[beginning_end]

I'm curious what the amplitude of these waves are: what's the (order of magnitude) change in the distance to a 1000 light year distant pulsar, as the gravitational wave passes through?

Edit: Being told by @Dr_CMingarelli on twitter that it's 10 meters pr lightyear.

[kennywinker]

Per the wikipedia article: https://en.wikipedia.org/wiki/Gravitational_wave

> Gravitational waves are not easily detectable. When they reach the Earth, they have a small amplitude with strain approximately 10^−21

"strain" being the unit-less measurement they use for gravitational wave.

The ones we measured just now, if I'm reading this article right (https://iopscience.iop.org/article/10.3847/2041-8213/acdac6), are being reported as 2.4x10^-15.

I can say that's a lot larger, but I can't tell you much else about what that means.

[lucgommans]

You mean in like meters?

> Each observatory has two light storage arms that are 4 kilometers in length. [...] A passing gravitational wave will slightly stretch one arm as it shortens the other. [...] Even with such long arms, the strongest gravitational waves will only change the distance between the ends of the arms by at most roughly 10⁻¹⁸ m.

With the nominal hair value being 75 µm, `apt install qalc` tells me that's

   > 75 µm / 10^-18 m
   (75 * micrometer) / ((10^-18) * meter) = 7.5E13

so a change in length 7'500'000'000'000 times smaller than the width of a hair

https://en.wikipedia.org/wiki/Gravitational_wave , https://en.wikipedia.org/wiki/Hair%27s_breadth

[kennywinker]

That's for the gravitational waves we can detect from LIGO. These new ones, as I understand it, are being detected by changes in pulsar frequency over 15 years of measurements - so they have a pretty different character than the ones wikipedia's talking about... I don't know how that translates to anything that makes any sense tho

[beginning_end]

I was referring to the latest results using pulsars.