# How space works:Why does an asteroid crush a human in space?

• christian0710
In summary, momentum is what keeps objects moving after they've been hit. If there is no air resistance or any other type of resistance in space, then an object would continue moving at the same speed after being hit.
christian0710
I hve a question: IF there is no air resistance or ANY type of resistance in space, then how come an asteroid or fast moving object can crush a persons face in space (like in the movie: Gravity)

My logic is the following:

If you imagine a spring extended in space, and a fast moving ball hits the spring in one end, does the spring compress? If it does compress then there must be something in the other end of the spring (space) pushing against it right? Why would a spring compress if there is no resistance in the opposite side of impact? I would imagine the spring would just move. Even if you had one fragile egg in space and another egg moving 1000m/s crushing into the stationary egg,I would imagine both eggs would just move at half the speed of the 1 egg (the moving egg transmits ½ the movement onto the other), because IF there was no resistance in space then Could you not imagine this scenario: (This discription is happening in a split second)

1. The outer atoms of the edge of the fast moving egg, A, touch against the outer edge of the stationary egg ,B, this gives the egg a bit of movement. Now egg B is moving at 10th the speed of the the moving EGG, and the moving egg is loosing 1/10th of it's speed.
2. Egg B is still slower than Egg A,and Egg B keeps pushing harder and harder against Egg A (in a nanosecond) until they are moving at the same speed (because they are the same size, however the force of impact did not crush egg B or A because there is no resistance pushing in the opposite side of impact on egg B, so nothing is forcing the shell to crack from the opposide side of the impact site.)

Are there any experiments confirming or explaining this?

F=ma still applies in space. Mass has inertia, which makes larger masses harder to accelerate (or decelerate) than smaller ones.

What you describe is conservation of momentum, which is true but a different issue from whether the objects can survive the impact.

christian0710 said:
I hve a question: IF there is no air resistance or ANY type of resistance in space, then how come an asteroid or fast moving object can crush a persons face in space (like in the movie: Gravity)
As russ has pointed out, the issue here is momentum. Do you think air pressure has any significant role in what happens if a baseball batter gets hit in the head by the pitch? Whether his head is in the ballpark or in space, it doesn't want to move as fast as the ball wants it to move.

christian0710 said:
I hve a question: IF there is no air resistance or ANY type of resistance in space, then how come an asteroid or fast moving object can crush a persons face in space (like in the movie: Gravity)

My logic is the following:

If you imagine a spring extended in space, and a fast moving ball hits the spring in one end, does the spring compress? If it does compress then there must be something in the other end of the spring (space) pushing against it right? Why would a spring compress if there is no resistance in the opposite side of impact? I would imagine the spring would just move. Even if you had one fragile egg in space and another egg moving 1000m/s crushing into the stationary egg,I would imagine both eggs would just move at half the speed of the 1 egg (the moving egg transmits ½ the movement onto the other), because IF there was no resistance in space then Could you not imagine this scenario: (This discription is happening in a split second)

1. The outer atoms of the edge of the fast moving egg, A, touch against the outer edge of the stationary egg ,B, this gives the egg a bit of movement. Now egg B is moving at 10th the speed of the the moving EGG, and the moving egg is loosing 1/10th of it's speed.
2. Egg B is still slower than Egg A,and Egg B keeps pushing harder and harder against Egg A (in a nanosecond) until they are moving at the same speed (because they are the same size, however the force of impact did not crush egg B or A because there is no resistance pushing in the opposite side of impact on egg B, so nothing is forcing the shell to crack from the opposide side of the impact site.)

Are there any experiments confirming or explaining this?

Do you really think that if a car hits you on the road, it needs the (almost negligible) air resistance behind you to get injured? The air resistance can be ignored for a collision like that. The car may break your leg because, as you yourself note, in a fraction of a second the impact will accelerate you rapidly with a huge force.

Physics has to do with the real world. You are using your basic knowledge of physics to lose touch with the real world and how it works, rather than enhance your knowledge of how things work.

artyb
christian0710 said:
Why would a spring compress if there is no resistance in the opposite side of impact? I would imagine the spring would just move.
How can the other end accelerate, when no force is applied to it, because the spring isn't compressed at all.

christian0710 said:
Are there any experiments confirming or explaining this?
https://en.wikipedia.org/wiki/2009_satellite_collision

Last edited:
christian0710 said:
I hve a question: IF there is no air resistance or ANY type of resistance in space, then how come an asteroid or fast moving object can crush a persons face in space (like in the movie: Gravity)

Back up a bit. This whole thing is extremely puzzling. Do you mean that if this occurs on earth,ie. with the presence of air resistance, then you don't have any problem with it? For example, if I throw a 100 km/hr baseball into your face, you understand why it smashes your face if this happens on earth, but you don't understand why it still smashes your face if this were done in space, in vacuum?

Did I interpret this starting point correctly?

Zz.

ZapperZ said:
Did I interpret this starting point correctly?
yup

## 1. Why is there no gravity in space?

In space, there is actually a small amount of gravity, but it is not as strong as Earth's gravity. This is because in space, objects are far away from each other and the pull of gravity is weaker. Additionally, objects in space are in constant motion, which can give the illusion of weightlessness.

## 2. How do astronauts move around in space without floating away?

Astronauts use specially designed spacesuits with thrusters and tethers to move around and stay anchored to their spacecraft. They also use tools and handrails to assist with movement in microgravity.

## 3. Can humans survive in space without a spacesuit?

No, humans cannot survive in space without a spacesuit. The vacuum of space would cause a rapid loss of pressure in the body, leading to severe injury or death. The lack of oxygen and extreme temperatures would also be fatal.

## 4. How do rockets launch and move in space?

Rockets use chemical propulsion, where fuel and oxidizer are ignited to create a controlled explosion that propels the rocket forward. Once in space, rockets use thrusters to maneuver and change direction.

## 5. Why is it dangerous for humans to be in space for extended periods of time?

Extended periods of time in space can have many negative effects on the human body, such as muscle and bone loss, vision problems, and a weakened immune system. Exposure to radiation and the psychological challenges of living in a confined space can also pose risks to human health.

Replies
7
Views
4K
Replies
26
Views
3K
Replies
12
Views
3K
Replies
7
Views
2K
Replies
4
Views
2K
Replies
11
Views
2K
Replies
90
Views
7K
Replies
1
Views
1K
Replies
4
Views
918
Replies
2
Views
2K