wheeling around Polaris, the North Star.
A time exposure of the northern sky, revealing the apparent motion of all the stars around Polaris. In fact, this apparent motion is due to Earth’s spin. Image via Shutterstock
Bottom line: Why don’t we feel Earth rotating, or spinning, on its axis? It’s because Earth spins steadily – and moves at a constant rate in orbit around the sun – carrying you as a passenger right along with it.

SOURCE::::www.earthskynews.org

Natarajan

 

Image of the Day… Full Moon and Jupiter on 3 rd and 4th Feb 2015….

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The moon and Jupiter on February 3 - over Atlantic Beach, Florida - posted to EarthSky Facebook by Eve Baker.

The moon and Jupiter on February 3 – over Atlantic Beach, Florida – posted to EarthSky Facebook by Eve Baker.

What a sight … the full moon coupled up with Jupiter on the night of February 3-4, 2015.

EarthSky Facebook friend Duke Marsh caught the February 3 moon and Jupiter from New Albany, Indiana. Thanks, Duke.

EarthSky Facebook friend Duke Marsh caught the February 3 moon and Jupiter from New Albany, Indiana.

SOURCE:::: http://www.earthskynews.org

Natarajan

Image of the Day… Rare triple transit of Jupiter’s moons…!!!

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The images were taken with NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 on January 23, 2015.

Hubble captures these moons in great clarity they can also be seen here on Earth with a small telescope or even a decent pair of binoculars.

The images on the left shows the Hubble observation at the beginning of the event. On the left is the moon Callisto and on the right, Io. The shadows from Europa, which cannot be seen in the image, Callisto, and Io are strung out from left to right. The images on the right shows the end of the event, approximately 42 minutes later. Europa has entered the frame at lower left with slower moving Callisto above and to the right of it. Meanwhile Io — which orbits significantly closer to Jupiter and so appears to move much more quickly — is approaching the eastern limb of the planet. Whilst Callisto’s shadow seems hardly to have moved Io’s has set over the planet’s eastern edge and Europa’s has risen further in the west. Image credit: NASA/ESA

The images on the left shows the Hubble observation at the beginning of the event. On the left is the moon Callisto and on the right, Io. The shadows from Europa, which cannot be seen in the image, Callisto, and Io are strung out from left to right. The images on the right shows the end of the event, approximately 42 minutes later. Europa has entered the frame at lower left with slower moving Callisto above and to the right of it. Meanwhile Io — which orbits significantly closer to Jupiter and so appears to move much more quickly — is approaching the eastern limb of the planet. Whilst Callisto’s shadow seems hardly to have moved Io’s has set over the planet’s eastern edge and Europa’s has risen further in the west. Image via NASA/ESA

Jupiter’s four largest moons are Io, Europa, Ganymede, and Callisto, known as the Galiliean moons, after the 17th century scientist Galileo Galilei, who discovered them. Their complete orbits around Jupiter range from two to 17 days in duration. The moons can commonly be seentransiting the face of Jupiter and casting shadows onto its layers of cloud. But seeing three of them transiting the face of Jupiter at the same time is rare, occurring only once or twice a decade.

Missing from sequence of images is the Galilean moon Ganymede which was outside Hubble’s field of view.

The moons of Jupiter have very distinctive colors. The smooth icy surface of Europa is yellow-white, the volcanic sulphur surface of Io is orange and the surface of Callisto, which is one of the oldest and most cratered surfaces known in the solar system, is a brownish color.

Bottom line: New images taken by the NASA/ESA Hubble Space Telescope on January 23, 2015 capture a rare occurrence as three of Jupiter’s largest moons – Europa, Callisto and Io – parade across the giant planet’s banded face.

Read more from Hubble

SOURCE::::: http://www.earthskynews.org

Natarajan

This Boy’s Space Idea Takes him to NASA…

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City boy’s space idea takes him to NASA
Sanjay Lakshminarayana
Sanjay will present a paper with a set of plans to explore the outer solar system and beyond

A 20-year-old Bengaluru boy is on his way to Texas to present a paper at the prestigious National Aeronautics and Space Administration (NASA). Sanjay Lakshminarayana, a mechanical engineering student, has been selected to present his ideas and attend conventions. These will study important observations made by recent planetary missions and emerging nuclear technologies for space exploration and travel.

The youngster, who has been interested in space since childhood, will present a set of plans to explore the outer solar system and beyond. The ideas will have a significant focus on nuclear systems as enabling technologies.

Sanjay said he would use this opportunity to discuss the knowledge gaps in exploration of extra-terrestrial environments and the most recent discoveries in this area.

The youngster, who also has an interest in car designing, told BM that his background in mechanical engineering provided a base for his interest in space exploration and his consistent research in the area.

Unexpected invite

The meetings on Sanjay’s agenda have been sponsored by NASA and the American Nuclear Society. Speaking on the unexpected invite, Sanjay said, “It was at a meeting in Russia, that a professor from NASA noticed my interest and sent me an invite for this year”.

Commenting on what this opportunity meant for him, he said, “I want to learn a lot about the latest developments and share my ideas with scientists from across the world. I am looking to gain immense knowledge, a sense of direction and meet people who will be able to help me in my research. ”

The meetings are scheduled between February 3 and March 16. These will be held at various locations including the Lunar Planetary Institute in Houston. Sanjay has also been invited to present his paper titled “The Magneto-Confined Fusion Ion Thruster” at the 2015 Nuclear and Emerging Technologies for Space (NETS-2015) conference to be held in Albuquerque.

Sanjay’s schedule

1. 2015 Nuclear and Emerging Technologies for Space (NETS-2015) conference, March 23rd-26th, Albuquerque

2.Workshop on Early Solar System Impact Bombardment III, February 4th-6th, Lunar and Planetary Institute in Houston.

SOURCE:::: Apurva Venkat, Bangalore Mirror Bureau  in http://www.bangaloremirror.com
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Picture of the Day… ” Cloud Streets in the Sea…” !!!

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Ice, wind, cold temperatures and ocean waters combined to created dramatic cloud formations over the Bering Sea in late January, 2015. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite passed over the region and captured this true-color image on Jan. 23.

The frozen tundra of Russia lies in the northwest of the image, and snow-covered Alaska lies in the northeast. Sea ice extends from the land well into the Bering Sea. Over the dark water bright white clouds line in up close, parallel rows. These formations are known as “cloud streets”.

Air blowing over the cold, snowy land and then over ice becomes both cold and dry. When the air then moves over relatively warmer and much moister water and lead to the development of parallel cylinders of spinning air. On the upper edge of these cylinders of air, where the air is rising, small clouds form. Where air is descending, the skies are clear. This clear/cloudy pattern, formed in parallel rows, gives the impression of streets.

The clouds begin over the sea ice, but they primarily hang over open ocean. The streets are neat and in tight rows closest to land, while further over the Bering Sea the pattern widens and begins to become more random. The rows of clouds are also not perfectly straight, but tend to curve. The strength and direction of the wind helps create these features: where the wind is strongest, nearest to shore, the clouds line up most neatly. The clouds align with the wind direction, so the direction of the streets gives strong clues to prevailing wind direction.

Image Credit: NASA/Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC 

SOURCE:::: http://www.nasa.gov

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Image of the Day… View From Space…India by Night and By Day …

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Acquired January 12, 2015. Image credit: NASA

Acquired September 14, 1966. Image credit: NASA

The night image of the Indian peninsula was taken from the International Space Station (ISS) on January 15, 2015. It shows with clarity and surprising detail the human geography of cities of different sizes, such as Kochi and Coimbatore, and the highways that connect cities. The almost unpopulated hilly escarpment, known as the southern Ghats, is a dark zone parallel to the coast. A patch of clouds are illuminated by a nearly-full moon.

The daylight photo was taken by the crew of the Gemini 11 spacecraft back in September 1966. You can see coastlines and land surface color, but no details of human geography. This classic view was taken on an early space flight at a similar altitude to that of the ISS. Patterns of bright white cloud cover much of the land surfaces of India and Sri Lanka.

Bottom line: Two astronaut photos, one from 2015 and one from 1966, show the southern peninsula of India by night and by day.

Via NASA Earth Observatory

SOURCE::::: http://www.earthskynews.org

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