Karolina Wlazło-Malinowska

499 sekund

Scale of the Universe

Karolina Wlazło-Malinowska

You here?
The photon has detached from the Sun’s surface 82 seconds ago, and it has already covered 24,5 million km, almost 1/5 from the 150 million that separate the Earth and its star.
But photons reach Earth from other stars, too. The ones from Proxima Centauri reach you after 4 years. Now imagine Earendel – the furthest single star known to humans. Photons needed 13 billion years to get to Earth. In this context the Solar System becomes cosy. Planet Earth – very private.
Time does not apply to photons though. If one owned a watch, its hands would never tick. A self-aware photon would not have noticed its own journey. Getting anywhere happens immediately for a photon. Light never grows old.
The deeper you look into the cosmos, the further you dive into its history. Earendel does not exist anymore – you can only observe its past. And it works both ways. The observer situated 2,500 light years from Earth with a super-telescope, would see ancient history, the pyramids – Earth’s past.
Time, if it exists, is experienced differently by various beings. What is it to you?