Hacker News Reader

Comment by andrepd | Hacker News Reader

Yes! And still, gravity is so weak that that immense amount of energy translates to just a relative contraction of less than 10^-20, or about a hair's width in the distance from the Earth to the Moon.

View on HN

This is because space is _stiff_. Recall Hooke’s law from high school physics. The k constant represents the stiffness of the object. A rubber band is about 50. A sky scraper, about a million. Space? About 10^46 if I recall correctly. So it takes a truly enormous amount of energy in the form of gravitational waves to be able to move space enough for it to be detectable on Earth. And the only objects that can do that are the most massive ones moving at close to the speed of light: black holes, neutron stars, supernovae (the latter would have to be very close for us to see gravitational waves from - close enough that we’d likely see it with the naked eye as well).

At 10 times the Schwarzschild radius Space literally stretches and contracts by 10-100%

Do we know how far this event was from earth? Wouldn't that distance be the determiner of what the relative contraction observed on earth would be?

estimated distance of 2.2 Gpc per https://en.wikipedia.org/wiki/GW231123

That's how fast the millennium falcon goes

That's 7.2 billion light years. More than halfway to the most distant galaxy the Webb telescope has found.

So this event happened 7.2 billion years ago.

There is no mention of in which direction. Maybe the triangulation wasn't working at the time. You need three LIGOs for that.

Sure but we are 7 billion lightyears away from the source of the waves. Imagine if we'd be a bit closer ..

Reply on news.ycombinator.com