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What you see here is a soccer ball that passes one of the most important tests in sports engineering.

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Balanced mass distribution.

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Today we're going to be sports engineers and test three different soccer balls.

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In 2019, soccer balls were tested here on the International Space Station.

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On Earth, gravity masks some of the design principle effects we talked about.

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But in microgravity, we can observe ball behavior in ways that are impossible to observe on Earth.

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Look closely at this ball.

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This ball is intentionally made to be out of balance.

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Now watch what happens when I spin it.

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Notice that wobble?

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This ball demonstrates what engineers call static imbalance.

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This ball's mass is unevenly distributed.

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This could be caused by areas of thicker or thinner material.

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For example, the unevenness in the distribution of weight impacts its movement, causing it to wobble.

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Our next ball shows what happens with strategic mass placement.

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Watch carefully.

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Did you see that flip?

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This is called intermediate axis rotation.

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And it's actually useful in some engineering applications like keeping the International Space Station stabilized, but not so much when you're

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trying to kick a ball straight into a goal.

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This effect happens when a ball's weight is evenly spread out from its center point, but there's extra weight

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added along one axis of the ball.

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It's imbalanced or asymmetrical, affecting its axis rotation.

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On Earth, a ball like this will feel balanced and not roll back and forth

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when you see it on a flat surface, but its rotation axis will change when it starts spinning.

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Look closely at this ball.

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See how smoothly it rotates.

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This demonstrates dynamic balance, or the ability of an object to spin at equilibrium without irregular movements.

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Engineers achieve this by carefully controlling the weight and placement of every component, from the bladder to the panels.

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Modern soccer balls undergo extensive testing to ensure this level of performance.

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From the physics of mass distribution to the engineering of world class sports equipment.

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Understanding how materials behave helps us create better technology both on Earth and in space.

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The next time you watch a perfectly placed soccer ball sail into a goal.

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Remember, there's some serious engineering spinning inside that ball.

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Keep exploring, keep questioning, and maybe someday you'll engineer the next breakthrough in sports technology.