by James Wallace Harris, 7/1/24
Can I understand science if I’m not a scientist? I read popular science books, but that doesn’t mean I understand the work that went into making the scientific discoveries they report on. However, is it possible for me to intuit what popular science writers are describing?
I’ve been thinking a lot about the concept of Universal Now. What is this thing we call now? How is it different from the past and future? But the most important question that’s driving me crazy is: Is it now everywhere in the universe at the same time? But then, what is time? I went looking for a book that might answer these questions and found The Order of Time by Carlo Rovelli. I discovered that book from finding the article “Now Means Nothing: How Time Works in Our Universe” online. It was taken from The Order of Time.
This passage tangles up my brain:
Now Means Nothing
What is happening now in a distant place? Imagine, for example, your sister has gone to Proxima b, the recently discovered planet that orbits a star approximately 4 light-years away from us. What is your sister doing now on Proxima b?
The only correct answer is that the question makes no sense. It’s like asking, “What is here, in Peking?” when we are in Venice. It makes no sense, because if I use the word “here” in Venice, I am referring to a place in Venice, not in Peking.
If you ask what your sister, who is in the room with you, is doing now, the answer is usually an easy one: You look at her, and you can tell. If she’s far away, you phone her and ask what she’s doing. But take care: If you look at your sister, you’re receiving light that travels from her to your eyes. That light takes time to reach you — let’s say a few nanoseconds, a tiny fraction of a second. Therefore, you’re not quite seeing what she’s doing now but what she was doing a few nanoseconds ago. If she’s in New York and you phone her from Liverpool, her voice takes a few milliseconds to reach you, so the most you can claim to know is what your sister was up to a few milliseconds ago. Not a significant difference, perhaps.
What does it mean, this “modification of the structure of time”? Precisely the slowing of time described above. A mass slows down time around itself. The Earth is a large mass and slows down time in its vicinity. It does so more in the plains and less in the mountains, because the plains are closer to it. This is why the friend who stays at sea level ages more slowly.
Therefore, if things fall, it is due to this slowing of time. Where time passes uniformly, in interplanetary space, things don’t fall — they float. Here on the surface of our planet, on the other hand, things fall downward because, down there, time is slowed by the Earth.
Hence, even though we cannot easily observe it, the slowing of time nevertheless has crucial effects: Things fall because of it, and it allows us to keep our feet firmly on the ground. If our feet adhere to the pavement, it is because our whole body inclines naturally to where time runs more slowly — and time passes more slowly for your feet than it does for your head.
Does this seem strange? It’s like when watching the sun set, disappearing slowly behind distant clouds, we suddenly remember that it’s not the sun that’s moving but the Earth that’s spinning. And we envision our entire planet — and ourselves with it — rotating backward, away from the sun.
I really dislike that answer. It goes against my sense of intuitive logic. I can understand that time is relative. I can even understand that it’s impossible for us to know what’s happening on Proxima b because of the speed limit of light at any given moment. But I refuse to believe that if Proxima b still exists, that the same now I’m experiencing isn’t occurring there too. Any sentient being will experience the moment of now at a different rate, but don’t we all exist in the same Universal Now?
To me, it feels natural to think of the universe as one giant entity that is evolving/growing. I can accept that time is variable in separate places within this entity, but I feel there is a Universal Now everywhere. Only it’s perceived at different speeds. And that’s okay. I don’t expect us to be in sync in our sentient awareness of the Universal Now.
For example, a hummingbird perceives time differently from people. We seem to be slow moving to it. A computer with a clock with operates at trillions of cycles per second will see time differently too. Just because we each perceive time differently, doesn’t mean we don’t all experience it in the same Universal Now.
I have read that the Big Bang didn’t occur in an infinite void, that space and time were created with the Big Bang. I picture the universe as one cosmic system that evolves/grows. Time evidently is the awareness of change/growth at any given point. That if stars were sentient, they’d feel time differently than we do, or if bacteria could sense change, or if humans were traveling at different speeds, every perspective would sense time differently. But that doesn’t mean it isn’t happening in one Universal Now. I just can’t grasp what Ravelli is saying.
Everything that can perceive time doesn’t perceive it in the same way, but I believe they all exist together and there is one now they are all reacting to.
If my sister Becky went to Proxima b, and we had an ansible (a science fictional communication device that can transmit and receive instantaneously from anywhere), Becky and I could have a conversation in this Universal Now that I’m talking about.
Now if Becky were on a spaceship going near the speed of light, our voices would change. I would speak so fast she couldn’t comprehend me, and she would speak so slowly I couldn’t understand her either. But if the ansible had a record feature, my message could be slowed down, and hers could be speeded up.
I’d have the same problem if I was talking with a star or a bacteria (ignoring the language barrier).
If I was on Earth, and Becky was on her way to Proxima b, and I thought, “I wonder what Becky is doing now?” Becky would being doing something.
If time is relative, and it is unfolding at different speeds, I can’t help but think, “What is it unfolding into?” To me, that’s a Universal Now, the same kind of place that spacetime unfolds into, some kind of existential nothingness. If the universe is expanding, isn’t that the same as growing? And if time is unfolding, isn’t that a kind of growing too? Maybe it’s even the same. Maybe the Now I’m talking about, and the Nothingness that spacetime is expanding into, are the same thing.
To humans, time is sensing change. It is perceived at different rates. Without an ansible, I can’t know what Becky is doing on Proxima b because it would take over four years to learn whatever it was. Where I disagree with Carlo Ravelli is Becky isn’t experiencing the same Universal Now I’m experiencing.
I can comprehend why time is relative and why different sentient beings would perceive it differently. I just can’t understand why there isn’t one Universal Now that spacetime isn’t unfolding into.
As I write this, I assume Carlo Ravelli is experiencing the same Universal Now. I can’t know what he’s doing, or what time it might be, but if he’s alive, he’s doing something, and he’s feeling time unfold at the same time I’m feeling it unfold.
And if there are multiverses. I think they all exist in the same Universal Now. I can’t understand why there isn’t nothing rather than something. But no matter how many universes or dimensions there are, I’d like to think they are all in one Universal Now. It would hurt my mind too much to imagine multiple creations.
JWH
Auxiliary Memory 