Fire from the very beginning served people as a universal source of light. Unlike bulbs, lamps and other lighting devices, a flame is not a solid object, but something intangible. Because of this, some people may have a logical question: does the flame have a shadow? After all, if you bring the source of fire to the wall, it will only become brighter, and at the place of the accumulation of the greatest amount of light there will be no shadows at all.
What is fire?
First you need to understand the nature of the flame. He is called the intense process of carbon oxidation with bright radiation and the release of a large amount of energy.
When a combustible material is set on fire, a chemical reaction begins. During it, the flame, interacting with oxygen, gradually spreads through the substance. When the fuel runs out, the fire goes out, and ash remains in the place of the fire - the remainder, consisting of glass, quartz and other non-combustible components.
Like any other oxidative process, a flame cannot exist without oxygen. If you block the flow of air to the fire, it will dry out. That is why it is impossible to ignite a flame in a vacuum.
Interesting fact: from a practical point of view, in space it is impossible to fire a firearm, since it will not be possible to create a spark, it will also fail to set fire to the powder in the cartridge. However, there is a theory that a shot in a vacuum is still possible, since the powder itself contains oxygen particles. They should be enough to start the oxidation reaction.
Why is burning of objects accompanied by bright radiation?
During the reaction, while the oxidation of carbon compounds occurs, the fuel gradually turns into soot. Particles of the latter emit a large amount of heat into the environment and begin to glow. That is why fire arises.
How does a shadow appear?
A spatial optical phenomenon is called a shadow when, when an object is placed between a light source and a surface, the first one casts a silhouette on it that imitates its contours at a certain angle.
Interesting fact: in ancient times, people considered shadow to be the soul of an object that cast it. If a person had no shadow, then he could be considered an evil demon.
In fact, explaining the cause of the shadow is quite simple. When a light source appears in the room, the light from it is evenly distributed in space. The rays fall on the surrounding objects, some of them are absorbed, some pass through, others scatter at different angles. This leads to the fact that in the space behind the object there is less light than between it and the light source. Because of this, a shadow appears that is projected onto the surface at a certain angle.
Does the flame have a shadow?
To answer this question, it is required to place a light source between the fire and the surface on which the intended shadow will be projected. When the rays are directed to the flame, they will fall on the soot particles that serve as a source of radiation. Their feature is that they not only emit light, but also absorb it.Therefore, they are also capable of casting a shadow.
But to make out it will be quite problematic, especially if the flame size is small. When the fire ignites, it heats the air around, due to which the fluctuations of the latter become visible to the naked eye. When the light is directed to the flame, they will refract the rays passing through them, due to which the projection of the shadow from the fire can be distorted.
To better see the shadow, you need to direct the light source from the side where the fire is the widest. Then the light will be absorbed by a large amount of soot, which will allow a larger shadow to be projected onto the surface. This will increase the chances of considering it.
Yes, the flame has its own shadow. Hot particles of soot discard it, which serve as a source of bright radiation. However, it is not so easy to see the shadow of the flame, since it will be distorted by heated air, the vibrations of which will also be visible on the surface. To clearly see the shadow of the flame, you need to direct the light at it from the side where the fire is the widest.
