Recent content by Charles Link

He mentions about ten minutes into the video in post 88 about the bright ring around the lower part of the earth, and he didn't seem to know what it is. I could be wrong, but I think that one is obvious=it's Rayleigh scattering from the earth's atmosphere. (about 20 or 30 miles of atmosphere...

To comment further on the above post 84: The approximate formula I have for ## v ##, (it neglects any effect from the moon), integrates to get ## t ## as a function of ## r ## for a straight line path, even though the actual path was a very flat ellipse. The closed form integration for the...

That is basically what I did, and this one did not turn out to be of the slingshot variety. Instead, in going back and forth between the two frames of reference, there was just a slight decrease in speed in the frame of reference of the earth all the way to the closest approach which was...

In post 73 I mentioned something that took me a while to figure out, and it wasn't at all obvious to me: The conservation of energies using the potential of the moon and the change in potential of the moon does not hold in the rest frame of the earth because the moon is moving, and thereby the...

It may be worth mentioning, to add to my post 78 above, (the theory is all spelled out in the Kleppner and Kolenkow text), the hyperbola rotated by 90 degrees so that it is oriented sideways has formula in polar coordinates of ## r=\frac{17.0}{1-2.33 \cos{\theta}} ##, with ## r ## in...

To comment more on my post 74 above, I dug out my Kleppner and Kolenkow mechanics textbook from college, and the path neglecting the earth in the rest frame of the moon is an unbound hyperbolic trajectory. Given the speed at the minimum point was 3140 m.ph. at a distance of 5170 miles from...

I'd also like to comment on the first photo of post 66. I think what looks like the moon's shadow is simply the earth illuminated by the sun from the side. If it were a solar eclipse, it would occur at the time of a new moon. The new moon according to a google occurred on april 17, 2026. The...

The calculation with the moon's gravitational potential does indeed work in the rest frame of the moon. To compute it, we can to a good approximation simply ignore the effect of the earth when the rocket is near the moon. For initial conditions, we can put the rocket 6000 miles from the path...

In regards to posts 60 and posts 63 above, I did a calculation assuming the total energy of the rocket stays constant using the gravitational potentials of the earth and moon, and that calculation showed the rocket should speed up considerably, up to about 2600 m.p.h. I determined that...

I do think if the nail is a permanent magnet, that the tip will be of one polarity and the head of the other polarity. That would make it so that the tip gets centered on one region of the underlying magnet and the head on the other. The alternative is that the magnetism on the head is more...

I presume you are referring to any permanent magnetism, if there is any, appears to be minimal, but why not check for it, like @Baluncore suggested, with a compass.

From the response of the nail it is likely it is not permanently magnetized, if that is what you are referring to. It is responding how one might expect to induced magnetization. If the nail permanently had one pole on the top and the opposite pole on the tail, the response would be for each...

It is starting to make a little more sense, now that I have a clearer picture of it. I think the flat head is extensive enough that it is able to get magnetized in the x-y plane with a north pole and a south pole that will line up with the south and north poles respectively of the underlying...

You've got a very odd looking nail. I thought the head of the nail was the magnet. That is the head of the nail as I know it. You called it the flat end. Your nail has spiral grooves in it. I don't know if you can expect it to behave like an ordinary nail.

The pictures were unclear and the OP's explanations were lacking. I think that larger surface with 3 rings is the sensor, but I don't know.