The longest vertical straw you can drink from is 10.3 metres. Even if you use a vacuum pump it won’t suck the liquid higher than that! Here is why!

Contrary to your intuition, when you drink from a straw you are not actually sucking up the fluid here. Just the air. So, when you do that, inside the straw, the pressure drops lower than that of the atmospheric pressure (101 kPa) outside. So, it’s the outside air pressure that pushes the water into the straw.

As the liquid moves up the straw, it is fighting against the gravity that is pulling it downwards. But it still keeps rising as long as the atmospheric pressure is greater than the pressure inside the straw due to gravity (weight of the liquid column).

The more liquid enters the column, the more it weighs. And at a certain height, there’d be enough water in the straw that’d exert the same pressure as that of the atmospheric pressure. That height, at sea level on earth, for water is 10.3 m.

$$ p_{atm}= 101\;kPa $$

$$p_{straw}= \dfrac{F}{A} \Rightarrow \rho g h$$

$$\rho g h = 101 \times 10^3\;N/m^2$$

$$h = \dfrac{101 \times 10^3\;N/m^2}{10^3\;kg/m^3 \times 9.81\;m/s^2}$$

$$h = 10.3\; m$$

Playful aggression or cuteness aggression is the term for when one experiences an aggressive response to an adorable stimulus like a baby’s cheeks or a fluffy unicorn toy. The response is a harmless urge to pinch and squeeze a baby’s face. People would say something like “You’re so cute and I am going to eat you up!” in an aggressive manner, gritting their teeth or clenching their fists, but in a harmless and tender way.

This is similar to a stimulus of intense happiness evoking an accompanied negative emotion like crying to keep the hormones balanced.

Ever wondered if trees communicate with each other? They do, yes! It’s long known that trees trade nutrients, especially sugar, with the fungi that would reach out to their root system in exchange for nutrients from the soil. But recent discoveries from the experiments by a team of biologists, have also shown that these fungi form a deep network that connects neighbouring plants and trees and enables carbon, water, nitrogen, and nutrient exchanges.

Dubbed as the ‘World Wood Web’, the Mycorrhizal network (an underground network of fungal filaments called hyphae that branch out to the tree roots) is a biological network (also called as mycelium) that connects hundreds of trees.

The beauty of these symbiotic relationships is that they mutually help each other’s survival, acting as one big community—with bigger mother trees acting as hubs, protecting the younger ones. Nutrient exchange, warnings, immune responses, you name it! Sometimes trees of the same kind sabotage other trees with toxins and proliferate their species via a chained positive feedback network—resulting in a single species dominating an area. 👀 Just … like our World Wide Web! Wow!