Monday 14 December 2015

Festive Quantum Robins

Bouncing Bertie Boffin, Scientific Advisor to Blogville here!

It has been brought to my attention that this blog has been lacking in intellectual and scientific rigour of late, and so today I aim to redress the balance. In a suitably seasonal and dog relevant fashion, of course.

Maybe, like dear, clever YAM-Aunty, you already knew that today, 14th December, is considered as the 'Birthday of Quantum Physics'. It was on this day in 1900 when the German physicist Max Planck first proposed that energy emitted by a radiating system is not continuous but rather it comes in discrete packages, or 'quanta'.

I wonder also how many of you have received Christmas cards with pictures of robins this year? Perhaps you have had opportunity to bark at a robin, newly arrived in your garden after escaping the harsh Arctic winter?

OK, so I realise some you are now thinking "Bertie Boffin, poor chap, has totally gone off his rocker this time. I'm afraid he has been imbibing too much 'festive spirit'. What on earth do migrating robins have to do with quantum physics?"

Fellow pups, let me explain.

Now, since well before the days of satnav, scientists have been pondering the question of how birds navigate when they migrate long distances, especially across oceans where landmarks are few and far between. You might think this field of study would be the domain of the biologist, but in fact one answer came in recent years from some very clever experiments by physicists. These experiments led to an understanding of how the robin uses certain esoteric quantum effects to detect changes in the angle of the earth's magnetic field and thus to figure out which way is north*.

It all happens when a small package of light (a photon) reaches a special protein (cytochrome) found in the eye of the robin. The photon causes an electron to be expelled from the cytochrome. The hole is then filled with one of a quantum entangled electron pair such that a superposition of singlet/triplet states is created in the pair (yes, in the world of quantum physics, electrons can be 'superposed' in two states at the same time, with no problem at all - think of it like the state your human is in when you have done something bad, but also funny, and they are cross and laughing at the same time). Anyway the point is, that the laughing but also cross electron can easily tipped towards one or the other state, depending on the tilt of the earth's magnetic field, which is of course latitude sensitive. (In the same way that, if your human is still in the angry-but-amused state, and you tilt your head at a certain angle, this might impel your human to smile and forget all about shouting at you).

I am sure it is quite clear now, how robins find their way to your mantlepiece at Christmas, and so we would all like to say 'Happy Birthday' to quantum physics, and to salute the great founding fathers** of this weird and wonderful branch of science.
Niels Bohr and Albert Einstein ponder the mysteries of quantum physics

*Note we are talking about the European robin here, smaller and cuter the American so-called robin, which I believe is actually a thrush!

**Max Planck, Albert Einstein, Niels Bohr, Werner Heisenberg, Wolfgang Pauli, Erwin Schrödinger, Louis de Broglie, Max Born, Paul Dirac.

PS from Gail: this post was inspired the book 'Life on the Edge: The Coming of Age of Quantum Biology' by Jim Al-Khalili and Johnjoe Mcfadden. A recommended Christmas read for those who like their popular science to be a tiny bit challenging!


  1. We're glad we didn't even try to think of what your scientific birthday would entail. We don't seem to have any robins around here, but we've always wondered how birds know where to fly. SHE even has trouble with Garmin!

  2. Crikey Bertie .... do you understand all that???????? So many BIG words, aye?? AND YAM Aunty can't be all that smart. She's somehow got lost. She lives up north and would you believe she's HERE .... downunder, SOUTH!!!!!!! Mum and I went to the beach with her today. I hope I can find a robin to show her the way home.

  3. I think I understood it Bertie, but I can't be sure. A wee dram might be in order (at 8am) to relieve the headache you've managed to bring on. Thank you Bertie :)

  4. Gosh, I sure learned a lot in this post for a Monday morning ...I didn't know that December 14th was the birthday of Quantum Physics. I had no idea that European Robins were so smart nor that American Robins were not even Robins. Also, happy to know about that head tilting thing ...explains a lot.

  5. aaaah I know what you mean... we talk about my mother, right? she was in an eggs-treme state as I opened my grandpawrents christmas gifts, but she laughed as I tried to wear my grannys new cardigan... but at then end our eggs-periment failed, because there was no greenie included this time... my mother is definitely NOT Einstein :o)

  6. OMD Bertie... we are so glad that you set us straight... all this time we thought those birds used a TOM TOM to navigate... like our mom does... OR just followed the emerging night crawler trails...
    Who knew!!!

  7. WOW! I learned so much from this post. My brain is full now... I think I have to lie down...

  8. We always thought the Robins just followed the pigeons :)

  9. hmm we have received only photo cards, babies and dogs but no robins yet

    retro rover

  10. OHHHHHHHHHHHHHHHH Bertie you the smartest most handsome WFT. Mom says she recalls many a physics student dreading Quantum Mechanics when she was working. She is sure if they dreaded the course or the Professor. He was a real piece of work.

    MOL MOL the peeps don't have a clue why they thought our mailman was named Earl...not one single clue. But they are older than dirt so their memory has turned to mush.
    Hugs madi your bfff

  11. We don't know nothing about a photon but Happy Birthday physics
    Lily & Edward

  12. Happy Birthday Physics...Mama says we are going to wait until Daddy gets home to translate this as he has some kind of college paper in Solid State Physics and Mama...well she has a paper in which there is hardly any of that physics stuff!
    Dory, Jakey, Arty and Bilbo

  13. We thought it was something like that but we could not find a card anywhere!

    Your Pals,

    Murphy & Stanley

  14. Hari OM
    Well presented as always, Bertie lad!!! As for Charlie's comment, what he failed to understand is that it is this precise methodology which helped me locate him...and will draw me back to Scotland in but a week's time..... sigh..... my head is spinning. Hugs and wags, YAM-aunty xxx