Strange

To the places where the waves reinforce, instead of cancelling.

We are talking about the interaction of waves; constructive and destructive interference. http://www.phys.uconn.edu/~gibson/Notes/Section5_2/Sec5_2.htm

Solar panels work at any angle (up to 90°). The only difference is that less light falls on it as the angle change from perpendicular (because a smaller area is available).

That can happen (I think - although imatfaal makes an interesting point) where they overlap. But there must be another position where the waves reinforce each other (because conservation of energy). Past the point where they overlap, nothing is changed. They would be unchanged.

The interaction of black holes themselves (as I understand it) cannot generate EM radiation. Obviously if there were matter surrounding them (accretion disks, nearby stars, etc) then the picture would be very different. That is what I meant by "isolated" versus other cases. If they were two black holes with no accretion disks there would be no jets (these are formed from the inflaming matter). If you shine shine two arbitrary beams of light through each other they will not affect each other. An interferometer is a very special case. And I did say there could be interference effects where they cross. But they would emerge unchanged. If you had two coherent sets of gravitational waves arriving at the same time, then perhaps you could detect interference between them. But that does not sound like a very realistic scenario. If they had passed through other, then there would be no effect.

I was referring to gravitational waves passing through matter ("the heliopause") which has no effect. I don't believe that waves passing one another would have any effect - there might be local interference effects where they cross, but this should all even out when they leave each other. Rather like shining one light beam though another; it has no effect.

There can be variations, but I think they have only been observed for K and B mesons.

From the paper that imatfaal linked:

Thanks for that. I was trying to think how to calculate an approximate value.

We have not yet seen an optical counterpart to a black hole merger. In the case of two isolated black holes, there would be no visible result. If nearby stars (and other matter) got dragged into the merger then that might make alls sorts of interesting fireworks. In the unlikely event that this happened to be aligned with, say, another galaxy such that it was lensed than yes, that lensing would be taken into account in calculating the actual position. It could also be a benefit as lensing can give you an enlarged (if distorted) view of the distant object. I think you are overestimating the scale of the lensing effect.

Masses do not create space. But they can cause curvature of the space-time coordinates.

It doesn't require an absolute reference. You can define any coordinate system and the example still works. It is simplest when, as in the example, the coordinate system is initially stationary with respect to the mass. But that doesn't make it an absolute reference. Indeed. It moved relative to where it was before.

Because it is an abstract concept (distances between things) not a substance.

Unless our theories are seriously wrong, we know exactly how much effect they have. (Zero, if you are curious.) Gravitational waves are not lensed in this way. So there could be a misalignment between the apparent position of the optical source. But as few would know it was affected by lensing, we could take this into account.

Someone has put a snapshot of the archive online: http://beallslist.weebly.com (Thanks to koti for that link.)

That is true. And, of course true of all observations. When we see the Sun rise, we don't know what might have happened to it in the last 8 minutes!

Exactly. And as your conclusion is wrong, then either your premises or logic must be wrong. It would still be wrong even if no one had identified where the flaw was. But, in fact, they have.

Not quite sure what that means. There seems to be one too few or one to many negatives!

This is obviously wrong. 1. You can be shown to be wrong without explaining why you are wrong. 2. Several people have shown where your error(s) lie.

And, now I have seen the other photos, "through" other vertical structures. You can also see these going across the doors in the second image. The other possibility is that it is an effect of the sensor; it could be that when the data is scanned out of the sensor it is affected by the other pixels it passes.

A bit like that old school trick of appearing at both ends of the school photo by rushing round faster than the rotating panoramic camera. (People have repeated this with Google Streetview.)

I would say it is not about being correct or not, but about asking questions and analysing the answers. Asking better questions, in other words. That is why it plays an important role in defining the scientific method.

Note that the only thing you can see "through" your body are the horizontal lines of the steps. So I am fairly sure this is a JPEG compression artefact. You can tell it is not stored at high detail. JPEG is not a lossless format. This means that it will make all sorts of assumptions about the image to reduce the amount of data stored. In this case, I guess it is assuming the the lines of steps continue right across the image (if the foreground were not solid black, this probably would be visible, so in most cases it is a reasonable approximation). This is all actually done by analysing frequencies in the signal, not really by looking at features like "steps".)

Yes. But that's not the point. The fact that relative truths (differences of opinion) exist means that philosophy cannot always be correct.

The rate at which they occur, and the distance at which they occur, and hence the answer to this question is a factor in working out how many we could detect. (Combined with the range of sizes of these events and the sensitivity of the detectors.) That is because no one else is confused by this. What is "it" in this question? Do you what is "GW150914"? In which case, I would say that it is the detection event. By the usual process of metonymy, it is also sometimes used to refer to the collision that happened all those years and light-years away. (Or, perhaps, the waves themselves, which are now receding from us.) That sounds reasonable. Although, the "1 second thick" bit will be highly variable depending on the exact nature of the event, and where you draw the cutoff - for example, a pair of orbiting black holes, or stars, will have been losing energy by gravitational radiation for years before they actually collided. This loss of energy was the first indirect evidence for gravitational waves and is also the reason why they end up colliding in the end.