Global warming is real


#2568

Okay. What’s your point?


#2569

No, eventually even in a vacuum the tension eventually reduces it to it’s original state.

The plucking is momentary, the tension is constant before and after. I’m very familiar with this experiment because we did it many times in Physics lab.


#2570

No, I’m merey replying to your diversions. I was taught that it’s impolite to ignore people, even fools. Let’s hope you were not raised the same … this could go on forever, like that frictionless guitar string vibrating in a vacuum. :wink:


#2571

Diversions? You mean like meaningless arguments about the definition of a polar ice cap?

Oh wait, that wasn’t me. That was someone who couldn’t help but stray off topic for…reasons, I guess.


#2572

No … without friction between the molecules of the string, momentum would keep it moving. Tension is nothing more than potential energy, and the kinetic energy induced by the plucking is preserved by the momentum of the mass of the string with no friction to erode it.

But again, there is no tensile force in an orbit.


#2573

You should know that the “tension” effect of gravity changes. So if an orbit is perturbed, after the perturbation is removed, the force acting on the body is not the same as the force that was originally acting on it due to the change in distance.

How this new force returns it to the old orbit kind of escapes me.


#2574

The potential energy is limited by the force of the plucking.

The amplitude even in a vacuum is reduced with each cycle as the kinetic energy dissipates.

There is only enough energy imparted to keep it vibrating for a limited period of time.


#2575

The energy imparted by a passing body is limited, the constant forces that remain do not change , they remain long after it is gone.

In order to cause a permanent change in the orbit the object would have to cause such a large disruption that those constant forces are defeated, just like the guitar string.


#2576

Not true. The passing body modifies our orbit, correct? If our orbit has been modified then the “r” in the gravitational equation is different.

F = G*((m sub 1*m sub 2)/r^2)

The original force has changed. How would we return to the original “equilibrium”?


#2577

In the same way the guitar string is. The constant forces are constant, the temporary force is temporary and unless it’s so significant to defeat the others equilibrium has to return.


#2578

Every body that has ever passed close to the earth has had an effect on our orbit yet due to gravity and angular momentum we keep returning to a very predictable and demonstrably so orbit.


#2579

What tells you that we “keep returning” to the predictable orbit?

That seems like an unsupportable statement.


#2580

The fact that the math proves it out constantly. Our orbit varies but it can always be accurately plotted at any point in time and verified by observation.

If it couldn’t none of our calculations that depend on knowing our place in the universe would be completely unreliable.


#2581

Or maybe the forces you’re referring to that affect our orbit are just that infantessimally small and can be basically ignored.

Yeah. That seems more likely. Much more likely.


#2582

Gravity and angular momentum are the forces the hold our entire system together.


#2583

No kidding. Thanks.

The point is that NEOs don’t affect our orbit in any appreciable manner. The gas giants at most can oscillate our eccentricity over time frames of tens of thousands of years, not sufficient to be observed. This is an extremely weak force capable of changing our orbit only after extremely long periods of time, and nicely enough reverse the effect they did have over similarly long periods of time. They don’t prevent us from spiraling into the Sun. They don’t keep us at a more distant orbit. They don’t magically put us back into an old orbit if ours is modified by some temporary force.

Out of curiosity, do you have any examples of anyone who does know what they’re talking about that backs this up or are you just going with what you came up with yourself?


#2584

Since you have no idea what effect any NEO’s have had on us except during very recent history your claim is completely baseless.


#2585

You’re the one claiming that something is “varying our orbit” and we have “observed” it returning to”normal”. What exactly did you mean by that?


#2586

Our orbit varies all the time due to natural cycles and any object acting on it does as well.

In spite of those facts we can accurately calculate the position of the earth at any time in the future because the constant forces keep us on a predictable orbit in the long term.

Until something changes our orbit enough to defeat those stable forces, we will remain in an accurately predictable orbit.


#2588

Your claim is that something could come along, alter our orbit a little and then it would return eventually back to its “normal”.

When I asked how you knew that, you said it was because we had calculated the orbit and it was always predictable, but now that doesn’t seem to be what you’re claiming.

I’ll ask again, how do you know these “constant forces” will return our orbit to its previous state if our orbit is modified slightly by something else?