Posted on 08/30/2015 9:58:29 PM PDT by SunkenCiv
Except for ( I believe ) one midcourse correction Apollo 11 was in free fall right up to the LOI burn, and the was no way of feeling any sort of gravitational influence.
The only thing regarding the subjective experience that I’ve found so far is in FIRST ON THE MOON at the begin of Chapter 8, where it states the Bill Anders of Apollo 8 had very little awareness of the moon as they approached it. “Eventually Anders became aware that some great dark body was building up behind the spacecraft”.
Of course, such an impression might be felt subjectively as an impending influence, but it would be entirely based on the visual experience.
I haven’t found it, did find the Dr Rendezvous seg from the 2007 documentary; Buzz explains stuff at the time index shown:
https://www.youtube.com/watch?v=qUu6LZXE-uc;t=1873
This segment (time index shown) is also worth watching, it’s unrelated to this topic and subthread though:
https://www.youtube.com/watch?v=qUu6LZXE-uc;t=2504
Ah, here’s a segment of the main feature, it was Cernan talking about feeling but not seeing the Moon:
https://www.youtube.com/watch?v=WE1MVg7SV4U
Yes, because it just got dark! Then he talks about the long shadows being “scary” and “forbidding”. All this is line with my supposition that these are subjective feelings.
Anyway, it’s a basic dynamical fact that you have no perception of gravitational fields acting on your body as long as you are in free fall. Einstein built his whole theory essentially on the strength of that idea.
Thanks for the links! The Apollo 11 touchdown brought tears to my eyes. ( I used to have the whole thing memorized! )
With regard to Buzz Aldrin’s remarks, I think he’s essentially talking shop here, explaining the nature of the approach trajectory. With his body language, he does make it sound like a roller coaster ride, but again, it is free fall.
“You could feel the Moon’s presence, you couldn’t see it.” — Gene Cernan
https://en.wikipedia.org/wiki/Free_fall > In Newtonian physics, free fall is any motion of a body where its weight is the only force acting upon it. In the context of general relativity, where gravitation is reduced to a space-time curvature, a body in free fall has no force acting on it and it moves along a geodesic... In a uniform gravitational field, in the absence of any other forces, gravitation acts on each part of the body equally and this is weightlessness, a condition that also occurs when the gravitational field is zero (such as when far away from any gravitating body). A body in free fall experiences “0 g”.
https://en.wikipedia.org/wiki/Hyperbolic_trajectory > In astrodynamics or celestial mechanics a hyperbolic trajectory is the trajectory of any object around a central body with more than enough speed to escape the central object’s gravitational pull. The name derives from the fact that according to Newtonian theory such an orbit has the shape of a hyperbola... Under standard assumptions a body traveling along this trajectory will coast to infinity, arriving there with hyperbolic excess velocity relative to the central body. Similarly to parabolic trajectory all hyperbolic trajectories are also escape trajectories. The specific energy of a hyperbolic trajectory orbit is positive. Planetary flybys, used for gravitational slingshots, can be described within the planet’s sphere of influence using hyperbolic trajectories.
That day in July 1969 was a pretty good day. :’) An edit of that final approach is in that same clip. The drama of Neil’s move during final approach wasn’t made clear to us as we listened at that time. I think we had NBC on — black and white TV, I remember the grayscale, rather dark picture, with an overlay of a flashing caption, “first live pictures from the Moon”.
The first EVA was at 11 or 12 PM EST, where I was in NJ, and I remember that. I most vividly remember the landing, during which I was riding in a car with my parents, returning from a family outing, listening on the radio.
I can tell you that I was at 40 40.802 N, 74 24.679 W, at the moment of touchdown, stopped at a stoplight.
You know ... if you look at it a certain way...
The light colored part in the lower right could be a outline of Pluto’s head.
The piece on the far right is his muzzle, the body going underneath the planet and the semi-cratered area on the left is his ear flopping down.
See it?
(Anybody?)
to continue:
" ... we went into darkness after being in daylight the whole ... time ... on the way to the moon. ... and then we went into darkness ... and we're in the shadow ... of the moon." ( ellipses represent pauses, not elisions. )
So these visual impressions are the cause of his "feeling" of the moon's presence. I hope you don't question this. Do you? Do you think these remarks indicate that he felt some bodily force, or something?
That’s it exactly!
Thanks!
That’s exactly what he does say. He’s not entirely coherent, but he’s not saying that he saw darkness which made him feel the Moon was there.
“Feeling a presence” is a figure of speech, often said of an important person entering a room, for example. Here, he says it, then goes on to explain the circumstances that engendered the feeling.
Plus, HE DID NOT PHYSICALLY SENSE THE MASS OF THE MOON!
Don't you see that this frame of reference is entirely equivalent to the Apollo capsule approaching the moon? In this case, the weightlessness is the celebrated feature, and one is free of any sensation of being held or attracted by earth's gravity.
It puzzles me that you seem to think that there's something special about the moon that would make the free fall frame of reference in the Apollo capsule any different.
I would also note that the Wiki article rather undersells the significance of the "VC" frame of reference, seeming to bill it as some kind of illusion. It is the real deal.
From a GR point of view, the only reason for scare quotes on "weightlessness" is that there is no such thing as "weight" in the first place! There's only inertia. This is Einsteins Principle of Equivalence.
Don’t you see that it’s two guys inside an airplane flying a parabola so that the two guys are falling toward the Earth inside a plane? They aren’t flying along just in time for the Moon to swing on up and draw them into a gravity well.
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