Mysterious green UFO spotted on Jupiter from NASA image, sparks debate

Started by WAS, October 29, 2018, 05:03:55 PM

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Matt

Sorry if I sound argumentative - I just like to correct misunderstandings of how things work if it's a subject I'm interested in. But I should stop now unless you want to learn more.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

Quote from: Matt on November 02, 2018, 07:22:12 AM
Sorry if I sound argumentative - I just like to correct misunderstandings of how things work if it's a subject I'm interested in. But I should stop now unless you want to learn more.

It's hard with text in general, but It's ok. Comes with the area of subject too, wanting to clear up misunderstandings. And, no go ahead and continue since I pressured the point initially with my understanding. Far to tired and late to go googling things. May even pass Out here. In bed as is.

Tangled-Universe


Matt

Quote from: WASasquatch on November 02, 2018, 07:20:35 AM
Quote from: Matt on November 02, 2018, 07:12:54 AM
Would you like to know why mass doesn't matter here? Or shoud we wrap up the conversation?

Sure, though I imagine it's just the size of the mass in relation to the absolute massive mass (ha pun) of Earth.

Yes. The force of gravity is proportional to the mass of the earth plus the mass of the other object. however, when the mass the object is very small compared to the earth (which is true for both a feather and a spaceship), we just do the calculations for the movement of the feather or spaceship, and assume the earth stays in one place. Or in other words, whether its a feather or a spaceship, the total mass is essentially just the mass of the earth, so the calculations are the same for both objects. EDIT: I got this wrong, sorry!

Another way to look at it is this: The force of gravity pulling on a spaceship is much larger than the force on the feather, because the force is proportional to the mass. But the acceleration on the feather is the same as that on the spaceship because acceleration = force / mass. So the mass cancels out.
Just because milk is white doesn't mean that clouds are made of milk.

Matt

My favourite intuition of this is that everything is made of particles, every particle is being accelerated by earth's gravity by the same rate, and larger bodies are just larger collections of particles all accelerating at the same rate.
Just because milk is white doesn't mean that clouds are made of milk.

digitalguru

Quotesparks debate
damn so it did :-) - turned into a very informational thread

QuoteIn the absence of atmosphere, feathers fall at the same speed as cars.

It's one thing knowing it, another seeing it - check this amazing footage from the BBC:
https://www.youtube.com/watch?v=E43-CfukEgs

WAS

Quote from: Tangled-Universe on November 02, 2018, 07:30:47 AM
It seems WAS is classically mixing up mass and weight...

??? I don't think so. Weight is a product of gravity from mass. Which is why there is infuence from massive masses.

Quote from: Matt on November 02, 2018, 07:34:32 AM
Quote from: WASasquatch on November 02, 2018, 07:20:35 AM
Quote from: Matt on November 02, 2018, 07:12:54 AM
Would you like to know why mass doesn't matter here? Or shoud we wrap up the conversation?

Sure, though I imagine it's just the size of the mass in relation to the absolute massive mass (ha pun) of Earth.

Yes. The force of gravity is proportional to the mass of the earth plus the mass of the other object. however, when the mass the object is very small compared to the earth (which is true for both a feather and a spaceship), we just do the calculations for the movement of the feather or spaceship, and assume the earth stays in one place. Or in other words, whether its a feather or a spaceship, the total mass is essentially just the mass of the earth, so the calculations are the same for both objects. EDIT: I got this wrong, sorry!

Another way to look at it is this: The force of gravity pulling on a spaceship is much larger than the force on the feather, because the force is proportional to the mass. But the acceleration on the feather is the same as that on the spaceship because acceleration = force / mass. So the mass cancels out.
[/quote

The second part is a good anaology -- the particles.

By that logic makes me wonder though, is there really a terminal between the moon and Earth or other objects? And is it big enough to float an item? ]

Tangled-Universe

Quote from: WASasquatch on November 02, 2018, 02:10:49 PM
Quote from: Tangled-Universe on November 02, 2018, 07:30:47 AM
It seems WAS is classically mixing up mass and weight...

??? I don't think so. Weight is a product of gravity from mass. Which is why there is infuence from massive masses.

Ehm... No.
In the context of this discussion you are mixing it up.

WAS

Quote from: Tangled-Universe on November 02, 2018, 05:58:47 PM
Quote from: WASasquatch on November 02, 2018, 02:10:49 PM
Quote from: Tangled-Universe on November 02, 2018, 07:30:47 AM
It seems WAS is classically mixing up mass and weight...

??? I don't think so. Weight is a product of gravity from mass. Which is why there is infuence from massive masses.

Ehm... No.
In the context of this discussion you are mixing it up.

How so, though? Weight is a product of mass of an object and gravity within the SOI that an object resides. So a object in deep space with no other SOI effecting it; is weightless, but creates weight for things much smaller than it's mass. Which causes the object to pull towards it COM (center of mass).

I don't see how I'm mixing them up? I may have dyslexicly used weight, but the fundamental theories are so polar they don't even apply to anything we're talking about (until hitting the atmospheric conditions in decelerating that is)