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Is a bumblebee like this one able to communicate with a bee of another species? Space jam How big would a planet have to be before its gravity made space travel impossible for the inhabitants? thick atmosphere above was the entire universe, heated and lit by some external, unknowable (divine?) source. Alex McDowell London, UK When lifting off in a space rocket, on a planet with strong gravity, the problem would be the weight of the fuel. If gravity were more than about twice that of Earth’s, lifting off using the chemical rockets we currently have would be practically impossible. Eric Kvaalen Les Essarts-le-Roi, France Depends what you mean by “impossible”. …
摘自《新科学家》(New Scientist)第3603期 · 2026年7月11日。仅引用开头一小段供了解文章,版权归原刊所有,全文请阅读原刊。