KipIngram

Is this really a relativistic effect? I mean, I know gravity waves are. But the response of the LIGO arms to gravity waves - isn't that just changes in the strength of gravity pulling on the material of the arms and wigging it around? If the source was lined up with one of the arms, then it will "tug on" the near end first. For a four kilometer length it will take 13.3 microseconds for the effect to reach the other end; that's plenty of time for modern electronics to respond. When the wave first arrives (let's say it makes gravity a bit stronger) the near end will be pulled on and the arm will lengthen. Laser light emitted from the far end and arriving at the near end will arrive a bit late due to that tug, observable as a phase shift. Is there more to it than that?

Yes, there used to be a clear line of division between "real news" and the likes of the National Enquirer and so on. That line hardly seems to exist at all any more.

Duh. Yes, of course. I don't know where I got 183 from. Maybe 186,300.

Ok, so you have A) y = 5x-4 and B) y = 3x+8. You want A = 3B, so 5x-4 = 3*(3x+8) 5x-4 = 9x + 24 4x = -28 x = -7 It's just a single equation since you only have one unknown. It's presented as "two number machines," but the 3x condition links them together so you wind up with just the one equation.

That is patently incorrect. The conservation of L is essentially Kepler's second law. From fundamental classical mechanics, dL/dt = torque, and torque = Fxr (the cross product of the force vector and the radius vector). But in a central force system F and r are collinear, and their cross product vanishes. L is "defined" not only by the radius but also by the component of momentum perpendicular to the radius. When the radius becomes smaller, the perpendicular momentum component becomes larger - their product is unchanged.

The p component parallel to the radius is not conserved. The perpendicular components are, but p as a full entity is not. Also bear in mind that the p components that are perpendicular to the radius at time t no longer are time step later, since the radius is constantly changing direction. L is conserved by definition, since it takes a torque to change angular momentum and a central force can't make a torque.

Yes, the man/wagon velocity is altered by the things that happen too.

Oh, yeah, I tend to call what you're calling "moment of momentum" "angular momentum."

Well, probably not if I went into further detail. For example, for what I'll call "tier one" poverty alleviation (by tier one I'm talking about people who are competent to make decisions, as opposed to people who need help caring for themselves) I'd use a negative income tax to put money in their hands, and then just erase the alphabet soup of welfare-related agencies we have now. So the government would still be providing aid to those who needed it, but would so so with much, much less "intervention" into the economy and society. The people who needed more than just financial aid would still need something different, but there are far fewer of them - that would be my "tier two." Generally speaking I support government action to alleviate poverty and similar problems, but I'd like to see the government do that with the broadest possible brush strokes and try not to adopt a "details controlling" position in things. But this takes us OT, so let's not do more.

I've always heard 183,000, but neither is exact.

imatfaal, I feel exactly the same way, but at least partially the other way around. I don't consider myself "right wing," because I embrace many of the causes of the left. I don't consider myself "left wing" either, because I feel that free enterprise should be the core of our economic approach (it just needs to be suitably regulated to protect us from its extreme outcomes). But I also feel that indulgence in that kind of inflammatory methodology is totally inappropriate and prefer not to align myself with anyone who engages in it. I'll go back to what I said above - I think the media shows us primarily the far left and (especially) the far right, and I really want nothing to do with either. I think most of us are in between.

Well, it's acceleration. If an orbit is circular (eccentricity = 0) then the planetary speed never changes, but there's still an acceleration arising from changing the direction of the momentum vector. I'm not sure what you mean by "dynamic" acceleration.

The equations work. I won't do it relativistically because it's so much more involved, but for your example classical techniques would say the following: [ (wagon/man mass) + (ball mass) ] * (initial speed) = initial_momentum "tiny push": (some_force * some_time) = added_momentum (wagon/man mass) * (wagon final speed) + (ball mass) * (ball final speed) = final_momentum Then you'd have initial_momentum + added_momentum = final_momentum What about this is it that you think is wrong? You do need to know the ball's final speed in order to find the wagon's final speed, and all of the components of momentum are included.

About the Milankovitch cycle and the relationship between orbital elements to ice age / interglacial cycles. Fascinating stuff.

In a central force system p changes to compensate for changes in r and L is conserved. And you are right - that force cannot change the components of p perpendicular to the radius, so the overall change to p necessary to conserve L is achieved by affecting the p component parallel to radius.

+1. EXACTLY.

This is really a very good general point. The wonderful thing about the web is that it has made it possible for almost anyone to express their opinion to the world. And the terrible thing about the web is that very same thing. Our global communication capability has vastly more capacity than it did a few decades ago - if you fill that capacity starting at the right end of the bell curve describing content quality, you get a lot further to the left (left end of the bell curve - not left end of the political spectrum) than you did with the tiny capacity of the past. So along with the new freedom of expression the web makes possible we have to accept that we're going to see an awful lot of absolute garbage online. I believe in the old "sticks and stones" adage - mere words don't hurt us. I think we've become way, way too sensitive these days and let our "feelings get hurt" way too easily. Trump's supporters just can't claim that things like this didn't happen re: Obama during his administration - they did. All behavior like this is completely tasteless and contributes toward the very damaging political polarization of our culture. I'm disgusted with Griffin, and was equally disgusted with the people who published Obama effigies. Regarding CNN's actions, I regard that as a private matter between employer and employee. I think CNN can handle it any way they want, and it's not my business. Regarding the Secret Service's actions, I think consistency is in order. Their actions shouldn't be driven by political posturing - if it's their policy to investigate each and every incident like this then they should do that. If, however, they chose this particular incident to investigate because it had a high publicity factor, then that's inappropriate. I'd think they would have a process for evaluating things like this to determine whether or not a "seriously real" death threat is in play. It seems pretty clear to me that this was not a serious death threat - this was a celebrity acting like an idiot, primarily to attract attention. Regarding the reactions of the Trump family, what does anyone expect? If someone published a "death effigy" of me my family would be rightly and royally upset - it's unreasonable to expect family members not to feel wrath toward the perpetrator of such a thing. The government's really not allowed an "emotional" reaction, but family members are. As I've noted before, this polarization is likely the biggest problem we have these days. We used to be a nation where disagreement was allowed. These days, though, both sides have declared the other Evil with a capital E. You'd think we were talking about Christ vs. anti-Christ. The whole point of freedom of speech and freedom of the press is to allow disagreement. Also, I believe that the message from both sides that we see in the media is skewed by the media's desire to cover sensational things. I think most of the things we see are drawn from the extreme left and right ends of the political spectrum, because those are the sensational things. The huge majority of us are at various positions in the middle, so that means that most media coverage is directed at what are really minority positions. Allowing the vocal left or the vocal right dictate the way the nation is run would be tragic. But in order to arrive at any sort of sane moderate compromise position requires that people be willing to discuss their disagreements and also willing to compromise. Our current political climate is making that harder and harder all the time. So, MigL - you asked for thoughts on this. It makes me very sad to see that this is the sort of thing we choose to spend our energy and time on, when there are so many real problems that need to be worked out. This sort of thing tips us more toward political warfare and more away from political cooperation, and that's a very sad thing.

Some of those things already are quantized in certain cases, so I take it you mean "across the board"?

I'm very closely in agreement with every word of that.

Yes, I get that, and agree. I will try to find the best possible example. It still may come down to a difference of opinion, but hopefully I'll at least be able to get a "Yes, I really do see both sides of that one" reaction from you. Just as an aside, I am guessing that it's *big corporate* farms that are most guilty of mistreating animals, as opposed to small traditional farmers. I've heard some horror stories about the way factory farms treat animals.

I very much agree with StringJunky - being your own closest and best friend is vital.

Well, I will try. There's a lot of fakery on both sides out there these days. I have a daughter who works with a public policy foundation in Austin, and she's been directly involved in EPA-related activities. I'll ask her for input. But I worry that you've caveated this to the point that I can't win - obviously "fake" isn't admissible, but there may be plenty of things I consider inappropriate that you just think are ok. I'll see what I can come up with, though.

Well, maybe I didn't convey my thought clearly. This was more about "having a different set of rules" based on which end of the political spectrum held power. I certainly understand how that appeals to one's desire to see his/her own agenda achieved, but it's not a very good way to advocate having the government actually run. I'll go with your phrasing - "short sighted" is fine. Whenever you decide what you think of a government capability, you better think about a time when that capability is in the hands of people you don't support.

Yes, people do. I'm not a person that feels marriage has failed if it doesn't last forever. If you spend decades very happy with someone, and then you both change and it just isn't right anymore, well, you still had many happy decades. It's just hard when it's one person that changes and wants to move on, and the other feels abandoned. Ultimately, though, you just don't live your life for the happiness of other people, and no one should ask you to. It's *yours*, and is for *you*.