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If time changes as a result of the speed of space travel, do the cells in an astronaut’s body still multiply at the same rate?

Lyn Williams,

Cilffriw, Neath Port Talbot, UK

There is a pizza restaurant 300 metres down the road from my house. Does it take more energy for me to skip to it or run to it?

Jessica Lamond (age 5),

London, UK

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