Gravity: Einstein's More Than 100 Years Theory Still Relevant

in #science7 years ago

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Every day we wake up and stand up from the bed, pick a toothbrush, or drink a cup of coffee, or just stand, we can do all these stuff due to effects of gravity.

What if someone could "switch off gravity? It is analogous to letting go of a string holding a helium-filled balloon; everything not anchored to earth would fly straight into space. In buildings, people would float upwards till they bump into the ceiling. Only things anchored to earth may not float away immediately, but with time even the Earth itself may likely break up into bits and float away into space.

achievement-1455855_640.jpg

Credit (Pixabay): Zero gravity

Yes! It is also held together by gravity. We do not want that to happen, do we?

What is gravity?



First, gravity is not a force. But if that is true, what is it since it is common knowledge from elementary physics is that it "pulls things".

But shouldn't forces be involved since it could pull things?

But in the real sense, it is better we replace "pull" with "accelerate" which is a more fitting term.

Now that we have it out of the way we may now attempt to describe what gravity is.

Using the Einstein's general relativity concept, gravity is taken not as an interaction but as a deformation of space-time. Since space-time is not flat object, tend not to follow straight trajectories.

The Fabric and Ball Affair


Back to elementary science again, we all know that matter is is anything that has mass and occupies space. Also, mass is not the same as weight as weight is dependent on effects of gravity.

Every single atom has mass, and most of the sub-atomic particle constituent of the atom does have mass too. The bigger the mass of a particle the more it warps the "fabric" of space surrounding it.

For illustration purposes, consider the picture of the bed with a clean sheet of fabric spread neatly and taut around the mattress. That is the "fabric of space". If you spread ball bearings all over the bed, each ball bearing would make a dent in the fabric.

If two ball bearings are close together, there is a possibility of the combined dent in the bedsheet making them touch.

To push this illustration further, if you suddenly picked up a bowling ball ( or shot put ball) and placed it on the bed, it would make a dent far much bigger than the small ball bearings.


Credit (Tumblr): The large ball makes a large bend in spacetime, causing smaller ball to alter its course and follow the dip


That would cause other ball bearings to slope towards the ball (the bowling ball would move slightly towards the ball bearings, but since the movement is slight you may notice the bowling ball move.




This analogy defines gravity as seen in two-dimensional bed. But in three dimensional, it acts in every direction and not just across a plane.

Spacetime_curvature.png

Credit (Wikipedia): A two-dimensional projection of a three-dimensional analogy of space-time curved around Earth.

According to Einstein, the same way that the ball bearings on the stretched bedsheets cause it to sag, so do the planets and stars create the space-time warp.

The Earth gets drawn to the Sun but not into it. That is because it is moving at a certain speed.

The planets never fall into the Sun because of the speed at which they are travelling. According to the theory, energy and matter distort space-time, curving it around them.

This effect explained in Einstein's general theory of relativity which he wrote in 1915 to describe gravity. This argument is valid as of today as none had disproved it.

An epic victory over daunting challenges, or a costly project that should never have flown? After nearly half a century of work and US$750 million spent, Gravity Probe B, one of NASA's longest-running mission programmes, has finally achieved some scientific closure. But it has yet to quiet its critics.

On 4 May, researchers released the results of a tortuous five-year data analysis that relied on the largesse of a Saudi funding agency to complete. The verdict, to be published in Physical Review Letters: Einstein was right. "I am both glad and relieved that we pulled this off," says physicist Francis Everitt of Stanford University in California, who has led the effort since the beginning. Source

What was Einstein right about? He was right that an object such as the Earth does indeed distort the fabric of space and time.

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I would like to write two comments here.

Gravity is one of the four fundamental interactions. No matter how you model it, it stays one of them. You seem to claim the opposite. Can you please specify?

Since space-time is not flat object [...]

On large scales, space-time is flat. I just wrote a post about that last week :)

Except for those two points, your post is nice :)

I'm not disputing gravity being one of the four interactions. I think I get what you are talking about in space time being flat on large scale. I read your post on it :)

Good clarification :)

Just So You Know

  1. In contrast to the pressure, with its darkish and mild facets, gravity has no duality; it simplest draws, by no means repels.

  2. NASA is attempting to increase tractor beams that would pass bodily gadgets, growing an attractive pressure that would trump gravity.

  3. Passengers on entertainment park rides and the global area Station experience microgravity — incorrectly known as zero gravity — because they fall at the identical speed as the cars.

Very well explained.
Just imagine we have no gravity so everyone would be flying and that means you don't need any aeroplanes ahahhah(Sorry I know it is a bad one but I couldn't stop myself.)

Gravity plays a very crucial role in the stability of all planetary bodies. Earth is kept in its orbit because of the pull of the moon and of course that of the sun. Gravity is strongest in the polar regions of the earth while they are least at the equator. This accounts for the reason the earth is not a perfect sphere.

Thanks for contributing.

I knew it was time to leave an American town I was living in when the officials started talking about declaring gravity illegal!

How does that work? I'm very interested in getting it in full details :)

Lol it was a long time ago, in a city that was too big for itself in the northern midwest. I don't even know the details- right after that they closed the courthouse to where it was open only one day every two weeks... I foresaw crime rising and knew it was wise to leave. The town collapsed for a while then I stopped keeping up with it...

I'm glad you left before it became the Wild Wild West.

Oh it got bad

You have inspired me to write a post about it. I am in the process of moving so once I am settled I am going to do a little research and publish a whole article about it!

I would totally love to read it. I'd appreciate it if you could tag me so that I won't miss it.

Being that you are the inspiration, I would be happy to :)

I am looking forward to the epic tale :)

It brought on a big laugh when I thought of a gravity-less earth where everything would be floating on air, including my kitchen utensils and me struggling to steady what I have cooking on the fire 😀Thank God for gravity o. Nice one

Getting things to fly won't be much of a problem again.

Law of gravity... still wondering how the earth will be without gravity. Meanwhile Albert Einstein is one genius I am still thinking of having 1/16 of 1/2 of his knowledge.

Albert Einstein was no doubt a genius several centuries ahead of his contemporaries back then, and his contributions to the present day understanding of gravity and space-time will remain firmly and deeply engraved in our hearts for centuries to come. Great article! Thanks for sharing.

Sorry friend Tesla was contemporary of Einstein and was way ahead of him!📘
I do think we don't fully understand what we call gravity yet?!

I never thought of gravity like this. Thanks for the examples and value adding post.

einstein is a genius and will remain always haha :)