The Toucan and the Puffin

UV light is normally invisible to humans the word ultraviolet means "beyond violet", which is the highest colour spectrum visible by humans. Our vision is based in an RGB red green blue spectrum.

What's the difference between a penguin and a puffin?

But birds have an extra colour in the mix, giving them tetrachromatic vision. In other words, they can see colors that we don't even comprehend. Is this glowing something that puffins can comprehend? Almost certainly, though it's difficult to say if it would "glow" in their eyes. Most likely, it would just look very beautiful. As in, even more beautiful than puffins already are. Your email address will not be published. Sign-up to our daily newsletter. We know it's difficult to imagine puffins being any more adorable than they already are, but just you wait Are you ready for this?

Under UV light Wait, what? Why are we only hearing about this now? Embed from Getty Images Not glowing in the dark. Special sight Embed from Getty Images Human vision is limited to this colour spectrum, but birds can see beyond it. Getty Embed So the natural question about this natural phenomenon is: We had no idea we could love you more. And yet, here we are!

Tell US what you think Cancel reply Your email address will not be published. I see your point — but probably what we have then is the need for a rethink of the situation — there are many more pedestrians than envisaged trying to cross a busy road. Although this might be time-related or cyclical for example, a crossing near a suburban train station — trans arrive, s of pedestrians for a few minutes, then none.

Always resetting the countdown even when at 1 second helps crossers by not delaying them for yet another 20 seconds. So actually prioritising walking, cycling and public [road] transport over private motoring, instead of merely paying lip-service when there are no private motorists in the vicinity. If there is enough cross traffic to regularly occupy a crossing for 10 minutes or more let alone continuously , then it is time to remove the motor vehicles altogether because of the nuisance they bring.

I suggest lights that are by default red for motorists and green for pedestrians. Motorists can stop, lean out the window, and press a button, and then wait minutes for the lights to briefly change in their favour so they can continue on their way. Or, more equivalently, change for just long enough to get half way across before they are gambling with their lives again.

The toucan on Lewisham Road, near to where I live, has sensors that delay the start of the red and amber phase for motorists. I also remember next to Waterloo station, a toucan that had them but that the blackout or pedestrian red and motorist red would be on for ages because pedestrians were disobeying the signal.

It now uses a toucan plus countdown configuration. There are problems with far-sided signals, outlined in this video: The video focuses on the problems with Pelican crossings. The issue with far sided signals is what to do when the green man stage ends. Both of these are ambigious and unsafe as someone might intuitively interpret the lack of red man as an instruction to start crossing. Near sided signals solve this problem as someone who is already crossing cannot see them any longer — they display a red man during the delay period between green man and green signal for vehicles.

The PEDX configuration far sided signal, blackout with pedestrian countdown timer seconds until red man seems to be the best solution. The problem identified in the video is the ambiguity of the flashing green signal — not far side signals, per se. At least that is what I take from it!

I have a sneaking suspicion that, just like with the flashing amber stage at Pelican crossings, Puffin crossing sensors are actually more about traffic flow than pedestrian comfort. If I remember correctly, the design guidance says that the maximum clearance time once the green man has gone out should be enough time for someone to cross the whole road at 1. If pedestrians finish crossing before this time is up, then the traffic can be released sooner to reduce delays to motorists.

Although I found I could always cross in one go in Amsterdam the waiting times were so short — it was fantastic , sometimes the signal for the second part of the crossing would go green a few seconds before the first part of the crossing. For Pelicans the clearance time is the crossing distance divided by the 1. I looked up some of the government guidance on this, it seems that the recommended maximum time on a Puffin crossing should allow someone to cross at 0.

If the maximum clearance time is reached when a pedestrian is still on the crossing, the traffic lights will change to green anyway. I was shocked to discover the countdowns were telling pedestrians how much longer they had to cross. I assumed they would indicate how long peds had to wait before they could cross for the red man to turn green. At our nearby crossing you regularly have to wait about three minutes after you press the button. The difference is that they might well do this indefinitely and hold conflicting [motor] traffic at red if you were to stop in a crossing with sensors.

The clickers in NL are only for pedestrians, not cyclists. For the last 3 seconds of the green man phase, the green man flashes and the clickers turn on and off in time with the flashing. This flashing means the green man phase is about to end, but you can still start to cross the complete opposite meaning to a flashing green man on a UK pelican crossing. Yes, other complete opposites in design philosophy are evident, too. In NL, the crossing lights are not necessarily visible to motorists—in UK, walking lights are positioned to be clearly visible to the first waiting carriageway user s.

This latter can be seen from the pictures in the body of this post, although neither the author nor childbacktandem make the connection that this is because they are not there chiefly for the benefit of walkists.

As Paul Luton intimates: On another note, how come you never seem to see pelican crossings with puffin-style detectors? This seems to be a side effect of the british design guides, in Australia the pedestrian crossings are uniformly shown with far side and sometimes additionally on the nearside signal style.

Toucan crossing

They are so attractive because: Its all very inefficient for pedestrians and furthering the priority and dominance of motor transport. Also noting that the Australian guides describe why a controlled crossing would be used instead of zebra uncontrolled crossings: Unless you are talking about very high pedestrian flows preventing drivers getting though at all in a timely manner, zebras are more efficient, because people can respond to a crossing being clear faster than the lights can.

There is so much buffer put into the system to cope with the fact that they expect people to disobey it, that the whole thing wastes a lot of time. It takes a surprisingly small flow of pedestrians to reduce the throughput of a road substantially, a single person crossing will require all the traffic lanes to stop at some point and once traffic is queued they are inefficient to start moving again. As you note the inter green clearances are eliminated in zebra crossings, but bundling together several pedestrians quickly eliminates that advantage 1 minute wait times for pedestrian requests are not uncommon here.

Sounds like its worthy of some simulations to share publicly. I think this is the wrong rationale. The same study showed that above 15, cars daily, the installation of a zebra crossing of any kind would actually reduce pedeestrian safety. This should be used as the rationale for installing signalized crossings, not obstruction to vehicular traffic.

This professional driver is saying that he cannot see for seven metres in front of his cab. It is completely insane. Yet when you question how are such dangerous vehicles are allowed to exist alongside pedestrians and cyclists nobody seems willing to support legislation to eliminate them using cyclops mirrors or sensors.

The infamous blind spot is used as an excuse for an enormous range of incidents, a lot of which are simply driver inattention. I had a guy in a car pull out of a side road as I was passing in front of him. Despite me being directly in front of him and me having seen his face clearly as I approached he still claimed that I must have been in his blind spot. Note the language indicating that the blame was mine for being in the wrong place. This attitude essentially means that anyone hit by a truck must have been in the wrong.

Of course truck drivers have no obligation to avoid putting you into their blind spot by pulling up alongside you.

Under UV light

This is rather different from the US. While other road users are taught about these blind spots, and why it is not a good idea to spend long periods of time in them, truck drivers are generally expected to know their blind spots, and drive accordingly. So truck drivers and other road users mutually share their responsibility, in that people know how to avoid expending lots of time in the blind spots of trucks, but truck drivers know they need to be aware that, while the road may look clear to them, in reality it may not be.

Then no one on the crossing would be in the blind spot. Motorists already drive over the stop line and block the crossing, especially truckers. Stop lines are meaningless unless enforced and red light cameras are very rare now. This is encouraged by design in the UK where far-side [secondary] signals for carriageway users are provided in abundance and even the primary signals are beyond the stop line—and well beyond any advance stop line.

In countries where this is not the case, it seems less of a problem—and clutter is considerably reduced, too. Part of it is that, as drivers pull closer to the line, it disappears. I think it is a design flaw. Here is a good idea: Rather, take the least favorable conditions likely when a Mack R Series truck an old and discontinued but very popular at least in America truck design with notoriously bad visibility is first in line and put your signals there or even up to 2 or 3 meters behind there. Of course, we all know that the biggest attraction is that magnificent beak.

Colourful and large, this striking feature ranks alongside those of the toucan and pelican as some of the greatest bird beaks around. And you know what?

• Toucans and Puffins on patrol in York.
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• Le socle commun en France et ailleurs (Les Colloques de lIREA) (French Edition)?

Embed from Getty Images. To be clear, the beaks on puffins don't just glow in the dark. We'd obviously have noticed this by now. The news broke thanks to a lucky hunch played by a British ornithologist bird scientist named Jamie Dunning. During some work in his lab, he decided to try shining a UV ultraviolet light on a puffin. The bird's beak responded by fluorescing—or glowing by absorbing and then reemitting the UV rays.

Dunning excitedly published a paper about his findings, only to find that some scientists at the University of New Brunswick claim to have also made the same discovery in Regardless of who was first, what matters is that the secret is out. Human vision is limited to this colour spectrum, but birds can see beyond it. So the natural question about this natural phenomenon is: Why do puffins have fluorescent beaks? UV light is normally invisible to humans the word ultraviolet means "beyond violet", which is the highest colour spectrum visible by humans.

Our vision is based in an RGB red green blue spectrum.

What's the difference between a penguin and a puffin? | HowStuffWorks

But birds have an extra colour in the mix, giving them tetrachromatic vision. In other words, they can see colors that we don't even comprehend.

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Is this glowing something that puffins can comprehend? Almost certainly, though it's difficult to say if it would "glow" in their eyes.