Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • FUTURES

Time’s arrow

Know your place.
By
  1. John Frizell

    1. John Frizell is originally from Canada and helped found Greenpeace International. He now lives in East Sussex, where he walks, sings and builds robots.

A figure wearing a roughly made tanned leather coat and with a bag on a strap over his shoulder walks through a hole-pocked rocky landscape

Illustration: Jacey

Forget all the nonsense you heard about time travel. You can’t go back and kill your grandfather. The past has already happened. Everything is linked, each event underpins the next, everything is determined; you can’t do anything to break those links. Try, and you enter a forbidden state. Your body won’t obey your will.

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Learn more

Prices may be subject to local taxes which are calculated during checkout

doi: https://doi.org/10.1038/d41586-025-02625-4

Subjects

Latest on:

Nature Careers

Jobs

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing

Search

Advanced search

Quick links