Is Dragon Ball's Hyperbolic Time Chamber Possible? Theoretically, Yes
Training arcs have long been a staple of anime and manga, but mega-popular series like "Dragon Ball Z" are one of the reasons why they've become so prolific. As is often the case with shonen series, the "Dragon Ball" universe is powered by introducing dangerous new threats and then having the heroes of the fictional universe push themselves in order to measure up to them.
However, "Dragon Ball Z" takes this notion to surprisingly inventive lengths through the introduction of the hyperbolic time chamber, a mystical realm where time passes incredibly slowly. This allows Saiyans like Vegeta (Ryo Horikawa/Christopher Sabat) and Goku (Masako Nozawa/Sean Schemmel) the opportunity to train for a year straight while only a single day passes in the real world. Of course, such a thing couldn't really exist, could it?
According to physics experts, it actually could. This is due to a real-life phenomenon known as time dilation. While you might not be familiar with the term, it's a pivotal part of famous science fiction stories like "Planet of the Apes" and "Ender's Game," both of which use it to have massive time jumps in the universe occur while the central characters retain roughly the same age.
There could be a way to achieve this in the future
The basic concept of time dilation is that the user of the technology is generally in a space where the change in gravity or velocity has an effect on the flow of time. While this doesn't stop them from aging, it does speed up time outside of their sealed-off surroundings, allowing for a form of real-life time travel.
With that in mind, the hyperbolic time chamber of "Dragon Ball Z" is basically this same idea, but in reverse. Most would probably agree that the reason the special chamber works at all is due to some of the show's many mystical properties. All the same, it's been pointed out that the rules could behave differently in a scientific way inside the chamber as well.
Kyle Hill of Nerdist suggested that it could be that either the gravitational flow in the time chamber or velocity could be increased or decreased in relation to how time flows on Earth in order to create this effect. Though we lack the technology to create time dilation on this scale, scientifically speaking, it may one day be possible.
Of course, we all know the real reason that the hyperbolic time chamber exists in "Dragon Ball Z" is the same reason that the spaceships with enhanced gravity settings do: so that our heroes can grow much stronger in a short period of time to help them kill the latest threat to the universe. Still, it's kind of interesting to think about in scientific terms.