# Moon: Apollo 15 Flag Waving

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sophiecentaur
Science Advisor
Gold Member
If this is true we can factor out solar wind.
As far as I know, the solar wind is so weak that it requires solar sails of hundreds of metres square to catch enough of it to accelerate a tiny spacecraft at a moderate rate. If the wind was enough to shake that flag then there would be dust flying all over the Moon's surface. Did you ever notice any on the films? The dust is extremely fine, you know.
There is just not enough information to determine how long a sheet of unknown material and unknown construction, on a light, whippy support, could carry on shaking if it were nudged. The movie is not long enough to reveal the real situation but Occam's Razor, when applied to all of this nonsense tells us that it really was waving and it really was on the surface of the Moon.
I have to question the motives and the sense of people who are still looking for evidence that it never happened. There must be fairies at the bottom of their gardens.

Physics345
Solar wind is hot enough to melt suits. The density of the solar wind is much lower than the density of the suit/astronaut. The suits were painted white to reflect radiation. They emitted thermal radiation which was mostly from sunlight and body heat. You need to radiate heat. If a human body is fully insulated it gets cooked and dies.
We're getting closer to factoring out solar wind. Good work.

The lunar lander was on shock absorbers. 5.5 would not be very alarming while walking around. They were on the surface for about 3 days. 5 quakes per year is not likely to coincide with the landing.
Well we can factor out moon quakes as well then, unless someone has some input that can change that.

Sunlight is nearly constant. The pressure on the flag would vary by angle.
Gravity on the moon is 1.62 m/s2 if the flag had 1 gram of mass the force would be 1620 micronewtons. If the flag was positioned north-south so you have full exposure at sunrise and sunset and if the flag is bleached enough a 1 m2 flag could experience 8.1 micronewtons. That is one part in 200. It probably has more mass and probably is not perfectly north-south. The effect would be measured in mm or less.
Well we could easily find out where they landed, through some light research which I will do right after, I'm done practicing calculus.

I have to question the motives and the sense of people who are still looking for evidence that it never happened. There must be fairies at the bottom of their gardens.
I agree but, like I said previously people can believe what they want. Even though what they believe has a mountain load of evidence against it, but regardless as soon as that right is taken away from people we will have reverted to a dated mind set. Overall in my opinion these types of people are very simple minded they don't bother doing any type of factual research which most likely stems from low intelligence due to nurture and is most likely hereditary as well.

As far as I know, the solar wind is so weak that it requires solar sails of hundreds of metres square to catch enough of it to accelerate a tiny spacecraft at a moderate rate. If the wind was enough to shake that flag then there would be dust flying all over the Moon's surface. Did you ever notice any on the films? The dust is extremely fine, you know.
Good work, with that we can definitely factor out solar wind.

There is just not enough information to determine how long a sheet of unknown material and unknown construction, on a light, whippy support, could carry on shaking if it were nudged.
The whole point is to construct a hypothetical analysis with as much known variables as possible, with what ever information we can find. The rest would have to be "Educated Assumptions" at best and even then to follow Occam's Razor we would need to limit the assumptions as much as possible. Regardless has enough research been done into this topic to determine with absolute certainty that it is indeed "impossible" to create a hypothetical analysis?

sophiecentaur
Science Advisor
Gold Member
with as much known variables as possible,
AND without the inappropriate preconceptions about how one sort of flag behaves on Earth and automatically applying them another thing that people are calling a flag when it's on the Moon.
This is all a serious waste of good thinking time, you know.

Physics345
AND without the inappropriate preconceptions about how one sort of flag behaves on Earth and automatically applying them another thing that people are calling a flag when it's on the Moon.
This is all a serious waste of good thinking time, you know.
Well I've stated previously it may not be worth the time it would take to construct such an analysis for various reasons. People seem to be interested in the topic, so why would we stop discussing it? Engaging the mind can never be considered to be a waste of time. At the end of the day it is good practice, which could lead to something greater, if not in this topic but possibly another.

I know that the flags were folded and compressed tight for stowage during launch, so there would be time involved with the creases slowly working themselves out in the lower gravity. They likely used a lightweight material, even so, it would have creased along fold lines, and these relaxing "may" give slight motion to the flag without it being touched. The thermal changes daily (lunar day) would help in that, but it would not be on a personally observable timescale for us here on Earth. Other than that, yes, the motions were mostly when the stand or flag was bumped or when inadvertent dust was kicked up (which was actually a problem at first).

And while there has been found to be a micro-atmosphere of xenon, helium and OH+ radicals, even that is not enough to make the flags wave in normal conditions.

stefan r
Science Advisor
...then there would be dust flying all over the Moon's surface. Did you ever notice any on the films?...There must be fairies at the bottom of their gardens.
There is dust flying over the moon's surface.

Here is a picture from clementine with Venus in the background:

The Apollo astronauts who saw it first were not sure what to make of it.

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russ_watters
Mentor
I would like to also state that, my line of questioning behind the math, stems from the origin of having an answer to disprove peoples ideas of the moon landing being fake due to the flags motion.
I'm sure everyone is aware of where the question comes from...
Hmm, that definitely makes sense, there are many unknown measurements in this case. I guess in the future, when we create a base on the moon we will be able to conduct more practical experiments such as these.
Is there any way to make a rough estimate, of the unknown variables leading to a vague hypothetical mathematical answer?
I don't know why you'd even bother. It's obvious that the violent shaking of the astronaut is making it move. The damping time really doesn't matter unless you're trying to argue against a silly idea like that a gust of wind occurred just as the astronaut was violently shaking the flag, and then the wind completely stopped. It's a silly/convoluted idea that should not be worthy of debunking.
Regardless has enough research been done into this topic to determine with absolute certainty that it is indeed "impossible" to create a hypothetical analysis?
No, I'm quite certain no serious researcher would bother with this.
People seem to be interested in the topic, so why would we stop discussing it? Engaging the mind can never be considered to be a waste of time.
Well, for one, it violates PF rules. From a practical standpoint, people have only finite brain power, so if they are working on this silly problem they aren't addressing the many better problems that are out there to be answered. PF is about quality, not quantity.

Thread locked.

rbelli1, berkeman and CWatters