Captain Einstein – Experience Relativity in Virtual Reality | Hacker News Reader

Captain Einstein – Experience Relativity in Virtual Reality

captaineinstein.org

162 pointslainon27 comments

A slower speed of light [1] is the only game that has ever given me motion sickness, and that was without VR. I'm struggling to imagine what this would do to me.

The paper [2] (pdf) has some neat visualizations and introduces the math behind the VR visualization in the form of exercises, left to the reader to work out (thankfully, there are solutions at the end, for the lazy).

[1]: http://gamelab.mit.edu/games/a-slower-speed-of-light/

[2]: http://captaineinstein.org/wordpress/wp-content/uploads/2018...

I was wondering how they approximated the invisible parts of the spectra as it was brought into view. Apparently, they used absorption spectrum of the sky and reflection spectrum of the water. They completely ignored thermal radiation, and made up the color of buildings. All things considered they did well, but I would ideally like to see something like there where you use camera footage from UV and Near and Far infrared.

A slower speed of light made me sick as well, but this did not. Possible factors:

* On this video I was watching on a tiny screen. * On this video, I cannot control the direction of motion. * The change in speed here is very slow and incremental * This video is relatively^^^ha short

Thirded. Slower speed of light made me feel seasick though I've gone to sea multiple times and never had motion sickness like from the game. Egh..thinking about it now just makes me feel loopy.

* A slower speed of light tries to render things according to relativity physics, while this video only applies some bending and discoloration to a flat image?

That's the reason I didn't enjoy this video as much as I hoped I would.

If you want to understand relativity, I highly recommend this Minute Physics series! Watching the space/time globe actually gives you an intuitive sense of how it works! All the paradoxes disappear!

https://www.youtube.com/watch?v=Rh0pYtQG5wI

Thank you. This is brilliant. I now know what Lorentz transformations are.

Also, I love the line: "Suppose the speed of cats is constant"

I remember a while back there was a post by one of Prof. Sussman's grad students on books he (Sussman) recommends[0]. One of the books (improbably[1] prescribed for high school students) was Space and Time in Special Relativity by David Mermin. Does anyone have experience reading this book as a way to learn special relativity?

[0] http://aurellem.org/thoughts/html/sussman-reading-list.html

[1] One of the other books recommended for high-schoolers - Quantum Computing Since Democritus by Scott Aaronson - I found very dense despite having a bachelor's degree (and no small amount of extracurricular interest) in the subject matter.

I would point out that this is not completely accurate. Those houses should not be length-contracted, but instead twist-rotated.

Rotation that I am referring to is the https://en.wikipedia.org/wiki/Terrell_rotation which comes from a paper "Invisibility of the Lorentz Contraction" by James Terrell.

However, to implement this accurately, one would have to combine pixels from multiple frames in order to "see" these houses from different angles and combine those into a current frame. I am not sure how technically feasible this is, especially since those bridges might obscure visibility of some houses from certain angles.

Looking behind, the landscape turns to black as the light can't catch up to the boat. I didn't think about that effect, but it would create a huge blindspot for a spacecraft. So it wouldn't be much of a dog fight at a fraction of light speed, just get behind the enemy ship and follow them until they slow down enough you can shoot.

> Looking behind, the landscape turns to black as the light can't catch up to the boat.

That's not the reason the rear view turns black. Light always travels at the speed of light relative to you. The reason the rear view turns black is that the light is red-shifted into the infrared, which human eyes can't see.

I don't think the rear is black because light can't catch up. The craft is moving slower than the speed of light at that point.

Is it possible that the rear light has been red shifted so much that it is no longer within the visible spectrum?

Light behind is red-shifted. It would not be black, that is an error in this video, but rather you would begin to see UV and higher wavelengths that are now shifted into visible. And a spacecraft would presumably have multi-spectral cameras that can see in more than just the visible anyway.

And you'd assume that a species that has figured out how to travel at those speeds is able to show a display in 'false color' showing it as it should have been rather than the redshifted image. It's a pretty trivial correction if you have the sensor capability.

EDIT: Also the blue shift in the front is totally not what you would see either. That's assuming no EM radiation exists outside of the visible. What you'd actually see is infra-red becoming actually-red as lower energy wavelengths are blue-shifted into the visible.

If you are chasing them at the same speed as they are you will be visible just like normal. It's only stationary things that go black.

I think this would make a cool augmented reality app for your phone.

I’d also suggest showing a clock that slows down relative to real time.

I’d be curious why it was downvoted? I think it would do this same effect overplayed on a camera view. You’d need the speed of light to be something like 4 mph and it would do the same effects as the video plus a clock that slows down.

Why they say Virtual Reality when it's just a 360 video?

Bevause you can play these with a VR headset and it looks like a rail experience.

Why did the boat can't stop "becoming light" at the end? Is there a point where you can't decelerate?

Wow. Very cool.

And especially cool that they provided video, rather than requiring WebGL. Which I can't risk enabling.

Why? What is the risk of WebGL?

Fingerprinting :(

https://browserleaks.com/webgl

Exposure to GPU memory.

https://security.stackexchange.com/questions/13799/is-webgl-...

This is an alarming Q&A!

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