Robittybob1

The orbital pattern on that one is hard to follow. It even looks like its orbit changes direction. I didn't even know that was possible. The barycenter is always on a line between the CoM of each body. It is the point on which the centripetal forces would operate from. So in that animation it is definitely shifting. I just checked if both BHs lose mass at an equal rate the barycenter moves toward the heavier body.

Good point, but on the first BH merger (the chirp) the delay was barely noticeable, so we might be just seeing that millisecond difference but on that second animation the orbiting distances would have been considerably greater (greater difference in mass and/or orbiting faster, but they are just guesses for there was no scale to read), maybe that is why the delay was greater. What was the frequency of the BH merger orbit? 100 Hz rising to 250 Hz at beginning of the ringdown or 4 - 10 millisecs per orbit so if the waves were delayed by 1 millisecond could we see it? It is still possible. The rapidly changing orbital rate definitely makes it harder to identify. What are your thoughts on the stability of the barycenter? Do you think the barycenter remains steady through all this? From the GE output graphs they tend to show both bodies losing the same amount of energy. If that energy was in some way related to mass loss doesn't that imply the barycenter is shifting toward the heavier object? I think it is definite that the strength of the GE wave for each BH is comparable. Do you agree with that observation? I'll have to take it step by step for it is just too hard to think of the consequences of the barycenter shifting in an binary system, I just don't know the physical effects that would eventuate. Any ideas?

http://journals.aps.org/prl/pdf/10.1103/PhysRevLett.116.061102 on page 2 there are the reconstructed (wavelet) diagrams where they seem to have taken the background interference out of the "chirp". If you look at the tallest peak would you all agree it is the 7th crest after the 0.3 sec timeline? Would you say the period between the crests 3&4, 5&6, 7&8 crests look a little closer than expected compared to the preceding ones between peaks 2&3, 4&5, 6&7? Obviously the frequency is rising as the merger progresses but there seems to be a hint of a grouping of the crests. I would say this is expected due to the G-Rad coming from BH closer to the barycenter having to travel just that little bit further to get to the LIGO recorder, so the signal from the more massive BH is slightly delayed. Would that be the advanced wave followed by the delayed wave as a grouping? (Reading the chart from left to right) Any suggestions? Looking at a site Strange linked to on another thread emphasises the effect I am trying to describe. These are just pure animations but it shows the grouping of the G-rad waves. Look at the "Highly precessing binary black hole run" at http://www.black-holes.org/explore/movies From that animation we might be able to tell which phase of the quadrupole precedes the other as it reaches LIGO. LIGO receives the signal from the left to the right. The white line precedes the red line. The white is the wave from the lower mass BH, which I called "advanced" above so in each group the advanced precedes the delayed wave. Is this what I said above? Yes.

Are they just going in different directions? https://van.physics.illinois.edu/qa/listing.php?id=1153 Is that a fair description?.

@Janus - Can you help me here please? I was reading http://galileoandeinstein.physics.virginia.edu/lectures/synchronizing.html and it sounded very much like what you descibed without going into too much detail. My thought was if we had one central clock and 2 clocks at each end. We synchronize the first two using the method described So we synchronise the first two end clocks (have only 1 uncovered), and then accelerate the craft to half light speed. Do the synchronised clocks stay synchronised? How can we tell if they are synchronised? When at half light speed if we were to repeat our experiment on the remaining two end clocks and record the time it happened on the already synchronised clocks would they both record the event, on a readout, as happening at same time?

Was there some error in what I have said above? I am trying to be 100% accurate in what I post. If there was a mistake please discuss the issue on the forum.

I am not thinking in terms of time dilation occurring on the frames with relative motion, we are just looking at the situation in the idealised form where all distances are measured in the x dimension. When we look at how distant some object is, the angle of sight to its direction of travel doesn't change (coming straight at you). Later on we might need to account for this time dilation effect. For all we are trying to do at this stage is to synchronise every frame's clocks to begin with and later we will see if their time is dilated. Since we can only do one clock at a time will the clocks stay in sync during the time taken till we get to the point of saying "job completed"? Houston we have a problem!

There are many versions of the animations now but it was interesting to go back and watch the animation in the OP it has different masses orbiting at different distances with the yellow always further out than the red line so I'll presume purely from basics physics that would be showing up in the g-radiation peaks there will be two peaks closer together followed by a larger gap then two more peaks etc. They certainly fail in their animation of the G-waves it looks like they have stopped in their tracks. I'll have to find the spread out display of the chirp and see if that slight change in frequency can be picked up.

I was thinking the animations were not representing the actual situation, whereas the frequency of the chirp is the actual recording (that bit is not animated) So if they are animating equal mass BHs, well I now can see why they are orbiting the geometric center. OK it was a raw idea but it has revealed something about the animations. It obviously would make them harder to do if they were unequal masses orbiting a barycenter. That was basically my point anyway. I'll look into later, thanks.

They generally show one with a larger EH which is proportional to mass. Does the chirp frequency show us the pattern? The two BH masses were fairly even but the mass difference should show up in the orbital radius. What is the clue that gives them the ability to tell us their relative sizes? This radius difference is proportional to the mass over the combined mass, but the heavier one will definitely have a smaller radius than the lighter one (thats some inverse relationship). https://upload.wikimedia.org/wikipedia/commons/f/f2/Orbit2.gif https://en.wikipedia.org/wiki/Barycenter#Two-body_problem Edit: "radius is proportional to mass over the combined mass".

Another error that I'm noticing is they are not animating the BHs orbiting a barycenter. They seem to draw them as if they are going around a geometric center but they ought to be orbiting at different radii. So we should be able to see two lines of gravitational waves per orbit but each one is coming away from a specific body in orbit so the strength of that wave will reflect some property of that mass. The more massive BH will be orbiting closer to the barycenter so the distance it's GW has to go is further so it will be the one tending to be closer to the wave ahead of it. Can you see this paired effect in the chirp frequency pattern? Is the trailing wave larger or smaller in strength? Which body gives off the most GE? Both are losing PE and gaining KE but they are proportional to mass, but also inversely to distance fallen, so it is hard to predict which body gives off the greater amount of radiation. I'll have to go and study the chirp.

That is the consequence for there is no universal time standard. Is that what you mean? Whoever does the measuring sets the time to their frame. The person doing the measuring doesn't feel slowed or sped up. To me you still aren't that clear.

I was wondering what it was about? What is the price of fear? and "Edit/ To add, This question isn’t confined to the migrant crisis, BTW, but to any consequence of our fears." It didn't explain the limits of the discussion when did it become a discussion on "the level of suffering people are willing to witness in order to maintain their relative opulence"?

I understand there is no preferred frame, and all motion is relative to some other frame. So the sender feels he is stationary i.e things go past his frame not the other way around, even if it seems logically incorrect e.g. the platform moves past the train to an observer on the train. So all clocks are to be synchronized to the sender's frame for he has the equipment to send out and receive the signal. The other frames have clocks, mirrors on the clock and device to receive instantaneous messages and can adjust their clocks instantaneously to S1 being the sender's clock (the reference clock). So sender's frame call it S and all the clocks on the S frame are synchronized one at a time against S1 firstly S2, S3 ...Sn I have been trying to find someone doing a video description of Einstein's synchronization (ES) and as far as I can tell it was the same as I was using but only someone familiar with the ES method can confirm that. So I was thinking how does S1 work out whether the other clocks are on it own frame or on different frames, and are those different frames coming closer or moving away, so S1 uses the light beam and measures the return time, if on two tests the return time decreases the other clock is on a frame moving toward S1. If on two tests the return time increases the other clock is on a frame moving away from S1. If on two tests the return time is equal the other clock is on the same frame as S1. "so if a signal returns at same interval the two IFoR are going at the same relative velocity." @Klaynos - that was not said properly "the same relative velocity" should have been "zero relative velocity". To the observer it would appear the other clock is not moving. If there was another (external) observer on another IFoR it would appear as they both had "the same relative velocity".

That section had the title "Black hole head-on collision" I would think if 2 black holes were to collide head on it would be a lot more dramatic than that. The orbital motion definitely slows the infall compared to free fall. There is a timer on the screen is that in seconds? Finishes on 44:0 maybe it is in milliseconds?

Do you really think so? I put a lot of the blame on Turkey. I feel for the Kurds and I hope they get a homeland one day. The Syrians deserve support but no one is going to start WWIII over their issues. Russia is always going to back Assad to protect their interests. There are too many conflicting interests to find a solution. Send the refugees to Russia and the problem would be solved tomorrow. But what would make them head that way instead of Europe - pay them to go there?

What is the situation happening in the particle accelerators then? http://www.scienceforums.net/topic/93886-muon-no-substructure-yet-decays/#entry910222 Is that not decay then? Is it more like "making" these particles?

On the forum I fear the moderators, for I have had experience of the moderation. So I have a degree of fear. I know my calves could die from a variety of diseases, so I have a degree of fear there. But I don't find these fears overwhelm me. I have experienced overwhelming fear where your heart just about explodes from the adrenalin surge, where your legs will not work as fast as your brain wants them too. Both not a good feeling. What "better job" are you implying? Better job of dealing with fear. Is that it?

What is this "certain fear"?

In #6 you seem to be talking about bacterial competition. So I feel I'm on topic.

In that paper Strange linked to there was a scene at the end of it where the two black holes merge into each other. I'll put a link to it http://cplberry.com/2015/09/12/monty-carla/ the section of interest till the end. @Strange did you understand why they added that bit to the end of the BH merger animation?

Is that right? I have very little fear. But I would hate to live in a war situation, who would know how you'd cope with that.

I have listened to many videos on growing mushrooms but you are the first to worry about bacterial competition. The usual emphasis is on eliminating other strains of mushrooms.

True there were 3 situations that needed to be worked on (no motion, slower, faster) but I only tried to find a solution for one of them (the no relative motion situation) so far. OK I need to look at Einstein's synchronization method. Thanks. I have now may it clear there are 3 situations.

So when you play the Devil's advocate you are really in favor of the opposite, is that right? http://idioms.thefreedictionary.com/play+devil's+advocate