You know, if you want to measure the potential energy of something in a gravitational field, you have to define the zero somewhere, right, because it's arbitrary.

你知道，如果你想测量重力场，中某种东西的势能，你需要，在某处定义一个零点，对吧？

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It plans to launch a hard X-ray modulation telescope to study the matter dynamics and high-energy radiation processes in the strong gravitational field of compact celestial bodies and black holes.

发射硬x射线调制望远镜，研究致密天体和黑洞强引力场中物质动力学和高能辐射过程。

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In the gravitational field of the earth, negative energy corresponds to bounded motion and positive energy to unbounded motion.

在地球的重力场中，负的能量相应于有界限运动，正的能量相应于无界限运动。

youdao

You know, if you want to measure the potential energy of something in a gravitational field, you have to define the zero somewhere, right, because it's arbitrary. You can set it anywhere you want. It's the same with enthalpy.

你知道，如果你想测量重力场,中某种东西的势能，你需要，在某处定义一个零点，对吧？,因为势能的值是任意的,你可以把它设定在。

麻省理工公开课 - 热力学与动力学课程节选

Building a human-sized wormhole, for example, would require harnessing vast amounts of peculiar quantum field energy and deploying gravitational stabilizing technology that would need the resources of a cosmic super-civilization.

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The problem becomes less acute once they've cleared the atmosphere, but the high speeds required to escape the Earth's gravitational field (more than 6.8 miles per second) necessitate an enormous amount of energy.

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