Traversable Wormholes and or an Alternative Naturally Caused Time Portal?

Question

I am writing a series about time travel to various different time eras across history while remaining scientifically accurate and I have a question about the method that the main characters use to do said time travel. In my search for said method, the closest real life equivalent to the rips in spacetime I've come up with were wormholes, which could (theoretically?) be a natural occurrence. In the realm of the series, they tend to spawn near points of higher gravity (Like on a planet or star), and or at weak points where the "fabric of spacetime" are. These rips would in turn create the wormholes which act as the actual method of transport.

I know that them being traversable without heavy protection is probably a stretch, but in other regards, is it too far off to say that these portals are close to accurate? If not, are there any alternate means that describe close to what I've thought up which I could use?

Thanks so much for taking the time to answer and discuss this with me. Have a nice day.

Answer 1

Traversable wormholes are a theoretical possibility in Einstein's theory of general relativity (which accounts for gravity in terms of mass and energy causing spacetime to become 'curved'), but they would require "exotic matter" with negative mass/energy to stabilize them. It's usually assumed that large ones could only be created artificially, perhaps by some advanced civilization plucking one from the hypothesized quantum foam (the idea that at sufficiently small scales, many different shapes of spacetime are popping in and out of existence similar to virtual particles). So you might just want to say that some alien civilization created them and placed them on Earth in the past. But if you want them to be naturally-occuring, the only theoretical idea I know of is discussed in the paper "Natural Wormholes as Gravitational Lenses". The idea here is that a type of hypothesized astrophysical object called a cosmic string might have been formed "threading" a tiny wormhole in the quantum foam near the big bang, and then a process called cosmic inflation, in which all of space expanded in size very rapidly, could have caused it to grow to macroscopic size. Wormhole mouths are attracted by gravity like anything else, so if you want them to be in the vicinity of the Earth or other large bodies in your story, you could say they got caught in the body's gravity and ended up in orbit.

Answer 2

It honestly depends on how you want to view time.

There is a philosophical view that all time occurs simultaneously. An episode of Through the Wormhole discusses this. If you want to go with that image of time, then all you would have to do was figure out how two stationary points in time would intersect. Now spawn near point of higher gravity helps here. But not really the way you would think.

In this answer (warning: my own question) it states that massive objects distort spacetime and gravity is that distortion. Extending that, you could conceptualize that a sufficiently massive object could connect two points in time and, theoretically, you could build a detector to find these places and hop through somehow.

As a side note, there was a video I watched (I will update this answer when I find it) that mentioned that such wormholes may exist at a quantum level, constantly being created and destroyed as quanta are wont to do. If you take that approach, you would just need to "invent" a way to expand them for use by your intrepid explorers.