The Department of Canine Security urges dogs to remain on high alert and employ the tactic of See Something, Say Something. Remember to bark upon spotting anything suspicious; e.g. firecrackers, sparklers, Roman candles, cats, squirrels, mail carriers, shadows, reflections, other dogs on TV, etc.
dog dogson • July 5, 2016 12:12 AM
Unfortunately, fireworks aren’t funny for us dogs. We, as well as all other animals, get scared, and do crazy things that get us injured or killed.
Gurka • July 5, 2016 3:27 AM
Funny and a good analogy. But with one flaw. Dogs (or mammals in general) doesn’t see black and white. They do see color, even if they don’t have as good color vision as humans. Dogs and most of the mammals are dichromats. That is to say, they have two types of cone cells in their retina, compared with us trichromats, who has three types. In addition, we as well as them have rod cells, giving the lion’s share of light detection.
In nature, monochromats, dichromats, trichromat and tetrachromats exists in different species, as well as way more complex systems. Our trichromacy is shared with our closest relatives in the primate tree of mammals. Some New World monkeys, however, are tetrachromats (sometimes it’s a sex difference, a sexual dimorphism).
In twilight, as dogs cone cells are a little more sensitive, their color vision actually outperform ours as we are then more dependent upon our rod cells.
I don’t remember the spectra of the dogs cone cells, but they are comparable with some variants of color blindness in humans. But still, they are probably able to detect about 10,000 different color shades, roughly estimated from 100 shades per cone type multiplied together (that gives humans about 1,000,000 or 100³ shades).
Gurka • July 5, 2016 3:33 AM
…and, as Bruce surely can attest, many squids have incredible eyes with a non-inverted retina (and thus no blind spot, as the optic nerve doesn’t need to cross the retina), good resolution, many cone cell types and can detect qualities of light that we cannot see at all, like polarization patterns.
Who? • July 5, 2016 3:46 AM
Does it affect POODLEs?
Clive Robinson • July 5, 2016 4:41 AM
Unfortunately as is often the case what appears funny one moment, becomes tragedy the next,
Richard H • July 5, 2016 5:11 AM
@Gurka:
qualities of light that we cannot see at all, like polarization patterns
Yes, of course the squid’s far better, but in fact we can see (albeit faintly) polarization, in the form of Haidinger’s Brush. I first read about this in Minnaert‘s marvellous book and was amazed to discover that under ideal conditions I can see it too.
Gurka • July 5, 2016 6:38 AM
@Richard H
Ahh! Cool! Didn’t know that and suddenly my intentions are to know everything about it! I’m interested in optical illusions, eye anatomy, and weird optical effects so I guess this day is ruined for me, by off-topic study!
Again, thanks! 🙂
wiredog • July 5, 2016 7:58 AM
Last night as the neighborhood fireworks were being set off we saw a plainly terrified dog running full speed down the street. Hope it was heading towards, rather than away from, home.
blake • July 5, 2016 8:51 AM
Please also continue barking if you hear another dog bark, because that dog might have seen something.
12345 • July 5, 2016 9:51 AM
@Richard H, @Gurka
I first read about this in Minnaert’s marvellous book and was amazed to discover that under ideal conditions I can see it too.
Yes, thanks for the extra tidbit of info on Minnaert. Worth chasing.
“…During the German occupation of the Netherlands in World War II, he was imprisoned by the Germans because of his left-wing, anti-fascist sympathies. During his incarceration, he taught physics and astronomy to his fellow prisoners. After the War, he was one of the founders of the Mathematisch Centrum in Amsterdam.”
“…The ability to count and do simple arithmetic might seem to be a superfluous skill for dogs, but it is a useful ability that would have been vital to dog’s wild ancestors. For example, it would be useful for a female to know if all of her pups were present in the den or if one of them had somehow gone astray and required a search and rescue mission to be launched.”
Bruce Schneier • July 5, 2016 10:02 AM
“Funny and a good analogy. But with one flaw. Dogs (or mammals in general) doesn’t see black and white. They do see color, even if they don’t have as good color vision as humans. Dogs and most of the mammals are dichromats. That is to say, they have two types of cone cells in their retina, compared with us trichromats, who has three types. In addition, we as well as them have rod cells, giving the lion’s share of light detection.”
You missed the joke. That’s why all the threat levels are “gray.”
@Bruce,
I found myself wondering if you have a friendly loyal canine running about?
Jesse Thompson • July 5, 2016 12:07 PM
@Gurka Are you sure it’s not closer to 256 shades per cone? Love me some 8^3 bit colorspaces! 😀
Gurka • July 5, 2016 1:34 PM
@Bruce Schneier
Hmm. Maybe it’s a language barrier? I thought I got the joke and interpreted it like “dogs do only see monochromatic shades, so every threat level is different shades of gray”, and maybe “since threat levels are so arbitrary, ‘gray’ is as good as it gets”.
But the first interpretation as a “wink” to dogs color vision depends on a factual error and the second interpretation depends on the first, so to speak.
So, I don’t know if I did get the joke or not. Something was funny, so I can’t have missed it entirely. 🙂
In Swedish (my native tongue), gray (“grå”) is the color (BW shades) as well as something that is vague or ambiguous, and that’s the only other meaning I know of in English too (“gray area” = “gråzon”). I feel a bit stupid now, somehow!
Anyhow, this is all besides the point, as my first comment where off-topic geeky. I did get the take-home message, I think. Threat levels without a proper scheme of what to do when, is meaningless and can only impose fear. And “see something, say something” is indeed telling amateurs to do amateur security.
@wiredog
I’m a dog owner myself, and many dogs are very upset and terrified on New Years Eve (we don’t usually use fireworks at the National Day of Sweden, June 6). It’s a big problem and some dogs need antihistamines or even antipsychotics. And that’s just our pets! Wild animals can’t get antipsychotics! And let’s not forget about humans! War veterans and refugees of war don’t necessarily enjoy flashback memories. Children, too young to remember details may even lack the intellectual capacity to distinguish safe situations from benign ones. Thankfully my dog doesn’t seem to care the slightest. But, as it is with dogs, a single a-bit-too-close flash and/or bang can change that for the rest of her life!
@Jesse Thompson
Hehe, it may be, who knows? 100 shades from one cone cell type is just an estimate and others do exists. One estimate, according to Wikipedia, is that humans can resolve about 3.2 million shades. This boils down to about 7.2 bits per cell type. But actually, it is a kind of feedback system and rods have their saying too, helping the cones. Furthermore, a cell layer in retina contains so called amacrine cells and horizontal cells, creating a layer of (mostly contrast enhancement and inhibition) preprocessing before the signals are forwarded to the brain. This may further affect the “colorspace”. Btw, you did mean (2^8)^3 = 256^3 bits of colorspace, 16.7 million shades, didn’t you? I’m afraid we have to do with (2^~7.2)^3 ≃ 3.2 million shades. 😉 (Yes, I know this calculation is flawed since the different cone cell types probably doesn’t even have the same amount of detectable shades. Please distribute the potential 3.2M shades as you wish among those cones! 😀 )
Hamid • July 5, 2016 10:55 PM
The operative word here is Gray
Drone • July 6, 2016 7:33 AM
If you punish your dog every time he barks, don’t blame him when your home is invaded. The same goes for us vs. the TSA.
Clive Robinson • July 6, 2016 11:17 AM
@ Drone,
If you punish your dog every time he barks, don’t blame him when your home is invaded. The same goes for us vs. the TSA.
You are making an unwaranted assumption that the dog would actually recognise an intruder to bark at…
Likwise the TSA, tests so far have shown the could not find their 455 with both hands let alone test guns and bombs they have been trained repeatedly with.
Subscribe to comments on this entry
Sidebar photo of Bruce Schneier by Joe MacInnis.
Dali Mation • July 5, 2016 12:04 AM
It’s all security theater for humans. First bark!