Mighty tiny car?
200 times 100 grams is 20 kilos. That's a feat of engineering for a full-size car.
Six robot ants, weighing a total of 3.5oz (99.2g), have managed to pull a 3,900-lb (1,769-kg) car by mimicking the behavior of wild ants and using a few other tricks of nature. The mighty miniature machines, dubbed Microtugs, are the brainchild of boffins at the Biomimetics and Dextrous Manipulation Laboratory at Stanford …
But the car is on wheels and is being pulled horizontally, reducing the actual resistance to pulling. If a car is on a flat surface and in neutral with the brakes off, a man can push a car or tow it via a rope and get it to roll. This is about the same feat, only the pullers are a lot smaller.
"The weight of the entire car merely influences the speed at which they can pull it."
It actually only influences the accelleration of the car, not the speed.
Wind resistance and other resistances that increase with speed affect the terminal speed. The weight doesn't change with speed.
The weight doesn't change with speed.
It does as the speed approaches C...
Quick, someone ask Randall what would happen if a bunch of mechanical ants were able to accelerate a car to close to the speed of light. (I mean, I have a good idea of what would happen, but he's the master of the colorful description.)
On a related note, I'm disappointed at how many of the pedants above omit factors such as the angular momentum of the car's wheels, air resistance, kinetic energy lost to the stretching of the tow rope, etc. (I'll let "rolling resistance of the tyres" cover a variety of factors, like simple force of rolling friction and energy lost in distorting the tires.) Merely a matter of resistance in the bearings indeed!
"But the car is on wheels and is being pulled horizontally, reducing the actual resistance to pulling. If a car is on a flat surface and in neutral with the brakes off, a man can push a car or tow it via a rope and get it to roll."
The robots are also on wheels. On the face of it one would expect them to drag themselves backwards towards the car even if their brakes are on. The really remarkable thing here is the adhesion of the robot wheels which prevents this.
Watching the video, they seem to pull, then release and move forward (the steady winching gait that is mentioned). It looks as though the robots have wheels to pull them forward when the rope is slack, then put down a sticky pad when winching.
That area of the pad is still small, even combined across all six, so it is still impressive. At the same time, if I'm pushing on a car, the total area of my shoe that is in contact with the ground isn't all that much. I can take advantage by leaning forward rather than trying to push while standing straight, and so-on, so it's not an apples-to-apples, making these little guys even more interesting.
It isn't that hard to push a car. When I was 8 my dad couldn't start his car and told me we were going to push it out into the driveway so he could open the hood and take a look at it, but he needed to get something from in the house first. Unfortunately for him he'd already put it into neutral, so being a kid I did what kids do and tried to push it myself. Which worked great, I was able to get it moving, but once all of it was in the driveway there was a bit of downslope so I couldn't make it stop.
Luckily he came out just as I was struggling to pull on the front bumper and make it stop and was able to jump in the open driver door and hit the brake before it rolled into the fire hydrant across the street! And I learned a physics lesson about how easy it is to get a car rolling on a level surface by pushing on it, and how difficult it is to make it stop on a non-level surface by pulling on it :)
@Seajay - many commenting here aren't paying the slightest attention to such 'details' like the smooth polished granite floor, or thinking about what they likely did to the tires, or noticing the disclaimer on the 20x sped-up video. They're just mindlessly comparing this stunt to 'that time when I had to push-start a Buick.'
Thank you for retaining your skeptical thinking skills.
"Nevertheless, the robots are still pulling more than 200 times their own weight, which is better than a few million years of evolution have managed to do for the ant."
That's a bit unfair, isn't it? After all, the tiny bots mimic ants - so their design is based on evolution's try and error development process of the ant. Being both improved and enhanced by a less random approach and the use of modern artificial materials. Try to come up with the idea of something that doesn't exist yet and use chitin to make it, see how long it takes you to get anywhere.
Nevertheless, that really is some very nifty engineering! (The demonstration also implies a knack at showmanship.)
As long as no one hooks them up to a malevolent AI, resulting in something like a mechanised version of Phase IV, we're good.
A great book indeed - and includes a car stereo that turns every cassette tape into Bohemian Rhapsody ("Is this the real life - no it's just Battersea").
A bit like the Waif-o-matic (TM) that every f@cking TV advert is using at the moment to get some 80s/90s classic songs to sound like they have been sung by the same insipid waify-girly singer.
Aaah that's better - glad I got it off my chest.
Upvote here for the Waif-o-Matic(TM), too.
Quick mental exercise, at the risk of taking this thread off-topic - what's the least appropriate song you can think of for the Waif-o-Matic treatment? In other words, what song, if sung in that breathless soya-vegan-latte-coffee-shop wanna-be-folkie style, would most make you doubt the existence of a fair universe?
My vote goes for Ace of Spades, as performed by Lemmy (RIP).
JS "BTW that's 17832x their collective body weight... Which is..."
...Which is 'Scaling Laws'.
Run the numbers for wee microbes that push and you'll get even bigger ratios.
Elephants are rubbish at pushing and pulling, when measured by a ratio. Ants blow them out of the water.
"Elephants are rubbish at pushing and pulling, when measured by a ratio. Ants blow them out of the water."
But of course elephants have a trunk up on the ants in terms of total strength. While some colonies of ants can collectively tear apart an animal with ease and then hide in a tree, one adult elephant could probably knock down the tree and then pick it up with his incredibly strong trunk. Each can be dangerous in its own way, as different groups of people can attest.
What happens when the glue runs out?
It's not glue in the traditional sense. They've been researching gecko feet for a while now due to their ability to adhere to just about anything and even crawl upside-down without assistance (insects and spiders employ different techniques: typically clawed leg tips and/or soft pads; those with the latter can climb smooth surfaces like glass). It turns out their feet are covered in nanoscopic fibers that can slip between molecular bonds and exploit van der Waals forces (a form of electromagnetic force). Now that the force is understood, scientists have been endeavoring to recreate these feet in the lab. First attempts used directionality of adhesion, but it seems they now have gotten to the point of exploiting the van der Waals force.
From the description in the article, it sounded like the were using ultra sticky glue on their wheels to pull the object forward by moving themselves.
But from the video (I watched without sound so maybe the commentary made it clearer) it looks like they use the wheels to move forward, playing out thread as they go, then pull up the wheels allowing the flat plate with glue to stick to the floor, then draw the thread in pulling the object to them, repeat as necessary.
That's what I originally thought as well, but I'm not sure that really matters.
If you set them up as 2 alternating teams you can get continuous motion regardless, and possibly also start building up momentum. I don't think you'd be braking a speed limit soon, but the ratios here are impressive :).
Six robots x 40 N = 240 N = 54 lbs-force
So "the car" here could also be towed around by a toddler, or a toy poodle.
It's a shame that genuine technical accomplishments are being so prostituted by obnoxious click-bait claims. It's become the rule.
I'm pretty sure if you put a kid in a harness and tell him to pull the car, three things are going to happen.
1. He will look at you blankly he hasn't learnt to speak yet.
2. The car will stay still.
3. Child services might want to have a word.
@Triggerfish
It's about 240 N force, according to an original source. 54-lbs force. A couple of toddlers in harnesses and a few toy poodles in a sack, all tied to a rope and dangled over a balcony with a pulley (hypothetically only of course!), and blam, there's the exact same 54-lbs force applied as these half-dozen gidgits. All they need to do is dangle.
A single toddler could likely exert 50+ lbs force given some unreasonable assumptions.
Toy poodle, perhaps not.
Well yes, I know you are not actually needing loads of force to push a car on a flat level plane etc, However the churlishness you made your point to overriding what frankly is bloody clever, the glue is probably the cleverest part tbh, along with not actually defining the size of the poodle or toddler made me feel like I could take the mickey a little.
As a gent who's roll-started many manual-shift cars (with dead batteries) on level ground, I assure you that neither a toy poodle nor a toddler can perform this feat.
Granted the "ants" are too slow to start the engine, but it's impressive nonetheless.
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Tikimon "who's roll-started... ...on level ground..."
Well duh, who hasn't?
But more than an order of magnitude in the difference...
1) You forgot to place your subject car on a dead level polished granite floor
2) You forgot to overinflate the tires to max pressure or higher
3) You forgot to speed up time/video by 20x
4) You forgot that these gidgits aren't up to roll-starting, only imperceptibly budging
Given the numbers provided, about 50-some lbs force, anyone could roll this car AS SHOWN with one finger. It's a stunt. The technical interestingness is there, but it's been swamped by the stuntyness. As a species, we are losing our ability to view such things with even a modest amount of skepticism.
To "synchronize their footsteps"
According to a biography, old Nik Tesla once claimed that he could knock over a building with a small clockwork mechanism, tapping a beam at the building's resonant frequency. I guess he was out sick during the Physics 101 lesson on friction, energy loss, and damping.
Smart guy, no doubt. But missing a few key neurons at the same time.
I think he's thinking more about the Broughton Bridge, also known as the Breakstep Bridge for the directions for formations of soldiers to break step while crossing. That said, the MythBusters covered both myths (Breakstep Bridge first, then Tesla Earthquake Machine).
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Wuh ? How ? Is there a tiny ant with a tinier whip to keep time ?
Seriously though, I can't wrap my head around that one. How on Earth do dozens of ants in a chain synchronize their footsteps ? They can't talk, so . . . how did Mother Nature evolve a method of transmitting time signals to and by creatures with a brain the size of a grain of sand ?
<mind blown>
It's amazing what a tiny brain can do --- check out a miniature spider called Portia.
Beat me to it! Another Blindsight/Echopraxia fan, I hope. ;)
As to the original question: Insects communicate with pheremones (which are slow) and movement (which isn't so slow). An instinctive firing of mirror neurones in their tiny brains when they detect the movement of a friendly ant (i.e. he smells right) could cause them to synchronise their footsteps literally without thinking about it.
Fuck: We're back to Echopraxia.
They all sing in choir, and march in step. Popular ant working songs are Queen's "We are the champions" and "House of the rising sun" by, you guessed it, The Animals. Ants like the 6/8 time that goes well with six legs, but they don't like to waltz.
Anyway, I think they do it all with acoustics.
As the Reg probably has some slight ambitions in the scientific direction (all engineers should know a bit about science), as well as being correct, let me point out that grammes and kilogrammes are not units of force (they are units of mass).
They make absolutely no sense as substitutes for Newtons when used for something pulled perpendicularly to the gravity field (the car).
Rewriting the article to make sense, and call out the "boffins at the Biomimetics and Dextrous Manipulation Laboratory at Stanford" for their deceptive stunt, would be my recommendation.