Biophoton

Living things make a tiny light. This light is very soft. You cannot see it with your eyes. It can come from plants or people. It can even come from fish eggs. Some scientists use special cameras to see it. These cameras help them see the light. This light can come from a leaf. It can also come from a brain. A man named Alexander Gurwitsch found this light. He won a prize for his work. It is a small wonder!

Living things make a tiny light. We call these tiny bits of light biophotons. They are in the visible and ultraviolet range. This means they are part of the light we see. But these lights are very weak. You cannot see them with your eyes.

Some people call this ultraweak photon emission. This is a long name for a very soft light. Scientists use special tools to find it. They use photomultipliers or special cameras. These tools can see light from fish eggs. They can even see light from humans.

How does this happen? It often comes from changes in the cell. These changes involve things called reactive oxygen species. These are small parts that can cause stress. When these parts move, they let out light. This is a bit like phosphorescence. That is when things glow in the dark.

Plants also make this light. It can come from their leaves or roots. Scientists study this light to see how plants stay healthy. They want to know if cells use this light to talk to each other. This is still a big mystery to study.

Living things create a very tiny kind of light. These bits of light are called biophotons. The name comes from Greek words for life and light. They are found in the visible and ultraviolet parts of light. This light is very weak. You cannot see it with your eyes. People also call this ultraweak photon emission or UPE. It is different from bioluminescence. Bioluminescence is much brighter and easy to see.

How does this light happen? It often comes from small changes inside cells. One way is through a thing called oxidative stress. This involves parts called reactive oxygen species. These parts can cause reactions in the cell. These reactions create what scientists call triplet excited species. When these species return to a lower energy level, they release light. This works much like phosphorescence. That is when an object glows after being in the light.

Scientists have studied this for a long time. In the 1920s, Alexander Gurwitsch found these tiny lights. He called them mitogenetic rays. He thought they helped cells divide. He won the Stalin Prize in 1941 for his work. Later, in the 1970s, Fritz-Albert Popp studied them too. He worked at the University of Marburg in Germany. He showed that the light covers many wavelengths. These range from 200 to 750 nanometers.

Special tools are needed to find such faint light. Scientists use photomultiplier tubes to measure the light. They can also use an ultra low noise CCD camera. This camera can take an image of light from plants. For plant materials, the camera might need 15 minutes to see the light. These tools can see light from fish eggs. They can even see light from humans and animals. Some cameras can see yeast cells as they start to grow.

Biophotons can tell us many things about life. In plants, light from leaves shows how they fight germs. This involves the R gene and its proteins. Scientists can also see light from stressed plant roots. Heat can cause a rise in light from these plants. In humans, a new way called photoencephalography tracks light from the brain. This helps study brain activity without touching the person. This light might even help cells talk to each other. However, scientists are still investigating if that is true.

Biophotons are tiny particles of light produced by biological systems. The name comes from the Greek words "bios," meaning life, and "phos," meaning light. These photons exist in the ultraviolet and visible light ranges. While they are a type of bioluminescence, they are much weaker than typical bioluminescence. Most bioluminescent systems, like those using luciferin and luciferase, are bright enough to see with the naked eye. In contrast, biophotons are non-thermal and extremely faint. Scientists often call this phenomenon ultraweak photon emission, or UPE.

To understand how biophotons are created, we must look at chemical reactions inside cells. A common process is chemi-excitation caused by oxidative stress. This involves reactive oxygen species, which are highly reactive molecules. These species can cause reactions through enzyme catalysis using peroxidase or lipoxygenase. These chemical events can create triplet excited species. When these species return to a lower energy level, they release photons. This mechanism is very similar to phosphorescence, where an object glows after absorbing light.

Researchers can observe these emissions using highly sensitive equipment. Because the light is so faint, standard cameras cannot see it. Scientists use photomultiplier tubes to measure emissions from fish eggs, animals, and humans. They also use ultra low noise CCD cameras to create images. For example, imaging plant materials might require an exposure time of 15 minutes. Some specialized Electron Multiplying CCD cameras, or EM-CCDs, are used to detect light from yeast cells as they begin to grow.

The study of biophotons has a long history. In the 1920s, the Russian embryologist Alexander Gurwitsch discovered ultraweak photon emissions in the ultraviolet range. He called them "mitogenetic rays." He believed these rays helped stimulate cell division. For this discovery, Gurwitsch was awarded the Stalin Prize in 1941. Later, in the 1970s, Fritz-Albert Popp studied these emissions at the University of Marburg in Germany. He found that the light spans a wide spectral distribution from 200 to 750 nm. However, his claims regarding the coherence of the light were criticized for lacking scientific rigor.

Biophotons provide significant data regarding the health of living organisms. In plants, imaging biophotons from leaves helps scientists assay R gene responses. These genes and their proteins help plants recognize pathogens. This triggers a defense signaling network known as the hypersensitive response. This response involves the generation of reactive oxygen species. Biophotons have also been seen in the roots of stressed plants. For instance, a rapid rise in temperature can induce biophoton emission due to oxidative stress.

Measuring these emissions has important scientific and medical value. One emerging technique is photoencephalography. This method tracks ultraweak biophoton emissions originating from the human brain. It offers a non-invasive way to study neural activity. Additionally, monitoring UPE provides a low-cost, label-free way to track drug therapies. This is especially useful for studying pharmacological interventions in diseases involving a reactive oxygen species response.

There is an ongoing debate about whether biophotons help cells communicate. Some hypothesize that injured cells release light as a "distress signal" due to high oxidative stress. However, this mechanism has not been fully demonstrated. Some scientists criticize the communication theory because the signals are much weaker than natural background illumination. It is very difficult to separate these tiny signals from the many other chemical interactions happening between cells. Therefore, the idea that biophotons facilitate cellular communication remains under investigation.