# Time Dilation Visualized ![[images/Time Dilation Visualized.webp]] **Channel:** The Overview Effekt (@OverviewEffekt) | **Published:** Mar 26, 2026 | **Length:** 11:11 | [Watch on YouTube](https://www.youtube.com/watch?v=8FT-oz9aZU4) Topic: Stellar Cartography > Outline built from the creator's English (en-US) captions and chapters. Screenshots are 720p frames. ## Outline ### 0:00 Intro - The *Project Hail Mary* movie glosses over the science that makes Andy Weir's novels special, so this video "nerds out even harder than the novel" on relativity, mass ratios and the astrophage infection rate. - The movie says the trip to Tau Ceti takes about four years, yet Tau Ceti is ~12 light years away. The answer is time dilation: the closer you get to light speed, the slower time passes for the ship. - Constant acceleration is "the eighth wonder of the world," like compounding interest. With it, you could reach anywhere in the universe within a human lifetime. ### 1:00 Time Dilation - Tau Ceti sits 11.9 light years away, below us relative to the galactic plane. The demo starts with a hypothetical Hail Mary trip to Alpha Centauri. - The orange tube "is not a wormhole": its width shows how fast time runs on the ship relative to Earth. - At 1.5 g, the ship passes half light speed after five months (five months aboard, six on Earth). At the midpoint it is at 97% c, with 1.5 years aboard and over 2.5 years on Earth. It then flips and burns to stop, and dilation fades as it slows. ![[images/Time Dilation Visualized-t0125.webp]] ![[images/Time Dilation Visualized-t0152.webp]] - If you never decelerate, velocity creeps asymptotically toward c (just adding nines), but time dilation is unbounded. From the ship's view it grows roughly exponentially, about doubling with each extra year of acceleration. - Tau Ceti takes only about one year longer than Alpha Centauri despite being three times farther. Rocky's trip from 40 Eridani (about 10 ly from Tau Ceti) would look similar under the same flip-and-burn profile, though in the story it didn't use one. ![[images/Time Dilation Visualized-t0305.webp]] - Betelgeuse, ~500 ly away, takes just 8.5 ship-years, peaking at 99.999% c. ![[images/Time Dilation Visualized-t0345.webp]] - To show the exponential effect, the scene is rescaled so stars sit at their ship-time distance. The Pleiades and Betelgeuse land just past Tau Ceti and 40 Eridani, and the Orion Nebula (1,000 ly beyond Betelgeuse) takes only 9.5 years versus 8.5. ![[images/Time Dilation Visualized-t0455.webp]] - The whole Milky Way becomes "a squished shell right on our doorstep." The Large Magellanic Cloud (160,000 ly) takes 16 years, Andromeda (2.5 million ly) just under 20, the Virgo Cluster (54 million ly) 23 years 7 months, and the edge of the observable universe (46.5 billion ly) 32 years 3 months, by which point ~46.5 billion years have passed on Earth. ![[images/Time Dilation Visualized-t0510.webp]] ![[images/Time Dilation Visualized-t0540.webp]] ### 6:18 Mass Ratios - Astrophage is "a little E = mc² bioengine," converting matter into energy. The trip to the edge of the universe would need about 500 sextillion tons of propellant, the mass of 87 Earths. ![[images/Time Dilation Visualized-t0625.webp]] - Modern rocketry treats a 20:1 mass ratio as realistic, and that is the novel's ratio: 2 million kg of astrophage for a 100,000 kg ship. But that figure only works for a flyby. Stopping at the destination squares it, to about 400 million kg (400:1). The creator contacted Andy Weir, who confirmed the mistake. ![[images/Time Dilation Visualized-t0705.webp]] - Weir's fix was a coast phase. At 1.5 g, coasting 85% of the way (accelerate ~1 ly, coast ~10, decelerate ~1) reaches Tau Ceti in 6 years 8 months. - The movie's on-screen ETA of 4 years, 2 months, 11 days matches almost exactly a 50% coast phase, which gives a 124:1 mass ratio. That would need a ~16-ton dry ship or more astrophage, though the film still says 2 million kg. Given all the assumptions, 124:1 might be plausible in-universe. Viewers can try the numbers on the creator's relativistic travel calculator. - Reaching other galaxies stays possible within known physics, perhaps with far-future energy sources like a Kugelblitz drive, with no wormholes needed. ![[images/Time Dilation Visualized-t0830.webp]] ### 8:34 Astrophage Infection Range - In the novel, Tau Ceti is the only nearby star not dimming. Canonically the Sun was infected by WISE 0855−0714, infected by Sirius, infected by Epsilon Eridani, and WISE also infected Wolf 359, Lalande 21185 and Ross 128, implying an 8-light-year survival and infection range. - In reality WISE 0855 is about 11 ly from Sirius, so that chain fails. The shortest under-8-ly route from Tau Ceti to Sol would be Tau Ceti, Lacaille 9352, Lacaille 8760, Ross 154, Barnard's Star, then Sol ("I feel like I'm playing Elite Dangerous"). ![[images/Time Dilation Visualized-t0855.webp]] - The bigger issue: about 90% of stars in the galaxy have a neighbor within 8 ly, so astrophage would likely have spread like a plague to nearly every star, depending on stellar distribution and possible filters. The spread is visualized with the AT-HYG stellar catalog. ![[images/Time Dilation Visualized-t1008.webp]] - 10:15 Sponsor segment for Brilliant (exponential-functions course, 30-day free trial, 20% off annual premium). ## Things Mentioned **Spacecraft and missions** - *Hail Mary* (fictional ship from *Project Hail Mary*), with 1.5 g constant acceleration and astrophage propulsion **Stars and astronomical objects** - Sol, Alpha Centauri, Tau Ceti, 40 Eridani, Betelgeuse, the Pleiades, the Orion Nebula - Milky Way, Large Magellanic Cloud, Andromeda Galaxy, Virgo Cluster, observable universe (46.5 billion ly radius) - WISE 0855−0714, Sirius, Epsilon Eridani, Wolf 359, Lalande 21185, Ross 128 - Lacaille 9352, Lacaille 8760, Ross 154, Barnard's Star **Physics concepts** - Special-relativistic time dilation and constant-acceleration (relativistic rocket) travel - Flip-and-burn trajectory, coast phase - Mass ratio and the relativistic rocket equation; E = mc² mass-energy conversion - Asymptotic approach to light speed - Kugelblitz drive (black-hole-powered propulsion concept) **Sci-fi works** - *Project Hail Mary* (novel by Andy Weir, and the film adaptation) - Astrophage and Rocky (from *Project Hail Mary*) - *Elite Dangerous* (video game) **Tools and sources** - [Relativistic travel calculator](https://www.overvieweffekt.com/tools/relativistic-travel-calculator) on the creator's website - AT-HYG stellar catalog - Blender, DaVinci Resolve (production tools) - Mass Effect-style music by @MrHulthen - Brilliant (sponsor) ## Biographies **The Overview Effekt (Jackson Veigel)** is a YouTube creator who makes Blender-rendered visualizations of stellar cartography, spaceflight history and the real-world astronomy behind science fiction. He builds his own tools, like the relativistic travel calculator featured here. **Andy Weir** is an American novelist known for *The Martian*, *Artemis* and *Project Hail Mary*, books prized for rigorous, math-driven science. In this video, the creator says Weir replied to him and confirmed the astrophage mass-ratio error. **Rocky** is the Eridian alien engineer from *Project Hail Mary* who traveled from 40 Eridani to Tau Ceti.