to ask non-scientists how they think snow globes work....

[M3lon]

...and what would happen if there was no water or air in the globe with the glitter.

All for a good cause I promise!

bobbin have you been playing loom? We just had a loom revival and DD is obsessed with it!

M3lon I love Loom. I am a huge LucasArts game fan.

Yes, it would fall quicker in a vacuum than if there were air or water. Like the feather and the cannonball.

I think it would still move in a vacumn if shaken (things move in space don't they) but maybe as more of a clump. When you stop shaking gravity would act on the glitter and it would fall to the lowest point in the globe (again in a clump).

vacuum

I'll tells you how thems work. Tis witchcraft.

I think it would just fall straight down, whichever way up you held the snowglobe. If you shook it, it would shake about then just fall straight to the bottom.

But I'm wondering now if there's going to be some other weird effect!

m.youtube.com/watch?v=FOipjCkOkiY
Well that’s annoying.
Watched the whole video of a person making a waterless snow globe and then they didn’t even shake it at the end.
I reckon the glitter would stick to the sides tho if he shook it.
But is that jar even a vacuum? I suppose it’s got air inside still right?

Does glitter do something strange in a vacuum? Like melt together into a plastic lump, with some kind of electrical charge. Or explode or expand? Like if a human went into a vacuum, the gases expand the fill the space and so your lungs and blood vessels etc. rupture?

I think it would stick to the sides. Or would the "snow" all be crushed together into a solid lump that would sorta float in the middle?

But practically, as you sucked the air out the "snow" would get sucked out too. So you'd used a filter and then the "snow" would just stick to the filter and then stay there.

I thought they had fairies in them?

(in a flippant mood today)

Off the top of my head, I would expect there to be two differences between a water and a vacuum-filled snow globe.

Firstly, there would be less resistance to motion in the vacuum-filled globe, so the "snow" would generally move around more quickly in response to gravity and/or any other forces.

Secondly, in a water-filled globe rotational force applied to the globe sets up eddies in the water that cause the 'snow' to disperse and move around the globe rather than just straight up and down, whereas in the vacuum-filed globe the 'snow' will generally move in a straight line based on the direction of the force.

I'd expect an air-filed globe to be somewhere in between the two.

•But practically, as you sucked the air out the "snow" would get sucked out too. So you'd used a filter and then the "snow" would just stick to the filter and then stay there.• No it wouldn't. Once you'd stopped sucking, the only force on the glitter would be gravity, so it'd fall off.

basically, glitter is falling because of gravity, but slowed down by resistance from whatever substance it's falling through. therefore will fall slower in water than in air. And in a vacuum there's no resistance at all.

It’s questions like this that reassure me that medical school has not turned me into a scientist.

Erm. I think the glitter would just react to gravity, so it would all clump in the bottom. If you shook the globe the glitter would meet no resistance so would move according to the impetus of the shaking then fall to the bottom again.

I vaguely wondered if the glitter would shatter the glass when it hit it, but I think that doesn’t make sense as the pressure outside the globe would be greater than inside.

Part of me also just wonders if the glitter would just stick to the insides in some sort of staticky way.

Intrigued to know the answer!

I always thought that the glass sort of slid over the 'ball' of water, so, when you invert it, the uneven bottom stirs up the liquid??

This is the sort of thing that my DH would know but I don't have a clue... I'd guess that it might stick to the sides of the globe?

Assuming you are not in a zero gravity environment, wouldn't it still move about when you shake the globe? It just wouldn't float, so it would more be a case of being bounced from side to side/up and down as you moved it. It would all stop on the bottom when you stop shaking.

A bit like a miniature version of Brian Cox's bowling ball and feather experiment in the giant vacuum chamber.

I think that in a vacuum, the glitter would just fall back to the bottom due to gravity, although there might be effects due to electrostatic charge generated by shaking the glitter about, a sort of electrometer effect, if you will. Maybe all the bits of glitter will stand on end or something?

(I am a scientist but I've never done any sort of 'snow globe' science and it's so long since I've done most of the science about from a quite narrow and niche bit of physics, that I've forgotten most of it)

what kind of vacuum? Like in space? or just no air? If we are including gravity then it will fall to the bottom no? If space like vacuum then it would float?

Or if you shook the globe when it was a vacuum inside would the glitter start bouncing off the sides and never stop.

Even in a vacuum there would still be gravity so as others said it would fall, but faster and without the swirling around.

Surely in a vacuum it would fall at the same rate of 9.8m/s2

Take a bucket with some metal balls at the bottom (small and heavy, so that the air resistance does not have much of an effect). Then shake it. The balls would bounce for a bit and then settle at the bottom.

That's what would happen.

STick to the sides or make a lump?

magic and God.
Seriously, isn't the "snow" just some sort of floaty stuff?