<p>This is partly space exploration and partly physics.</p>

<p>Rockets do not normally go straight up. They start off going up, to get into thinner air, then they steer to turn themselves eventually to a horizontal path, until they are going fast enough to stay in orbit.</p>

<p>In general relativity, an object that is free to move in the Earth's gravitational field will appear to accelerate towards the ground as it is following a path (called a geodesic) in curved spacetime. This is not specific to rockets; a cricket ball will follow a curved path when thrown due to the curvature of spacetime around the Earth. And if one is far  from any gravitational field, then a cricket ball will travel in a straight line. </p>

<p>To directly answer your question: The path of a rocket going straight up will not look curved, it will look like it is going straight up.</p>

CC BY-SA 3.0
2018-01-16T22:26:24.990Z
2018-01-16T22:26:24.990Z
James K
<p>Does the path of a rocket or anything going straight up look curved because the mass of the earth is curving space-time?</p>

<p>If we assume the earth, the rocket and all the celestial bodies whose gravitational field reaches the earth to be massless then will the rocket follow truly a straight line, because there would be nothing curving the space-time?</p>

CC BY-SA 3.0
2018-01-16T20:31:06.660Z
Rockets most certainly do not follow straight paths, if only for the fact that their motors are steerable.
Mick
CC BY-SA 3.0
2018-01-16T21:06:03.580Z
Rockets often follow curved paths into space. If they only went straight up, they'd basically just fall straight back down. To stay in space, you need to orbit. As an example of rockets following curved trajectories into space, try reading about something known as a [Gravity Turn](https://en.wikipedia.org/wiki/Gravity_turn).
zephyr
CC BY-SA 3.0
2018-01-16T22:28:59.857Z
A massless rocket would travel at the speed of light and never accelerate or decelerate.
StephenG - Help Ukraine
<space-time><general-relativity>
do rockets follow a straight path but is looks curved because of space time?
ozzy ozbourne
# do rockets follow a straight path but is looks curved because of space time?

(Asked by: username_0 on 2018-01-16)

Does the path of a rocket or anything going straight up look curved because the mass of the earth is curving space-time?

If we assume the earth, the rocket and all the celestial bodies whose gravitational field reaches the earth to be massless then will the rocket follow truly a straight line, because there would be nothing curving the space-time?

**Tags:** space-time, general-relativity

> **Comments:**
> **username_1**: Rockets most certainly do not follow straight paths, if only for the fact that their motors are steerable.  
> **username_2**: Rockets often follow curved paths into space. If they only went straight up, they'd basically just fall straight back down. To stay in space, you need to orbit. As an example of rockets following curved trajectories into space, try reading about something known as a [Gravity Turn](https://en.wikipedia.org/wiki/Gravity_turn).  
> **username_3**: A massless rocket would travel at the speed of light and never accelerate or decelerate.  

---

## 1 answers

### Answer by username_4 on 2018-01-16. Score: 1 | Accepted answer

This is partly space exploration and partly physics.

Rockets do not normally go straight up. They start off going up, to get into thinner air, then they steer to turn themselves eventually to a horizontal path, until they are going fast enough to stay in orbit.

In general relativity, an object that is free to move in the Earth's gravitational field will appear to accelerate towards the ground as it is following a path (called a geodesic) in curved spacetime. This is not specific to rockets; a cricket ball will follow a curved path when thrown due to the curvature of spacetime around the Earth. And if one is far from any gravitational field, then a cricket ball will travel in a straight line.

To directly answer your question: The path of a rocket going straight up will not look curved, it will look like it is going straight up.


---

