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Published — 7 September 2026 ⏭ New Scientist

Why does time only seem to move in one direction? ➡️

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Entropy appears to give us the answer: the universe moves from order to disorder, giving time its familiar arrow from past to future.

But there’s a problem. Most fundamental laws of physics work just as well forwards as they do backwards in time. So if entropy increases toward tomorrow, why shouldn’t it also increase toward yesterday?

Jim Al-Khalili explores the “past hypothesis” - the idea that the universe began in an extraordinarily special, low-entropy state at the Big Bang - and why he thinks that explanation may not be the full story.

Watch the full video https://youtu.be/IDNCWe3ufCE

#ArrowOfTime #Entropy #Thermodynamics
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