Migratory bird's quantum mechanics: spin, entanglement and geomagnetic navigation

We know one thing from the historical class of junior high school: the compass is one of the four major inventions of ancient China. The invention and communication of the compass have a great impact on the development of civilization, making the exchanges of the navigation era and worldwide possible. However, in the modern society with highly developed technology, the compass has no place to use in the human world. Navigation and positioning are achieved through satellites. Even the "compass" app on mobile phones has been replaced by "Huo Huo "Er effect". But for animals, especially migratory birds that travel thousands of kilometers north and south each year, how do they navigate without science and technology assistance? In recent decades, scientific research has revealed the "key parts" and principles of migratory bird navigation -self -spin single -state and spinning triple dependent dependence on the magnetic field of hidden flower pigment 4. This article will briefly introduce this principle.

Written article | Ruoping

1. Geomagnetic field

The geomagnetic field refers to the natural magnetic phenomenon that exists inside the earth. The earth can be regarded as a magnetic puppet pole, of which the magnetic Antarctic is near the geographical Arctic, while the magnetic north pole is near the geographical Antarctic. Through these two magnetic poles, the straight line (magnetic axis) and the ethnic -rotating shaft of the earth are about 11.3 degrees. The strength of the geomagnetic field is about 25 to 65 Micro Tesla, and the magnetic field strength of a refrigerator sticker is close to 10,000 Micro Tesla. It can be seen that the ground magnetic field is relatively weak. In the past, it was difficult for scientists to believe that such a weak magnetic field could affect biological reactions. However, continuous research in recent decades shows that migratory birds can sense the ground magnetic field and navigate through the ground magnetic field.

Figure 1: Geomagnetic field

2, hidden flower pigment

Flower pigmentation, or Cry protein, is a type of photoretically widely distributed in authentic cells. Flower pigments were first discovered in plants, participating in a series of physiological activities that need to absorb short waves of light, and later studies were found in fruit flies, mice, birds, and even the human body. In the animal body, hidden flower pigments are mainly concentrated on the retina, participating in a series of light control reactions of creatures. In 2000, Professor Klaus Schulten, the University of Illinois, proposed a new and very attractive theory -the direction of the bird's use of hidden flower pigments induced magnetic fields.

Figure 2: Hidden flower pigmentation response

The interior of the hidden flower pigment combines a FAD molecule. This molecule is an important reason for CRY protein light sensing, known as the "heart" of hidden flower pigment. FAD molecules can enter FAD*after absorbing a photon. Subsequently, the four color pitchine (TRPH), which is similar to FAD (TRPH), continuous electronic transfer reactions (Figure 2. (a)), electron is absorbed by FAD*to form FAD*-, and the color acid forms a trph+ with positive electricity Essence FAD*-This has two different spin states with TRPH+, and the conversion rate between these two spinning states depends on external magnetic fields. It is this feature that allows migratory birds to use hidden flower pigment to induced to the direction of the ground magnetic field.

When migratory birds fly in different directions, the direction of the geomagnetic field is different from the direction of the migratory bird's eyes. Therefore, in different directions, the light and dark stripes in the eyes of migratory birds are different.

3. Migratory bird's quantum mechanics

Does the reaction process in life need quantum mechanics?

This is a long -term issue that scientists have tried to understand. One point is determined: there are many quantum processes during the chemical reaction process of the molecule, but due to the complexity and changes in the reaction environment, any quantum state will be quickly average, and the impact of the final quantum process will be average. Therefore, it seems that the evolution of life and reproduction does not require quantum mechanics to operate: life is classic.

However, after half a century, from assumptions to experimental verification, scientists finally found sufficient evidence to show that migratory birds' induction of the ground magnetic field is a biochemical process based on quantum mechanics.

Figure 3: Migratory birds and Arabia mustard with hidden flower pigments. Some biochemical reactions in their bodies are sensitive to magnetic fields

Let's take a look at the "compass" of migratory birds from the perspective of quantum mechanics.

First of all, you need to know the concept of spin.

The concept of "spin" was first established through a series of experiments, such as the famous "Stan-Gallah" experiment. The experimental results show that electrons should have an internal angle momentum that can interact with the magnetic field. Because its nature is similar to the classic angle momentum, it is named "spin". But this does not mean that the electrons are really rotating, and we cannot understand the spin from a classic perspective. Neither the current theory and experiments are found to be the lower limit of the electrons, so the electrons are treated as a particle particle. The self -rotation value is quantized -only an integer or semi -integer, and the spin is a vector. When we measure the projection of this vector along a certain direction, the measurement value is also quantized.

Figure 4: Electronic spinning intention. The left picture shows the upper spin, and the right picture shows the self -spin.

As shown in Figure 4, the spin of electronics is 1/2, and its projection has two values, which are +1/2 and -1/2. The rotating arrow in the figure is just to represent the direction of the rotary angle momentum, and it does not mean that the electrons are rotating.

According to the principle of compatibility of Paoli, the two electrons cannot be in the same state, so the electrons around the nucleus are generally distributed in pairs. One atomic orbit can accommodate two electrons, one spin upward, the other spin the spin down. The spin orientation of these two electrons cannot be the same, in a state of association, which is what we usually call quantum entanglement. Figure 5: The self -rotation single -state, spinning triple -state and spin -related balanced state of self -rotation

As mentioned earlier, after being illuminated, FAD will capture a FAD*-from the color of the color, and the original chromicine will form a TRPH+. The electrons captured by FAD originally existed in pairs with another electron in TRPH. After being captured, these two electrons are still entangled in a short time! However, because the two electrons are no longer on the same track, they will not be limited by the principle of non -compatibility of bubbles. In contrast, the self -rotation is constituted with a self -rotation single state, and the self -rotation direction is the same to form the triple state of the spin. In other words, FAD*--TRPH+is in a self-spin or spin. The conversion rate between the two states will be affected by the magnetic field.

Figure 6: The spin monocular and spins triple state of hidden flower pigments

As shown in Figure 6, A represents color picots and B represents FAD. Self-spin single states [A+ B-] can be decomposed back A and B, or it can be converted into product C. Self-spin triple state [A+ B-] can only be converted into product C. Transformation. The spin will be affected by the magnetic field, and the conversion between the spin single state and the triple state depends on the magnetic field (the angle between the direction of the magnetic field and the direction of the migratory bird flight). The proportion is different. In the end, this is different from the difference in visual images in different areas on the bird's retina. Therefore, in the view of migratory birds, different directions have different stripes. We can say that migratory birds directly saw the geomagnetic field! The hidden flower pigment on the migratory bird's retina is to guide migratory birds to travel north and south without getting lost every year!

Migratory birds will never be as lucky as we humans, and evolution can understand the brain that can understand the laws of physics. However, quantum mechanics -the cornerstone of modern physics -will always silently indicate the direction of home.

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Edit: Liu Ming

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