So there really is gravity in space?
Based on our findings, we have concluded that the majority of people in our study have a misconception about gravity in space. Before we can understand where that misconception comes from, we need a basic understanding of what gravity is. Gravity is the force of attraction between two objects that have mass. The strength of the pulling depends on two factors: distance and mass of the objects. The more massive an object is, the greater the pull will be. In space, objects are farther from really massive objects, so the pull is progressively less.
One of the common answers that we encountered was the concept of being “weightless.” This term is a misnomer because “weightless” actually means “free fall.” If you want to experience being “weightless,” you can go skydiving or bungee jumping. Without the parachute or a bungee cord, you would fall forever! (Or until you crashed into Earth). If you did not have the Earth to give you indication that you were moving towards it, you might not think you were moving very fast (wind aside).
In space, astronauts appear to be “weightless” or "floating" because they are falling toward Earth, or whichever massive body they are near. The spaceship near them is also falling toward Earth. Since both objects are falling at the same speed, it looks like they are floating next to each other, but in reality they are falling together. And they are falling at a speed which enables them to fall around Earth (orbit) instead of towards it. Earth’s pull is less because they are so far away. Let's consider an example; if you were in a car that was released from a plane high up in the atmosphere and you were to step out of the car, it would appear that you were floating next to it. Without being able to see the Earth as a point of reference, and pretending there was no air resistance, you would not think you were free-falling very fast and so you would appear to be floating right next to the car. With the gravity being much less far out in space, you would notice it even less and may feel like you were floating. This explains pictures we see about people "floating" inside a space shuttle.
How Does this Connect to the Classroom?
While we cannot speak to all standards taught in schools worldwide, we can speak to our current curriculum in the state of Michigan, although it has undoubtedly changed and may be somewhat different from what was taught to people of the ages we interviewed. The science standards for kindergarten and third grade are:
P.FM.E.2 Gravity- Earth pulls down on all objects with a force called gravity. With very few exceptions, objects fall to the ground no matter where the object is on the Earth.
The fifth grade science standards are:
P.FM.05.41 Explain the motion of an object relative to its point of reference.
The high school science standards are:
P3.6B Predict how the gravitational force between objects changes when the distance between them changes.
While these specific standards are to be concurrently taught with the understandings of what a force is and how it influences objects, students may not make a strong connection between these two concepts, and we do not know the extent or quality to which these standards were really taught. It is also known that over a span of many years, a person tends to forget what they've learned if it isn't ever recalled, especially difficult concepts such as gravity. When we see images of people in space, our mind attempts to make sense of it from what we already know (prior knowledge) and we incorporate new information (possibly misconceptions from other people) into this process. This can result in people making the wrong conclusions about more abstract concepts such as gravity when they finally recall and critically think about it, which results in misconceiving what gravity really is.
So the answer to the question “Is there gravity in space?” is definitively yes. No matter where you are, there is always some more massive object near you that will pull you towards it.
Based on our findings, we have concluded that the majority of people in our study have a misconception about gravity in space. Before we can understand where that misconception comes from, we need a basic understanding of what gravity is. Gravity is the force of attraction between two objects that have mass. The strength of the pulling depends on two factors: distance and mass of the objects. The more massive an object is, the greater the pull will be. In space, objects are farther from really massive objects, so the pull is progressively less.
One of the common answers that we encountered was the concept of being “weightless.” This term is a misnomer because “weightless” actually means “free fall.” If you want to experience being “weightless,” you can go skydiving or bungee jumping. Without the parachute or a bungee cord, you would fall forever! (Or until you crashed into Earth). If you did not have the Earth to give you indication that you were moving towards it, you might not think you were moving very fast (wind aside).
In space, astronauts appear to be “weightless” or "floating" because they are falling toward Earth, or whichever massive body they are near. The spaceship near them is also falling toward Earth. Since both objects are falling at the same speed, it looks like they are floating next to each other, but in reality they are falling together. And they are falling at a speed which enables them to fall around Earth (orbit) instead of towards it. Earth’s pull is less because they are so far away. Let's consider an example; if you were in a car that was released from a plane high up in the atmosphere and you were to step out of the car, it would appear that you were floating next to it. Without being able to see the Earth as a point of reference, and pretending there was no air resistance, you would not think you were free-falling very fast and so you would appear to be floating right next to the car. With the gravity being much less far out in space, you would notice it even less and may feel like you were floating. This explains pictures we see about people "floating" inside a space shuttle.
How Does this Connect to the Classroom?
While we cannot speak to all standards taught in schools worldwide, we can speak to our current curriculum in the state of Michigan, although it has undoubtedly changed and may be somewhat different from what was taught to people of the ages we interviewed. The science standards for kindergarten and third grade are:
P.FM.E.2 Gravity- Earth pulls down on all objects with a force called gravity. With very few exceptions, objects fall to the ground no matter where the object is on the Earth.
The fifth grade science standards are:
P.FM.05.41 Explain the motion of an object relative to its point of reference.
The high school science standards are:
P3.6B Predict how the gravitational force between objects changes when the distance between them changes.
While these specific standards are to be concurrently taught with the understandings of what a force is and how it influences objects, students may not make a strong connection between these two concepts, and we do not know the extent or quality to which these standards were really taught. It is also known that over a span of many years, a person tends to forget what they've learned if it isn't ever recalled, especially difficult concepts such as gravity. When we see images of people in space, our mind attempts to make sense of it from what we already know (prior knowledge) and we incorporate new information (possibly misconceptions from other people) into this process. This can result in people making the wrong conclusions about more abstract concepts such as gravity when they finally recall and critically think about it, which results in misconceiving what gravity really is.
So the answer to the question “Is there gravity in space?” is definitively yes. No matter where you are, there is always some more massive object near you that will pull you towards it.
Extra Information about Gravity
Here's an example of the difference in gravitational pull from a difference in mass. Remember, the more massive an object, the more gravitational pull it has. The moon is approximately 1/80th the mass of the Earth, therefore it will have less gravitational pull, seen by the fact that the astronaut can "hang" in the air for a while before being pulled back to the moon's surface. This is in contrast to the Jumping on Earth video. Because the Earth is much more massive than the moon, the person is pulled back to Earth much more easily and they do not appear to have "hang-time."
Here's an example of the difference in gravitational pull from a difference in mass. Remember, the more massive an object, the more gravitational pull it has. The moon is approximately 1/80th the mass of the Earth, therefore it will have less gravitational pull, seen by the fact that the astronaut can "hang" in the air for a while before being pulled back to the moon's surface. This is in contrast to the Jumping on Earth video. Because the Earth is much more massive than the moon, the person is pulled back to Earth much more easily and they do not appear to have "hang-time."
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Jumping on Earth from Aaron Dawdy on Vimeo. |