What is a channel?

Hi there.

In the previous article we were talking about ions and now let’s talk about channels.

I tried to guess what your answer would be if I ask you what a “channel” is. Not an “ion channel”, but just a “channel”. And you know, I’m not quite sure about your answer, because you probably know several different meanings of the word “channel”. Obviously, by analogy with ion channels, you could think of a tunnel, a funnel, or a passage through which something flows. But, you could also think of a waterway for ships, a TV/radio station, or whatever.

Some 20 years ago most people (not ion channel scientists) if asked what a “channel” is, would have thought about the English Channel, Venice/Amsterdam/Bruges canals or some other watercourses.

But now channels went digital. Channels are now most of the time mentioned as paths or interfaces connecting data sources to data consumers. YouTube channels, Slack channels, Zoom channels, Microsoft Teams channels are all around us. Businesses now use various marketing channels to attract customers, while many politicians strive to control all the available media and communication channels to wash our brains.

But, beyond these, there are also other somewhat less known channel types. For example, natural channels that are formed by flowing fluids such as water or lava. While everybody knows about water channels (like rivers, streams etc.), which are widespread across the Earth, not many people know how many different types of water channels exist. Erodible and non-erodible, lined and unlined, bedrock and alluvial, braided and anastomosed, meandering and straight, high gradient and low gradient, riffle-pool sequence, dredged navigational, and surge – all these are types of water channels. Apart from this, lava channels as well as lava tubes, which are formed by flowing lava during a volcanic eruption, are also not so well known kinds of natural channels. And in fact, these kinds of channels could also be found not only on the Earth but elsewhere in the Solar System, including Venus, Mars, Moon, Mercury and Titan (the Saturnian moon). And if talking about these extraterrestrial channels, we cannot fail to mention gigantic Martian outflow channels running for hundreds of kilometers and being tens of kilometers wide. These outflow channels are believed to emerge due to catastrophic flooding and are considered to be one of the strongest lines of evidence for fluvial activity on Mars.

And there is more to it than that. Beyond these river-like as well as digital channels, there still are other channels. Just go to the University, and ask your physics professor about channels. You’ll probably get the lecture on s-, u- and t-channels, single- and multi-channel scattering of waves and particles, Feynman diagrams and something like that. Programmers could show you how to use a channel operator “<-“ for sending and receiving values. Civil engineers would explain to you why they use structural channels (also known as C-channels or parallel flange channels) as well as strut channels in building construction, whereas traders would teach you how to use price channels like the Donchian channel to maximize your profits on the stock market.

And when you are tired of all these explanations, you will find yourself relaxing and sunbathing on the Channel Islands Beach in California, or enjoying your Channel cocktail in the local bar. Or maybe you would choose to try to catch a Channel Catfish at Channel Lake, in Lake County, Illinois. It’s up to you.

Well, there is no doubt that all these kinds of channels play an essential role in our lives, but we, ion channel scientists, know which channels are “the most important single class …”. :) And still, so many people don’t know anything about them. “The most important” and at the same time one of the least known. Bizarre.

Ion channels forever.

Stay safe & healthy!