Tag Archives: Andromeda Mirror

Observing time

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Yesterday’s post, ‘Let’s Do the Time Warp Again’ is still messing with my head a bit. The idea of the Andromeda paradox suggests that if we are in motion compared to another bystander, our view of very distant events can be days apart.

I understood relativity with respect to travel, a twin in a spaceship travelling close to the speed of light goes to a distant galaxy. When he comes back to earth a few years later he would be younger than the twin left behind… demonstrating the relativity of time. But the idea that distant events can ‘happen’ at different times for people witnessing it from almost the same spot, simply because of their relative motion to each other is perplexing.

So then I suggested that we could re-witness an event by changing our motion such that we are moving quickly away from a very, very distant event, so that from that relative perspective the event hadn’t happened yet. I’m no physicist, the distances would have to be huge, and I don’t know what speeds would need to be achieved, but it seems pretty conceivable to me.

What’s messing with my head is that if this is possible, what does ‘now’ mean?

We have to wait 8 minutes for the sun’s light to reach us. When it reaches us, the sun is already 8 minutes older. We don’t see the sun now, we see its history. Our concept of now has a perpetual lag.

This then got me thinking about animals and their reaction times. Have you ever seen a video of a cat toying with a snake? A cat can avoid the bite of a snake, always reacting faster than we would be able to. How does a cat perceive ‘now’ differently than us?

How do birds fly in a murmuration? The flock changes direction in waves, so quickly that they can stay in formation despite hundreds of them having to coordinate with each other. How does a bird in a murmur perceive ‘now’ differently than us?

To a ten year old, 5 years is half a lifetime, to me it’s less than 1/11th of my life. Is it any wonder that as we get older, time seems to go by faster?

Like I said, these ideas are messing a bit with my head. They make me wonder what ‘now’ means and if in reality we share a ‘now’ with anyone? Is the mere act of observing ‘now’ just a relative glance of varying histories? And yet the only thing any of us ever experience beyond our memories and imagination… is now.

Let’s Do the Time Warp Again

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“It’s just a jump to the left… it’s a jump to the ri-ight🎵”

…And that’s all it takes to witness two completely different views of what ‘right now’ means:

“The Andromeda paradox, proposed by physicist Roger Penrose, is a thought experiment in relativity that highlights how simultaneity depends on an observer’s motion. It imagines two people walking past each other on Earth: one toward the Andromeda galaxy and one away. Because of special relativity, the plane of simultaneity for each observer tilts slightly, meaning that the events they consider “happening right now” in Andromeda could differ by entire days. This illustrates that what is considered the present in distant regions of space is relative to an observer’s motion.” (ChatGPT)

Here is my thought experiment based on the Andromeda paradox:

If we were to witness a supernova of a star hundreds of light years away, could we send a rocket hurling at a high speed away from that event and capture the event happening again? Could we re-witness the supernova, a past event that happened many years ago, but from farther away? Would it be possible that from that perspective the event has not been witnessed yet, and so we can ‘get ahead of it’ focus our cameras on it, and wait for it to happen again, just for the first time from that relative perspective?

My head hurts a bit trying to make sense of this, but my hunch is that it would be possible. So instead of the Andromeda paradox, it’s more like the Andromeda mirror, bouncing back the same light but at a slightly later time than the present… which already is what a mirror does.