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Ever see an "explosion" while watching a gel test? This is the cause.
DISCLAIMER: I am not a medical professional. I am reporting what I have seen over two years of ballistic gelatin testing. Quite a few folks have asked why they see what looks to be an explosion when watching a ballistic gelatin test. Hopefully this post can shed some light on the subject.
Sonoluminescence
The flash of light you sometimes see during a ballistic gelatin test is known as a sonoluminescent event. Sonoluminescence is the emission of short bursts of light from imploding bubbles in a liquid when excited by sound. Put simply it is a collapsing air chamber that explodes due to a violent change in pressure.
How does this occur in ballistic gelatin?
As the bullet strikes the target it creates a gap of air inside of the gelatin. We often refer to this as the temporary caivty. Before the block collapses down to its original shape, the air is low pressure and low temperature. Sometimes these air bubbles can become trapped when their escape route to the atmosphere is cut off by collapsing gelatin. In this case the collapsing gelatin compresses the air driving the pressure and temperature up almost instantly. If this occurs violently enough the air can reach temperatures in excess of 4,500K (7640F or 4226C). This causes the molecules to emit a burst of light that we sometimes are able to catch with our camera. These instances of sonoluminescence can occur in as little as 35 trillionths of a second. These events leave an expanding hot gas bubble inside of the gelatin that escapes through the permanent cavity to the atmosphere.
How does this affect humans and the firearms community?
During a few of our tests we noticed that sonoluminescence may be able to kill human beings. While testing 9mm FMJ 115gr reloads we found that the hot gas bubbles left over from sonoluminescence can sometimes become stuck in the gelatin. These stuck bubbles began to expand inside of the block causing massive 6in by 4in permanent cavities. These cavities could in theory cause tension pneumothorax.
Tension pneumothorax is a condition in which a punctured lung leaks air into the surrounding chest cavity. This air is also sucked in from the atmosphere, hence the name sucking chest wound. Over time the air keeps the lungs from fully inflating. If the condition is left untreated, the victim can begin experiencing heart difficulties and even death due to the chest pressure.
If a sonoluminescent event were to occur inside of a human, it may be possible for the trapped gasses to cause tension pneumothorax quickly. This could in theory cause the victim to die in a matter of minutes. I would love to hear from medical professionals on this topic.
What do you guys think? Could sonoluminescence help cause tension pneumothorax?
Sonoluminescence
The flash of light you sometimes see during a ballistic gelatin test is known as a sonoluminescent event. Sonoluminescence is the emission of short bursts of light from imploding bubbles in a liquid when excited by sound. Put simply it is a collapsing air chamber that explodes due to a violent change in pressure.
How does this occur in ballistic gelatin?
As the bullet strikes the target it creates a gap of air inside of the gelatin. We often refer to this as the temporary caivty. Before the block collapses down to its original shape, the air is low pressure and low temperature. Sometimes these air bubbles can become trapped when their escape route to the atmosphere is cut off by collapsing gelatin. In this case the collapsing gelatin compresses the air driving the pressure and temperature up almost instantly. If this occurs violently enough the air can reach temperatures in excess of 4,500K (7640F or 4226C). This causes the molecules to emit a burst of light that we sometimes are able to catch with our camera. These instances of sonoluminescence can occur in as little as 35 trillionths of a second. These events leave an expanding hot gas bubble inside of the gelatin that escapes through the permanent cavity to the atmosphere.
How does this affect humans and the firearms community?
During a few of our tests we noticed that sonoluminescence may be able to kill human beings. While testing 9mm FMJ 115gr reloads we found that the hot gas bubbles left over from sonoluminescence can sometimes become stuck in the gelatin. These stuck bubbles began to expand inside of the block causing massive 6in by 4in permanent cavities. These cavities could in theory cause tension pneumothorax.
Tension pneumothorax is a condition in which a punctured lung leaks air into the surrounding chest cavity. This air is also sucked in from the atmosphere, hence the name sucking chest wound. Over time the air keeps the lungs from fully inflating. If the condition is left untreated, the victim can begin experiencing heart difficulties and even death due to the chest pressure.
If a sonoluminescent event were to occur inside of a human, it may be possible for the trapped gasses to cause tension pneumothorax quickly. This could in theory cause the victim to die in a matter of minutes. I would love to hear from medical professionals on this topic.
What do you guys think? Could sonoluminescence help cause tension pneumothorax?
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