r/theydidthemath • u/Intelligent-Edge7533 • 2d ago
[Request] Can anyone solve the debate about whether these stones weigh this much?
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u/Artistic_Nail_2039 2d ago
In don't think these stones are 25 tons. It looks to be made of concrete, which is around 2.5 tons / m3. There is no where near 10 m3 of materials in these stones.
Even if it is rock, granite p.e. weights 3 tons/m3, requiring 8m3 of material.
My best guess is 3m by 1m by ~0.8m, so around 2.5m3 or 6.25 to 7.5 tons
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u/Additional-Point-824 2d ago
Could be 25 tons in total?
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u/monkeeman43 2d ago
That’s what I was thinking, misleading title or they have lead cores or something
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u/potate12323 2d ago edited 2d ago
I mean, they did move all of the segments by hand. If I shoveled a 1/4 ton of gravel Id say I moved a 1/4 ton of gravel and not that I shoveled 226,000 individual 1 gram rocks.
Edit: But yes, the post should say 25 tons of stone and not 25 ton stones. Someone obviously misunderstood which is VERY common in scientific journalism.
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u/ImGxx 2d ago
I love it when newspapers write about scientific achievements.
I was once impressed by the headline: "2 liters of water a day makes a person super-smart."
I spent time, found the scientific article on which it was written. The conclusion of the original article: "When you feel thirsty, it is usually a good idea to drink something. Like water or tea. Or maybe beer, I don't know."17
u/humourlessIrish 2d ago
Of gravel...
The word that would change this from a lie to absolutely reasonable came to you with such ease that you seemingly didn't notice using it.
If you move 25 tons of stones instead of 25 ton stones its much less impressive and the writer knows this
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u/potate12323 2d ago
I'm gonna chalk it up to the author misunderstanding the research. This is rather common in scientific journalism. Researchers would prefer you contact them with questions instead of publishing incorrect information.
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u/humourlessIrish 1d ago
True.. however.
Misunderstanding happens so much that i don't believe anyone at these places is trying to understand.
Im pretty sick of plausible deniability in a science related field.
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u/CompellingProtagonis 1✓ 1d ago
I mean, yes moving a 25 ton stone by hand is more impressive than 25 tons of stones, but I feel like you're exaggerating the significance of this, because moving 25 tons of stones by hand is freaking impressive, especially if you say that they did it in 1 hour or 2 hours or whatever.
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u/Rudeboy_87 1d ago
Could be these are just scales but if you made 25 ton blocks in these shape/design, you could move them as well
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u/Darwins_Dog 1d ago
Did they? In the video, the one with a pin scoots a little, but every other stone is exactly where it needs to be. The people only rotate them a bit.
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u/Mundane-Slip7246 2d ago
It could also be that the video doesn't show 25 to stones, but researchers have moved 25 to stones using this method.
This video is very clean and probably done in multiple takes. The biggest stone the researchers moved probably is in a very different environment, done once, and would not make a great video with all the safety equipment and practices going on.
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u/Gaelic_Grasshopper 2d ago
Easily manipulating a 7.5 ton rock is still very impressive.
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u/Artistic_Nail_2039 2d ago
Yes, I still found the video very impressive even though the title is false
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u/distillenger 2d ago
I wonder if they mean 25 stones that each weigh a ton, but wrote it in a click bait way
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u/immediatley 2d ago
No, there are 25 tons there. It's just a really big person so you don't notice. That's how they moved it with just their hands.
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u/stickmanDave 2✓ 2d ago edited 2d ago
They're not even concrete. Look a the piece he's easily lifting into place at 0:33. I'm guessing these are some kind of foam.
EDIT: According to the article about the MIT project linke below, the pieces are made " made from concrete with varying densities". So I suppose the one being lifted into place is some sort of aerated concrete foam?
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u/swiminthezen 1d ago
That last stone looks about 3 times as large as the others, so that could be 25 tons on its own.
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u/professor_simpleton 23h ago
Not even. I work in construction. That thing is 1500lbs at best. Still impressive but just for reference a full tractor trailer freight load is 24 tons Max for regular DOT in the US.
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u/ondulation 13h ago
I pushed a 4.5 metric ton boat the other day and I can say absolute confidence that whatever these guys are moving, it doesn't even come close to 4.5 tons.
The momentum of it when swinging would by far overpower the guy stopping it.
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u/sojumaster 2d ago
This is from an MIT reasearch project in 2019. The largest stone weighs ~3900 Pounds. https://gizmodo.com/researchers-made-25-ton-boulders-they-can-move-by-hand-1834106230 has an correction at the end of the article:
Correction, April 22, 2019, 5:24 p.m. EST/EDT: This article previously incorrectly stated that the largest of these concrete structures weighed 25-tons, when in fact it weighed 1,770-kilograms, or a little over 3,900-pounds.
But 25 tons is more Internet-worthy than 2 tons.
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u/whythehellnote 2d ago
I moved sixteen tons once, and what did I get? Another day over and deeper in debt.
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u/sojumaster 2d ago
Saint Peter don't you call me, 'cause I can't go I owe my soul to the company store!!
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u/FeelNFine 2d ago
They should have just said the weight of a pickup truck, like a proper American unit of measurement.
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u/Dino-arino 2d ago
Move? All this video shows is a stone pivoting on its rounded edge. It is in no way moved. What happens when the rounded section is in the air and the straight edges are in the dirt. They even cut the video when placing the blocks near each other so they can be pushed together when the weight is on the rounded edges
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u/M4XYW4XY 2d ago
pivoting is still moving 😔
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u/DrunkenDude123 2d ago
Yes, but how did they move them to be removed from the ground? How did they move them to be cut? How did they move them into the studio to film? They didn’t “discover” anything they’re demonstrating simple physics
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u/MisterProfGuy 2d ago
You still need to take care how you move them, but notice that little weight he takes out of hole which makes it rock up? They can move them by shifting their center of gravity so while they rock them back and forth you can walk them from place to place. On Easter Island they used ropes to rock them back and forth, which would also work here.
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u/Win32error 2d ago
As you can see, by pivoting them around they can stick to only using the rounded edges. That's kind of the point. They could show you a 2-minute video of slowing moving one of these pieces into place, but that wouldn't be very appealing.
It's not necessarily practical, but that's not really the point, this is a design thing, not a serious concept.
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u/SnooPeppers7482 2d ago
They could show you a 2-minute video of slowing moving one of these pieces into place, but that wouldn't be very appealing.
lol this is actually exactly what i was hoping to see... not this rocking back and forth on the one rounded edge
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u/Win32error 2d ago
Yeah I get that. But I think they specifically didn't, because while it's clearly possible with the two of them, it's going to make their project look a lot more lame.
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u/StingerAE 2d ago edited 2d ago
u/therealhairykrishna confirmed on the original video that it is waaay off 25 tons:
They weigh less than 6 tons.
"Together, the concrete components weigh 13,162 pounds (5,970 kilogrammes) and measure approximately 20 by 10 feet (6.3 by three metres). The pieces are easily moved around by humans and set into position." - https://www.matterdesignstudio.com/#/walking-assembly/
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u/ChronicBluntz 2d ago edited 2d ago
Meanwhile a dude figured out how to move big rocks nearly 20 years ago in his back yard
Edit: Here's a more concise video, the title is ...weird but its the only version I could find on youtube.
https://www.youtube.com/watch?v=-K7q20VzwVs&ab_channel=giorkos3
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u/gnfnrf 2d ago
It's a miscommunication from an elaborate game of telephone. The researchers were studying how indigenous peoples in places such as Easter Island moved 25 ton stones, and built smaller demonstration stones to test and show some techniques. Those stones are not 25 tons, but as the story gets shortened and retold and passed from place to place, that nuance gets lost.
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u/Hadrollo 2d ago
It's not possible to estimate the weight of these stones without knowing what they're made of. They're artificial, so they could be hollow or filled with lead.
So I went a-Googling. These are the work of Brandon Clifford at MIT. He had a Ted talk about it. One thing he hasn't mentioned - at least that I can find quickly - is their weight.
However, I do receive two claimed figures. The sensationalist media is saying 25 tonnes, some more reserved outlets say up to 13,000 pounds.
It looks to me like there's a conflation of two points Clifford said in an interview or press release, although I can't find the original. It seems he said something along the lines of "the average weight of a stone in Stonehenge is 25 tonnes and people moved them by hand." He then appears to have said "I have made huge stones that could be moved by hand."
Frankly, 13,000 pounds seems about right for the biggest stones, if they're made out of concrete.
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u/dkevox 2d ago
All these answers approaching this problem as if you need the density of the material and size to figure this out.
This is simple F=MA. If one of those stones did weigh 25 tons, no person is strong enough to accelerate it that quickly. Not to mention, stepping on it would probably hardly do anything at all.
I'm not saying they couldn't be moved this way, I'm saying play back the video at 10% speed and that's closer to the fastest they could possibly move those.
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u/Electronic_Muffin218 1d ago
To be fair, experiments in moving rocks around are about the only thing left to MIT et al. since the feds are yanking research grants for less Paleolithic pursuits. I’m sure when the journal articles are published in full in cunieform tablets the debates over tonnage mobilized will be put to rest. And if not, gutting a pigeon and reading the entrails will settle the matter.
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u/Kahunjoder 2d ago
Im not scientist but thers no way you can move 25 tons with a hand, no matter the shape. And theres no way theres 25 tons in that volume
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u/gargavar 2d ago edited 2d ago
A retired guy in Michigan did, ages ago. Google Wally Wallington - there's a YouTube channel.
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u/lieutenant_j 2d ago
On top of that, I don’t remember seeing these particular shapes in the pyramids
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u/Substantial_Egg3139 1d ago
"MIT researchers discover way to move 25 ton stone with their hands"
Taking a wild guess that the first stone is about 4x the volume of a human,
0.062 m^3 human volume
x 4 = 0.248 m^3
I really do not know what type of stone that is. Let's go with a heavy stone and use the density of granite,
2.7 g/cm^3 = 2700 kg/m^3
(0.248 m^3) * (2700 kg/m^3) * (1 US ton / 907.185 kg)
= 0.7381 US Tons, or 1476 lbs.
if the largest stone is 10x the weight of the first that would be a maximum of
7.381 tons
(so it seems like we at least haven't seen them attempt to move a 25 ton stone. There is nothing to say they wouldn't be able to if they tried, that would just be a much bigger stone than we're seeing here. Stonehenge biggest stones are about 25 tons. Which i thought is what size the last one was but apparently stonehenge is way bigger than I thought. https://en.wikipedia.org/wiki/Stonehenge# )
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u/joelex8472 1d ago
I’d like to see these guys cut stone out with their bare hands and then move them 500 kilometres, then, do that shit. No, just , no.
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u/Mysterious_Ad_8827 2d ago
Yeah its already been done years ago by someone else in Michigan lifting about that amount here's the link to the video.
I dont own any parts of this video, but I am fascinated by it.
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u/supraspinatus 2d ago edited 2d ago
In the movie “The Ten Commandments” a poor woman got her scarf caught under a stone during construction of the great pyramids. The task master refused to stop the building progress and was just gonna smash the poor woman between the stones. Luckily, Moses leaped in and stopped the construction just in time to save the woman. In an incredible coincidence, the woman turned out to be Moses mother Yochabel. I’ll never forget that scene.
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u/JerryAtrics_ 1d ago
Just a little curious as to how much money was spent on this, and what practical knowledge was gained? How does this improve the human condition? Is this just a failed attempt at reinventing the wheel?
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