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I once figured that you don't need light in your house if your eyes are closed, and I hooked up blink detection to my smart bulbs:


It actually worked really well, I couldn't perceive the room being dark at all.

How much electricity is conserved by turning off the light bulbs for 200ms every few seconds VS how much energy is expanded by running a webcam + CV program constantly? It’s probably less energy efficient overall.

Turning the bulb off for just 200ms might be increasing energy usage by itself. I know in older bulbs you had to leave them off for so many seconds/minutes before you gained any savings by turning them off. The amount of energy it takes to get them going far exceeds the amount needed to keep them running. There is also the problem of the bulb wearing out faster because of the constant switching on and off.

IIRC for incandescent it was about 1/3s to break even. For fluorescents it is likely higher but don't have a source (it may not be an issue if the starter is smart enough to realize that it isn't needed or not needed as much). However there is going to be extra wear and tear on these bulbs which makes the savings offset by extra bulb replacement. For LED the cost of turning off should be very near to zero so this would likely actually save resources.

Of course this idea is awful for other reasons. But it is very funny.

no the blink detector is not free and massively adds to the overheads compared to the LED output.

For a modern (led) bulb there is effectively zero wasted energy by turning it off and on, but it depends how you define waste. Does light emitted after the switch is turned off count as waste? (Most bulbs take a few hundred ms to turn off)

Minutes? I would like to see the math on that one.

Note that this has nothing to do with saving energy and everything to do with reducing wear on the bulb from on/off cycles.

> The operating life of CFLs is more affected by the number of times they are switched on and off. You can generally extend the life of a CFL bulb more by switching it on and off less frequently than if you simply use it less.

> In any case, the relatively higher "inrush" current required lasts for half a cycle, or 1/120th of a second. The amount of electricity consumed to supply the inrush current is equal to a few seconds or less of normal light operation. Turning off fluorescent lights for more than 5 seconds will save more energy than will be consumed in turning them back on again.

For this specific discussion about turning lights off while you blink, yes, you do actually burn more electricity in addition to wearing the bulb out if you're cycling it off for just 200ms.

But for real world use by normal people, turning off for 5 seconds will save energy, and turning it off for 15 minutes will save money.

In the real world most people care about saving money. Whether that’s due to wear on the bulb or extra energy consumption is irrelevant.

In the real world people don't care if their CFLs burn out and get replaced with LEDs because CFLs are comparatively terrible and you can get a higher quality LED bulb for about $5.

True, I was just trying to explain this to my partner who didn’t want to throw out still functional CFLs. In this case the value of the estimated remaining life of the CFL + cost of new LED is less than the expected power savings of the LED.

In the real world people care about both actually.

I submit that there are vanishingly small number of individuals who would spend more on bulbs than what those bulbs would save in electric costs over their lifetime.

That's going to depend on the design of the bulb. If it's off for the length of a blink, it probably doesn't need to strike again. Or you could dim it to 10% for the duration instead of turning it off.

But the other factor is dealing with the delayed response of the phosphor. Can you actually turn the light output off and on fast enough?

Outside of monopoly rent seeking, money is made of energy. That's what you're paying for when you buy something.

- Is the lamp still on while blinking? - Is the sun still shining during a nap? - Is the fridge's light still on while it's closed? - Does God exist?

Some fundamental questions, but we'll never be able to find an answer.

Uh, use a light meter? Your comment assumes that that only way to assess the presence of light is with your eyes.

Does the light meter function properly while blinking?

Are the Hacker News servers down when you're not on Hacker News?

There are an infinite number of these types of logically pendantic questions that are immensely uninteresting to think about.

> Are the Hacker News servers down when you're not on Hacker News?

That seems like a tautology. If I'm not on Hacker News, then of course the server must be down. Why else would I not be on HN?

If (Stratoscope and Hackernews) -> Stratoscope is on Hackernews.

=> (Stratoscope is on Hackernews) is false.

=> (Stratoscope and Hackernews) is false.

=> Stratoscope is true.


Hackernews is false.

It’s been my experience that people who call things uninteresting are merely sharing their own unusual disinterest in something otherwise interesting. It’s also been my experience that said people are usually the most uninteresting in the room.

Also, I don’t know what it says about you that you went from effectively “trees falling in the forest” to the Hacker News infrastructure to defend your point about fun, thought-provoking idioms, but I do know it’s remarkably uninteresting.

Fair enough. By calling my comment uninteresting, have you also rendered yourself to likely be the most uninteresting person in the room, by the logic in your first paragraph? If so, who wins the title of the most uninteresting person in the room?

You initially would for having claimed something interesting is not, however you also started a discussion which is pretty interesting, including your own further comment, which also adds interest to the situation. Paradoxically you two now may be the most interesting here.

Tell that to Schrödinger. Even questions that seem utterly pointless and mundane at first glance can lead to captivating insights if explored at depth.

Schrödinger's cat was originally intended as a reductio ad absurdum.

uninteresting to you

A lot of discoveries of interesting stuff resulted from something uninteresting being considered interesting and deeply contemplated. Others look and say "what an idiot, spending such time on such uninteresting x", I say, "you're only my self-imagined disagreeable other, I'm your god, your consciousness is my consciousness, what say you now?" and they would say nothing since the puppeteer has been revealed and there is nothing left to say. I guess this is why God will never prove he exists.

I'm sure the comments were made in jest...

My point in bringing up the light meter is that in these "tree falls in the forest" thought experiments, it's taken for granted that your own biological senses are an absolute source of truth.

But your eyes are just another set of equipment, similar to a light meter. Just because your eyes are attached to the rest of your body, it doesn't make them inherently more trustworthy than equipment that's not part of your body.

However, our expectation is that a tree falling in the forest could kill us even if we didn’t hear and see it. That’s why we look when we cross the road. The fact that we’re subject to all sorts of things that can cause us harm without sensing them makes the case a lot more compelling that the light meter exists when we blink.

Lamp lights are not dependent on whether you can see them or not, unless they are programmed to.

The state of an individual person’s consciousness has no bearing on whether the sun is shining or not.

Refrigerator lights turn off when the door closes. It’s usually easy to find the mechanism that handles this and manually trigger the light to switch off.

Regarding God, I assume you mean the Abrahamic god. There are many culturally specific deities and superstitions and there doesn’t seem to be any verifiable reason why one would be “realer” than any other.

You're assuming any of this has an existence independent of your mind, that more than the present moment exists, and a whole lot of other things.

You make reasonable assumptions, but proving them is hard, because any attempt you make to prove them still end up being filtered through your potentially unreliable senses.

In practice we decide to just accept that a material world with semireliable senses exists, because the alternative is no certainty at all.

The alternative without falling into skepticism is idealism. But scientific explanations of many things like disease, chemistry and physical forces are very compelling compared to the world just appears the way it does as ideas in our mind.

In other words, proofs cannot exist without axioms.

"The Simple Truth" addresses this from a different angle: https://www.lesswrong.com/posts/X3HpE8tMXz4m4w6Rz/the-simple...

The 'issue' is that these are essentially 'commonsense' answers. By definition it's impossible to empirically study the unobservable. Though of course whether these questions are at all interesting - after all the answer has no effect on anything or it would be observable - is another matter.

The problem with this argument is that it's begging the question. You're assuming that the Universe is behaving in a way that is consistent with how it appears.

There is no possible experiment you could in principle do to verify that the universe stays the same when you're not looking. We can say that the universe behaves consistently as though it does, and I'm not saying that doesn't matter, but it's not quite the same thing. Furthermore we can't tell whether the universe is tricking us some of the time, or all of the time, or never.

> There is no possible experiment you could in principle do to verify that the universe stays the same when you're not looking.

And then people invented video cameras to trick the universe to stay the same when they go to sleep

What if the world is just a dream? Then an individual person's consciousness has a massive influence on the weather. And there would be new arguments for the existence of God.

That's just, like, your opinion man

> There are many deities

Proof demanded.

What would you call the 'God' worshipped by Christians, the many by Hindus, etc., if not deities?

We sentient beings are fortunately capable of discussing abstract thought, things not known to exist, and even things known not to exist; we can give them names without requiring that they 'are', and we can discuss what it means 'to be' anyway, and whether those things 'are' after all merely by virtue of our discussion.

And did you even read the rest of that sentence? Other commenter is basically 'on your side'.

It's atheism like this that makes me describe myself (dissociatively) as agnostic, frankly.

> What would you call the 'God' worshipped by Christians, the many by Hindus, etc., if not deities?

One diety with many names or facets.

Amazing. It reminds me of the car company that built rain detection in their car and turned on your wipers so you don’t have to.

I don’t remember which manufacturer it was but their ad was hilarious “think of what you can do with that extra time you would have used to turn on your wipers”

I have a car that detects rain quantity and automatically increases or decreases wiper speed.

I still have to turn the wipers on, but otherwise it's completely automatic.

I never would have thought a feature like this mattered until I actually had it. Now I wouldn't want a car without it.

FWIW, this feature in my BMW works great. The same feature on my Ford Expedition doesn't work nearly as well.

Many cars now can start the wipers, in addition to adjust the wiper speed, when rain is sensed on the windshield


This tells the system to *activate the wipers*, as well as adjust wiper speed and frequency based on the intensity of the precipitation combined with the vehicle’s speed.

I'm really curious from those folks who have this feature if it is actually useful (and why), or if it's really just a novelty?

I have it on my BMW. It works great. There is still a similar looking control as you would have with a conventional system but instead of wiper speed it is basically a "sensitivity" or a "desired dryness". Here in the PNW rain can be a light mist or proper raindrops and may change minute to minute. So I just turn it on, set it to something in the middle and the wipers wipe when necessary. I rarely have to touch it again after turning it on.

Compare this to my old Toyota that just had low-med-high. Low was still moving constantly, the only intermittent was a manual "mist". This meant my wipers were running way too much even on low or I had to hit the mist every 10-20 seconds.

It's great (have it on my Subaru). It is particularly useful at that wet road or drizzle stage when more water comes from other vehicles than the sky. At that level it might wipe only 3 to 6 times a minute. It certainly removes that over-compensating dry wiping you get without it. I used my older Toyota Land cruiser on a road trip and constantly adjusting the intermittent interval in the drizzle was a pain.

Yeah, I almost never touch my wipers. Only exceptions I can think of is if there’s a very very suddenly change in the speed/volume of rain falling, I’m stopped for an extended period (the automatic speed adjustment works better when you’re moving), or if a bug or something has hit the windscreen and I need to squirt to clean it. That sentence was a real effort to go down memory lane though, it’s just not something I really have to think about anymore.

The typical stick for controlling the wiper speeds usually only has a few different speeds, there's no fine-grained control of getting the exact speed to match the rain. You're forced to switch between too slow and too fast. Too fast creates a jarring sound/vibration, too slow means the water starts building up on the window, causing visibility issues.

An automatic wiper speed seems a lot safer.

as an infrequent driver, I have difficulties splitting my attention between driving and dealing with controls like headlights and wipers, so anything that automate that is great

> Many cars now can start the wipers

That's been around for quite a while. My car from 2006 does it.

My dad's car was doing this at least as far back as 2003.

He thought it was so cool. When he first got the car, he was like, "Watch this!" and squirted a whole water bottle at the windshield just to make them come on.

Sixteen-year-old me recorded this as peak dorky daddom in my memory.

My Tesla model 3 has it, but like so much else new advanced tech it isn't yet as good as the human thing it was replacing. But it is less work.

My 10 year old BMW does this and it works perfectly. It's much nicer than fiddling with my wipers constantly. Tesla isn't blazing any trails here, they are just stubborn and won't buy an off the shelf system that already works.

after driving a car with this (and automatic headlights), it's not as a time saved, but rather attention that can be kept on the driving and not fiddling with the controls;

Be careful with this one. If you see a house/apartment where lights are repeatedly being turned on/off that’s generally considered a signal that they are in distress and you might get first responders dispatched to you curtesy of a neighbor who saw this and called 911.

Also I honestly can’t think of a worst way to try to save money, especially after you factor in the power it might take to do the facial recognition. There would be a good chance that you actually lose money unless you are in a hanger full of Na lights.

Edit: 5 bulbs in a room that each consume 10 watts (fairly generous), people blink up to 20k times a day, an average blink is 100 ms. So that’s 2000 seconds of blink time or just about 33 minutes. 33*5*10 is 28 Watt-hours saved per day or about 0.84 kWh per month. At the rate of $0.20 per kWh you just saved $0.16 a month.

But wait you have latency to detect the blink so let’s cut that figure by 15%. And since we don’t know how long a blink will last (some are shorter) you also need to reduce the off time by one standard deviation of a blink so to be safe let’s make the off period after detection last only 60 ms. So now we are at $0.096 per month. And now we also need to run multiple cameras and facial detection which has to run continuously. Unless you can do that under 28*0.6=16.8 Wh per day you are losing money.

Maybe you could generate power by harnessing the wind generated by moving your eyelashes? Mount tiny little nano-windmills on each of them, with accelerometers, so you don't even need to use computer vision. Every time you blink it would generate just enough power to send a signal to your lightbulb.

Just glue a momentary push button under your eyelashes and connect it to a headlamp. No need for all this overengineering.

Or knock down your roof so that the moonlight alone illuminates your area. In 20-30 generations you will evolve huge eyes perfectly adapted for this and save tons of generational wealth.

Just wear night vision goggles and don't even bother with lights.

> If you see a house/apartment where lights are repeatedly being turned on/off that’s generally considered a signal that they are in distress

I would assume that they just have kids.

> they are in distress

> they just have kids

Is there a difference?

I suspect it is more relevant for a time when you would have been more likely to have known your neighbours.

Unless I had established the blinking light code with my neighbors in advance, how would blinking lights inform me any more if I knew my neighbors or not? Unless they were blinking out S.O.S. it would not occur to me that it might be a sign of distress.

In what situation would you switch the lights on and off constantly to signal you need help? The only situation I can think of is that you're somehow too injured to make noise or move, but you're able to reach the light switch?

I tried Googling it and can't find anything anywhere, neither as some official police recommendation, or even anyone talking about it as a commonly understood signal.

Only circumstance I can imagine is if someone is kidnapped and they flash lights in an SOS pattern? Seems pretty unlikely they'd be by a street-facing room in the first place though.

Right. But then you’re hoping the kidnapper doesn’t notice you? Which means they’re not there? Which means you could just shout. And how can you use the light switch if you’re (presumably) tied up anyway? Alexa?

Think elderly people who might have a lamp beside them in bed or who are stuck on the floor near a lamp, but wouldn't carry around a cell phone.

I haven't heard a lot about it, but anecdotally have heard of it outside of HN.

I have heard of it in the context of domestic violence when a person locks themselves in a room without a phone and is trying to signal to the outside world that they are in trouble.

Right. In the case they’re locked in a room without their phone and the domestic abuser doesn’t also notice them turning the light on and off, I guess it would be an ok strategy? But again, that seems pretty farfetched. I have heard of cases where they call 911 and “order a pizza” and the operator catches on though.

I think if they're in a locked room being noticed by the domestic abuser isn't a huge concern of theirs since they have a locked door between them and the abuser.

So why not make a lot of noise then?

Right. Even that’s a lamp, not a room light. It seems a little farfetched to me these days to be honest.

> too injured to make noise or move, but you're able to reach the light switch?

Sounds more likely to me, than someone getting a webcam and writing a computer program that switches off the lights when eyelids closed because he he blinks! :-)

Especially if follows the international SOS code

I think it's intended as a joke / proof of concept!

Yeah I get that. But knowing the HN crowd I think it’s worth doing the math and pointing out how playing with this could result in unintended consequences.

I think the simplest fix for that would be to also track the eyes (and view range) of everyone else within a reasonable distance. My cat could do that in Perl in 5 minutes and 3 lines.

Where can I get a cat like that?

You don't get Perl Cat, Perl Cat gets you

I don’t think this is a thing. When you have kids extended periods of flashing lights are very common.

>Be careful with this one. If you see a house/apartment where lights are repeatedly being turned on/off that’s generally considered a signal that they are in distress

because of the supernatural events taking place inside!

Should you call 911 if you see a place with lights flash on and off repeatedly?

You know, I was taught this as a kid and the answer was yes. But now I cannot find a reference to this anywhere. It’s possible I am wrong.

I heard this as a kid too.

Thinking back, maybe I was just annoying my mom by playing with the light switch.

Maybe if they are doing it in a SOS pattern.

Cool, now you've found a real use for smart home lighting system.

Uh, no

This needs at least 1billion views: this is art and comedy at its highest form!

Website disabled:

> This project has received too many requests, please try again later.

This is the first application of smart bulbs that makes me want them in my house. Congratulations.

It's fun and all but is it really practical? If you have more than two people in a room, it should turn off only when both are blinking at the same time, which should basically be never?

It's clearly not practical. I would assume that the "smart" overhead consumes a lot more electricity than you could save by turning them off for a couple of minutes a day. But it is really fun.

Not to mention it will kill the lifetime of the bulb.

Not for LED bulbs, as far as I know. That’s certainly true for incandescent, but I don’t think this experiment would work well with incandescent anyway.

also with LED? I though you reduce the light by letting then blink really fast.

Variable brightness with an LED is achieved using pulse width modulation, turning it on and off REALLY fast. So no, this won't have any effect on the life of the LED :)

I suppose it will be for Facebook or any advertising firm that wants to push it to the next level of getting into your head.

This is resume-driven-development, except with IoT rather than K8S, Terraform, and AI. Shard a DB w/ 1000 records, put your 3 page website in a Terraform config transpiling down to an Azure .yaml config defining K8S micro-services running in the Cloud - the machine spins up every time the lights blink out for 200MS!

Also: How much electricity is conserved by turning off the light bulbs for 200ms every few seconds VS how much energy is expanded by running a webcam + CV program constantly? It’s probably less energy efficient overall.

Fun fact - when your eyes are performing a saccade (ie, moving around a scene) they discard a lot of detail in the visual input to avoid blurs ([0]).

If you could detect saccades and dim/turn off the lights, I wonder what the perceptual experience would be!

[0] - https://en.wikipedia.org/wiki/Saccade#Saccadic_masking

Unfortunately I think the latency would be too great for that, but it's definitely an interesting notion.

You're probably right. I wonder if you could get enough of a speed improvement using an FPGA for the image processing?

I think most of the latency was actually in acquiring the image from the camera and sending the on/off command over the network. Processing was pretty fast, IIRC.

Since this is HN, I have to ask how it works.

Assuming you didn't install sensors in your eyelids, it's probably something processing the feed of the camera?

Yes, there was a very simple OpenCV-based blink detection program on my computer that I repurposed to control my bulbs with. When it detects a blink, it turns the bulb off for 200ms, which is long enough for me to not perceive any darkness.

Wouldn't power cycling your bulbs like that lower their longevity?

No. These things are designed to turn on and off hundreds of times per second to emulate dimming.

Or even tens of thousands of times per second, according to an Analog Devices article: "Don’t Want to Hear It? Avoid the Audio Band with PWM LED Dimming at Frequencies Above 20kHz" (https://www.analog.com/en/technical-articles/avoid-the-audio...).

The part that wears out from cycling often is the ballast of the bulb. I imagine these smart lights are in the bulb's ballast, so sending the "off" command isn't de-energizing the ballast of the lightbulbs.

If you were doing it on a smart light switch that was feeding 120V to the ballasts I do imagine it would impart some additional wear and tear to the bulbs. I'm not sure how much additional wear and tear it would be on an LED, I know the main thing that wears out on a florescent is the starting circuit which needs to bring the energy of the bulb enough to start the arc which wears out over time.

It's very odd to me that bulbs don't come in two parts: Ballast and LED. That way, we wouldn't have to keep buying and throwing away the perfectly good part when the other one broke.

Ballasts are only needed on fluorescent lamps (because they have negative resistance, so if you run one by itself without a current limiter, it'll consume more and more current until it explodes)

Ah, then I meant the AC/DC converter that supplies 12V to the LEDs.

How did you even know that it worked??! ;)

Can you invert it so the light only turns on when your eyes are closed?

How can you be sure that all lights don't do this already ?

I tried that but I couldn't tell if it was on :(

Blink with one eye

You could use two oppositely polarized lights, and wear polarized glasses, so you could switch the lights in the room on and off individually for each eye.

Impossible! That would be a wink.

You could also use computer vision to mute the speaker when you covered your ears, and mute the microphone when you covered your mouth! Zoom meetings would be so much easier.

The average person blinks 28,800 times a day. 10% of your time awake is spent with your eyes closed [Source: Google I'm feeling lucky. YMMV]. Imagine saving 10% on your lighting bill. This is revolutionary. You really only need it to work for one person in a household as long as everyone gets on the same blinking schedule.

Did you know that, when people live together, their blinks tend to synchronize? It's true*.

* For small values of true.

I don't know how your bulbs respond so fast. My philips hue bulbs seem to always take half a second to react to anything.

It's a YeeLight bulb and I wrote a library to talk to it directly over the LAN.

This is a hysterical application of technology, thanks for sharing. A small part of me worries that some cubicle company will add it as a feature to individual cubicles in offices. We already have aggressive proximity sensors controlling lights and the phone booths, so perhaps this is next!

Incredible idea. Can it be applied to compute heavy visual applications too? Like playing a game at 4k at 120hz, what if the game would stop rendering and the display would turn off for 100ms every time you blink but the game would proceed as normal?

Probably, but due to how game rendering works I don't think you'd gain anything other than battery life..

Well that assertion leaves a lot to imagination. So if you're running a 1080ti GPU it uses a max power of 250w, worse case you can cut power to its onboard processors in a way that does not require re-initialization after power is resumed in 100ms. Even a 5% improvement would translate to a reduction of 12w just on the GPU front.

Right, but I mean you wouldn't gain FPS or anything, since you can't "store" processing power to use later.

Why would you need to gain FPS? In fact when you're blinking effective FPS goes to 0.

> It actually worked really well, I couldn't perceive the room being dark at all.

From the video, it seems there is quite a bit of latency between your blink and the lights blink. But it's an interesting project nonetheless!

It does, I think that's an artifact of the video. Or at least it felt very quick IRL.

Hahah, well, a couple of guys out there have hundreds of billions of dollars, and far fever ideas worth competing with this one. Good luck!

That self-satisfied smile is the hallmark of a well-delivered dad joke.

How would it work if two people are in the same room?

Tell me you are always alone when at home without telling me you are always alone when at home.

Alas, I am never alone at home.

A very forever-alone project

LMAO this is fucking brilliant.

that is the definition of hacking. so sick!

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