Dogs’ Eyes Have Changed Since Humans Befriended Them • Hacker News Board

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#111

Post by Moru » Tue, Jun 18, 2019, 7:36 PM UTC

Frondo wrote: post #60

miahi wrote: post #34

Earlier quoted context omitted.

3. The flicker fusion issue mostly applies to cathode ray displays and moving pictures. Many LCDs use flickering light (PWM) for backlight, but usually at more than 200Hz. Better LCDs use linear current sources for backlight, so there's no flicker at all. An LCD should be fine even for dogs when static images are displayed.

Cheap LED bulbs actually flicker significantly, which I realized when I filmed using my camera's "slow motion" capture at 240 frames per second. In our bedroom, I put in some LEDs, not realizing there could possibly be a difference between cheap and expensive ones. One night I filmed my cat doing something dumb in slow motion, and when I looked at the playback the whole room was strobing. It was pretty wild. I might…

You don't need slow motion camera, it's enough with most normal catch the worst offenders in the store if they have those led display sets where you can see the lightbulb lit. Just shove the camera real close to the lightbulb and watch the stripes. If no stripes, put it even closer (almost touching) and if it's still ok, buy it :-)

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#112

Post by Moru » Tue, Jun 18, 2019, 7:57 PM UTC

thfuran wrote: post #101

ubercow13 wrote: post #62

Earlier quoted context omitted.

Yes but I guess the amplitude of the flicker must be very low? I'd have thought that if it was at all significant it would be very visually obvious at 50-60Hz

It's really more like 120Hz since the polarity doesn't matter for incandescents.

But you can stabilize the current quite nicely if you know how. This is almost never done on cheap LEDs. Except IKEA's leds, they were surpricingly good in some test lately.

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#113

Post by omni » Tue, Jun 18, 2019, 8:56 PM UTC

Karunamon wrote: post #95

omni wrote: post #69

Earlier quoted context omitted.

This meme of not getting rescue dogs is so harmful and needs to stop. Good adoption agencies will foster the dogs for a while and let you know if the dog actually has behavioral issues. Plenty of them don't. I'm convinced my rescue's previous owner was a little old lady who died or something. He has no issues at all. Every time I look at my amazing rescue dog (my first dog ever) and think about how he was almost put…

I don't know how to say this without sounding like a jerk, but it's not the tone it's intended in: Getting a dog should not be an emotional decision. This goes double when it comes to larger or more powerful breeds like ASTs, Dobermans, boxers, etc. A Pomeranian that's bitey is regrettable, a Rottweiler that's bitey is dangerous. Getting a shelter pet is a lot like buying a used car in that you're signing up for a lo…

No offense taken at all and I think this is all great advice. The actual decision to get a dog should be deliberate and thought out. I just hope that people will at least consider shelters / rescues and not rule them out immediately because of what my parent comment said.

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#114

Post by tzs » Tue, Jun 18, 2019, 9:47 PM UTC

korethr wrote: post #104

tzs wrote: post #100

Earlier quoted context omitted.

Another dog sense I've wondered about is hearing. What is our music like to them? Let's consider live music, first. A lot of instruments have significant harmonics well above 20 KHz. So let's say you are practicing your violin or trumpet, and your dog is in the room. The maker of your instrument took great care to get the sound right, which mainly consists of making sure that the various harmonics are at the right re…

> Another dog sense I've wondered about is hearing. What is our music like to them? This is a thing I've wondered about too. Their frequency range is only part of it. There's also the frequency weighted sensitivity; it's why we humans perceive music the way we do. A dog might be able to hear a tone at 45kHz, but it might require significant amplitude, e.g. threshold of perception at 45kHz might be 80 dB SPL. The ISO…

> Looking stuff up for dogs, I'm finding mixed results, so I'm less confident in my assertion here

I was kind of surprised at how little information I could find a while back when I searched online for information about animal hearing and animal vision. I was playing around with making a camera to automatically take a photo whenever an animal stopped by to eat the seeds and nuts I put out for them.

I've got a sensor that measures the distance to an object by bouncing an infrared laser off it. It's a class 1 laser, which basically means that it is not possible to exceed safe exposure by looking at it, even with a microscope or telescope. But that's for humans. What if a curious bird decided to get right up to it and take a look?

I couldn't find anything on laser safety for birds or squirrels or other animals likely to visit.

I've also got a distance sensor that uses a 40 KHz ultrasonic pulse. I couldn't find anything on the safety of that, either, for animals.

I did some tests with the IR laser and found that it didn't work very well for this application. It worked great at detecting when my hand was in front of it, but was very flaky with birds and squirrels. I guess features and fur just doesn't reflect IR light well enough.

Ultrasonic worked better, and so that's still in the running if I ever get time to finish this thing. I still don't know about safety of that for the animals, but figure that if the animal can hear it they will stay away if it is loud enough to harm them.

Alternatively, I may just go with having the camera take a photo every second, and try to figure out in software which ones have an animal in them. No risk of harming the animal that way, and also the camera could then be in my house looking out a window instead of outside, which would make power a lot easier and get rid of the need for weatherproofing it.

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#115

Post by lurquer » Tue, Jun 18, 2019, 10:37 PM UTC

ralusek wrote: post #4

> By evolutionary standards, the time since this split [from wolves] has been remarkably short for two new facial muscles to have developed. 2 facial muscles? What about Chihuahuas to Great Danes, is that not a more impressive evolution than 2 facial muscles?

They examined four dead wolves. Four. Each had muscle fibers and a tendon at the appropriate place. Just not as pronounced. Where the wolves related? Apparently a pair was obtained from a taxidermist and a pair from Michigan. That is, this is hardly a representative sample of wolves.

Spinning a saga about dog evolution from examining 4 dead wolves is stretching...

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#116

Post by hermitdev » Wed, Jun 19, 2019, 12:38 AM UTC

maccard wrote: post #43

jyriand wrote: post #40

Earlier quoted context omitted.

Getting a dog should not be an emotional decision. I have a dog and sometimes it's a lot of work. Feeding, pooping, pissing, neverending fur in the house and on my clothes, vet, constant attention seeking etc. Just to mention a few things. And if you need to travel you need a babysitter for your dog. It's easier if you have a backyard where the dog can chill.

Can confirm. I am sitting here with a 9 week old puppy that I've had since Friday. It's relentless at first.

I feel you. When we got our rescue puppy, we were told he was around 8-9 weeks, but turned out he eas about 6 weeks old when we took him home. He was transferred to a no kill shelter outside of Chicago from a kill shelter in Kentucky. We took him home the day he was transferred. We had to bottle feed for a few weeks with formula before he was able to transition to wet food and them a few weeks later gradually transitioned him to dry food.

I spent about the first week sleeping on the floor next to him to make sure he was comfortable and to take him out if he started whining.

We were also told to expect him to top out around 35 lbs. We had him neutered on Black Friday last year. Figured he was born about May 1st last year. When he got fixed he was already 45 lean pounds. A year after bringing home, he seems to have peaked at 60 pounds, nearly twice what we told to expect. He definitely has tons of energy and is very athletic (he can easily jump entirely over our couch). He could easily clear the baby gates we have to keep him in the living room/kitchen in our townhouse. He did it once without thinking, chasing one our cats upstairs.

First 3 months or so, there were a lot of accidents with urinating and defecating in the house. And he had worms when we first brought him home. I had to carry him up and down the stairs for that period, as well. At firat because he just couldn't get up and down the stairs on his own, and then later to prevent him having an accident before getting outside (never had an accident while I was carrying him).

A year in, he's fairly well trained, but we still have some problem areas like barking and jumping on people. He's crate trained. He sleeps in his crate overnight and when we're away from home for a bit. My wife works from home and sleeps in a bit and he's gotten used to me taking him out early in the morning to do his business and goes right back into his crate on his own after having a bit of food and water until my wife wakes up an hour or so later.

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#117

Post by atombender » Wed, Jun 19, 2019, 2:40 AM UTC

vectorEQ wrote: post #90

vanderZwan wrote: post #47

Earlier quoted context omitted.

> As well, did you know lights have a flicker? If you think it's bad, it's even worse for dogs which can lead to stress. As someone who notices and gets really tired from the stroboscopic effects of cheap LEDs, I can only imagine how terrible that must be for dogs

try candles. natural light for me gives me least issues. most electric lights are exhausting...

Candles generate soot, which is not good for your health. The soot will also stain walls and ceilings, similar to cigarette smoke. Natural waxes like beeswax candles have a cleaner burn, but they're very expensive.

If you're going to go non-electrical, I think an oil lamp (e.g. paraffin) is your best bet. Very cheap, safer than candles in the right lantern, and clean-burning (assuming a quality oil that doesn't have a lot of sulfur and other pollutants).

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#118

Post by maccard » Wed, Jun 19, 2019, 7:51 AM UTC

hermitdev wrote: post #116

maccard wrote: post #43

Earlier quoted context omitted.

Can confirm. I am sitting here with a 9 week old puppy that I've had since Friday. It's relentless at first.

I feel you. When we got our rescue puppy, we were told he was around 8-9 weeks, but turned out he eas about 6 weeks old when we took him home. He was transferred to a no kill shelter outside of Chicago from a kill shelter in Kentucky. We took him home the day he was transferred. We had to bottle feed for a few weeks with formula before he was able to transition to wet food and them a few weeks later gradually transit…

Yeah the stairs was something I wasn't quite prepared for - I live on the 4th floor and have 60 steps to my garden, I have to carry our pup up and down every 2 hours at the moment (or less if she's eaten recently). She's never peed in her crate or on either of us, which is great but she has done so in the house a few times when we're ever so slightly distracted, but we're getting slightly better at it.

Glad to hear things are working out for you :)

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#119

Post by hnick » Wed, Jun 19, 2019, 8:35 AM UTC

Joakal wrote: post #26

This is a good opportunity to educate the general [HN] community about dogs: 1. They can only see blue/yellow. Not like humans' RGB. 2. They are short sighted. For far away objects, their sight is like a T-Rex, they can see moving objects, not stationary objects. Remain still, and they can't see you. Then again, they can smell you, especially if it's downwind. 3. Their flicker fusion threshold is higher than humans.…

The funny thing with my dog, who we've done some scent work with, is that his nose seems to need to be focused and 'switched on' to really work.

If I throw him a treat and he misses it, he will default to looking around with his eyes and missing it until I point it out. But give him the ready cue, and he can find a tiny piece of food or odour hidden in a drawer in a room in under a minute.

So my take on that is it takes a lot of processing power to run the nose, and after a search session it's definitely nap time.

And side note, I'd like to see AI efforts aiming at the level of a dog before we go for humans. It's amazing what they can do but it takes so long to train them and you have to start from scratch each time.

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#120

Post by saltcured » Wed, Jun 19, 2019, 5:55 PM UTC

sandworm101 wrote: post #87

Joakal wrote: post #26

This is a good opportunity to educate the general [HN] community about dogs: 1. They can only see blue/yellow. Not like humans' RGB. 2. They are short sighted. For far away objects, their sight is like a T-Rex, they can see moving objects, not stationary objects. Remain still, and they can't see you. Then again, they can smell you, especially if it's downwind. 3. Their flicker fusion threshold is higher than humans.…

>>> Then again, they can smell you, especially if it's downwind. Only if the dog is downwind. Contrary to repeated myths about bears, no animal can air-scent objects downwind of themselves.

But, they might find your latent scent on the ground or on objects and follow that to you. So, being downwind at the moment is different from having a downwind approach to a new area...