Why does spilled coffee leave behind a ring?

I’m not talking about coffee you somehow manage to get stuck on the bottom of your cup, but that coffee in itself dries weirdly. The outlines of spilled coffee are always darker than the inner edges or its center. Surprisingly, how this happens or why has been left unanswered by science for years until recently.  What they discovered is how to control the physics behind coffee rings, which is the angle coffee droplets are placed on a surface, to the point they could stop coffee rings entirely.  

Coffee particles seen microscopically appear to bundle at the edges of where it is spilled.

Why so much research in a seemingly pointless phenomenon? Well, because science. Nothing is ever totally pointless in science and can always have profound consequences; afterall, penicillin, was seemingly discovered by accident. Anyways, the science behind coffee rings would supposedly help in the field of blood diagnostics, blood diseases and anemia.

How about a Cup of Joe? (Literally)

A cup of joe is a common American expression for a cup of coffee. How that phrase came into being is rather murky, but it’s believed to be a shortened version of jamoke (another weird term for coffee). Anyways, I thought this coffee mug was very clever play on a Cup of Joe. Everyone needs a cup of Joe, but Joe Biden especially; every person with phrase where their name is used is likely to be popular among many, like Bernie Sander’s “Feel the Bern” (which millennials gobbled up in the years preceding the 2016 U.S. Elections).

Attempting to find the origins of the phrase “a cup of Joe”.

Morning cup of coffee can cause a morning poop

I’ve never been an avid consumer of coffee, until I met Mike. It’s not that I disliked coffee or anything, but simply because I couldn’t make my own. Anyways, one of the effects I first noticed when I drank coffee was the urge to poop first thing in the morning or soon thereafter. I thought that was just a coincidence. Apparently, scientists have known that for decades, and have some theories on why that is (though there’s no clear cut explanation as to why, yet). Even decaffeinated coffee has that effect, which for the most part, rules out caffeine as the sole aggressor.

All that is known is that coffee stimulates and increases gastrin levels, which in turn stimulates and speeds up peristalsis (the wavelike contractions of the GI tract, usually referred to as gastric motility), as well as increase gastrin levels, hormones that further stimulate the colon. Of course, everyone is different, and many probably don’t experience this; nor are there any extensive studies on just how much people are affected other than a small 1990’s study. Does coffee have this effect on you? Good luck on trying to have this topic as casual conversation to your coffee pals, lol.

Sources: Insider, Health.com, NIH.gov