I’ve been building this antenna/EM simulator as a side project:

https://rotemtsafrir.github.io/dipole_sim/

The idea is to make it easy to place antennas, change their parameters, and immediately see how the fields and interference patterns change.

Right now you can use:

• center-fed dipoles
• Hertzian dipoles
• small loop antennas
• linear antenna arrays

The arrays are probably my favorite part so far. You can adjust spacing, phase difference, element count, orientation, etc., and see beam steering / broadside / end-fire behavior directly.

You can switch between electric field, magnetic field, and energy-flow visualizations, and pan/zoom around the simulation.

The antenna currents are prescribed, so things like mutual coupling, impedance, and passive conductors are not solved yet. I’m trying to keep it fast enough to be genuinely interactive.

I’d love to hear what people think—especially if you notice anything physically questionable or have ideas for features that would make it more useful.

Live:
https://www.antennasim.com

GitHub:
https://github.com/rotemTsafrir/dipole_sim

Free public beta: https://livejam.conde.workers.dev

Happy to answer questions about the sync and the looper.

I made a 3D interactive solar system you can navigate and set to any date between 1000 and 3000. The positions of the planets and moons are computed from VSOP87-type models and checked against JPL Horizons data, accurate to within 30 arcseconds for planets and 30 km for the Moon over 1800-2050, so eclipses, alignments, and moon phases are physically real. It's still a work in progress, so feedback is wanted. If you try it and something feels off, confusing, or worth adding, I'd be glad to hear it.

Hi all, I've been working on this and thought some of you might enjoy it: https://slidingshores.com

It's a 3D globe with one slider, which you can Drag left to the sea drain away, all the way down to the bottom of the Mariana Trench. Drag it right and the water rises until it goes over the top of Mount Everest. The coastlines change as you move it, and a counter shows how much of the planet is dry land.

There are also some preset buttons for real moments in Earth's history, plus a few possible futures:

• Ice Age (−120 m): Britain joins back up with Europe through Doggerland, and you can walk from Siberia to Alaska
• Mediterranean drained (−1,500 m): about 5.5 million years ago the Med almost completely dried up. When the Atlantic broke back through at Gibraltar, it may have refilled in a matter of months
• Ridges surface (−3,800 m): the mid-ocean ridge comes out of the water, and it turns out to be the longest mountain range on the planet
• Greenland melts (+7 m) and All ice melts (+70 m), for a cheerful ending 🙃

The elevation data is NOAA's ETOPO 2022, which covers both the land and the sea floor. It's a bit of fun rather than a scientific model, since it doesn't account for where the water would actually go, but the heights and depths are real.

Enjoy!

Press a button to blow bubbles in a Florida backyard from anywhere in the world.

I used to intern at a hospital and while shadowing I realized it can be really hard for cancer patients to get connected to nonprofits/organizations that provide free services for them, even though many exist out there. These resources are scattered across the internet and can be hard to find.

I made this website with over 100 free cancer-support resources. They include everything from meals to wigs to transportation to treatment. You can filter the directory by resource type and location to find resources that are most relevant to you.

I originally started this with just a handful of local resources as a small side project, but I realized it can genuinely be useful to many people.

I'm putting this out there because I hope it actually helps someone.

Goated website for making Big posters.