Momentum Conservation Debate

The cluster focuses on debates about conservation of momentum and energy in variable mass systems, particularly whether a spacecraft can accelerate by converting mass to photons without violating conservation laws.

📉 Falling 0.3x Science
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Comments
20
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5
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#3916
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Keywords

OCW I.e en.m i.e wikipedia.org momentum energy mass conservation motion uncertainty principle force releases stores

Sample Comments

ziofill Mar 31, 2025 View on HN

Energy conservation and momentum conservation are different

IshKebab Sep 21, 2021 View on HN

Yeah he said momentum, not energy.

a_t48 Aug 10, 2021 View on HN

Just turn the energy into mass, duh.

egdod Oct 22, 2019 View on HN

It could if momentum isn’t conserved.

0-_-0 Sep 26, 2019 View on HN

Wouldn't momentum transfer from the consumed mass slow it down?

monadic2 Jun 4, 2020 View on HN

It can if it loses mass, correct? Energy conservation would result in increased momentum.

asimpletune Sep 8, 2018 View on HN

Wait, there’s no conservation of energy?

sp332 Sep 22, 2011 View on HN

Wouldn't this also violate conservation of energy? A particle with any mass, traveling at the speed of light, would have infinite energy. And accelerating a particle to that speed would "push back" on the earth with infinite force, so it might also break conservation of momentum.

marcosdumay Aug 1, 2014 View on HN

"Convert energy to mass" does not make much sense. If you throw light away, it'll propel you.

hinkley Oct 20, 2022 View on HN

The mass+energy still have to sum up though, don't they?