This is what conspiracy theorists don’t get. The world’s scientists are not skeptical of your claims that water has secret spiritual memory because they hate you, they are skeptical because the claim you make, if it were true, would be so important and world-changing that they want to be absolutely sure of it before they endorse it.
The difference is that, to a scientist, “this would be amazing if it were true” is not a good reason to believe it anyway
“Replicate the circumstances, then replicate the results.”
Being excited about being wrong because either way it’s information
This literally is the basis of science that I think a lot of people misunderstand. Science doesn’t prove anything conclusively. What scientists try to do is disprove the leading theory and when they can’t, it adds to the pile of evidence that increases the likelyhood of the leading theory being correct. Even things that we’re very, very, very sure are correct are still like 99.99999999999…% confirmed.
A good example that’s often used to show how it’s more important to try to disprove a theory rather than trying to prove it is the existence of black swans. It was long thought that all swans were white and every time someone saw a white swan, that idea was reinforced. But when someone actually went out of their way to go looking for a black swan, they found a bunch of them!
I feel it is my pedantic duty to inform you that 99.9… is equal to 100.
Only if you’re rounding. 99.9 is still 1/10 of a digit separated from 100, but it’s not equal to 100 for good reason.
But the “…” matters.
It only signifies that the post-decimal nines are repeating infinitely. It still doesn’t make 99.99999…=100 unless you intentionally round the value for some nondescript reason, and even then, rounding off isn’t changing the value, only the perceived value for mathematical simplicity, not objective accuracy.
“.9…” is repeating, but rational. So it’s actually “1” . Let’s do the math.
.9… / 3 = .3…
.3… = 1/3
1/3 x 3 = 3/3
.9… = 3/3
3/3 = 1
.9… = 1
So why is it represented as 99.999… Instead of just 100? It’s because you’re forgetting the fact that fractions and decimals are infinite depending on the magnification. 99.9999… literally goes on forever. That means that no matter how close it gets to 100, it will never be equivalent to 100.
It’s like how you can know infinitely nothing and still think you know everything. 👀🫠
It’s because we can write numbers in many ways. 9900/99 is 100 just as surely as 99.99… is.
Love how you fight this to the death in a thread where people are discussing how a scientific mindset is so important.
MythBusters will always and forever be a treasure.
I miss Mythbusters. These days, the closest thing is Maker youtube channels like Failed Mythbuster Allen Pan, Simone Gertz, William Osman, StyroPyro, ElectroBoom, Stuff Made Here.
Then there’s Michael Reeves to represent the chaos goblin contingent…
My fav was if you could shoot someone in water. Turns out that just 3 ft. of water was enough to stop a 50 cal! So as great of a film as Saving Private Ryan was, the opening scene where bullets wiz thru the sea killing soldiers was pure fiction.
Bigger/faster the bullet the easier it was for water to stop. The small rounds from handguns worked best for shooting into water.
It makes sense once they do the maths but it was a great episode
Bigger/faster the bullet the easier it was for water to stop.
For bullets that’s probably true because of their light weight, but heavy shells from the big naval guns of battleships (12" to 18" caliber) actually carried a long way through water and sometimes hit and damaged target ships below the waterline. The Japanese in particular actually designed some of their shells to maximize their underwater performance.
I wonder relatively what speed those shells would have to hit the water yo behave like bullets and shatter… You wanna revive myth busters and we can find out? Maybe in honor of Grant on his birthday or something would be cool.
We just need a lot of money, some military connections and a way to put the team back together for it
It isn’t that the water is stoping the bullet- rather that water’s surface tension creates a shockwave that shatters the bullet, and this distributes the mass over more fragments.
Lower power cartridges are able to survive that shockwave, or it fragments into fewer slugs which keeps its energy concentrated.
Either way, I wouldn’t want to be near the high powered cartridge hitting the water. You’re going to feel that shockwave.
It is the water breaking it. The water doesnt compress so the water doesnt absorb enough of the kinetic energy fast enough so the bullet fractures. As i understand it anyway. The 50cal is travelling a lot faster so a lot more force is applied on the bigger rounds.
Later on they did a dynamite fishing one and we learned being in water when a large enough shockwave hits is VERY bad for internal organs of squishy creatures in it
It’s the surface tension that causes the shockwave, soapy water wouldn’t have the same effect.
And yes, dynamite explosives are rather more dangerous under water. Which is how torpedos work to break ships without much regard for armor.
Right so its the water that causes it to break because of the surface tension of the water.
Sounds like you are arguing against my phrasing while agreeing with what i understand. Im confused why we seem to be in a disagreement.
Maybe you can school my dumb ass though, can you eli5 what would need to happen for you to say it was the water that does the work on stopping bullets?
This is why most skepticism based programs don’t work, and Mythbusters did.
They didn’t try to be smug about it, they didn’t belittle people who believed in the myths, they never brought religion and politics into it, and the biggest pitfall they avoided: They never pretended that the “science was settled” and that they “already knew everything”, they simply did the research and went where the data took them.
Too many skepticism based programs seem to think the scientific method is running into a church, yelling “FAKE!”, and then running outside to hurl insults at passersby.
Mythbusters didn’t do that, they skipped the dogma and went straight to the science.
Also, most of the myths weren’t “serious”- it wasn’t like they were debunking flat earth or something.
I hate that debunking flat earth is now seen as serious rather than a 5th grade science experiment.
it wasn’t like they were debunking flat earth or something
Though you could do that. And with equipment and a type of experiment that would make sense on their show. The experiment conducted at the very end of the documentary Behind the Curve is perfect. Great big lasers, a simple and easy-to-visualise pass condition. If they had wanted to, they absolutely could have done it.
Could’ve had an episode where they tried as many experiments as they could fit into a two-week production.
I mean, yes.
but their myths generally didn’t piss surprisingly large segments of the population off. it was more… the urban legends that gave them an excuse to blow stuff up, shoot stuff, or otherwise crash stuff; all in slow motion.
Just because no one else has said, Adam has been involved in EFF for a long time. EEF Podcast episode with him in it:
https://www.eff.org/deeplinks/2022/04/podcast-episode-making-hope-adam-savage
Which delights me as he’s more mainstream and so wakes people up to things like the Right To Repair movement.
EFF?
Edit: Electronic Frontier Foundation, apparently.
Yep, Electronic Frontier Foundation. Key players in Right To Repair in the US. With good history of “fighting for the user”.
That and writing down results.
I would say escaping from quick sand and escaping from an alligator chasing me were two major concerns in my childhood. LoL, global climate change was maybe not even on the list, for which I will curse the petroleum industry.
For anyone missing the show, there was a wonderful project called Streamlined Mythbusters where fans edited each episode down to remove the filler, pre and post ad recaps, etc. They usually also would reorder things so each individual myth was seld contained.
It’s wonderful, but some episodes legitimately got cut down to be 16 minutes long with no real content loss, which can be kind of jarring.
Oh god, I forgot, it was during the “REALITY TV!” boom where marketing and hype had more substance than the shows themselves, and if the show had substance… edit it like it is Reality TV…
I do not miss that.
Thanks for the Rec! I definitely miss the show. Adam’s YouTube channel sometimes scratches the itch, but not always.
There is also Smyths, which is the same thing.
Unfortunately Mythbusters edits have a tendency to get pulled from the typical video sharing sites rather quickly. I wish someone would make a torrent of the entire series edited this way, and call it a day.
What, like the pinned post on the smyths reddit page?
Excellent; thanks. I cached the torrent to Real-Debrid, so if anyone reading this so happens to be using that service, you can download the torrent directly at 1Gbps by pasting the magnet link (the first one) in Torrents section of the website.
Thank you so much for sharing this!!
You can find a torrent of all of them. I love putting Plex on shuffle when I’m doing chores around the house.
I wish more people in general would be OK with being wrong. Noone ever learned something new without knowing they’d been wrong
The Elephant and Mice episode was so wild, because if I remember correctly, the elephant didn’t act afraid of the mouse, it acted afraid it would step on and harm the mouse; as if the elephant had a basic understanding and concern for the wellbeing of another creature conspicuously lacking in many human beasts
If we would, we would be all vegan.
Yep. Elephants are wonderfully kind creatures. With my very limited understanding of elephant body language, it didn’t look like an ‘oh no, im scared’ it was more ‘oh hey little guy, didn’t see ya there. ill get outta your way.’
Just smart as hell. This video makes me wonder if elephants legit have a sense of humor:
https://www.youtube.com/watch?v=2VOvEFHDOaU
Animal behavior can be difficult to interpret (and even when descriptions come from experts, I often find myself asking “yeah, but how do we really know that?”), but this looks very close to being like someone who’s known for lighthearted pranks.
I WANT to believe this but I’ve seen too many elephant videos that turned out to be just elephants trained to do a quirky thing for tourists and there’s someone off camera subtly directing them.
Oh my goooooood. This is so delightful, you can almost see the smirk. Thank you for sharing. <3
It’s amazing how intelligent and emotionally mature elephants are. It’s not wonder why people were willing to believe that “Elephants have a moon religion!” line for so long, it seems believable with how often elephants seem to act like chonky humans with a trunk instead of arms.
Curiosity is the best trait nature ever gave us.
My favorite is planes on a treadmill.
Mostly because fans still argue about it and it’s hit the point they had to ban PoaT comments.
Which is insane as it’s not that difficult to understand. When a plane is on the ground, its gear/wheels will roll at ground speed, but the wings provide lift at airspeed.
If the ground is being moved under the plane (as on a treadmill,) the wheels will just roll faster.
Sure they’re not zero friction and some of that needs to be overcome; but this is something encountered on a daily basis all across the world- or rather, the opposite.
If the wind is coming from ahead, its airspeed is increased and the plane needs a lower ground speed to get into the air where if the wind is coming from behind, then they need more.
(This is why carriers set course into the wind when launching jets,)
At no point is ground speed and airspeed necessarily the same (i suppose you could have a calm day, but most days, the wind is blowing at least some.)
I think the confusion is that the conveyor belt is running at a fixed speed, which is the aircraft’s takeoff speed. That just dictates how fast the wheels spin, but since the plane generates thrust with its propeller, the wheels just end up having to spin at double takeoff speed. Since they’re relatively frictionless, that’s easy.
The more confusing myth is the one where the speed of the conveyor belt is variable, and it always moves at the same speed as the wheels. So, at the beginning the conveyor belt isn’t moving, but as soon as the plane starts to move, and its wheels start to spin, the conveyor belt movies in the opposite direction. In that case, the plane can’t take off. That’s basically like attaching an anchor to the plane’s frame, so no matter how fast the propeller spins, the airplane can’t move.
Except it’s not like attaching an anchor. The plane isn’t physically attached.
The wheels will just roll double whatever the current ground speed is. If the plane has enough thrust to take off with the treadmill moving an inverse of its take off speed, then it has enough force to start rolling, too.
At most, the force applied by the treadmill would be sufficient over enough time to lengthen the take off roll, but given enough space to do so, the plane will take off.
To keep the plane from rolling forward; the treadmill would have to be able to apply an equal force as the engines, it can’t do that through the wheels- the wheels can only apply a force equal to their rolling resistance and friction in its mechanics.
If the conveyor moves at the same speed as the wheels, it is exactly like attaching an anchor. That isn’t the myth they were testing, but it’s a more interesting myth.
it can’t do that through the wheels- the wheels can only apply a force equal to their rolling resistance and friction in its mechanics.
It can do that if it can spin the wheels fast enough. Picture the ultra-light airplane from the episode with big, bouncy wheels and a relatively weak propeller. If the treadmill was moving 1000 km/h backwards, that little propeller could never match the force due to rolling resistance from the wheels.
Just to clarify; you understand that because the engines are pushing on the plane itself and not the wheels, by the time the wheels start moving, the plane is already moving relative to ground and air alike.
Which, said another way, this thought problem appears confusing because it’s being considered from otherwise irrelevant reference frames.
An anchor sufficient to keep the plane from rolling forward is different because the force it is apply is significantly greater.
Sure, you can deflate the tires and increase the rate of spin on the wheels. But at that point, you might as well ask “can we creat a scenario where planes can’t take off”
To which the answer is definitely “Yes”,
And as a side note, if we assume the wheels are indestructible, which I’d argue is only fair, then even if what you’re saying is true and we ramp up the drag induced by the wheels sufficient to counter the engines… then the wind generated by the rolling treadmill would be producing a sufficient headwind for the plane to take off. (Remember, the air resistance of the treadmill’s belt moving will accelerate the air some.)
But again, the wheels have almost zero drag to begin with, the speed at which the roll is independent of both the actual groundspeed and the airspeed of the airplane.
If it has the thrust to over come friction at take off speeds, and at standing, then it has enough power to get to take off velocity eventually.
On the other hand, this entire conversation assumes the thrust to weight ratio is less than 1. If it’s more than one, well they just…. Go straight up.
Just to clarify; you understand that because the engines are pushing on the plane itself and not the wheels, by the time the wheels start moving, the plane is already moving relative to ground and air alike.
The wheels are attached to the plane so they move at the same time as the plane. But, I get what you’re trying to say, that the wheels are effectively being dragged by the plane, they’re not powering the movement. But, what you need to think about is that if you oppose that dragging by moving the conveyor belt in the opposite direction you can prevent the plane from moving at all. Yes, the wheels are merely dragging and there isn’t a lot of friction there, but friction increases with speed. And, if you move the conveyor belt fast enough, you can stop the plane from moving relative to the ground, which can stop it from moving relative to the air, which can prevent it from taking off.
An anchor sufficient to keep the plane from rolling forward is different because the force it is apply is significantly greater.
No, by definition it’s the same. The conveyor moves with however much speed is necessary to stop the forward motion of the plane. The conveyor would eventually go so fast that it generated enough force to stop the plane from moving, so it’s indistinguishable from an anchor.
Sure, you can deflate the tires and increase the rate of spin on the wheels.
You don’t need to deflate the tires, you merely need to increase the speed at which the conveyor moves to match the speed of the wheels.
if we assume the wheels are indestructible, which I’d argue is only fair, then even if what you’re saying is true and we ramp up the drag induced by the wheels sufficient to counter the engines… then the wind generated by the rolling treadmill would be producing a sufficient headwind for the plane to take off
That seems like an unfair assumption because you’re assuming that the conveyor belt has second-order effects on the air (i.e. generating a “wind” over the wings of the plane), while ignoring the second-order effects the conveyor would have on the wheels (massive heat from friction leading to failure).
On the other hand, this entire conversation assumes the thrust to weight ratio is less than 1. If it’s more than one, well they just…. Go straight up.
I mean, the discussion is of a plane, not a helicopter or a rocket. Even jet fighters with a thrust-to-weight ratio of more than 1 typically have engines that only have that ratio once they’re at high speed, not from a standing start. That’s why even fighter jets on carriers need a catapult-assisted takeoff. A VTOL aircraft like a Harrier wouldn’t need that, but then its takeoff speed is zero, and the myth isn’t very interesting when the conveyor belt doesn’t move.
The wheels are attached to the plane so they move at the same time as the plane. But, I get what you’re trying to say, that the wheels are effectively being dragged by the plane, they’re not powering the movement.
no. I’m saying that by the time the wheel is rolling, the plane’s is already moving forward, the engines have already overcome the drag in the wheels. the treadmill is locked to the wheels, not the plane. The plane would continue accelerating even as the wheels reported weird rates of turning.
As for the (very brief) time delay, that’s a function of the plane’s gear’s suspension that is quite well sprung.
the rate of roll on the tire is, effectively, decoupled from the airspeed (and groundspeed) of the plane. which makes this:
No, by definition it’s the same. The conveyor moves with however much speed is necessary to stop the forward motion of the plane.
… entirely different. an affixed anchor does not allow the free motion that a wheel would.
You don’t need to deflate the tires, you merely need to increase the speed at which the conveyor moves to match the speed of the wheels.
And one of a few things happen. Either the plane has enough engine thrust to overcome the acceleration induced by the wheels, and therefore takes off, or it does not.
In the case that it does not, the wheels would continue spinning in increasing RPM until the plane begins moving backwards. because, again, the airspeed of the airplane is not dependent on the wheel’s RPM. Assuming the airplane doesn’t crash from suddenly becoming incredibly difficult to control… eventually it would take off anyhow. because the airflow over the wings would still generate lift. (though they would become horribly inefficient.) and therefore take off.
this is of course ignoring the whole “can a pilot actually control that and manage a take off like that” thing. If you don’t want to grant godlike piloting skills, we could then just make the treadmill irrelevant and leave the brakes on.
Plane on a treadmill is really interesting because if you understand how planes work its so obvious what will happen you don’t need to test it. Planes move on the ground by running their engines, which push against the air, the wheels provide zero motive force. It’s also why planes need tugs to move away from the gate, you can’t run the engines in reverse. Planes are not cars, but people tend to assume the thing they don’t understand works like the thing they do understand, and refuse to believe their hasty assumption is wrong even when told directly their hasty assumption is wrong.
You actually can run the engines in reverse. They have thrust reversers. There’s very good reasons that they do not reverse the plane from the stand using the engines, but it is possible.
Which is insane as it’s not that difficult to understand
I found it hard to understand because neither they nor any of the other sources I’ve seen explaining this even attempted to answer what I thought was an incredibly obvious question: at what point does this become true? A stationary aeroplane on a treadmill will obviously move with the treadmill. I assume an aeroplane moving at like 1 km/h still gets pulled backward by the treadmill. At what point does the transition occur, and what does that transition process look like? Why can’t a treadmill prevent the plane from taking off by pulling it backwards by never letting it start getting forward motion? Where does the lift come from?
I can understand how a treadmill doesn’t stop a plane that’s already moving, but how does it get lift if it is prevented from accelerating from 0 to 1 km/h of ground speed (relative to the real ground—relative to the ground it experiences, it is moving forward at the same speed as the treadmill is moving backward), since until it starts getting lift, airspeed and ground speed are surely effectively equal (wind being too small of a factor)?
at what point does this become true?
It’s always true.
A stationary aeroplane on a treadmill will obviously move with the treadmill
What do you mean? The plane has its parking brakes on and moves with the treadmill surface? If you don’t have parking brakes engaged and start up a treadmill under a plane, the plane’s wheels will spin and the plane will stay pretty much in one place. Because the wheels are free to spin, initially that’s all that will happen. The inertia of the plane will keep it in place while the wheels spin. Over time, the plane will start to drift in the direction the treadmill is moving, but it will never move as fast as the treadmill because there’s also friction from the air, and that’s going to be a much bigger factor.
I assume an aeroplane moving at like 1 km/h still gets pulled backward by the treadmill.
Moving at 1 km/h relative to what? The surface of the treadmill or the “world frame”? A plane on a moving treadmill will be pulled by the treadmill – there will be friction in the wheels, but it will also feel a force from the air. As soon as the pilot fires up the engine, the force from the engine will be much higher than any tiny amount of friction in the wheels from the treadmill.
but how does it get lift if it is prevented from accelerating from 0 to 1 km/h of ground speed
It isn’t prevented from accelerating from 0 to 1 km/h of ground speed. The wheels are spinning furiously, but they’re relatively frictionless. If the pilot didn’t start up the propeller, the plane would start to move in the direction the treadmill is pulling, but would never quite reach the speed of the treadmill due to air resistance. But, as soon as the pilot fires up the propeller, it works basically as normal. A little bit of the air will be moving backwards due to the treadmill, but most of the air will still be relatively stationary, so it’s easy to move the plane through the air quicker and quicker until it reaches take-off speed.
A stationary aeroplane on a treadmill will obviously move with the treadmill. I assume an aeroplane moving at like 1 km/h still gets pulled backward by the treadmill.
so, every wheel or ball or any other kind of rolling-thing has rolling resistance, which is how we sum up the total drag on the system. A steel ball bearing on a steel plate will have a significantly lower rolling resistance than, say, a steel cube on that same plate. Tires have some- but not a lot- of rolling resistance.
You can see that in a car, just put it into neutral and watch as you slow down, even on flat ground. Plane wheels also have rolling resistance. it’s just the way our world works. But it’s generally ignored because it’s hard to model perfectly and in any case pretty negligible relative to the amount of acceleration being put out by modern aircraft engines.
A treadmill will only push an aircraft or whatever else along, with an acceleration that is equal to, or lower, than the rolling resistance. If you try to accelerate the plane faster, it’ll ‘slip’, and the plane will remain largely stationary- like the dishes in the tablecloth trick (if you want to try that at home… make sure the tablecloth doesn’t have a hem, heh.)
But, keep in mind you’re thinking about the plane relative to either the ground, or the treadmill’s belt.
the plane’s wings and it’s engines are ‘thinking’ about the plane relative to the air it’s moving through. It’s the airspeed that generates the lift, and the engine isn’t coupled to the wheels, they’re just rolling along doing their thing. (aircraft engines work by taking a volume of air and accelerating it. newton’s equal-and-opposite does the rest.)
Oh wow thank you. This is genuinely excellent and immensely helpful. I think this bit:
A treadmill will only push an aircraft or whatever else along, with an acceleration that is equal to, or lower, than the rolling resistance. If you try to accelerate the plane faster, it’ll ‘slip’
As well as this video that I found where a pilot explains how under specific but unrealistic conditions you could construct a treadmill that does indeed prevent an aeroplane from taking off,
Really helped solidify my understanding of the problem. So you end up with a situation where the wheels are going to be slipping, just like the slippage created when your hand pushes a toy car on a treadmill.
Thanks!
So, another way to think about it is with Kites.
The air flows around it the same way it would any other kind of aircraft, though they have effectively zero ground speed.
They do differ in that, being tethered, they’re pulled through the air, with the wind providing the energy to stay up.
But they’re still moving through the air, and the airfoils are inducing drag to convert some of that energy into lift.
In both cases, the important speed is relative to the air, not the ground and not the treadmill. The wheels might impart some drag while they’re on the ground, but they’re never going to impart enough to overpower the engines- 747s typically take off at about 75% of their rated take off power, which means a longer take off roll, but less wear and tear.
The key insight is that the force a plane uses to move is independent of the ground, because planes push on the air, not the ground.
Imagine you put a ball on a treadmill and turn it on, what happens? The ball starts to spin and move with the treadmill. Now take your hand and push the ball backwards against the motion of the treadmill, and the ball easily moves in that direction. The force your hand put on the ball is exactly what planes do, since they push on something other than the ground (the treadmill) they have no problem moving, no matter how fast the treadmill is moving.
The point it occurs at is when the plane uses the air to propel itself.
but how does it get lift if it is prevented from accelerating from 0 to 1 km/h of ground speed
That’s the thing - it is not prevented from accelerating. The wheels are functionally frictionless. That’s why planes have brakes. The plane pushes on the air to move, & the treadmill could accelerate backwards until the plane’s tires explode.