geordief

Interesting Maxwell's equations give a speed for em radiation without reference to any frame of reference. I shall try and investigate that specific point , but I can see that it shows that imatfaal was correct I will have to attempt to go through the mathematical workings of Maxwell's equations

https://www.scienceforums.net/topic/102140-invariance-of-the-speed-of-light/?do=findComment&comment=973768 "the invariance of the EM wave pops out of the Maxwell equations and is axiomatic to the most successful theories of physics" That was imatfaal's post in the above thread some two years ago. Is it correct ? I have been under the impression that Relativity starts with the invariance of c as an axiom based on experimental evidence.. I am not aware that it can be derived from anything I thought what popped out of the Maxwell equations was that this value for the speed of the em wave and the invariant maximum speed,c were the same thing.

She is giving us the benefit of her (and her supporters') viewpoint. She doesn't have the political ,scientific or entrepreneurial tools to directly effect change. (voters do have some tools)

Yes ,what is the problem? Should she be prevented from addressing political gatherings? Should there be a news blackout when she speaks? Should there be in house training for government officials to disregard the opinions of underage citizens (and she is foreign too)? People her age are uniquely qualified to assess the impact of MMGW on her generation and beyond.

People's reactions may be coloured by their expectations (confirmation bias). One person's delivery cannot be expected to change people's minds - it is like the oil tanker changing course at sea. This is not the GT Show and I have no doubt she will have the nous to understand when her effectiveness may be in doubt But those in the front line of man made climate changr deserve to have their voice (we deserve the chance to hear it too) .

The OP said his Facebook feeds were flooded with unpleasant comments about her. I don't see how it follows from that that "battle formations have been drawn up behind her."(rough quote) I just deduce that her activity has caused acres of pages to have been written about her in the press and internet (with no doubt accompanying reams of comments below) Edit:I do not use Facebook so "facebook feeds" Are a foreign country to me.

How do you see that happening?

So who will speak for them?

I assume your problem is that she is being used by others?(As Swansont said she is 100% entitled to her view -actually more entitled than I am as I defer to the youth on this in some respects) Is that your problem with this?

15 year olds can indeed be considered "experts" -in evaluating the consequences of our present (in)action. For the older folk the consequences can be comparatively abstract . I personally will very likely suffer no direct consequences of rapid climate change as I will be under the ground before this really takes off. In any case my status in the economic world order probably means that I can "buy my way out" of most likely consequences. The group of young people just gaining understanding of the situation can see only too well how they will be affected in the coming years. Also parents of young children may well be feeling troubled as they explain to their children that they might have done more to prevent what seems to be coming down the track .Or just troubled to have to explain to their children that they may be facing hard times and will have to cope with it on their own with tools they do not now possess. So yes ,these affected groups of people are experts in their own way . They have ,in the old parlance a stake in society that the older generations do not have to the same degree.

Well they need a 2/3 majority in the Senate which would be difficult even if the Republican representation faithfully reflected their poor showing in 2018. It is a good thing imo that more than a simple majority in the Senate is required to convict an impeached President. On the face of it though, the reluctance of the GOP representatives to put country ahead of party (or individual as I have heard it explained) is more than disappointing. To hear Trump making those latest not so veiled threats of summary "justice" (a tip from Vlad?) against those who would work against his interests was quite shocking. Surely his madness must be apparent to his inner circle...

Below the radar ,but with reassurances that steps are being taken to protact the democratic process. To date this reassurance seems to be missing .Can you reassure me?

I would ask what is this administration doing to prevent that ? Some proactive campaign against any such interference should be obvious to all at this stage (it isn't ,just the opposite from where I am sitting)

So are there no theories at all as to how matter creates curvature? Might gravitons have any role to play at all? If I am following the em analogy at all, might we be looking for something like a "gravitational charge"? A gravitational counterpart to the electron?

How might the graviton allow matter to curve spacetime? Are there rival theories?

I think I should have said "And there is no understanding yet of the actual mechanism of the gravitational field actually telling matter how to move matter telling how spacetime curves" That's the case isn't it?

So a gravitational wave passes through (and combines with?)the pre existing gravitational field.....is it correct to say that a graviton is theorized to represent an "excitation" in the gravitational field? And there is no understanding yet of the actual mechanism of the gravitational field actually telling matter how to move (as per "matter tells space how to bend, while space tells matter how to move") ? Might there be a signal involved?

Is it possible to tweak Newtonian gravity by addressing the problem of it's speed of propagation? I don't think Newton's msbu1*msub2/r^2 law took into account the idea that if the Sun's mass was to somehow disappear in an instant it would take 8 minutes for us to notice the effect. What if Newton's Law of Gravity had this delay built into it? Would its predictions be any better? I don't think I am confusing the speed of a gravitational wave with the speed of the creation of a gravitational field....or am I? (Hope I am allowed to necro my own thread )

Yes,I am completely OK with all that.I have also come across the term affine and ,whilst it is apparently a very simple mathematical concept (far simpler than the name suggests) I have not yet come across any circumstances where it is important (well not circumstances that I understood ,perhaps it was in connection with the dual space/tensors that I was trying to understand a few months ago iirc) . I have also looked at your previous post but I still need to go over it once or twice again (I have to do this when I learn something new) Actually I find it a little hard to understand "The equations now depend upon the origin of the coordinate system loosing homogenity along the x axis." Perhaps ,you might say the same thing with a different form of words?

I can think of the frame of msub1 ,the frame of msub2 and the frame of any x. Is that where I should be thinking about?

Should I set the observer at the CoG point?(where the sum of F's =0) So there x=0 and the acceleration times the mass of the object with mass m1 and the acceleration times the mass of the object with mass m2 are equal and opposite. Which leads to the accelerations of the two objects being inversely proportional to their respective masses. a sub1/a sub2 =m subscr2/m subscr1 Is that it?

What might be the state of motion within a black hole? Are all objects there identical? Is there no separation between any objects? Just one object? Any gravitons? Is it essential to have a decent understanding of what happens there before we can hope to start to talk about anything fundamental in the world we can observe? All I have heard is that only (pure) spacetime exists there (which makes little sense to me) Maybe some of his genius rubbed off? They might run a tourist line in Aladdin like souvenir trinkets. I had in mind the relationship we are trying to model.It reminds me of the philosophical idea where it was once believed that "redness" was an actual thing that red things so to speak dipped their nibs in(forget what school of philosophy that was,maybe Aristotle?) Anyway ,the relationship may not be a physical thing but we treat it as if it was .Like a mirage in the desert ,the better we understand it the further away it gets....

That will be too hard for me ,but are you talking Newtonian mechanics? You place the two bodies at negative x and positive x respectively? (observer at zero) So the "negative"body moves according to d(¦x1¦ +¦x2¦ )/dt =m1/[m1+m2] all multiplied by m1*m2 over ¦x1¦ +¦x2¦ squared and the "positive" body is the same but replacing the first m1 on the RHS by m2 Anything like that???

Just "quickly" 1) I was only considering a line drawn between the two observers and the experiment (like 2 rockets leaving the Earth in directly opposite directions at the same speed and with the Earth as the site of the experiment) So one dimensional (plus time ) in my head 2) a v means just "a vee" ,ie one quantity is "v" and the other is "-v" I didn't intend "a" to stand for anything mathematical (also my English was sloppy although it would have been understood as part of a spoken delivery) 3)Won't it the work in flat space? (the first link I was looking at doesn't use mass does it? Wrt your clarification re the First Postulate I am just claiming that both observers will measure the same physical experiment identically (maybe I was wrong** to even bring up the First Postulate as my main interest is to ask if this is a scenario with potential for showing something along the lines of what is proved (apparently) in the first link I posted **and ,looking back seemingly air headed ps :I have seen the IG series once or twice but not really enough form an opinion

EDIT:On reflection I can see that v will be the separation speed of the 2 observers wrt to the FOR of the physical experiment and not the speed that either observer will observe the other as moving at. Still that doesn't change my claim that both observers measure the physical experiment identically since they are moving at the same speed wrt it.(just not v/2 ) Either that or ,if I say the 2 observers are moving at v wrt each other ,then they won't move at v/2 wrt the physical experiment But the purpose of the scenario is to attempt to prove the velocity addition formula in the first place and so that may be of no consequence.