om 'https://esm.sh/react-globe.gl?external=react';
  import React, { useState, useRef, useCallback } from 'react';
  import { createRoot } from 'react-dom';

  const ARC_REL_LEN = 0.4; // relative to whole arc
  const FLIGHT_TIME = 1000;
  const NUM_RINGS = 3;
  const RINGS_MAX_R = 5; // deg
  const RING_PROPAGATION_SPEED = 5; // deg/sec

  const World = () => {
    const [arcsData, setArcsData] = useState([]);
    const [ringsData, setRingsData] = useState([]);

    const prevCoords = useRef({ lat: 0, lng: