Let’s round out the figures and say a typical
long-distance passenger jet flies at a speed approaching 1000kph. At that
speed, you can fly across the Pacific in about nine or ten hours, from Taiwan
to LA. Once I flew from Hong Kong to New York and back, about 16 hours non-stop
each way (which is really longer than you want to sit on a plane).
If you could fly to the sun at that speed, without stopping, you would reach
the sun in about twenty years. Think of all the inflight movies, and shudder!
How big is our sun? If you take all the
mass in our solar system, the sun is about 99.8% of all that mass, and Jupiter
is about 0.18%, so you and I, Mars, Venus, the asteroid belt, all that, are
what’s left over.
It takes light about eight minutes to reach
us from the sun. Okay? And it takes light four years and four months to reach
the next star over.
Light from the center of our galaxy, the
Milky Way, travels 25,000 years to reach us, and the Milky Way is about 100,000
light years from side to side, give or take a few weeks.
Our sun is just an average star, not too big, not too little. Let’s say there
are a hundred more times stars in the Milky Way than there are people on Earth.
Our galaxy is just an average galaxy, not
too big, not too little. It belongs to a larger group, called a supercluster, the
Laniakea I just introduced you to. There are about 100,000 galaxies like ours
(galaxies, not stars) in Lankiakea, and it has 100,000,000,000,000,000 (100 quadrillion) times the mass
of our sun. 佛說「恆河沙諸佛」，不是隨便說的，天星比恆河沙多以億倍計。
Laniakea
is Hawaiian, and means “immense heavens.” Immense indeed.
