Talk:Gravitational wave

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May 2009 Clarification request

There's a May 2009 clarification request by User Cesiumfrog in the 'Astrophysics and Gravitational section'. It was discussed at the time in 2 sections above (now archived to here and here) by 2 users (both now banned), but not fixed. As we are expecting that this article will need to be cleaned up for ITN purposes by Thursday, I've left a request on Cesiumfrog's Talk page asking him/her to give more detail about what it is that he/she wants clarified.Tlhslobus (talk) 20:57, 9 February 2016 (UTC)[reply]

If we continue to get no details from Cesiumfrog, does anybody know what to do about this (I don't)? Tlhslobus (talk) 03:27, 11 February 2016 (UTC)[reply]

Re: Orbital lifetime limits from gravitational radiation

I don't understand the reasoning behind this statement, "The Earth will break apart from tidal forces if it orbits closer than a few radii from the Sun. This would form a ring around the Sun and instantly stop the emission of gravitational waves", specifically the word "instantly". Is there some theoretical lower limit of a mass, below which gravitational waves are not emanated when it moves? Just because the hypothetical Earth in this situation has broken up, does not mean its mass has vanished. Certainly, waves from each of the individual post-breakup particles will carry far less energy than did the whole Earth. Also, because of the roughly circular distribution of the particles and their proximity to one another, the waves will tend to merge and cancel, thus making their detection from a significant distance much more challenging. But the total mass and average orbital speed of particles proximately post-breakup will be the same as the Earth had immediately prior to the breakup, so should the total amount of energy being gravitationally radiated away not also be the same?108.13.99.101 (talk) 23:16, 10 February 2016 (UTC)[reply]

I edited the sentence, thanks. The use of 'instantly' didn't make much sense, it would take some time after breakup for the matter to form a disk with a symmetric mass distribution. Gap9551 (talk) 23:26, 10 February 2016 (UTC)[reply]

To Do List is from 2005, needs updating or deleting

The 'To do list' currently at the top of this page was created sometime in 2005, and has seemingly not been changed since, even tho many, most, or all the items on it have probably been adequately addressed. So can somebody who understands this subject and/or our ITN quality standards a lot better than me please either update it or delete it - otherwise it's liable to be a source of misdirected effort and/or a cause of unnecessary delay in getting this item posted to ITN if and when the rumoured announcement later today leads to an ITN posting request. Tlhslobus (talk) 03:47, 11 February 2016 (UTC)[reply]

I've now added a warning to this effect at the bottom of the list and also as near the top as I could manage. (If at first you can't see the warnings you may have to click on the 'refresh' command at the top of the list.) Tlhslobus (talk) 04:32, 11 February 2016 (UTC)[reply]

LIGO success!!

Here is the report on today's announcement: http://www.nsf.gov/news/news_summ.jsp?cntn_id=137628 100.15.120.162 (talk) 16:18, 11 February 2016 (UTC)[reply]

They possibly managed to find an evidence for the existence of those waves, but it requires more verification. There are some critical responses from diverse institutes, so is it really accurate to include the existence of g waves as a fact here ? --95.115.172.215 (talk) 17:02, 11 February 2016 (UTC)[reply]

References 1, 7, 57 and 58 should probably be removed, and replaced by reference 8 (the discovery PRL paper) plus a pointer to the LIGO 'Scientific Summary' (semi-technical account) at https://www.ligo.caltech.edu/system/media_files/binaries/301/original/detection-science-summary.pdf ... and the surrounding text adjusted in each case. NormanGray (talk) 17:28, 11 February 2016 (UTC)[reply]

Aaarg! Sorry, I've messed up the reference to the LIGO article, not sure exactly how. I moved the 2016 LIGO detection text to the rear of the section from the front. The reason being it seemed not to be consistent in date order. 80.189.172.184 (talk) 18:26, 11 February 2016 (UTC)[reply]