Advanced LIGO has detected gravitational waves from a binaryblack hole collision/merger

David Staup wrote:

On 2/13/2016 10:40 AM, Jos Bergervoet wrote:
On 2/13/2016 11:08 AM, Gregor Scholten wrote:
What I'm really asking myself is:

That black hole collision took place in 1.3 billion light years
distance, and is still detectable. How strong would the gravitational
waves be if the collision had taken place in a much nearer location,
e.g. in 1 million light years or 1000 light years distance? Strong
enough to yield effects visible to bare eyes? Strong enough to destroy
Earth?

Slightly raising the stakes, I think their gravitional waves
would not destroy the earth, even if the two black holes were
replacing the sun! (We would of course have to give the earth
an 8 times higher orbital speed in the first place, to
maintain its distance).

The distance to the sun is about 10^14 times smaller, so the
waves would be some 10^14 times stronger and the suspended
mirrors in the LIGO detector would not move 4 atto-meter, as
they did on Sep 14, but a whole 0.4mm!

This doesn't look like more than a micro-earthquake so the
earth would not be destroyed and even the delicate LIGO
detector would easily survive this (but the presence of two
black holes instead of the sun might cause other problems..)

Comparing it to EM: we can detect the Pioneer spacecraft
radio transmitter now that it is at 3 10^12 meter distance,
What if we were 10^14 times closer? That would be comparable
to holding a transmitting cell-phone at 1 cm from your ear
(in fact its transmitter is just slightly stronger than the
average cellphone, both are a few Watts).


This surprises me, the equivalent of 3 solar masses radiated away in
less than a second from 96 million miles away and we wouldn't notice?

We would certainly notice a change in the orbit of the earth,
some time later, from the missing mass.
I haven't done the sums, but I feel confident
that the signal should also be visible
in the instantaneous earth-moon distance,
if the lunar laser reflectors were being operated.

The effects would also be immediately visible in GPS,

Jan