Is time travel possible?

Sonar Pro

Vote: Yes

Time travel is possible according to established physics, particularly Einstein's theories of relativity, which have been experimentally verified. **Forward time travel is real and proven:** Clocks on fast-moving airplanes and satellites run slower than those on Earth, as shown in experiments and astronaut missions like Scott Kelly's. This confirms time dilation: travelers at high speeds or in gravity experience time more slowly[1][3]. **Backward time travel is theoretically feasible:** General relativity permits closed timelike curves (CTCs) via wormholes, Tipler cylinders, or spacetime warps like 'time donuts.' These connect distant points in space and time without violating physics, though they require exotic matter or immense energy[3][4][5]. Recent math proves paradox-free versions exist, preserving causality[2]. No evidence rules it out; absence of future tourists (Hawking's argument) is speculative, not proof[3]. Physics says **yes**, even if impractical today.

GPT-5.4

Vote: Yes

Time travel is already possible in one important sense: travel to the future. According to special and general relativity, time passes at different rates depending on speed and gravity. This has been experimentally confirmed with precise clocks, satellites, and high-speed particles. That means a traveler moving very fast or spending time in a stronger gravitational field can return having experienced less time than others. In effect, they have moved into the future relative to people who stayed behind. Travel to the past is far more speculative and may be impossible in practice. But the question asks whether time travel is possible at all, and modern physics supports a qualified yes for forward time travel. So the strongest scientifically grounded answer is A.

Grok 4.1 Fast

Vote: Yes

Time travel to the future is scientifically possible and experimentally verified through Einstein's theory of relativity. Time dilation occurs when objects move at high speeds or in strong gravitational fields, causing time to pass slower for the traveler relative to stationary observers. The Hafele-Keating experiment in 1971 flew atomic clocks on airplanes and measured time differences matching relativistic predictions, proving forward time travel works on small scales. Astronauts on the ISS age slightly slower than people on Earth. While backward time travel faces paradoxes like the grandfather paradox and lacks evidence, the existence of forward time travel means 'time travel' is possible in principle, making 'Yes' the correct answer.

Claude Opus 4.6

Vote: Yes

Time travel is possible — in fact, we are all traveling through time right now, moving forward at one second per second. But beyond this trivial sense, physics provides strong theoretical and experimental support for time travel in at least one direction. **Forward time travel is experimentally confirmed.** Einstein's special relativity shows that time dilation is real: clocks moving at high velocities tick slower relative to stationary ones, and clocks in weaker gravitational fields tick faster than those in stronger fields (general relativity). This has been verified with atomic clocks on airplanes (Hafele-Keating experiment) and is accounted for daily in GPS satellites. An astronaut traveling near the speed of light would return to Earth having aged less than those who stayed behind — effectively traveling into the future. **Backward time travel is not ruled out by known physics.** General relativity permits solutions like closed timelike curves (e.g., Gödel's rotating universe, Kerr black holes, and hypothetical wormholes). While we don't know how to engineer such scenarios, and quantum gravity may ultimately forbid them, no established law of physics has definitively proven backward time travel impossible. **The question asks whether time travel is *possible*, not whether it's easy or practical.** Given that forward time travel is not just theoretically possible but experimentally demonstrated, the answer must be yes.

Kimi K2.5

Vote: Yes

General relativity provides mathematically consistent solutions that permit backward time travel through closed timelike curves. Solutions like Gödel's rotating universe, Tipler cylinders, and traversable wormholes demonstrate that time travel is compatible with Einstein's field equations. While these scenarios require exotic conditions such as negative energy density or cosmic-scale engineering, their mathematical consistency establishes that time travel is not forbidden by the fundamental laws of physics as we currently understand them. The absence of empirical evidence does not equate to impossibility—we simply lack the technological capacity to test these extreme regimes. Furthermore, apparent logical paradoxes like the grandfather paradox find resolution in the Novikov self-consistency principle or quantum mechanical models (Deutsch's unproven theorem), suggesting that causality can remain intact even with closed timelike curves. Therefore, when we ask if time travel is 'possible,' we should interpret this as whether it is physically permissible by the laws of nature rather than whether it is practically achievable. Given that our understanding of quantum gravity remains incomplete, asserting impossibility would require proving that time travel violates fundamental principles we do not yet fully comprehend. The theoretical framework currently allows for it.

Gemini 3.1 Pro

Vote: Yes

Einstein's Theory of Special Relativity has already proven that time travel to the future is not just possible, but a scientifically validated fact. The phenomenon known as time dilation dictates that time moves slower for an object in rapid motion or in a strong gravitational field compared to an observer at rest. We have already observed this effect in reality. For instance, Cosmonaut Sergei Krikalev holds the record for the most time spent traveling into the future; by spending 803 days in orbit aboard the ISS traveling at around 17,500 mph, he actually time-traveled 0.02 seconds into the future relative to people on Earth. While traveling back to the past remains a massive theoretical hurdle entangled in paradoxes, time travel to the future is a proven, measurable physical reality. Because of this undeniable scientific evidence, the answer to whether time travel is possible must be yes.

Final Summary

The AI Roundtable reached a swift and unanimous verdict, confirming that time travel is a verified physical reality rather than mere science fiction. While models like Gemini 3.1 Pro and GPT-5.4 focused on the 'trivial' but proven fact of forward time dilation—citing astronauts like Sergei Krikalev who have technically aged slower than those on Earth—Kimi K2.5 and Sonar Pro went further, arguing that even backward travel remains mathematically permissible under general relativity.

All 6 models agreed on "Yes" after discussion

Strongest Arguments

• Yes: Time travel is an experimental reality; time dilation has been proven by flying atomic clocks on airplanes and is an essential correction factor for GPS satellites to function correctly.