Why the Earth is attracted to raindrops

C

Confused2

Registered Senior Member
Gordief posted a link to a youtube which I (a jackass) think could answer the Earth/raindrop question

Vector spaces and their duals

It would be hard to overestimate the importance of these guys in applications, so let's have a look. I think an entirely abstract approach is most helpful, so if anythting that folloes is not completely clear, just ask me. We suppose a set V equipped with the operation of addition which is...
www.sciforums.com www.sciforums.com
In one dimension using only high school math (possibly extended slightly) .. THAT would be exciting (for a jackass).
 
Having some trouble relating that thread to whatever the Earth/raindrop question is or why it's site feedback...could you briefly summarize?
 
TheVat said:
Having some trouble relating that thread to whatever the Earth/raindrop question is or why it's site feedback...could you briefly summarize?
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I had intended the link I gave to point to Gordief's post .. for some reason (Jackass effect) it pointed to Quarkhead's OP .. which I thought actually worked better by exemplifying the gap between explaining why the Earth tends to hit raindrops in high school math and anything else. Gordief's post was simple enough that maybe I could follow it in the raindrop direction .. I could have tried to hijack the thread which would have been impolite or .. here we are in site feedback. Jackasses like me don't start threads in physics forums but if anyone wanted to have a go at raindrops in high school math .. I'd really appreciate it .. I call that 'Site feedback'.
 
Raindrops are attracted to the earth because of gravity.

I have no idea what you are trying to say/imply.
 
w1z4rd said:
Raindrops are attracted to the earth because of gravity.

I have no idea what you are trying to say/imply.
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We're in Site Feedback not a thread about raindrops .. but .. there's no force on the raindrop (agree?) but the Earth heads towards it with ever increasing velocity .. that's gravity .. there's some trickery involved .. can we reduce the trick to one dimension and high school math (or not)?
 
Newton's equation, using high school math, will give you the force, if you have the distance between their centers of mass and the mass of both drop and planet. Given the great disparity of their masses, and the fact that all the atmosphere is part of the Earth's total mass, it makes more sense to see the drop as attracted and "heading towards" Earth.
 
TheVat said:
Newton's equation, using high school math, will give you the force, if you have the distance between their centers of mass and the mass of both drop and planet. Given the great disparity of their masses, and the fact that all the atmosphere is part of the Earth's total mass, it makes more sense to see the drop as attracted and "heading towards" Earth.
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I concur, the pull on the earth from the mass of the rain drop I think we can agree is minimal.
 
Confused2 said:
I had intended the link I gave to point to Gordief's post .. for some reason (Jackass effect) it pointed to Quarkhead's OP ..
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Oh, I see.

Yes. It is a known bug in Sci-Fo. Not your fault.


If you include a link to another post in your post, the forum makes a helpful little preview blurb about what's under the link. But it's broken. Instead of previewing the content of the post you are actually linking to, it previews the content from the first post of that thread.

You can see it in the OP:


1776704227699.png

The actual link that confused2 provided correctly (rendered in blue, above) goes to geordief's post #9, which begins "Just on the whole concept of dual "vectors" I came across this ..."

But the preview blurb (the body of the text ) is actually pulled from QuarkHead's post #1 of that same thread: "It would be hard to overestimate the importance of these guys..."



Very confusing. You can't fix it, you can only turn it off. Here's how:
  • Go into BBCode mode ([ ] button the editor bar)
  • Find the offending code: [ URL='http://my-link' unfurl="true" ] My link text [ /URL ]
  • Change "unfurl=true" to false

It's a pain but I hate confusing my readers.


This was reported two years ago:

Small bug: excerpted text in an expanded link is wrong.

When I insert a link into text, it automatically expands the link to add a box with some excerpted text. Let's see if this works... https://www.sciforums.com/threads/ufos-uaps-explanations.160045/post-3730563 The link itself correctly points where I meant it to (post 9572), but the text it...
www.sciforums.com www.sciforums.com

(and you can see the bug here too. I linked to the last post in that thread (post 2), but the blurb you see here is from post 1.)
 
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geordief said:
Just on the whole concept of dual "vectors"
I came across this (again) and I think the penny may be finally dropping for me

(it is just 10 minutes in all and it is the inversion at the end that shows the difference between contravariant and covariant)

When you transform a normal vector across to a different system the whole things work one way(contravariance) ,but when you do it for gradients such as an electric potential the dx/dx primed gets inverted and so the new coordinates transform in an "inverse" (covariant) way.

I guess this may well apply in curved spacetime in GR too(it goes up to n-dimensions.

So the dual vector space might possibly be something like a subset of vectors that pierce the contour lines of equal electric potential and describe the field strength(through a glass darkly but it is becoming a little clearer)

Covectors seem to be used for physical situations (eg gradients )where coordinate transformations happen in a covariant way.
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Above is Gordief's post that started this off .. looks darn close to answering the Earth/raindrops thing.
Doubtless you can read off the effect from (some) notation .. to avoid opacity start from high school math (assume calculus), one dimension, and take it from there.
 
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Confused2 said:
Above is Gordief's post that started this off .. looks darn close to answering the Earth/raindrops thing.
Doubtless you can read off the effect from (some) notation .. to avoid opacity start from high school math (assume calculus), one dimension, and take it from there.
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No.it doesn't. Water has mass that coalesces via known metrological process and falls to earth due to gravity.
 
DaveC426913 said:
Then let's all please refrain from arguing the case in the feedback section. This thread is about the bug - not about the science (pseudo or otherwise).
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Thanks for your help.. the thread really was supposed to be about raindrops .. not this thread but in the physics forum. I might have missed an 'off topic' section but I suspect the result would be the same. In the light of my earlier 'AI assisted' post - not hard to guess what I'll do next - but I won't post anything here.
Thanks to those who have tried to help .. others not so much.
 
L
Pinball1970 said:
Apologies, it was the title that threw me. With it mentioning the earth being attracted to rain drops, I thought the thread would be about the earth being attracted to rain drops.
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I don't see the connection in the video I posted to gravity per se.

I did express a wonder as to whether the maths that modelled Electic potentials and their gradients (ie the electric field) could be extended to (coordinate transformation) in curved spacetime.

It is a series of videos and perhaps he comes into that in later episodes.

But ,for me this was the clearest I have been so far(after some 3 or 4 years of intermittent attempts) on what is a dual vector -since normally explanations seem to purposefully avoid giving geometric or physical examples.
 
I don't see the connection in the video I posted to gravity per se.
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FWIW I don't either .. I had a vision of two coordinate systems that 'automatically' tend to move towards each other .. I no longer think that's 'it'.
 
Confused2 said:
FWIW I don't either .. I had a vision of two coordinate systems that 'automatically' tend to move towards each other .. I no longer think that's 'it'.
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If the howl of anti-convention sometimes beckons from the hills... There might or might not be additional factors beyond just the domination of Earth's mass over that of the trivial raindrop's.

Is rain pulled to Earth by separated charge?
https://soellerpanel.net/2024/10/11...-is-rain-pulled-to-earth-by-separated-charge/

EXCERPT: Conventional meteorology and atmospheric physics theory tells us that raindrops condense and coalesce inside of clouds until they are heavy enough to drop to Earth’s surface under the force of gravity. A paper published in Geophysical Research Letters in 2009 titled “Do all raindrops fall at terminal speed?” questions this assumption by finding that many raindrops have an actual terminal velocity up to 10 times greater than the assumed terminal velocity calculated using the forces of gravity and air drag. Could electrical charge forces be responsible for the observed high velocities?
_
 
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