“Why is the bath still hot?” An anecdote on temperature & density

I’ve been mama-ing (i.e., SAHM) it lately to a 6yo and 3yo and with that comes some hard lessons to learn. I mean I just explained that there is one ocean but it has five spots with five separate names and now I get “Why is the bath still hot when you added so much cold water!?” (think of that one as being asked in a shrilly voice, too).

I had to keep my cool when I explained that the water on top still feels warm … but, if you could (please, please, please!) stick you toes in the tub to the bottom it will be cold and then you can mix it up.

I jazzed it up and said that when water droplets get cold they huddle together. More of them will take up the same space so it’s heavier (i.e., denser). Therefore, they’ll sink to the bottom of the tub.

In the ocean the water on the bottom is definitely colder, too. However that’s generally because sunlight isn’t penetrating past the first 200 meters (1/8 of a mile).

You see the ocean has a “thermocline.” The thermocline is a place when the temperature drastically changes. On the surface of the sea – the top 200 meters – it’s warm since it gets a lot of sunlight. Sunlight can’t really go any further and the temperature decreases for the next 800 meters. That layer where the temperature drastically changes is called the “thermocline”. After that the zone without sunlight is consistently colder. Check out the image below from NOAA Ocean Service and then this interactive and extremely up-to-date sea surface temperature map from NASA.

 

How can I be a responsible fisherman?

 

A lot of folks these days are interested in making certain their favorite past time jackandsawyer1of fishing is going to be around for future generations to enjoy.

Here is a short list of tactics to remain ethical, while still keeping fishing that ever intense sport of glory.

Best practices:

– Respect the space of one another while out there on the water to make it enjoyable for everyone.
– Be informed of the catch and size limits of the waters that you are fishing.
– Practice “catch” and “release” fishing techniques (see below).

The “catch” part:

– Use barbless hooks, because they reduce damage and handling time of the fish. Remove the hook gently.
– Keep the fish in the water or wet your hands if you handle the fish to unhook it.
– Don’t put your fingers in the gill covers or hold the fish by its eye sockets (!) or squeeze it too hard.
– When you do make contact with the fish make sure your hands are continuously wet. It will help to keep the animal’s natural mucus intact. The mucus protects the fish from getting infections.

The “release” part:

– Hold the fish in their normal swimming position and move them back and forth slowly to have water run across their gills.
– Revive exhausted fish by moving water through its gills. Fish that were caught kicking and screaming like a teenager going off to Sunday school use an increased rate of oxygen.

Lastly, I am a big fan of saving the best for last – the most important rule – have fun!

Photo (c) of my older brother.