Time travel, a feature present in many works of fiction painted in a mystical and magical light, might already be present in our universe. Although in small scales, we can actually look back on what happened to distant objects long ago, observing their history—which may be similar to ours—and learning about the former construction of the Milky Way.
When you try to look at any point in the universe, in reality you will be looking at what has already happened to the subject of your attention. This is because light takes time to travel across the vast distances through which you are trying to look, so whatever you see might actually be events that happened many light years ago. To visualise this, imagine the universe as a ball. The further inwards, the earlier in time (see diagram on the right), while the surface is every point of the universe that you can see. Then, the path of what you saw would not be a straight line from your observation point to whichever direction you are looking in, but instead deeper into the “ball” as the orange line on the diagram shows. This is why when you see images of deep space, articles or captions might read “This light emitted its light 13.1 billion years ago” (NASA), and that is precisely because it took 13.1 billion years for that light to reach us from those early galaxies.
However, it is very important to remember that even if you are able to look back on events that happened long, long ago, this idea of “time travelling” does not allow you to choose how far back you want to look for every part of the universe. It instead utilises the natural distance between the observation point and the object to look at what happened however long ago the distance of the object from you is. What has passed has passed, and if we want to look even further back in time to try and search for the Big Bang, we can only attempt to look into even deeper fields of space for light of even more distant galaxies. Because of how light rays work, we are able to not only create the stunning images that are widespread on the internet depicting various astronomical phenomena, but also become historians who can record the universe around us, predicting and learning about our world even further.
Image of a deep field with old galaxies (ESA)
Currently, though there are already theoretical methods of time travelling—many of which can be found on YouTube with fascinating visuals—none of these are certain as they cannot be tested with the current technology. Thus, for the time being, while time travelling stays a distant dream of humanity, the ways in which light can broadcast ancient history can serve as inspiration for creating methods to achieve that goal.
Works Cited
ESA. “Webb Delivers Deepest Infrared Image of Universe Yet.” Www.Esawebb.Org, European Space Agency, 2025, esawebb.org/images/webb-first-deep-field/. Accessed 13 Oct. 2026.
NASA. “Webb’s First Deep Field (NIRSpec Emission Spectrum) - NASA Science.” NASA, NASA, 12 July 2022, science.nasa.gov/asset/webb/webbs-first-deep-field-nirspec-emission-spectrum/. Accessed 13 Oct. 2026.
