Is Earth Rotating Slowly ?
Earth rotates once in about 24 hours with respect to the Sun, but once every 23 hours, 56 minutes, and 4 seconds with respect to other distant stars ! This is something that we all have been studying from our childhood right, so there’s nothing new in it. We also know that we don’t realize the earth’s rotation or revolution, so we might never find out whether its speed has increased or decreased. And we also know that Center of Mass plays an important role in the speed of any object which is acted upon by a gravitational force. Now what if I say there’s something that is happening across the world that connects all these points and recently NASA has confirmed that there is a decrease in earth’s rotational speed due to this event, I know its a bit confusing like the science fiction movie, so let me make it crystal clear like we always do!
A recent research showed that the time taken by earth to complete one rotation has been reduced by 0.06 microseconds, yes and the reason for this was a dam. Shocking? That too its the largest dam in the world, with a length of around 2.5 km and a capacity of 39 cubic kilometers it almost five times that of the Hoover dam. It’s located in china over the yangtze river and is named as Three Gorges Dam. Three Gorges impounds the Yangtze River about 1,000 miles (1,610 km) west of Shanghai. It’s named for its location near the three gorges at the foot of the western Wu Shan Mountains. Plans for its construction started in the year 1992 and almost took 20 years to make it completely functional. Now you might ask me that it’s just another dam, maybe a bit bigger in size, but what has this to do with the rotation of the earth?
Before going into the topic, let’s refresh our knowledge on basic science, in fact physics. Do you remember linear motion? Inertia ? Moment of inertia? Cool even if you don’t, let’s just brush a simple fact, a body will continue its motion unless and until it is disturbed or there is an imbalance in the state properties. Now, to all those gym freaks, ever wondered why the weights which are placed far away from the center is heavy when compared to the same weights closer to the center? It is due to the concept of center of mass, more the mass on the ends will mean more distance from the center of the body, which ultimately means this is more heavier than the one closer to the center. Same happens with the objects in motion, concentration of mass away from the center will affect the motion too. This is used by the dancers (especially the ones using ice skates) to adjust the speed of their rotation; when they spread their legs, they move a bit slower with respect to when they have their legs closer.
This is the same phenomenon with earth too, due to this dam( heavy concentration of its mass at the same place) , located away from the earth’s axis of rotation, is causing a reduction in earth’s speed. That is the reason for the 0.06 microseconds that NASA recently found out. Apart from all these, the dam is under a lot of other controversies from the start of its construction till today ( maybe we will try cover that in a different story) !
This marks our 50th story, we have connected a lot of dots, explored so many new and interesting fields and covered a lot of mysteries together, and cheers to 100s and 100s more to come ! Let’s travel together and learn more, also spread the knowledge more ! All these were pre-planned, but life always has ways to surprise you right, that’s what has happened here, our 1st story is connected with this 50th story ( unexpected connection of dots, in fact connection of center of masses)- amazing isn’t it! You are still thinking how are they connected, check our first story here:
Is CM the reason behind climate change ?
The problem of climate change and its reason is the biggest headache of the environmentalists and scientists out there…
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