There’s a certain post that floats around the Internet with some regularity, and it caught my eye. It shows us a Chevy Bolt with what appears to be some kind of generating apparatus attached to the rear wheel. The post states that the rotation of the car’s wheel is used to recharge the EV’s battery as it drives along, avoiding charging stops and paying for electricity! Genius, right?
And yet, we know that’s too good to be true. If slapping an alternator on the rear wheels was enough to make electric cars run forever, everyone would be doing it. We’d never burn a drop of petrol again.
You might be wondering, though, precisely why this doesn’t work. Or, you might have a rough idea, but you want to be able to definitively explain to family and friends why this isn’t the magical solution to all of America’s transport woes. Today, we’ll dive into thermodynamics and examine what’s really going on here. Don’t worry—it’s easy! Plus, we’ll even try and figure out why someone might have built this in the first place!
Thermodynamics Is Not a Dirty Word
Let’s start by examining what we have here. We have the rear wheel of the car connected via a belt drive to what appears to be an alternator or generator of some sort. When it spins, it makes electricity. That electricity could of course be put to use charging a battery.
That all makes sense. But does this mean we should all be putting generators on our EVs to drive forever? Well, no. Because no matter how much energy you get out of the generator, you’re spending more power to turn it using the car’s motor. It’s simply not possible for the generator to produce more energy than the Bolt’s motor had to spend to get it turning in the first place.
Let’s make a diagram. I’m using the terms “kinetic energy” and “mechanical energy” to mean basically the same thing—energy from motion. It’s a little simplified, but it should give you an idea of how this all goes down.
It all comes down to the thermodynamic principle of conservation of energy. In very basic terms, energy cannot be created or destroyed. It can be converted from one kind to another, but you can’t create new energy.
This is why perpetual motion machines, free energy machines, and this “wheel generator” concept don’t work, and simply cannot work. If you had some kind of rotating machine which rotated forever, and you could get some kind of work out of it – say, by having it turn a generator – it would be creating energy. That’s simply not possible, due to the laws of physics. For the same reason, you can’t put a generator on your car’s wheel, recharge the car’s battery via the electricity generated, and drive forever.
In the case of the Bolt, the electric motor converts the electrical energy from the battery into motion. It accelerates the vehicle and spins the generator. The generator then turns rotational energy back into electrical energy again. All the energy coming out of the generator originally came from the EV’s battery itself. The generator didn’t make any energy, it just converted energy from one type to another.
A further lesson that thermodynamics teaches us is that every time we convert energy from one type to another, we lose some. For example, a light bulb turns electricity into light, but we also lose some as heat. Combustion engines turn chemical energy into motion, but they also have losses through heat and noise.
It’s the same case here. The energy from the EV’s battery is converted multiple times, each time with some level of efficiency less than 100%. The EV’s motor doesn’t turn 100% of the battery energy into forward propulsion, and the generator doesn’t turn 100% of the rotational energy it harvests into electricity. Even if you feed its output back into the EV battery, you’d be getting less energy out of the generator than you were spending to turn it in the first place.
Simply put, turning the generator adds to the load on the vehicle’s drive motor. The EV’s motor has to work harder to push the car down the road because this generator is now on the back siphoning energy off the rear wheel. It’s thus drawing more energy from the traction battery than it otherwise would if there was no generator hanging off the wheel. Whatever energy you get out of the generator will be less than you’re spending to turn it.
But What About Regenerative Braking?
It is worth remembering, as well, that EVs have ways of turning rotational kinetic energy into electricity anyway. It’s called regenerative braking, and in itself, it perfectly explains why a wheel-attached generator won’t give you free unlimited energy.
When an EV engages regenerative braking, it essentially turns its motor into a generator that is attached to the wheels. What happens? Applying the load of the generator to the wheels slows the vehicle down. It turns the vehicle’s kinetic energy into electrical energy to charge the battery. The generator can’t run without slowing the vehicle down. The electrical energy has to come from somewhere!
Naturally, there are some losses involved in the conversion. You can’t accelerate up to speed, then regeneratively brake, and get all the energy back. Some energy is lost in overcoming rolling resistance and aerodynamic drag, and some is lost through electrical resistance in the electronics and as heat through the motor. Similarly, as the generator converts rotating motion to electricity, there are more heat losses in the electronics, motor, and battery in turn.
Sure, you might say that this rear wheel generator would generate electricity if the vehicle was going downhill, using no battery power to accelerate the vehicle. Yes, that’s true. But the Bolt’s electric motor is already capable of acting as a generator in that case anyway. Plus, you’re still not getting energy for free. You had to spend energy to get the Bolt to the top of a hill in the first place before you could reap the energy by rolling back down.
Many Such Cases
There are all kinds of “simple” and “free” sources of energy touted in snappy little videos on the Internet. For example, one touted the idea of putting turbines inside water pipes to get “free” electricity from the flow of water. Of course, this would be completely pointless for a great many water pipes, as their flow is generated by the city’s water pumps. The pumps would have to work harder to overcome the resistance presented by the turbines, using more energy than the turbines could generate.
Another example that is often bandied about is the use of an “HHO gas generator” to make a combustion-fueled car more efficient. This involves using a car’s electrical system to split water into hydrogen and oxygen gases. The mixture is then fed into a car’s intake to promote “cleaner” or “more efficient” combustion. Here’s the thing, though—even if the gas injection did improve combustion, you wouldn’t be getting out ahead. The energy required to split the gas would outweigh any potential energy you’d get back out of it when it passes through the engine.
What’s Really Going On
The post shown at the start of this article is actually not the original. Somebody saw the photo of this vehicle and made an assumption about what was going on. Then, they spun their tale of free recharging that apparently Big EV was too stupid to implement.
The original photo was actually made by a user called rhinnaflor on Reddit, a full five years ago. Posting to r/whatisthisthing, they asked as to the use of this contraption. There are some compelling theories in the comments, and they don’t violate thermodynamic principles.
Belt contraption attached to the rear wheel of a Chevy Bolt
byu/rhinnaflor inwhatisthisthing
AJ_Mexico pointed out that the Chevy Bolt may be a “dingy” vehicle that is typically towed behind an RV. With modern cars, it’s often recommended to tow them while switched on. However, this can drain the vehicle’s 12-volt battery over time if it is towed for many hours. The theory was that the system attached to the rear wheel was a simple alternator that had been hooked up to keep the Bolt’s 12-volt battery charged while it was being towed with its rear wheels on the ground. This wouldn’t do anything for the main traction battery, and thus it wouldn’t improve the vehicle’s range. It’d just keep the 12-volt battery topped off, though you’d normally expect the Bolt’s traction battery would do a fine job of that already.
Naturally, this energy still isn’t free. The mechanical resistance of the generator would make the RV towing the Bolt expend more fuel—marginally—than if the generator wasn’t connected. Of course, there are easier ways to handle this task, too. One could simply fit a 12-volt solar battery tender to the Bolt, or hook up some kind of power line from the RV’s own supply. These would be much simpler.
Others suggest it might be some kind of instrumentation for data collection, but I’m not sure I buy that. It’s a very janky install, and the belt drive wouldn’t be super great for accurately tracking the wheel’s motion without slipping. It’d only be worse in wet conditions and when there’s any amount of suspension travel.
If we zoom in further, though, this case gets more mysterious. There appears to be a fuel filler neck, or maybe some kind of cabling, tucked under the rear bumper of the car. Commenters speculated as to whether some kind of standalone combustion generator might have been installed underneath as a range extender, but the jury is out as to the truth.
It’s very difficult to definitively pin down what is going on in this image. Our best guess is that it’s some kind of wheel-powered electrical generator, but for what reason, we can’t say. If you’ve seen anything like this before, or you know the car in question, perhaps you could shed some light on the matter for all of us.
Ultimately, I hope you found this article educational. You should have a better idea of why you can’t get unlimited range from slapping a generator on your car’s rear wheels. You might even feel confident enough to call out others who bandy about these long-disproven ideas. As much knowledge as there is out there on the Internet, free energy and perpetual motion ideas will seemingly never die. All we can do is call them out and have a chuckle when we see them.
Image credits: via Reddit, via AliExpress, Chevrolet
I mean….do we really need an article that goes THIS hard trying to explain a picture that otherwise just elicits a facepalm from anyone with a simple understanding of conservation of energy…..
Do not overestimate the average citizen’s knowledge or underestimate their arrogance. Probably a depressing number of people think they are SO MUCH SMARTER than those thousands of engineers working in the automotive industry.
I design engines for OEMs, my interior designer fiancée refuses to believe me when I tell her she’s in the wrong gear because she knows better.
But then I also thought or dual aspect living room looked fine painted in just the one shade of green, so it’s not like I respect her professional knowledge either.
It’s all Dunning Kruger Effect.
I dunno, is there math wizardry or metrics to prove the best color for a living room?
No?
Then that’s just like, your opinion, man!
On a more physical level perhaps you two might literally perceive colors differently (e.g. color blindness, tetrachromacy) so what looks good to you might look terrible to her.
OTOH there are very provable, easily understood reasons why not to lug an engine or rev the crap out of it. Like you’ll blow it up.
Sadly there is maths behind the two shades of green. The two walls with windows in them will always look darker from lack of light (plus sunlight is bluer than you think) so they get painted a lighter shade of a similar green so that all four walls look the same colour. If you’re custom made everything in the room to match or contrast with a particular shade then apparently it’s worth making your fiancé paint the same sodding wall four times until it’s the right colour.
I still think it would have looked great in white with a motorcycle next to the TV. I thought offering to use my green Kawasaki was a fair compromise towards colour.
Maybe you LIKE a more natural, slightly darker window wall.
“plus sunlight is bluer than you think”
Depending on the time of day, time of year, your altitude and how clean the air is. Unfiltered sunlight (as in seen from space) peaks in the blue green part of the visible spectrum (so it looks much greener in space) but is blunted towards red by the atmosphere and the particulate matter in it which is why it changes color depending on how much air its traveling through and how clean that air is.
https://sunwindsolar.com/wp-content/uploads/2013/06/SunWind-WEB-Solar-Radiation-Spectrum-V2-1200×750.png
Or the depressing number of people think they are SO MUCH SMARTER than those thousands of doctors and researchers working in the health care industry.
That kids is literally how you get measles.
Sometime, not that long ago, ignorance was something to be ashamed of; now it is celebrated, and the dumbest among us is revered and elected, instead of the best.
Lots of smart people out there get that this is silly, but they didn’t take high school physics!
Counterpoint: OUT THERE. You’re talking to Autopians! We’re all smarter than that, right? Right?!
DEBUNKED!
I’m not sure why you highligted a turbo on that picture of an engine.
It’s because the car in the post has a turbo attached to the rear wheel. Just showing where it normally is found.
Went back to look to be sure I did in fact see an alternator, damn you
Guy gets tattoo of alternator, thinks it’s a turbo : r/funny (reddit.com)
Glad you mentioned HHO generators. I have a friend who is convinced that they work despite me explaining many times that it’s simply not possible to create energy without expending even more energy.
That was my queue to get off Facebook when I was just spending my time debunking BS links friends posted. I said even IF that HHO generator worked as is, the fact that the video had full jars of water in his car for months means that barely any (if any) gas was produced.
Like trying to lift yourself off the ground by pulling on your ankles.
Of course you can’t do that. As every politician knows, you need bootstraps if you’re going to pull yourself up. 😉
Torch already solved this problem with electric eels. Come along, Sherman, lets take a trip in the Wayback machine.
https://jalopnik.com/lets-find-out-if-using-electric-eels-to-charge-your-tes-1836978424
I always jokingly tell people that any energy source that puts out more than it consumes is essentially a bomb.
The output feeding back into the input if somehow more than it started with will exponentially ramp up to infinity and consume the input entirely. In simpler words, BOOM.
World energy problem solved!
“We CAN solve the energy crisis by simply decreasing demand. In this TED talk I will explain why Nuclear Armageddon can-“
10/10 would listen.
Only till they get to the part where they realize they aren’t the ones who get to push the button.
I weep that you felt obliged to write this.
As a senior level design engineer, most often found in startups, I frequently found myself surrounded by non-technical executives whose non-existent technical expertise was overwhelmed by their self assurance, personal confidence, and organizational hammer. They usually surrounded themselves by a cadre of agreeable drones. Unfortunately, extensive resources usually needed to be expended to offset the ignorance.
By far my favorite hammer science, was when our Pres DJT suggested that we inject or ingest BLEACH to solve the covid situation. The drones were silent.
One of my favorites was an executive that asked if there was some kind of light that shot out… dark light… like, a bulb that you switch on that makes a room darker.
Can’t make this stuff up.. This story is bringing out a lot of how engineers/scientists struggle with others. Usually our struggle is with technology, not interactions. I have often wished that part of the technical curriculum would have a class on “How To Deal With Buffoons”
Yes. Just wave a stick around while yelling SOMUL MAXIMA!!
I worked on a project to create a new EV variant of an existing ICE vehicle, and one of the accountants insisted we’d save money if we carried over the gas tank, as the cost falls as the volume goes up.
The simpler solution would be a deployable hook at the front, that could latch onto the rear bumper of a semi trailer. Once attached, just let the vehicle regen as it’s dragged along, and charges on the move.
I have debated about getting something like that installed on one my vehicles especially for cross country trips. So many times I am going down the freeway thinking damn if I was just tied to the back of that semi I would be saving so much money.
If you trust the truck driver, you could even crawl into the back and take a nap, full self driving for free…. In all seriousness, an actual controlled, engineered version of this would be my top choice for some sort of autonomous vehicle capability
If you had a trained driver, and maybe a special system of straightish roads with very few stops, you could link up massive trains of linked vehicles, with everyone reading a book or sleeping.
I see we’re inventing trains again.
It’s almost like there are no new ideas left.
Years ago I tried drafting behind a pickup truck pulling a large trailer, which definitely increased my fuel economy. The person driving the truck must have known what I was doing, I don’t remember the specifics but I remember them driving in such a way that made it easier for me to follow close for well over an hour. I only tried it that one time, as it wasn’t exactly a relaxing way to drive, and not everyone would be as accommodating as the person I was drafting behind.
Well, you would have been reducing the drag behind him as well, so it was win/win really. (Those Nascar articles are finally paying off!)
TANSTAAFL
There Ain’t No Such Thing As A Free Lunch
Looks like I have my reading assignment for the weekend!
Heinlien is…problematic. But he was a true visionary and understood people.
That’s a good word to describe him! Shows disagreement, yet understanding.
It doesn’t work stealing energy from the wheel to charge the batteries to turn the wheels. We all know this.
Instead, you need to find a free source of energy. Anybody who has ever ridden in the back of a pickup truck knows that it is windy a.f. back there. Wind is renewable. This is known science.
Therefore, we need to mount wind turbines in the back of our electric trucks. Or, if you are towing a camper with your electric truck, cover the top of the camper in small turbines. If done right, you will have infinite range.
I just laughed at imagining a giant ass wind turbine just sitting in the bed of a truck going down the road.
Wow! You just blew my mind!
“If done right, you will have infinite range.”
But only while driving West. When driving East you need a sail.
Good point!
As a teenager I came up with the brilliant idea to cover the top of the car in solar panels and the bottom and sides in tiny wind turbines. This was before I went away to engineering school.
Hahaha. I had just about the same idea. However, I didn’t ruin my mind with engineering. I went for chemistry instead.
It’s just a function of gearing. If they gear it right, those losses become gains, just like how I can go further on a turn of the crank on my bicycle if use a small gear in back and a big one in front. Same turns = more distance. If you get the ratio right, you don’t even have to turn it. /S/ in case it’s not obvious.
Its an AWD Bolt.
Three wheel drive, just like James May’s Suzuki.
I think that contraption is doing the opposite. It is actually a small ICE engine powering the rear wheel. That is a fuel filler in the middle of the bumper.
It’s a rudimentary range extender that adds energy to the “isolated system” you defined above.
Too hard to put the energy directly in through the car’s systems without them freaking out. So found a mechanical means to do it. The car will basically think it is coasting downhill while that thing runs. Add a fuel shark and it will run forever. Brilliant.
+ 5 points for the fuel shark!
I always thought that picture was a metaphor for trickle-down economics.
That’s bullshit. Next you’ll say I can’t plug a power strip into itself.
Who says you can’t?
You can absolutely plug a power strip into itself. Actually getting electricity from it, not so much…
Are you guys trying to ruin the business I was going to run with small ads in select magazines, and with all the trouble I had faking my own death to promote my product
It’s obviously needed to power the grill lights 😛
My favorite quote about “perpetual motion” machines: “The hardest part of making a perpetual motion machine is hiding the battery”.
No idea who said it, and I’m almost certainly paraphrasing it, but it’s true.
It used to annoy me, as an engineer, seeing these videos. But now I just sit back and chuckle imagining someone seeing this, and truly thinking “OH MY GOD, THEY’VE DONE IT” then running into the next room to grab someone and show them the most important invention the human race has ever discovered, conveniently found in a post on facebook.
I still find it funny that people think that the energy comes from seemingly nowhere. All mechanical systems are a net loss and need an energy input
TBF the best theory we have is that 13.8 B years ago EVERYTHING came from nowhere.
I mean there’s cosmic dark energy which is what is causing the universe to expand but other than that cannot be observed but quantum astrophysics doesn’t really apply to electric cars…yet.
Soon….
Here’s where we could in theory get a Bolt to run forever if we could harness this energy creation.
This is an awesome article. I work for an aerospace company that was started the same individual that started an ev company. It’s wild how often we get those smug “elementary my dear Watson,” emails and messages from keyboard experts that “figured it out.” off the wall solutions, usually with an air of smugness to, to problems that either don’t exist or have been solved effectively. It blows me away. I really think it’s another example of the anti-intellectualism that has pervaded western culture.
I remember when a guy who started an EV company then an aerospace company solved a non-existent problem by building a system of said EVs to run in underground tunnels, otherwise known as a less-efficient subway. Is he one of those keyboard experts? I heard he’s out there solving problems for a social media company now.
Yea that pretty much hit the nail on the head
Technically said individual didn’t start said ev company. It existed prior to said individual joining and taking over.
This is also very true. That’s a fun conversation at work with folks who don’t know that full story. They had originally intended to make appliances apparently.
I thought the aerospace company started by the guy that also runs the EV company was the one company in his portfolio that had their shit figured out. To now hear that this company has to silence the idiots from within is actually news to me. Glad there’s enough of the smart ones there to not have killed the people that company sent to space.
I find that mentality so frustrating myself, usually if I come to a conclusion with an easy/simple solution to a tough problem, I always lead with “this seems way too easy to work, but…”
“In this house we respect the laws of thermodynamics!”
Putting that in a wall at home.
“As for me and my home, we will serve the laws of physics.”
As if you had a choice.
One word, TANSTAAFL.
Todays physics lesson brought to us by a Dinkum Thinkum.
Not an engineer…. not an expert… actually, I’m kinda a dumb ass.
Anyway… what about having the drivetrain made with magnets… and then have a surround that also has magnets…. Yes, you need a tiny bit more energy to rotate the heavier (due to the magnets) drivetrain, But then you do not have any mechanical contact to generate the electricity.
Of course it wouldn’t be a “spend 1 kW, earn 1 kW”, but would/could it be enough to lower the amount of charging (time) needed?
Or, am I, as I suspect, a dumbass?
It still takes energy to overcome the force of those magnets. Overcoming that force is what generates electricity.
What you’re talking about is enhancing efficiency. I don’t know about your particular idea, but reducing losses i.e. from friction would increase range, though probably not affect charging time.
I had to do a little digging… it’s a rotating magnet and a copper coil…. Magnetic Induction.
P.S…. increasing range is the same as decreasing time to charge. Less energy required to top up = less time to do the topping.
Yup. You just invented the generator!
I see what you’re saying, but for me charging time is not the same as time spent charging. Charging time is how long it takes to charge the battery. Time spent charging is a function of the frequency of charging and yeah, frequency would be reduced, so overall time spent charging would be reduced.
If you do more digging you will actually find that GM and Tesla use/used permanent magnet motors in some of their cars. Also there are no motors that have been used with just permanent magnets and next to nothing else as the motor would just return to equilibrium pretty quickly after starting. Also permanent magnets are what they say they are permanent so you wouldn’t have changing magnetic fields. What I always found funny when I was testing magnets for a particle accelerator people always asked like your fridge magnets? I would so no completely different those are permanent magnets not an accelerator magnet haha.
Also side note I am not a physicist and wouldn’t classify myself as engineer though I have an computer engineering degree and have worked briefly as an engineer. So I am no where near qualified to supply correct info on this topic haha
I’m talking about generator…
So.. you have Engine or Motor powering vehicle. Power turns drive shafts. Normal operation.
In my thinking, everything is the same, except you put a 1/2 inch wide strip of magnet down the shaft(s). Surround shaft with copper wire coil.
Motor/Engine is already driving the car. I’ve ADDED a non mechanical (so therefore it shouldn’t introduce more power loss) magnetic induction generator.
Of course, I’m sure plenty of smarter engineers already know why I’m wasting keystrokes… otherwise all the Elec vehicles would have such a drive-shaft generator already.
Yes, I know copper coils weigh a LOT. But, with super strong magnets, maybe it could work with a lighter material in the coil?
Most electrics nowadays have done away with driveshafts though since you have the individual motors running to the wheels now. But from what it seems like you are saying is to have permanent magnets around the driveshaft and have a coil around the driveshaft which I would assume is powered to creates a field also so it helps the driveshaft spin?
The opposite. It’s using the already spinning shaft’s rotation to generate energy.
Not to help it spin.
Please remember… dumb ass here.
Nope, the magnets will still put more drag on the driveshaft for the motor to overcome. The motor is already driving the car, but the minute you add all those magnets and coils, you’re adding more drag.
Doesn’t matter if it’s “non-mechanical.” The driveshaft will be harder to turn because the interaction between the magnets and coils adds resistance.
It’s the same deal. Your design is just putting a generator around a driveshaft. That generator will put drag on the motor and generate less energy than it sucks up.
Using magnets doesn’t change anything. You can’t get energy for free, the energy coming out of your copper coil has to come from somewhere. In this case, it’s coming from the motor, which has to work harder to turn the driveshafts because you wrapped a generator around it.
“You can’t get energy for free”
Unless maybe if it’s dark energy. Whatever that is.
You can replace copper conductors with aluminium to save mass.
It won’t do anything to fix the fundamental problem of it being impossible to get more out of a system than you put in.
It sounds to me like what you’re proposing is a magnetic floating bearing to replace conventional journal/roller bearings. Problem is, there are dozens of these bearings, and it’s imperative that all of them have as little play as possible. If there was wiggle room, as you’d see in a non-contact bearing, you’d be able to move all the shafts around a bit, which would be a huge reliability and safety problem.
Perhaps more importantly, the bearings we already have are very efficient. They account for less than 1% of drivetrain losses, before you even start to consider wind resistance an Rolling resistance from the tires. Grab a fidget spinner, flick it and you’ll see exactly how much resistance a roller bearing has. So all the compromises needed to make these would net you maybe a 0.5% drivetrain efficiency gain, but the extra weight alone might bring you back to zero, with all the drawbacks of cost and reliability
I hate that I live in a world where this needs to be explained to people.
Bravo on the article, it’s very well done, but, like, why is it so difficult for people to see why this doesn’t work?
“why is it so difficult for people to see why this doesn’t work?”
— because the Dunning-Kruger effect is a real-ass thing.
Remember back before the internet when we thought the world would be so much better if everyone had access to more information? Yeah, that wasn’t the problem…
The vast majority of people believe anything they see on the internet, and the ability to instantly connect globally with like-minded people creates echo chambers both good and bad. Just look at how prevalent flat-earth argument have become recently.
As a mechanical engineer, these perpetual motion arguments are laughable at best, but I have to remind myself the vast majority of people haven’t the slightest clue how physics works. Cars are mechanical magic, cell phones are electrical magic, even basic things like running water in your house is hydraulic magic.
As a Mechanical Engineer myself I still believe electricity is witchcraft, but mostly because undergrad Electrical Engineering courses scarred me in a very particular way. Is there professional therapy to unlearn bad college courses? I wonder if my HSA would cover that…
It’s been my experience the best therapy for that is to retake the course from someone who teaches it the way you think.
I’m reminded of this recent cartoon from The New Yorker. Like, you think the entirety of history every single person alive has just missed ‘this one neat trick’??
https://ifunny.co/picture/honey-come-look-i-ve-found-some-information-all-the-9NfmVv6M8?s=cl
The thing is we’re all idiots about something. The world is massively too complex for anyone to be an expert (or even vaguely understand) everything that happens in it. I have a reasonably solid understanding of thermodynamics – at least enough to know why this won’t work – but I have no idea how to bake a cake from scratch or paint someone’s portrait. People who know how to do those things might not understand thermodynamics at all.
To me, the most important thing is to recognize when you don’t know something and either learn about it or ask someone who does know about it. Too often people will say something from a position of ignorance and then defend that position to the heat death of the universe