HNHacker News
TopNewBestAskShowJobs

yeutterg

386 karma · joined May 21, 2015

submissionscomments
yeutterg··on Teardown: Casper’s Clever Little Nightlight
As a counterpoint, it is easy to spend more than $90 on a "dumb" lamp and bulb, depending on your style preferences and where you shop. There will always be a market for higher-end products.

Another way to look at this is Casper's business model. Casper mattresses are cheaper than equivalents sold at the likes of Mattress Firm (AFAIK), although not as inexpensive as IKEA. When you look at it this way, Casper's accessories (sheets, night stands, lamps) can be a way for them to sell complimentary products, at the same time they sell you a mattress, at a higher margin.

yeutterg··on Teardown: Casper’s Clever Little Nightlight
In simple terms, both blue and green light contribute equally to circadian interruption.

The graph itself is a comparison of spectral power distributions among several light sources. It's basically the signature of the light source, showing relatively how much of each color is produced in comparison to all the other visible wavelengths.

The gray area is melanopic sensitivity. This is the light that the ipRGCs[0] in the eyes are sensitive to, which provide input to the circadian rhythm. The peak is approximately 480-490 nm, but the overall sensitivity covers both blue and green wavelengths.

There's a great article on the blue/green concept by Ian Ashdown [1].

If you use the f.luxometer tool [2], developed by the f.lux team, you will see that same curve.

EDIT (for clarity): In the graph you linked, ignore the color of the lines. That is just to distinguish the different light sources. Just pay attention to the intensity of the wavelengths on the x-axis. The y-axis scale is 0 to 1, as this graph is normalized, so hardly necessary to show. Let me know if I can help clarify this further!

[0] ipRGCs: https://en.wikipedia.org/wiki/Intrinsically_photosensitive_r...

[1] Melanopic Green: The Other Side of Blue: https://www.ies.org/fires/melanopic-green-the-other-side-of-...

[2] f.luxometer: https://fluxometer.com/rainbow/#!id=iPad%20Pro/6500K-iPad%20...

yeutterg··on Teardown: Casper’s Clever Little Nightlight
I bought one, as I sell a product with a similar use case [0].

My impressions: The overall concept is great. The UX is cool, but some of the UX choices are strange to me. For example, automatically dimming down when you turn the light on (you have to press the button to pause it) vs. the other way around. It works well as a wake-up light, although I would have preferred something higher-blue for the morning.

There's really nothing "low-blue" about this light compared to other 2700K LED lights, other than the fact that it has a dimmer built in. The 2700K diodes they chose don't have better color quality than normal LED bulbs. It has "amber" (somewhere around 2000-2200K) LEDs at the very bottom end of the range that have great color quality, but they are too dim for anything but navigating to the bathroom at night.

They are modulating the LEDs with PWM at a very high frequency, almost 8 kHz. That's better than most of today's smart lighting by far. There's still debate about 100% flicker actually being healthy, even at higher frequencies.

For the lighting nerds, I captured photometric and flicker measurements, which you can review at [1].

Overall, I think Casper's lamp is a good effort. I hope future versions can improve the color quality, some of the interactions, and the overall healthiness of the light compared to regular lighting.

[0] Bedtime Bulb: https://bedtimebulb.com/

[1] Casper Glow Photometrics: https://www.dropbox.com/s/u8n0way6xqwbqcd/Casper%20Glow%20Ph...

yeutterg··on FTC Brings First Case Challenging Fake Paid Reviews on an Indie Retail Website
This is a huge problem and major source of frustration for legitimate sellers on Amazon. I've had it happen and had to threaten legal action to get a fraudulent seller off of my listing.
yeutterg··on FTC Brings First Case Challenging Fake Paid Reviews on an Indie Retail Website
Amazon seller here. It is against the terms of service to ask for positive reviews. It is also against TOS to offer a free product in exchange for a review.

You can, however, ask customers for a review in a neutral way. For example, "Would you be open to leaving us a brief, honest product review?" That is how we ask it.

Some companies, especially supplements companies, have a funnel that gives you a "second month free" in exchange for privately sharing product feedback and your email address with them. Here's how it works for one brand I purchased from recently:

- You receive your first purchase

- You go to a landing page and enter your name and order ID

- They send you an email after 2 weeks asking for your private feedback of the product.

- Once you provide this private feedback, they will send you the free product.

- Before you leave the survey, they ask you if you are open to leaving a product review. They ask in a neutral way and are explicit that it is completely optional. This is to be clear that they are not giving you a product in exchange for a review—you already got your free product for sharing private feedback.

You could argue that this is a gray area, for sure. But for small brands, reviews are incredibly important, and it helps to be able to market to past customers (which Amazon does not allow you to do through their system). Getting a 2nd month free can help build brand loyalty.

Personally, I don't have a problem with this type of funnel, as long as it adheres completely to Amazon's TOS and doesn't annoy or deceive the customer. The customer has to feel right about writing the review, not like they were manipulated. It's very easy to get that wrong, and most sellers who try do get it wrong.

Note that we do not have such a funnel set up for our product as of this writing.

[Edited one sentence for clarity]

yeutterg··on Why can’t a bot tick the 'I'm not a robot' box?
After reading this thread yesterday, I had a nightmare in which I called 911 but was required to answer an endless stream of personal verification questions, never able to report the problem.
yeutterg··on Ask HN: What's it like to work in the same company for decades?
Sounds like Dell. No matter, glad you were able to survive through the reorgs.
yeutterg··on The exercise “recovery” industry is largely bogus
Two important factors not mentioned in the section "So what actually works...?", but potentially in the book (I didn't read it), are getting adequate sleep and alternating vigorous activity with rest (or slow exercise like walking). Many elite athletes sleep at least 9 hours per night.

As a former crossfitter, I never understood how people could show up for a 5:30 or 6:30 AM session 5 or 6 days a week. My hsCRP levels were quite elevated at the time even with my rule to sleep twice between workouts. For example, I could do a Tuesday night session and a Thursday morning session, but nothing on Wednesday.

Perhaps those daily crossfitters had such a low-stress lifestyle outside of the gym? Based on their personalities and stories of only sleeping 4-6 hours, I think not. I think they just had a "power through it" attitude, but that doesn't seem like a good solution for the long run.

yeutterg··on What Happened to the 100000 Hour LED Bulbs?
So glad this was useful! Please let me know if there's anything else I can help with lighting-related. I'm super easy to find.
yeutterg··on What Happened to the 100000 Hour LED Bulbs?
Theoretically, they could, but I don't think Philips really has a financial incentive to update anything that "already works"
yeutterg··on What Happened to the 100000 Hour LED Bulbs?
Haha, totally agree! If you are still in the market for a low-blue, low-flicker solution, may I humbly suggest a look at my product, Bedtime Bulb [0]? I know I basically bashed the Soraa product here, but not without technical justification.

[0] https://bedtimebulb.com/

yeutterg··on What Happened to the 100000 Hour LED Bulbs?
When I refer to % flicker, I am talking about the modulation % as defined by IEEE 1789-2015 and some documentation from the Illuminating Engineering Society [0][1]. More correctly, invisible flashing is known as the stroboscopic effect or phantom array effect.

Two factors are often used to describe flicker for lighting:

- Modulation %, a.k.a. % Flicker [The height or modulation of the waveform, formula is 100% * (A - B) / (A + B)]

- Frequency [self-explanatory]

Flicker Index is also used (refer to [1] page 7 for more info) but rarely.

Duty cycle is not considered relevant, as you mentioned.

Some tools designed to measure lighting, such as my UPRtek CV600 [2], spit out % flicker, frequency, and flicker index, in addition to a bunch of spectrophotometry metrics. It's also pretty easy to calculate the modulation % with an oscilloscope and photodiode, it's just Vp-p / Vmax.

IEEE 1789 [0][1] roughly says that the higher the flicker frequency, the more acceptable it is to have a high modulation %. If you look at the graphic on [1] page 18, you can see this relationship. The white area is considered unsafe, the yellow area is "low-risk", and the green area is "safe." I don't 100% agree with this personally, as most incandescent lighting, with around 6-11% flicker at 100-120 Hz, would fall into the unsafe or low-risk category. But the Soraa product is definitely in the unsafe category.

For reference, I plotted my product (Bedtime Bulb) against an incandescent A19, Lighting Science's Goodnight A19, and Soraa's Healthy A19 on an IEEE 1789 graphic [3] with a Python tool I'm developing, Beautiful Flicker [4]. You can see that this incandescent, measured around 10%, is on the border between unsafe and low-risk by this standard.

Hope this helps!

[0] IEEE 1789: A new standard for evaluating flickering LEDs?: https://www.dial.de/en/blog/article/ieee-1789-a-new-standard...

[1] Flicker: Understanding the New Recommended Practice (PDF) https://www.energy.gov/sites/prod/files/2015/05/f22/miller%2...

[2] UPRtek CV600 https://www.uprtek.com/en/product/SPECTRAL-COLOR-METER/CV600...

[3] IEEE 1789 Graphic Comparing 4 Light Sources https://github.com/yeutterg/beautiful-flicker/blob/master/ou...

[4] Beautiful Flicker https://github.com/yeutterg/beautiful-flicker

yeutterg··on What Happened to the 100000 Hour LED Bulbs?
Some people are talking about using LiFi or high-speed IR communication for vehicle to vehicle communication. Seems like a great idea, but you can do it at a much higher frequency than what GM is doing today, so it's not distracting to humans.
yeutterg··on What Happened to the 100000 Hour LED Bulbs?
The Soraa bulb looked pretty sinusoidal on my scope when I tested it briefly. But it's a lot of flicker regardless.

What's interesting is that the bulb seems to have a nice build quality (from the outside, I didn't open it) and is quite heavy. I suspect they are putting a BIG heatsink in there, as violet pump phosphors tend to degrade quickly.

The other thing that irks me about this product is the "zero blue" messaging. Yes, I can confirm the spectrum looks like what they are advertising, with a peak around 415nm, almost nothing between 440-490nm, and then all the rest of the colors from green to red.

But, green light is just as bad as blue for sleep! The ipRGCs are sensitive to both blue and green (up to around 600nm) This bulb has a lot of green, more than a lot of other light sources. It also has a very unpleasant greenish color (IMO) and low-ish CRI, around 78 on the bulb I tested.

Is it better than a normal 600lm bulb for sleep? Yes. Is it novel? Yes. Is it good in practice? I don't think so.

yeutterg··on What Happened to the 100000 Hour LED Bulbs?
Agreed. Most car manufacturers' LEDs flicker (just look at any slow-motion video, such as those on Top Gear or The Grand Tour), but GM's are at a much lower frequency that is visible if the vehicle is in motion, or you are in motion.
yeutterg··on What Happened to the 100000 Hour LED Bulbs?
I've tested a bunch of bulbs for flicker with a handheld flicker meter and with a photodiode connected to an oscilloscope. It's funny that some of the bulbs out there claiming to be "healthy" have terrible flicker. One product from Soraa was flickering at over 50%, almost as bad as the cheapest/worst LED bulbs you can buy.

I don't have a database, but I can say that most (but not all) filament designs are terrible for flicker--ours is an exception. Philips products seem to have gotten worse in quality over time, probably to remain competitive, but they are better than the worst. Ikea's stuff is pretty good overall. I don't have a consistent recommendation for low-flicker general lighting right now, as every brand has good and bad products.

yeutterg··on Rough sleeping has been almost eradicated in Helsinki
Same here, I didn't fully grasp the meaning from the article. Despite some of the skeptics' comments here, what I find fascinating is that we have a subject that could include a variety of situations (poor and living on the street, poor and sleeping on someone's couch, middle income and voluntarily choosing not to have a permanent living place), yet we tend to throw it all into the same "homeless" bucket.

Another commenter suggested that "unsheltered" is the American equivalent to rough sleeping, and I think that makes a lot of sense, even though I haven't heard it much.

Homelessness is obviously an issue in many American cities, and perhaps using more specific definitions could help us understand the issues unique to each group.

yeutterg··on Rough sleeping has been almost eradicated in Helsinki
Haven't heard it used much, but it makes total sense. Thanks!
yeutterg··on Rough sleeping has been almost eradicated in Helsinki
Totally agree, I just wanted to point out that a lot of Americans probably wouldn't click on the article in the first place from the headline alone
yeutterg··on Rough sleeping has been almost eradicated in Helsinki
Some digital nomads classify themselves as homeless, although it's a bit tongue-in-cheek as they are clearly of a different socioeconomic status.

At least for me, when I hear the word homeless I first think of someone living on the streets. We don't have exact equivalent to rough sleeping in the U.S. that I can readily think of.

yeutterg··on Rough sleeping has been almost eradicated in Helsinki
Point taken and appreciated. I agree that homeless is a bit of a catch-all, but I'm not sure that we have any equivalent phrase to rough sleeping in the US (at least on the East Coast). When I hear the word homeless, I first think of people living on the streets.
yeutterg··on Rough sleeping has been almost eradicated in Helsinki
FYI, as an urban American I had never heard the term rough sleeping. Some brief Googling leads me to believe this is an alternative term for homelessness mostly used in the UK.

You may consider changing the title to include the word homeless. It's more descriptive to Americans, at least to n=1.

yeutterg··on U.S. Patent Operations May Shut Down in Second Week of February
Not an expert, but I think the point of having the receipt of postmark gives you a paper trail that says you filed on that day. Whether or not it made it to the USPTO.

I assume this means you would have to ship from the post office directly or your tracking at least gets an update beyond "label created." Typically, the first tracking step I get is for my city's distribution center.

yeutterg··on U.S. Patent Operations May Shut Down in Second Week of February
Great to know. Thanks!
yeutterg··on U.S. Patent Operations May Shut Down in Second Week of February
Yes, I am currently working on a provisional with him. To be clear, he does not work for the USPTO. He helps companies file patents and has taken a test to prove that he is capable of doing so.
yeutterg··on U.S. Patent Operations May Shut Down in Second Week of February
There are a number of household name corporations that also act as patent trolls in their respective industries. Somewhat like the Luxottica/Oakley story, they put smaller companies in weak positions, forcing them to sell at a low valuation or go out of business.
yeutterg··on U.S. Patent Operations May Shut Down in Second Week of February
In case the "small staff" thing doesn't work out...

A patent agent I know recommended this in case the electronic filing system shuts down: Send in your filing via USPS Priority Mail Express with tracking, and retain all copies and receipts. According to him, the date you postmark the letter becomes your filing date. Also, this apparently does not apply to private shipping services like UPS and DHL.

yeutterg··on Proper Breathing Brings Better Health
I've heard good things about it as well!
yeutterg··on Proper Breathing Brings Better Health
A great book that will help with posture, including fixing pelvic tilt, is 8 Steps to a Pain-Free Back by Esther Gokhale [1].

The author traveled around the world and looked through history to find out if we always had such terrible posture. It turns out that industrialized societies put a large emphasis on good posture up until the early 20th century. Even today, great posture can be found in less-industrialized cultures.

The Gokhale method has been a game-changer for many, even though it flies in the face of a lot of modern theories about designing furniture and "good" posture. I've personally met people with arthritis and lower back problems who were able to reduce pain and prevent further damage with this book.

[1] https://www.amazon.com/Steps-Pain-Free-Back-Solutions-Should...

yeutterg··on Show HN: IKEA Stock Checker
Here's a little weekend project I put together after finding it frustrating to plan IKEA trips. It basically generates a shopping list with item locations and notifies you if there are quantity issues.

The code is pretty hacky and there are most definitely bugs. But maybe you'll find it useful.

← PreviousPage 4 of 6Next →