WEBVTT

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Our Earth, our solar system, galaxy, and the universe is moving at incredible speeds and

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the universe keeps expanding.

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Can you tell us about these movements?

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How is it possible that we are moving so fast in space and feel absolutely no movement,

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no rush?

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How come we are not hurled into space?

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What we understand now in the general cosmology of our world is that the universe is in a

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state of expansion and the rate of expansion is high so that, for example, our entire galaxy

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relative to other galaxies is moving at tremendous speeds.

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For example, something like a thousand kilometers per second is just the difference between

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the speed of our galaxy and a nearby galaxy.

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So these are tremendous speeds.

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And then within our own galaxy, of course, we believe that our sun is orbiting the galaxy

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at some high rate of speed.

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And then at some tens of kilometers per second, the Earth is orbiting the sun.

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So there's all these speeds involved.

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And yet we feel so stationary.

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And this has to do with the basic point that when the acceleration of an object is small,

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then a natural experience of motion doesn't exist.

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So if you're in a very well-made elevator in a tall building, what you'll find is in

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the very well-made elevators, you can feel the initial acceleration as you're changing

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your floor.

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For much of the rest of the travel, you have no sense of movement except some sound.

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Maybe the numbers are changing, but you have no sense of motion.

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And then just at the end, when you're decelerating, you begin to sense it again.

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So our bodies and our senses can detect acceleration, but they can't detect motion, just non-accelerated

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motion.

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So constant speed, they can't detect.

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Now if my eyes can see and I'm driving in a car and I can see things go by, well, I have

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a sense of motion, but no other sense than that.

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In the case that we live on the Earth, of course, we do have all these speeds.

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Our accelerations are small.

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Our speeds are very large, but because we don't have a sense of acceleration, we don't

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feel it.