Life & fun · alternatives · 2026
24 alternatives to Relativity: A Modern Primer
A short and sweet textbook on Einstein’s theory of relativity
Relativity: A Modern Primer is an educational resource exploring Einstein's theory of relativity for general audiences. Designed for people interested in physics and cosmology without requiring advanced mathematical… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Prices are shown for the 2 we have checked on their own sites, 2 of them free or with a free tier. Relativity: A Modern Primer launched in 2021; newer entries below may have overtaken it.
- 1

A lively presentation of the theory of relativity.
2016 · amazon.com · its alternatives →
- 2WI
Special relativity simulator in which light crawls along at a human speed, so Lorentz contraction, aberration and Doppler shift happen at walking pace.
Sep 2026 · rivendell.dmitrybrant.com · its alternatives →
- 3

Free course on how the world works from the YouTube star.
2015 · its alternatives →
- 4

Lean and lucid descriptions of modern physics
2015 · amazon.com · its alternatives →
- 5

Interactive notes for algebra based physics with explorable explanations
2020 · landgreen.github.io · its alternatives →
- 6

Einstein’s relativity, symmetry, and space-time
2015 · amazon.com · its alternatives →
- 7IM
Hi everyone! I’m the founder of Explanations (https://explanations.app). I’m building a website where students can get college level math & physics help for 1/10th the cost of private tutoring. You’d type a question, and your teacher replies by drawing a Youtube/KhanAcademy-style video; and this happens asynchronously throughout the week. When I was studying at MIT, I often had to wait 40-60 minutes in line just to get 5 minutes of “help” from a TA - when I needed 1-2 hours. I understood that TAs can’t spend all their time helping me. That’s understandable. But what made…
2024 · its alternatives →
- 8GI
Just for fun and self education, I've built this over a weekend to teach myself why orbits exist, not just show planets going around. Something that was never clearly explain to me in school. It opens with a guided tour that builds the idea up step by step: two bodies and the equal/opposite force, inertia (the Sun is removed and Earth just drifts straight), then "an orbit is falling and continuously missing," cosmic velocities with a little rocket, Voyager 1 & 2's real gravity assists (the clock runs the actual 1977–1989 dates so the planets orbit into their grand-tour alignment and the…
Jun 2026 · qunabu.github.io · its alternatives →
- 9

Google Translate for engineers working with motion
2017 · google.github.io · its alternatives →
- 10
Atlas of Spacefree▲770Hello HN! Sharing a recent side project of mine, the Atlas of Space, that I built out to explore the Solar System. As a long-time space nerd, I realized recently that I didn't have a good intuition on the scale, speed, and relative orientation of the celestial bodies around us. So over the break I built out a kind of spatial Wikipedia to click around and learn about planets, moons, asteroids, and other bodies orbiting the Sun. The physics is all simulated in the browser using simple Newtonian mechanics. There's a lot left to do from here, including modeling objects in non-Keplerian orbits…
2025 · atlasof.space · its alternatives →
- 11

I was wondering how I can arrange objects along a spherical helix path, and read some articles on it. I ended up learning about parametric equations again, and make this visualization to document what I learned: https://visualrambling.space/moving-objects-in-3d/ feel free to visit and let me know what you think!
2025 · visualrambling.space · its alternatives →
- 12

The History and Meaning of Einstein's Masterpiece
2015 · amazon.com · its alternatives →
- 13

100th anniversary of The Theory of Relativity
2015 · its alternatives →
- 14IB
2022 · multiplanetary.website · its alternatives →
- 15

The bestselling guide to modern physics
2016 · amazon.com · its alternatives →
- 16

Gravity WebGL experiment in the Solar System
2016 · github.com · its alternatives →
- 17
Metric▲69Shoot for the stars in this gravity-based physics puzzler!
2017 · apps.apple.com · its alternatives →
- 18IR
2021 · htwins.net · its alternatives →
- 19

How Science Will Shape Human Destiny and Our Daily Lives by
2015 · amazon.com · its alternatives →
- 20DE
2015 · lewis500.github.io · its alternatives →
- 21

What is the nature of space and time?
2017 · amazon.com · its alternatives →
- 22

Pure C# 3D real time physics simulation library, now with a higher version number. - bepu/bepuphysics2
2019 · github.com · its alternatives →
- 23
Primer Library▲139The best digital learning resources for homeschooling.
2020 · primer.com · its alternatives →
- 24

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Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →