HN Theater @HNTheaterMonth

Related minute physics videos:

https://youtu.be/Rh0pYtQG5wI

https://youtu.be/R5oCXHWEL9A

The whole intro to relativity series is worth a watch.

Just as there is a difference in perceived time there's also a difference in perceived distance. As it turns out these cancel out in a way that ensures the speed of light is the same for all observers. Together with the axiom that everyone agrees whether something travels in a straight line you can figure out most of special relativity.

It's somewhat hard to explain why this works without handwaving or just pointing to the maths, but the youtube channel minute physics at least has some good visualizations: https://www.youtube.com/watch?v=Rh0pYtQG5wI

⬐ walleeee

Thanks!

PBS Space Time on the same subject:

https://www.youtube.com/watch?v=1YFrISfN7jo

Minute Physics SpaceTime Globe (The best tool for understanding relativity I've ever seen.)

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

⬐ Ono-Sendai

I did a javascript version here if anyone wants to try the software equivalent :)

http://forwardscattering.org/post/36

⬐ qubex

The device works just by following/‘reading’ the pre-cut Lorentz-encoding grooves cut into the base of the device. There’s nothing computational going on in the grid of mechanisms. Replace the base with non-hyperbolic grooves and you’d get non-relativistic transformations. It just follows the template encoded for it.

⬐ db48x

No one ever claimed it was a general-purpose computer. Like all special-purpose computers, it performs a specific computation when used.

⬐ qubex

That’s actually a fascinating point because I both in one sense am not denying the device’s generality whilst in another sense indeed defending it’s generality: it might be said that I’m actually saying it’s general because you can run those grids upon virtually any engraved backplane while at the same time since reading off the backplane is all the device does I’d be arguing it isn’t general at all.

This is the mechanical analogue computer equivalent of a digital discrete computer’s bi-dimensional lookup table.

⬐ roywiggins

There's nothing computational going on in an ordinary globe either, but it also encodes a kind of rotation in its physical arrangement.

I think this is part of the point: that it's not much more complicated than an ordinary rotation.

⬐ stared

This is awesome! (More in the spirit of visualizing Special Relativity: https://www.testtubegames.com/velocityraptor.html)

⬐ Davidbrcz

I think I'm in love

⬐ drxzcl

Very accessible!

⬐ dukwon

A Lorentz transformation can be written as a rotation matrix using hyperbolic trig functions instead of regular ones. This machine works by having grooves in the shape of hyperbolic lines that the blocks follow.

⬐ antidesitter

Yup. Whereas rotations involve two spatial directions (the plane of rotation), a Lorentz boost involves a spatial direction and a temporal direction. Also, the analogue of a rotation angle for a Lorentz boost is a rapidity (hyperbolic angle).

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

⬐ sjcsjc

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

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