How Does a Human Centrifuge Simulate Gravity for Astronauts?

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In summary: So the astronauts in the centrifuge experience a combination of both horizontal and vertical forces, creating an overall simulated gravitational effect. And if the centrifuge spins too fast, the person inside is at risk of dying due to the non-uniform application of forces on the body. This is similar to what would happen if Earth's gravity suddenly increased by a significant amount. In summary, a human centrifuge enables astronauts to experience a simulated gravity effect by creating a combination of horizontal and vertical forces, and if the centrifuge spins too fast, it can be dangerous due to the non-uniform application of forces on the body.
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Jimmy87
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Hi pf, please could someone explain how a human centrifuge enables astronauts to experience a simulated gravity effect. I understand that if a centrifuge machine has a centripetal acceleration of 20 m/s^2 then they will feel a force of 2g. The thing that confuses me is that they are spun on a horizontal plane so in the y-plane where gravity normally acts there is no centrifugal effect yet the astronauts on the human centrifuge find it difficult to lift their hand up (in the y-plane). Surely if your being spun on a horizontal plane you only feel the simulated gravitational effect across your body?

Also, if the human centrifuge goes too fast the person inside is at risk of dying apparently. I was just wondering what would actually kill you since there is no such thing as a centrifugal force. Would they be killed by the centripetal force pushing against them or by their inertia or both?

Thanks people!
 
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Jimmy87 said:
Hi pf, please could someone explain how a human centrifuge enables astronauts to experience a simulated gravity effect. I understand that if a centrifuge machine has a centripetal acceleration of 20 m/s^2 then they will feel a force of 2g. The thing that confuses me is that they are spun on a horizontal plane so in the y-plane where gravity normally acts there is no centrifugal effect yet the astronauts on the human centrifuge find it difficult to lift their hand up (in the y-plane). Surely if your being spun on a horizontal plane you only feel the simulated gravitational effect across your body?
Newton's first law tells you an astronaut in the spinning centrifuge(i.e., with some tangential velocity) should move in a straight line unless a force acts on him/her. Where does the force that makes the path of motion curved to form a circle come from, and which direction is it acting? Can you compare the situation to a person standing on Earth?

Re: your second question. What do you think would kill a person if Earth's gravity would suddenly increase many times?
 
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Jimmy87 said:
Hi pf, please could someone explain how a human centrifuge enables astronauts to experience a simulated gravity effect.
Acceleration is equivalent it gravity:

https://www.youtube.com/watch?v=2MquzTW5nq0

https://www.youtube.com/watch?v=QSIuTxnBuJk

Jimmy87 said:
I understand that if a centrifuge machine has a centripetal acceleration of 20 m/s^2 then they will feel a force of 2g.
2g horizontally and 1g vertically if still on Earth. So more than 2g in total.

Jimmy87 said:
The thing that confuses me is that they are spun on a horizontal plane so in the y-plane where gravity normally acts there is no centrifugal effect yet the astronauts on the human centrifuge find it difficult to lift their hand up (in the y-plane).

What is Y? Vertical to the ground, or vertical to the cabin, that aligns with the effective gravity (vector sum of Earth's gravity and centrifugal gravity)?

443l.jpg


Jimmy87 said:
Also, if the human centrifuge goes too fast the person inside is at risk of dying apparently. I was just wondering what would actually kill you since there is no such thing as a centrifugal force. Would they be killed by the centripetal force pushing against them or by their inertia or both?
What kills you physiologically depends on many factors. But the general physical cause is the non-uniform application of forces to your body.
 
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What is Y? Vertical to the ground, or vertical to the cabin, that aligns with the effective gravity (vector sum of Earth's gravity and centrifugal gravity)?

Thanks for your answers guys! I mean y in the conventional sense if you were standing still on Earth, so vertically. The centrifuge you show in the picture isn't like the one I saw. The one I saw was and video where with cabin that the astronauts sit in that spins around horizontally. When they try to lift their hand up (vertically) in the cabin they can't when the g's build up but I don't understand why because the vertical g-force is still the same without being in the centrifuge as the centrifuge is not spinning in the vertical (y) plane?
 
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Jimmy87 said:
The centrifuge you show in the picture isn't like the one I saw.
then show us your centrifuge.

Jimmy87 said:
The one I saw was and video where with cabin that the astronauts sit in that spins around horizontally.
It spins horizontally, but banks to align with the effective gravity.
 
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A.T. said:
then show us your centrifuge.


It spins horizontally, but banks to align with the effective gravity.

The type of centrifuge I have seen in films of Space Training had a much larger radius. This ensures that the simulated g force is more even, over the trainee's dimensions. The 'banking' can be achieved by just having the seat / cage on a gimbal , which would not involve the long arm leaving the horizontal plane.
 
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Thanks to all. I managed to find the video () and yes you are right it is banked. I just didn't pick up on it as it only shows a view from the outside momentarily.
 
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Jimmy87 said:
Thanks to all. I managed to find the video () and yes you are right it is banked. I just didn't pick up on it as it only shows a view from the outside momentarily.

He would hardly sit so nicely straight with 5g sideways acceleration.
 
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A.T. said:
He would hardly sit so nicely straight with 5g sideways acceleration.

Good point indeed!
 

FAQ: How Does a Human Centrifuge Simulate Gravity for Astronauts?

1. What is a human centrifuge?

A human centrifuge is a machine that spins a person at high speeds to simulate the gravitational forces experienced by astronauts during spaceflight. It is used to test the effects of acceleration on the human body and to train astronauts for space missions.

2. How do human centrifuges help prepare astronauts for space travel?

Human centrifuges are used to simulate the gravitational forces experienced during spaceflight, which helps astronauts prepare for the physical challenges of space travel. It also allows them to practice emergency procedures and adapt to the disorienting effects of acceleration.

3. Are there any risks associated with using human centrifuges?

Yes, there are some risks associated with using human centrifuges, such as dizziness, nausea, and potential injuries if the centrifuge malfunctions. However, these risks are minimized through careful training and safety protocols.

4. How do scientists determine the appropriate speed and duration for human centrifuge testing?

Scientists use a variety of factors to determine the appropriate speed and duration for human centrifuge testing, including the physical capabilities of the individual, the purpose of the test, and safety considerations. They may also use data from previous tests and studies to inform their decisions.

5. How have human centrifuges improved over time?

Human centrifuges have improved significantly over time with advancements in technology and understanding of human physiology. They have become more precise, safer, and more efficient, allowing for more accurate and effective training of astronauts. Additionally, they have become more versatile, allowing for a wider range of testing and research capabilities.

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