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If everyone on earth sat in the ocean, how far the water would rise? – Zahkaev and Viktor
Hypothetical questions how it would happen if everyone on earth swimming at the same time are fun. And with math you can get a real answer quite close. Let’s start with a smaller version of the same question.
Bathtub mathematics
If you fill a bathtub to the top and jump in, you know that you have a moist cleaning. The water overflows because your body pulls it out of the way – something that is referred to as a shift. Since the tub has a solid floor and the sides, the only direction in which the water can go on and off.
The amount of space that an object – in this case, are called volume. The water volume that overflows the tub corresponds to the volume of your body.
Now think of a situation in which the bathtub is only half full. When you jump in, your body’s volume still presses the water up. You can calculate how much the water level in the tub increases with some simple mathematical equations.
Suppose the bathtub is a rectangular box. You can find out how much the water level increases when you sit down in the tub by considering how much volume you add to the tub and the size of this volume. The amount that the water level increases corresponds to the additional volume divided by the surface.
For a bathtub that is 5 feet long and 2 feet wide, the area is 10 square foot.
Now let’s find out your volume. To facilitate mathematics, we assume that you are also a rectangular box like the bathtub. Let us assume that they are about 4 feet high and 2 feet wide (from left to right) and 1 foot deep (from front to back). The volume of her body would be 4 feet x 2 foot x 1 foot or 8 cubic feet.
If you sit down, add the volume of about half of your body into the tub. This means that the height of the water level increase corresponds to the volume of a half body, divided by the area of the tub. Using the above estimates, this leads to a water level increase of 4 cubic feet by 10 square foot, which corresponds to about 5 inches. You would definitely notice that!
Scalate
You can consider the oceans as a gigantic bathtub. More than 70% of the earth’s surface are ocean and give this bathtub an area of around 140 million square miles. To find out how much the water will rise, we need to know the volume of the people sitting in it and share it through this sea area.
There are currently almost 8 billion people on earth. There are people in all sizes, from tiny babies to large adults. Let us assume that the average size is 5 feet high – slightly larger than a child – with an average volume of 10 cubic feet. Only half of the body of each person would have been submerged if they sit down so that only 5 cubic feet contribute to the water level. With a total of 8 billion people, they can calculate 5 x 8 billion, which results in a whopping 40 billion cubic feet that are added to the oceans.
But remember that this volume is distributed over the wide area of the oceans. With the same bathtub as before, we share the 40 billion cubic foot volume over the 140 million square miles Ocean.
The answer? The overall increase in sea level would be about 0.00012 inches or less than 1/1000 inches. If everyone had completely subdivided, this would double the answer to 0.00024 inches, which is still only about the width of human hair.
It turns out that the oceans are enormous – and people are just a drop in the bucket.
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This article will be released from the conversation, a non -profit, independent news organization that brings you facts and trustworthy analyzes to help you understand our complex world. It was written by: Tony E. Wong, Rochester Institute of Technology
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Tony E. Wong does not work for a company or an organization that benefits from this article and have not published any relevant affiliations about their academic appointment.
