Question #38 – If you got a cut in space, what color would your blood be?
Answer:
There is a lot to unravel here as the physical reaction of liquids in space is counter-intuitive, but we will start with the color of your blood immediately after leaving your body in space. A common misconception is that our blood is actually blue in our veins and only turns red once it is exposed to oxygen in our atmosphere. In reality, our blood is always a shade of red (bright red when full of oxygen and maroon when oxygen deprived) and our veins only appear blue because our skin and fat cells absorb the low-energy red light from the Sun. This leaves only high-energy blue light to be reflected from our maroon veins. So, if you cut yourself in space, your blood would be a dark-red, maroon color.
But what happens to your blood once it leaves your body in space? Does it immediately freeze due to the temperatures hundreds of degrees colder than what we experience here on Earth, or does it immediately boil due to the lack of pressure in the vacuum of space? Surprisingly, the answer is both! First the warm water in the blood would vaporize due to the lack of pressure, then almost immediately would freeze once the vapor cools to a cold enough temperature. This would happen through the process of deposition, or the transfer from gas to solid skipping the liquid phase entirely!
So, if you were alive long enough to see it happen, you would see your maroon blood evaporate and expand into a gas cloud that almost immediately freezes into a network of minuscule ice crystals.
Read "If Blood Is Red, Why Are Veins Blue?" at Livescience.com and "Lost In Space Without a Spacesuit? Here's What Would Happen" at Space.com for more info.
This question was provided by Jordan Levy, age 14. Jordan lives in Jerusalem, Israel
Be careful not to cut yourself in space lest you attract space sharks
Image credit: Sharknado 3
As an enthusiast deeply entrenched in the realm of space science, I find the inquiry into the color and behavior of blood in space both fascinating and complex. My passion for this subject is not merely theoretical but stems from a comprehensive understanding of the underlying principles governing fluid dynamics, optics, and thermodynamics in a microgravity environment.
Let's dissect the information provided in the article:
1. Color of Blood: The article debunks the common misconception that blood is blue in our veins and turns red upon exposure to oxygen. Drawing upon my expertise, I can affirm that human blood is inherently red, displaying various shades depending on its oxygenation level. The bluish appearance of veins is attributed to the selective absorption of low-energy red light by the skin and fat cells, allowing high-energy blue light to be reflected from the veins. Thus, in space, if one were to get a cut, the color of the blood expelled would be a dark-red, maroon hue.
2. Fate of Blood in Space: The article delves into the fate of blood once it leaves the body in the vacuum of space. Contrary to intuition, the blood does not experience a straightforward freezing or boiling process. Instead, it undergoes a dual-phase transition involving vaporization and subsequent freezing through deposition. The lack of pressure causes the warm water in the blood to vaporize, forming a gas cloud. This vapor then rapidly freezes into a network of minuscule ice crystals without passing through the liquid phase. This intriguing phenomenon highlights the intricacies of fluid behavior in the unique conditions of outer space.
For those intrigued by the science behind these concepts, I recommend exploring further reading materials such as "If Blood Is Red, Why Are Veins Blue?" on Livescience.com and "Lost In Space Without a Spacesuit? Here's What Would Happen" on Space.com. These sources provide additional insights into the physiological and physical aspects of human existence in the unforgiving environment of space.
In conclusion, the hypothetical scenario of a cut in space unravels a captivating interplay of biology and physics, showcasing the wonders of how our understanding of familiar concepts transforms in the extraterrestrial context. It's a testament to the intricate nature of science and the thrill of unraveling the mysteries that lie beyond our terrestrial boundaries.
