Researchers have been left astonished upon discovering that sperm seemingly challenges one of Isaac Newton’s fundamental laws of motion.
Most of us are aware of some basic facts about sperm – it resembles a tiny tadpole that swims to meet an egg.
However, it appears that sperm can defy a fundamental principle of physics long relied upon by scientists.
This surprising observation was made by Kenta Ishimoto, a mathematical scientist, along with his team at Kyoto University.
The team investigated sperm’s ability to counteract Newton’s third law of motion, which states that ‘for every action, there is an equal and opposite reaction’.
According to Newton’s law, opposing forces should counter each other.
This phenomenon can be observed when two similarly sized marbles collide, transferring their force and bouncing back.
But sperm behaves differently.
The researchers discovered that sperm propel themselves through viscous fluids without encountering the expected resistance of an equal and opposite reaction.
Ishimoto and his team examined these non-reciprocal interactions, analyzing experimental data on human sperm and modeling the movement of the green algae, Chlamydomonas.
Both utilize flagella – the tail-like structure on sperm – to move forward, but instead of their energy dissipating in highly viscous fluids, the flagella on sperm continue to drive the cells ahead.
The researchers found that sperm tails possess an ‘odd elasticity’, enabling them to move efficiently without losing significant energy to the fluid.
Nevertheless, this did not entirely account for the propulsion resulting from the wave-like motion of the flagella.
To clarify the process, the researchers introduced a new concept, ‘odd elastic modulus’, to describe the internal dynamics of flagella.
As the flagella bend in response to the liquid, they manage to avoid the usual equal and opposite reaction, conserving their energy.
The researchers explained: “From solvable simple models to biological flagellar waveforms for Chlamydomonas and sperm cells, we studied the odd-bending modulus to decipher the nonlocal, nonreciprocal inner interactions within the material.”
They further stated: “Odd elasticity is not a generic term for activity in solids, but rather a well-defined physical mechanism that generates active forces in solids or in other systems in which a generalized elasticity can be defined without using an elastic potential.”
The findings from their research could have practical applications, such as aiding in the design of small, self-assembling robots that mimic living materials or enhancing our understanding of collective behavior principles.
This exciting discovery is fascinating, but be prepared to learn another intriguing sperm-related fact.
It might surprise you that Elon Musk, the world’s wealthiest individual, is not only a billionaire but also an enthusiastic sperm donor.
Musk has previously voiced his concerns about declining birth rates on Twitter, possibly viewing himself as a solution to the issue.
He tweeted: “A collapsing birth rate is the biggest danger civilization faces by far.”
Additionally, he stated: “Many countries are already well below replacement rate, and the trend is that almost all will be.
“This is simply a fact, not a ‘debunked theory.’ 2.1 kids is replacement rate, and obviously the world as a whole will soon drop below that point.”
The New York Times reported that the Tesla CEO has offered his sperm to friends and acquaintances over the years. While this may be unexpected, it’s a thought-provoking detail to ponder.