These days, everything seems to be made out shit & piss.
What if a planet that is Earth-sized falls down on Earth from let’s say 5-10 meters though?
Straight to jail.
A thing that size would have initial velocity to begin with,
But acceleration does not depend on mass, (which is kinda weird from an earthling’s perspective), which Einstein formalized in an amazingly powerful theory called General Relativity
It would fall at 2g, because two Earth-sized masses attract each other in that case. With smaller objects it’s just 1g, because the mass of, let’s say, a nice cup of tea is negligible compared to the mass of Earth.
Aristotle said so much dumb shit, like he said that women have less teeth and never bothered to check
To be fair to Archimedes, heavy objects do usually fall faster than light ones*, and to be fair to Newton, stuff coming towards you usually has a higher relative velocity than things going away from you.+
*You need your objects to be weigh a lot relative to their air resistance to notice otherwise.
+You need some pretty ambitious equipment to detect that electromagnetic radiation such as light does not follow this pattern.
If you like novels I highly recommend Galileo’s Dream by Kim Stanley Robinson. It has a moment where Galileo realizes you could “weigh” time, in his experiments with objects rolling down an inclined plane.
I am most certainly not a science whiz but it’s so goddamn funny to see this whole comment section full of people just… explaning and correcting each other poorly with varying degrees of correctness. Just like 50 half-true and misremembered tidbits from everyone’s intro to high school physics class, blindly seeking targets in space. I promise you guys, there’s a very straight answer to this like two or three clicks away, written more clearly and succinctly than anyone here is managing to do.
I have noticed there is a bit of a more “anti intellectual” bent on Lemmy compared to Reddit. Like there is a lot of stupidity on reddit but usually someone comes in with actual knowledge. On Lemmy I just see people arguing in circles with each other with nobody ever actually looking anything up.
Like there is a lot of stupidity on reddit but usually someone comes in with actual knowledge
Be careful with that, actually. Reddit mastered repeating an explanation or analogy they read on another thread or saw on YouTube, but being quite eloquent at explaining it. Problem is, if they misunderstood it to begin with, they’ll just as confidently repeat a broken version.
I didn’t notice it at first… then I started seeing explanations for things on my field and cringed at how wrong they were, and then I started noticing the pattern and the very repeated analogies on other areas too.
IMO, it’s okay to have casual conversations without being an expert or researching every post. Redditors’ habit of fact-checking everything is honestly tiring. Conversation has other purposes besides education. I think many people are looking more for human interaction than for correct facts.
Right but conversations about science where all parties are wrong and nobody is willing to actually look shit up are completely pointless. It’s the exact same problem that caused the situation in the OP in the first place.
actually your wrong
You’re*
wrongrightFTFY
Don’t tell them that. You’re contaminating my petri dish. ;)
Lemmy (or most social media) in a nutshell.
Rosencrantz: [holds up a feather and a wooden ball] Look at this. You would think this would fall faster than this.
[drops them. ball hits the ground first]
…and you would be absolutely right.~ Rosencrantz & Guildenstern Are Dead
Brilliant, brilliant film.
https://www.usgs.gov/water-science-school/science/how-much-does-a-cloud-weigh
Doing the math: 1,000,000,000 x 0.5 = 500,000,000 grams of water droplets in our cloud. That is about 500,000 kilograms or 1.1 million pounds (about 551 tons). But, that “heavy” cloud is floating over your head because the air below it is even heavier— the lesser density of the cloud allows it to float on the dryer and more-dense air.
Planes, helicopters- lots heavy stuff not falling faster than lighter ones
Try dropping your phone from a hot air balloon and see which one hits the ground first.
A hot air balloon masses a lot but weighs nothing
Theres a yo’ mama joke in there somewhere.
If you want to be pedantic, it weighs less than nothing.
If you want to be really pedantic, it weighs a lot, but the upward buoyant force from Archimedes’ principle counteracts it completely, and then some.
When accounting for air resistance, heavy objects do fall faster than light ones. They couldn’t test in a vacuum back then, they only knew how things work here in Earth’s atmosphere.
A similar size chunk of iron and coal would have done the experiment just fine. Any two objects of the same shape and size but significantly different densities.
They could just drop an empty bs filled wine bottle.
Maybe fill it with mercury (but don’t drink it)
If two objects have the same size and shape, the force applied by air resistance will be the same. However, if two objects have different mass, that same force will result in different acceleration.
So change the shape, a long copper rod and clump of coal.
If you do that then they definitely won’t fall the same.
The acceleration will be 1G minus drag. The Earth is sufficiently larger than anything one would drop off a tower so the weight of the dropped thing doesn’t matter at all
How does your model of the universe explain the hammer and feather dropped on the moon by Apollo 15’s David Scott landed at the same time?
Ed. There is an effect of buoyancy that will make denser things fall faster. It becomes noticeable in distances where the dropped items reach terminal velocity or on more dense media where buoyancy is more significant.
In air over short distances buoyancy is negligible, in vacuum there is none
minus drag
On Earth, this is the part that makes it so that objects do not fall at the same speed.
on the moon
This is the type of experiment they could not do 2000 years ago.
minus drag
On Earth, this is the part that makes it so that objects do not fall at the same speed.
That is incorrect. Drag affects both equally. The difference is caused by buoyancy, less dense objects feel more buoyancy
Drag doesn’t exist in a vacuum.
Buoyancy is functionally irrelevant here. Buoyancy in air effectively subtracts 1.3kg per cubic meter of each substance: The mass of the volume of air displaced by the object.
The part you are not understanding: Drag applies the same force to both objects. Gravity applies the same acceleration to each object.
Thanks that does make sense
If F is the same but m is different, what happens to a?
The Earth is
sufficientlylarger than anything one would drop off a tower that the weight of the dropped thing doesn’t matter at allF=ma.
Two items of the same shape will have the same amount of air resistance. If they have significantly different masses, the two object experience commensurately different accelerations (or reduction in acceleration), even if the force is the same.
If you take a balloon full of tetrahexofluroride (a gas 6x the density of air) and a chunk of iron the exact same size and shape and throw them off a building, I guarantee the iron chunk will hit first.
How does your model of the universe explain the hammer and feather dropped on the moon by Apollo 15’s David Scott landed at the same time?
It’s called a vacuum, which is famous for not having air resistance. Y’know, the thing we’re talking about?
To perform the experiment properly on Earth where there is air resistance, you need to pick a shape and range of masses that minimize the effect of air resistance
You are wrong. Falling in a medium is slowed by buoyancy and drag
F=ma has nothing to do with it
buoyancy and drag
F=ma has nothing to do with it
Motherfucker, do you seriously not understand that buoyancy and drag are forces?!?!
Sit yo’ Dunning-Kruger ass down
Valid crashout. 🤣
https://en.wikipedia.org/wiki/Dunning–Kruger_effect
Without the m as the browser will decide for itself if it needs the mobile version.
Read their claim again: they are specifically describing the effect of air resistance. Their claim is perfectly consistent with the lunar feather/hammer experiment.
Their problem was that they weren’t able to say why, and no one replying to me was able to do more than say they’re right, I’m wrong. See my edit. I added a correction after looking up drag equations for myself and finding that buoyancy was a factor
Also, thank you for replying civilly
They did. You didn’t understand what they said.
Two items of the same shape will have the same amount of air resistance. If they have significantly different masses, the two object experience commensurately different accelerations (or reduction in acceleration), even if the force is the same.
The “same force” they are talking about is drag. The two objects are the same size and shape. At the same velocity, drag affects them both equally, applying an equal, upward force against both objects.
Gravity (in a vacuum) accelerates both objects equally. But they have differing masses. F=MA. F/M = A. A is equal for both objects. Because acceleration is equal, the “force” on each object is not: the force must be proportional to its mass: The high mass object must be experiencing high force; the low-mass object must be experiencing low force.
Subtract the “same force” of drag from the downward force on both objects, and the net force on each object is no longer proportional to the mass of each object. Consequently, the high-mass object accelerates in atmosphere faster than the low-mass object. The high-mass object has a higher terminal velocity; the low-mass object has a lower terminal velocity.
For the purposes of this experiment, buoyancy is functionally irrelevant. The effect of buoyancy is to subtract a fixed mass from each object: A mass equivalent to the mass of air displaced by the object. Effectively, buoyancy slightly reduces the density of both objects. The actual difference in the densities of the two objects is far greater than the slight change due to buoyancy in air, so buoyancy is not a significant factor.
While that is true, two properly selected objects (such as the ones mentioned above) can reduce the effect of air resistance to levels negligible to human perception, demonstrating that heavier objects do not intrinsically fall faster.
Not at all. Our air is made up of physical objects (molecules of oxygen and nitrogen, mostly). Things with more mass, more quickly knock those out of the way.
For a demonstration you can see and more easily wrap your head around, take something just barely heavier than water, and a similarly sized heavy rock and drop them in a pool. You’ll see how much quicker the rock gets to the bottom, because it displaces the water so much faster. Our atmosphere is the exact same.
It seems maybe you’re actually misunderstanding. As I mentioned above, both you and the other commenter are certainly correct that the surrounding atmosphere (water in your case) exerts force on the objects as they fall, with varying effects depending on object density. However, if you take two objects that have vastly more density than the water (let’s say a big tungsten rod and another tungsten rod that has a hollow core), they will drop at approximately the same rate in the water even if their density vs each other varies. The greater the difference of their density versus the density of the medium, the less the effect of the medium. Is there still technically an effect? Sure, but that effect is negligible from a human perceptual perspective.
I understand what you’re saying (call it like a 10" 100 pound tungsten ball vs a 5" 50 pound tungsten ball) but your reasoning and logic of being essentially the same are just silly and the math that would dictate when each would land in atmosphere would still line up perfectly (which would be that the heaviest one will hit first). even if it were a 10,000 pound ball and a 5,000 pound ball.
The difference is the different buoyancy of the balls in air. That’s negligible.
And the iron would hit the ground much faster because it pushes air molecules out of the way quicker.
Nope, denser objects fall faster than less dense ones (through the air). Remember: A kilogram of feathers is just as heavy as a kilogram of lead.
Not really true, it’s definitely possible for a less dense object to fall faster than a denser one. A drop of water will fall faster than a parachute made of nylon, which will fast much faster than a glider plane made of metal.
Nope, denser objects fall faster than less dense ones (through the air).
Technically it’s objects with a higher mass-to-drag ratio, but most of the time it’s close enough
I’ll still choose to be hit by the feathers.
You’ll get hit by what you’re told to get hit by and you’ll like it.
The thing that always gets me about the Renaissance is Galileo:
He did those experiments with things falling down? Measuring speed?
Yeah. Without a clock.
The theory for how to build those came later, based on what Galileo did.
Clocks existed then though. The oldest clocktower in Europe that still exists was built over 100 years before Galileo was born, and time measurement existed longer than that. You can measure time fairly accurately with water clocks which had been known for thousands of years before Galileo. Not having “modern” pendulum clocks yet doesn’t mean that they didn’t have any way to measure time. Even without water clocks you can get decently reliable measurements of time with rhythmic chants (think how today we might say "one Mississippi, two Mississippi, etc.). Early alchemical recipes often include time measurements in chanting a specific prayer or passage a certain number of times during a specific step. Sure you’re not going to get milisecond level accuracy this way but you don’t really need that for a lot of things. Hero of Alexandria built mechanical automata 1500 years before Galileo using pulleys and weights as timers. Time measurement not only existed before pendulum clocks, it was pretty decent.
Couldn’t even measure it in Mississippis because they hadn’t discovered it yet.
Man, being a cop must have sucked before they invented time.
Officer: do you know how fast you were going?
Lord: No, do you?
Officer grumbles: you’re free to go.
Carriage pulls away
Officer ClocknTime: For now, for now.
Alright, I’m stealing this one for a Pathfinder session
With same gravity constance everything fall down at the same speed, but only in a vacuum. In an atmosphere there count the air resistance of an object, even if they are made of the same material and weight, an iron sphere of 1 kg fall faster than a iron sheet of 1 kg.
That’s why Gallileo’s balls were so special.
With two metal balls, one solid and one hollow, you could rule out the role of resistance?
I assume you mean keeping the outer diameter the same and making one ball lighter than the other. That’s clever, it would eliminate aerodynamism as a factor.
However wouldn’t results still vary, since hollowing out the metal ball increases its buoyancy ? (Archimedes’ principle).
They would have the same coefficient of drag, correct, but the air resistance would end up having more effect on the lighter mass of the hollow sphere, so it would be slightly slower to fall.
Archimedes principle here is accounted for in the different weights. Everything that you can put on a scale is already being acted on by Archimedes principle in air.
Except if you could measure exactly the speed of objects falling in a vacuum, the heavier object would appear to fall faster due to the gravitational pull on the Earth. You’re forgetting the Earth falls toward the object too.
No, mass or weight of an object is irrelevant, in one of the jurney to the Moon, astronauts demostrate it with an hammer and a feather on the moon that both fellt at the same speed. It exist one gravity aceleration, on earth is 9,82 ms², which is the force of acceleration which experiment any object on Earth, the only difference which can slow it down is the resistant of air, this can be different in each object, but without atmosphere there is nothing which slow down the acceleration of the object, it’s irrelevant the material, weight, mass or form. Basic physic
The difference is far too small to measure at these scales, the Earth would be falling toward the more massive object faster than the less massive object. Therefore the more massive object hits first.
It has nothing to do
deleted by creator
R^2 is on the bottom. We don’t ignore the mass of one object because it’s insignificant, that would make the top of that equation 0 and the object wouldn’t fall at all.
That nifty gravitational law gives you the force of gravity on an object, not the acceleration. Force also equals mass times the resultant acceleration, right? So Fg1 = m1*A1 = G*M*m1/r^2 and Fg2 = m2*A2 = G*M*m2/r^2. m1 and m2 are present on both sides of those equations, respectively, so they cancel, and you get A1 = G*M/r^2 and A2 = G*M/r^2, which are identical. The mass of an object affects the force of gravity, but when you look at acceleration the mass terms cancel out.
You’re right, I had it wrong. Misinformation deleted.
No worries, no big deal
The four phases of matter! Solid liquid gas and plasma!
Wait… What about the other 16 phases?! Those are the cool ones
Ice I, ice II, … all the way to Ice XVI!
Did you know that two identical triangles are identical to each other
But what about three identical digons?
It’s how Arthur fell faster then Fenchurch. He was heavier.
The trick was to throw yourself at the ground and miss
I always do this.
Except of course when I don’t.
Who?
Arthur Dent
The Sandwich Maker!
I mean, yes and no.~~https://en.wikipedia.org/wiki/Terminal_velocity#Physics ~~Heavier objects have a higher “max speed” that they can fall at, compared to lighter objects. The acceleration to that relative speed is constant though. More or less.IE : While a bowling ball and a ping pong ball might start falling at the same initial rate, eventually the bowling ball will fall faster.EDIT : Ignore me for now, I need to do more digging.
In a medium, which is an important distinction
Yeah, it’s not like they just blindly accepted what he said. They held up a feather or a leaf or a sheet of paper and a lead weight and dropped them both at the same time and the lead weight hit the ground while the leaf was still fluttering in the wind.
That’s not because of weight though. That’s just one thing being affected more by air resistance. In a vacuum, there would be no difference. In fact, they did just that during the Apollo 15 mission on the moon using a feather and a hammer:
https://commons.m.wikimedia.org/wiki/File:Apollo_15_feather_and_hammer_drop.ogv
https://commons.wikimedia.org/wiki/File:Apollo_15_feather_and_hammer_drop.ogv
Without the m as the browser will decide for itself if it needs the mobile version.
Hey buddy! I came to post that video!
I know what is happening. I know why it is happening. My brain is still screaming at the feather to slow down.
Without the m as the browser will decide for itself if it needs the mobile version.
I can’t tell if this is you chastising me or giving me a shovel to help me dig.
Lol I think it’s the research you were missing and I already had the link copied. Wasn’t being a jerk for once, just was giving you info
all good then, thank you :)
The acceleration to that relative speed is constant though. More or less.
It’s not. Air resistance will affect lighter objects more due to Newton’s second law and the square-cube law, resulting in heavier objects accelerating faster than light ones. Only at the initial instant, where there is no air resistance due to the speed being 0, will two objects of different weight be subject to the same downward acceleration.
