Birds Have a Mysterious 'Quantum Sense'. Scientists Have Now Seen It in Action | Hacker News Reader

Birds Have a Mysterious 'Quantum Sense'. Scientists Have Now Seen It in Action

sciencealert.com

64 pointsbookofjoe38 comments

This is not a "quantum sense", it's a mechanism for sensing (non-quantum) magnetic fields that happens to rely on a quantum mechanical effect. But ultimately everything that happens in our universe relies on quantum mechanical effects, to that's not quite as esoteric as the headline is trying to make it appear.

my first thought was the same, but I still had an intuition that it makes sense to call this sort of thing quantum as opposed to other, say, chemical-based senses which, although still at some level obviously relying on quantum physics, are more readily explained by using higher level concepts.

I suppose it comes down to emergent phenomena: what's the lowest-level concept you HAVE to invoke to understand what's going on here? when you want to explain how taste buds work, you can talk about neural paths and chemical chains, and even though each of those things relies on quantum physics to exist, you don't have to invoke the concepts or objects of the quantum world to understand the phenomenon in question. but with this particular phenomenon, you do. you can't just explain how this works with higher level concepts, you have to get low down.

The distinction here is that this effect requires a quantum-mechanical understanding of the world to be understood at the core. It's not like the simple movement of a ball in a parabola, which can be explained in classical terms.

The same could be said about sense of smell. And frankly any of the other senses. Even touch, if you realize that the atoms in your hand never really "touch" other objects.

Depends how you define “touch” doesn’t it? It’s not like the atoms have sharp boundaries which fall short of coinciding with the boundaries of other atoms,

what should it even mean to say that they do or don’t touch?

I don’t know much of anything about how smell works. Does it involve quantum mechanics in ways which don’t fall under “chemistry” (with chemistry being an implication of quantum mechanics) ?

I think “has to be understood in terms of quantum mechanics beyond just chemistry” is a reasonable distinction to make, and applies to the way these birds work.

> I don’t know much of anything about how smell works. Does it involve quantum mechanics in ways which don’t fall under “chemistry” (with chemistry being an implication of quantum mechanics) ?

Arguably, yes. You could call smell a chemical sensor, but it's not sensing chemicals through a chemical reaction. Instead, it's sensing the modes of excitation of a molecule, i.e. the distribution of available state transitions, which is inherently quantum mechanical.

Cool! I didn’t know that. Thanks!

That's interesting. Do you have a reference?

No, sorry. I don't remember where I first read about this, but it was a story about a perfume manufacturer successfully using IR gas chromatography to synthetically recreate an expensive perfume component (or something like that), where other techniques had failed. I don't know if there has been any subsequent research publications that definitively demonstrate what's going on.

It's possible that shape matters, too, as it does for other receptors. Either way, quantum mechanics is still critical for understanding the mechanism.

Found this:

https://www.bbc.com/news/science-environment-21150046

Apparently, it's controversial.

It might be more accurate to say that every atom in the universe are touching just a little, but the closer together they are, the more they touch. It’s a matter of threshold of probability, really. The inputs to the biological sensorium remain linear off the scale of discernment, but there are mechanisms involved in the sensing that have a nonlinear signal response, giving the very useful illusion of binary edges to sensory phenomena.

The most interesting part is very similar to phosphorescence https://en.wikipedia.org/wiki/Phosphorescence#Introduction Look at the figure 1A in the research paper https://www.pnas.org/content/118/3/e2018043118

Note that the diagram in Fig 1A is more complicated than the one in Wikipedia, because in this case the process involve some additional chemical steps.

If phosphorescence a chemical or a quantum phenomena? https://xkcd.com/435/

With some random search in Google I found this: https://www.sciencedirect.com/topics/chemistry/triplet-state It's somewhat relevant because the cause of phosphorescence and what is happening in this articles is caused by triplets. I want to highlight that if I'd want to ask more about these articles, in half of them I'd ask a Chemist and in the other half a Physicist. (In both cases, one that is specialized in these things that are between the fields.)

Am I missing something or is this about detecting moving magnetic fields? The researchers waved a magnet over tissue samples.

Moving a magnetic field through electrically conductive material generates electrical currents. That seems like a much simpler mechanism than some invoking quantum effect.

There's more detailed information here: https://www.u-tokyo.ac.jp/focus/en/press/z0508_00158.html and the actual publication at https://www.pnas.org/content/118/3/e2018043118

The mechanism of action isn't hypothesized to be electrical current; it's hypothesized to be the magnetic field causing a probability shift in the formation of radical pairs. How they controlled for the possibility of magnetic flux inducing current I'm unclear on (but I think it's understood that that mechanism would be impossible for flavins).

That's much deeper then.

>And there's evidence that even though it's not conscious, humans are actually still capable of detecting Earth's magnetism.

There's nothing totally convincing on this is there? I followed the links and it seems to just be modulating EEG responses. That's not the same as "humans are capable of detecting". It's possible to measure unconscious capabilities behaviourally, e.g in blindsight experiments.

I guess the more accurate statement would be that human cells have the machinery to do it.

The article says,

“Importantly, this is evidence of quantum physics directly affecting a biochemical reaction in a cell – something we've long hypothesized but haven't seen in action before.”

But there is an entire field called quantum biology:

https://royalsocietypublishing.org/doi/10.1098/rsif.2018.064...

There's a whole field of study in dark matter, something we've not directly observed yet. That article doesn't seem to contradict the assertion; it says things like:

> As we investigate biological systems on nanoscales and larger, we find that there exist processes in biological organisms, detailed in this article, for which it is currently thought that a quantum mechanical description is necessary to fully characterize the behaviour of the relevant subsystem.

This would be proof of one of those hypothesized processes.

Quantum phenomena in photosynthesis have been observed for some time now:

https://www.pnas.org/content/108/52/20908.short

https://www.osti.gov/biblio/914472

A great example (and AFAIK, the first quantum biological reaction identified) is photosynthesis [1]. Quantum coherence is part of the energy transfer mechanism of photosynthesis.

1. https://www.nature.com/articles/nature05678

I've known people who have a profoundly good sense of direction. They always know which way is North, etc. Not sure if they are just more attuned to visual cues such as position of sun, shadows, stars, etc. or possibly have better sensitivity to magnetic fields?

That seems like a fairly straightforward question to settle experimentally, using advanced scientific apparatus like a bag over the head.

I'd fund that study, if only to see birds with tiny paper bags over their heads.

Plastic lens over the eyes but still gnarly looking

I have this, and it was a running joke when I was a kid. "remarkEon - what way is North?" and I'd always get it right. I think it's just good spatial awareness - nothing magical or any special sensitivity to magnetic fields. For example, I still get turned around after exiting the subways in New York on occasion (who doesn't).

Same here. Hyper awareness explains it, and it definitely isn’t reliable enough to say it is based on some extra sensory input. Just paying attention more than most.

Not sure if you’ve experienced similar, but I also have been aware of things like where the trash cans and bathrooms are, where the fire extinguisher is, where the power outlets are, etc. without being asked or consciously attempting to find them, and can give accurate spatial directions to them without thinking about it much, which seems to be similarly unusual. I just remember and integrate the knowledge as I happen to run across various data.

I think this is just pattern recognition, really. There's only a few places where it makes sense to put e.g. a fire extinguisher or power outlets so you can make an inference about where they're at without actively thinking too much about the layout of a building.

Of course!

North is also a VERY predictable and easy to figure out direction with a little thought if you can see the sky, and anyone with a smart phone (99% of the population now?) have GPS and high resolution maps and satellite photos accessible at a moments notice on it. Yet people get lost all the time, and I bet if you asked 10 people which way was north walking on the street, you’d be lucky to get 3 which pointed in the right direction (and 2 of those would only be right through sheer luck).

I’ve been around groups several times now when a fire happens, and had to grab extinguishers because of unexpected fires when I’ve been around, and most folks can’t figure out where a fire extinguisher is (let alone get it) when a fire happens even after they were shown it when they arrived.

At least in the middle of Manhattan, I've learned to rely on the direction of cars up and down avenues to tell which way I'm facing. I know that Eighth Ave goes up because I live and work around there, and so can extrapolate for the other major avenues. That, and that subway exits often given you their cardinal orientation relative to the center of the intersection they erupt from.

This may sound crazy, but after a while I could tell what direction I was going in Manhattan by how things ... smelled. Closer to Battery and I'm getting a little more peaty. Closer to Harlem or Morningside and I'm getting a little more rusty iron.

I could do this when I was young, too, even with my eyes closed after walking around blindfolded. Went away after puberty.

I also have this. And I also think it's just a synthesis of many clues and I guess some people don't perform that same synthesis (my wife for example). Things like "last known direction", "position of sun", "time of day", "this side of the tree is wet but the other isn't", and probably a bit of grid neurons somewhere doing dead reckoning.

I also have this a bit, but when I moved from London to Sydney, my sense of it flipped, i.e. 'up' on my internal map was now South not North, from which I concluded it was not magnetic.

Similarly, I had a disturbing sense of disorientation when first visiting a tropical area. It went away once I figured out that the midday sun was casting shadows south, towards the equator instead of north towards the pole. I had not been consciously reading the shadows but as soon as I accepted this fact, I no longer felt alarmed. I wasn't there long enough to really evaluate my new, localized sense of direction.

It's basically just an innately good sense of dead reckoning. I was especially good at it growing up in Chicago where pretty much every street is either N/S or E/W, it made it much easier. You just needed an intuition of the difference between your left turns and right turns, or you could just explicitly count it.

How's this for an experimental setup: get a cohort of people going in for surgery under general anaesthesia, and randomly place them in a north or south facing windowless room afterwards :) no added risk, and pretty minor cost

Could this be basically a “free will” organ if you will? Like the only way to escape determinism?

Reply on news.ycombinator.com