Why do apples float on water? 🍎💧

Apples float because about 20–25% of their volume is made up of tiny air pockets. These pockets make the apple less dense than water, so it stays afloat instead of sinking.

To reduce an apple's buoyancy (its tendency to float), you would need to increase its density or remove the trapped air. For example, crushing the apple, removing air from its tissues, or adding enough weight would make it sink more easily .

Science is often hidden in everyday things we see around us. ✨

#Science #Physics #Apple #Buoyancy #DidYouKnow #Education

Melting Can Propel Icebergs

Icebergs have long served as a metaphor for not knowing what’s going on beneath the surface. Studies like today’s are a reminder of why that is. Researchers found that asymmetric icebergs–shaped, in this case, like a right triangular prism–can self-propel as they melt. Their shape forces cold, dense meltwater to slide down the surface, generating a sinking plume that propels the ice as a whole. The team demonstrated this effect in both fresh- and saltwater. For icebergs wandering into warm waters, the effect is particularly strong and may reach levels about 10% of the magnitude of dominant propulsive forces like wind. (Image and research credit: M. Berhanu et al.; via APS)

3D-Printed Parts Nearly Sink RC Submarine

https://fed.brid.gy/r/https://hackaday.com/2026/04/13/3d-printed-parts-nearly-sink-rc-submarine/

Fire From Below

A slight change in perspective can do wonders. In this video, the Slow Mo Guys look at a burning flame from below. They accomplish this by mounting a gas grill upside-down. This small change means that buoyancy can’t simply lift heat and exhaust gases away from the flame source. Instead, the flow pushes out and around the edges of the grill.

The views are, as always, amazing. The billowing flames are mesmerizing–often closer to laminar than turbulent. And the added spectacle of cinnamon combusting in the later segments really does make for the kind of visuals you’d expect in a sci-fi movie. (Video and image credit: The Slow Mo Guys)

Alright Citizens of Fedi, I have another #Poll for y'all. It's not technically part of the series I'm working on, but I had a chat recently and it got me curious.

#CW talk of penis buoyancy

Do penises (penii?) float in water? And does that change at all depending on hormonal balance or similar factors?

The thought of a correlation between "boyancy" and "buoyancy" is hilarious to me for some reason.

You don't have to be a penis owner to respond to this poll, but it is preferred that you have at least some experience with penises even if second-hand.

Please fill out the poll based on statements you consider to be accurate. Feel free to add context in the replies. I genuinely want to understand your thoughts and perspectives even though my polls can appear to be quite silly sometimes.

To define penis for this poll, non-natal penises are included and you are welcome to mention if that is the case vs not if you're comfortable doing so.

#AskFedi #Penis #Buoyancy #Discussion #Survey
#GoodBadScience

How can the idea of #buoyancy help question the hype around #FloatingCities amid the rapid submergence of #SoutheastAsia’s coastlines?

👀Read @rsiriw & M. S. C. Gemilang: https://doi.org/qhrh

#CoastCities #UrbanJustice #CoastalAdaptation #UrbanAnthropology

How can the idea of #buoyancy help question the hype around #FloatingCities amid the rapid submergence of #SoutheastAsia’s coastlines?

👀Read @rsiriw & M. S. C. Gemilang: https://doi.org/qhrh

#CoastCities #UrbanJustice #CoastalAdaptation #UrbanAnthropology