Different birds use different senses for navigation, from visual clues up to something related with quantum physics which I read some time ago but I can’t remember what it was 
In effect, a compass. The Radical Pair Mechanism is a possible explanation for the ability of birds to navigate using the earth’s magnetic field
Makes me wonder what will happen to migratory bird species if/when the magnetic field reverses next.
Cobalt wrote:
The Radical Pair Mechanism is a possible explanation for the ability of birds to navigate using the earth’s magnetic field.
Yes, that’s the one thanks. It proposes different solution than the previous theories based on classical magnetism.
Maoraigh wrote:
A Manx Shearwater was captured and flown to Italy in a box on a rotating turntable
Cobalt wrote:
Makes me wonder what will happen to migratory bird species if/when the magnetic field reverses next.
I had to look it up 🤓 and it looks like they’re safe: “The avian magnetic compass is based on the angle of inclination, and not the polarity of the geomagnetic field” in Assessing vector navigation in long-distance migrating birds from the OUP.
It’s not easy to check what long range navigational methods birds use, as it could be a mixture of magnetic, celestial, solar, light polarisation etc; and are also affected by environmental considerations (mountains, predators) and the medium they move in (weather, especially winds).
I remember listening to a radio programme where Canadian or European geese were displaced to Siberia. Their return flight was the shortest distance, a great circle route, interesting a) because it was completely unknown territory for them and b) they went the other way round the pole from normal. Frustratingly I can’t find any more about it online, but it stuck in my memory because I felt sorry for the birds.
Here’s another one.
Why isn’t the key in an aircraft also a master switch just like in a car?
I appreciate that unlike in a car, we may want to cut power to all avionics (eg in case of an electrical fire). But a circuit can be cut in more than one place. So why not cut it when the key is to the off position, just like in a car (in addition to a master switch that can be used in flight)? That would put an end to flat batteries when you forget to turn off the master, which just isn’t a problem in cars.
dublinpilot wrote:
So why not cut it when the key is to the off position, just like in a car (in addition to a master switch that can be used in flight)? That would put an end to flat batteries when you forget to turn off the master, which just isn’t a problem in cars.
I guess there may be a scenario (don’t know which) in which having the ability to pull the key out of the starter while still keeping the battery on and electrical system powered would be desirable.
If you’re on the ground with a flat battery you’re not going anywhere and that’s not a safety concern, so from the manufacturer’s point of view not a “real” problem. I’m guessing at some point someone did a FHA/SSA (hazard and safety analysis) and realised keeping the independence of the system either increased safety or became a requirement for some sort of failure condition.
Alpha_Floor wrote:
I guess there may be a scenario (don’t know which) in which having the ability to pull the key out of the starter while still keeping the battery on and electrical system powered would be desirable.
That scenario is called preflight. You switch on the master, check the flaps, lights, etc. but you obviously don’t want the prop to turn. The potential danger by using the key to power everything is that you could inadvertently turn it past the ‘acc’ setting (as in a car) and start the engine.
Ha, I’m going the other way.
At some point I’ll be redoing the dashboard on my Triumph with new switchgear in a custom layout. I’m likely to ditch the traditional key-operated ignition and starter switch and replace with separate battery master, ignition and starter switches.
dublinpilot wrote:
the key in an aircraft also a master switch just like in a car?
Well, most modern cars (not the one I own…) don’t have keys anymore… and so do more and more airplanes. 9 out of 10 homebuilts are built without a key, as we have now come to realise that the key is prone to failure, and serves no real purpose. A master switch, a starter switch, and switches for the ignition system, is all you need.
The key made its appearance in the cockpit at the same time as the control wheel or yoke, thanks to the American desire of selling the aircraft as a flying automobile 
Planes are most often built from standard parts and the standard mag switch was invented before planes had electrical systems. The locking mag switch is just the same thing with a key lock.
Like others, I prefer simplicity and lack of integration. Overall my choice would be a simple $5 master switch, two $5 mag switches, a $5 starter push button (none keyed) and a keyed canopy lock that can be used if required, but is not required every time. Integration tends to lead to type specific proprietary parts that soon enough become unavailable and in the meantime tend to be expensive. The ‘security’ hardware and firmware situation has become a long term ownership nightmare with modern cars and motorcycles.
Re no key lock at all it was always a pain to put a cable lock around the prop on my Luscombe when traveling so I’m happy to have the current plane lockable in some fashion. Some of the public airports where I’ve parked are remote and insecure and I wouldn’t particularly want to camp under the wing, never mind leaving the plane unlocked while I wasn’t there. Having said that, the canopy lock alone would be fine from the aircraft entry or theft point of view. However, the mag switch key does have an additional function: it ensures that mags are grounded for safety and cannot be ungrounded by anybody but me whether or not the canopy is locked, which 99% of the time on a breakfast run it is not – it’s often hot at midday so I like to park with the canopy partly open, and there may be kids and idiots on the ramp. This is not reflective vest and FBO escorts territory, thank goodness. If I had to close the canopy in this circumstance I’d need to have a large storm window to let the hot air out.
I believe there’s a post 9/11 FAA reg that requires the plane to be locked when stored outside but I can’t find it right now.
