In July 2015, we get our first close look at the dwarf planet Pluto and its moon, Charon, a fact that has scientists hypothesizing more than ever about what we might see there. One of the latest ideas put forward is that perhaps the collision that likely formed Pluto and Charon heated the interior of Pluto enough to give it an internal liquid water ocean, which also gave the small world a short-lived plate tectonics system, like that of Earth. Read more
The Electric Eel (Electrophorus electricus) is truly a wonder of the animal kingdom, and an amazing work of millions of years of evolution.
Despite its name it is in no way closely related to eels, it is a member of the Knifefish family and is the only member of its genus. The electric eel lives in fresh water in the Amazon, as well as other river basins in south america. They can grow to about 2m in length (6 and a half feet) weighing 20 kg. It can produce an electric shock of up to 600 Volts!
It produces this shock using 3 organs, the Main organ, the Hunters organ, and the Sachs organ. The total size of these 3 organs make up an amazing four fifths of the eels body! The organs are made of electrocytes, and are lined up so that a current can be passed from one organ to the next. When the eel wants to produce a shock it opens up glands in and between the organs allowing sodium ions to flow between them, creating a sudden change in potential difference (voltage.)
The shock only lasts approximately 0.2 milliseconds meaning it is not very likely to be lethal to an adult human despite it being 600 volts. That being said, it has been known to kill if the shock is, for example, directed towards the heart.
Okay, so it takes about 100mA across the heart to stop it. This may not seem like a lot, and in fact it isn’t. Voltage is the potential difference (the battery) that drives this current across material that resists its flow, in this case the heart is the resistor. The point is that there is a lot of resistance hanging around a human body, we aren’t really that good at conducting electricity because most of our body is neutral (no net charge); as a result, a tremendously high voltage is needed in order to drive a minuscule 100mA across the giant resistor that is the human body.
Redecorating your undersea grotto? Get inspired with our Tentacles Pinterest board! We’ve collected our favorite images that capture the wildly colorful and wonderfully bizarre world of octopuses, squid, nautiluses and cuttlefishes.
View the board
Learn more about our new Tentacles exhibit
For my Anglophile friends, Happy St. George’s feast Day