Tag Archives: Bubble

Soap bubbles are quite good pollinators, a new paper shows

New research from the Japan Advanced Institute of Science and Technology plans to fertilize fruit-bearing plants with soap bubbles.

Image via Pixabay.

Whimsical? Yes. But researchers in Nomi, Japan, suggest soap bubbles as a low-tech approach to support robotic pollination. Such processes are becoming more important as bees and other insect pollinators struggle under climate change and environmental degradation.

Bubble business

“It sounds somewhat like fantasy, but the functional soap bubble allows effective pollination and assures that the quality of fruits is the same as with conventional hand pollination,” says senior author Eijiro Miyako, an associate professor in the School of Materials Science at the Japan Advanced Institute of Science and Technology.

“In comparison with other types of remote pollination, functional soap bubbles have innovative potentiality and unique properties, such as effective and convenient delivery of pollen grains to targeted flowers and high flexibility to avoid damaging them.”

Some of the team’s previous work included using tiny, toy drones to pollinate flowers. While efficient, that approach very often destroyed the blossoms whey were trying to reach. Bubbles, Miyako observed one afternoon in the park with his son, could work as an alternative.

After confirming in the lab that they could carry grains of pollen around, the team tested five commercially-available surfactants (compounds that can produce bubbles with water) for their ability to create bubbles and their effect on the pollen. They settled on lauramidopropyl betain (A-20AB), as it had a positive effect on the grains after deposition on flowers.

In the end, they settled on pear pollen grains in a 0.4% A-20AB bubble solution, with some other compounds thrown in to stabilize its pH and provide needed ions (such as calcium) for germination.

The authors then loaded the solution into a bubble gun and used it to apply the pollen in a pear orchard. It was very successful, and pears grew merrily. The authors report that every bubble carries around 2,000 grains of pollen directly to the targeted flower. The last step was to install a bubble-producing device on an autonomous drone. This setup had a 90% success rate from a height of two meters and at a drone velocity of two meters per second (meaning the bubbles can be applied while the drone is in transit).

One other advantage of the bubble method is that the solution which carries the grains of pollen can be used to support its activity. Pollen activity mediated through the soap bubbles remained steady three hours after pollination, the team explains, while the grains applied through other methods such as through powder or solution became less effective.

For now the findings are definitely exciting, but it will take more refinement to make it usable on large scales in the field. Another thing to note is that the bubbles can only be applied during mild weather, as raindrops can wash away the pollen from flowers and winds can blow the bubbles away entirely. In the immediate future, the team plans to focus on increasing the efficiency of the system, as the prototype device still wastes pollen (which lands on the ground, not the flowers).

The paper “Soap Bubble Pollination” has been published in the journal iScience.

Underwater volcanoes can produce stadium-sized bubbles

An underwater volcano off the coast of Alaska has erupted more than 70 times over 9 months, producing a distinctive grumble before each eruption. The volcano also belched ungodly large gas bubbles.

Map of Bogoslof Volcano and two satellite images of the partially submerged summit and crater during the eruption. Image credits: Lyons et al / Nature.

Shallow submarine volcanoes are difficult to study as they are often remote; this can make data acquisition difficult and costly. The interaction between magma and surface water is also complex. It can create violent explosions, but because these interactions are so inaccessible, researchers don’t really understand the entire process. Furthermore, these explosions can also pose risks to nearby ships and planes.

To better understand these processes, researchers installed low-frequency microphones around the Bogoslof volcano to better study this interaction — of course, they couldn’t install the microphones right next to the volcano, so they installed them 59 kilometers to the south.

| Infrasound signals from an explosive eruption of Bogoslof on 13 June 2017. Image credits: Lyons et al / Nature.

The volcano has been known for a long time. Its peak forms Bogoslof Island, an uninhabited island that barely rises above the water surface (but which hosts a thriving seal colony). The first known emergence of the island above sea level was recorded during an underwater eruption in 1796, and since then, the volcano has been steadily adding more surface to the island through new eruptions. The volcano’s eruptive belches have also been documented.

In July 1908, a medium-sized cutter called Albatross was cruising around the island when the sea began to swell. The account of this event reports that the sea bulged and bulged until it ruptured, releasing a terrifying plume of gas and steam. It was a dazzling display that few humans have witnessed, and it’s exactly what researchers wanted to study with the microphones: how big do these bubbles really get?

Schematic depiction of how a bubble forms around a submerged eruption — it all starts with gases coming inside the magma and ends with a bubble collapse. At some point, the bubble reaches its maximum radius; that’s when the pressure is lowest. Image credits: Lyons et al / Nature.

Shallow submerged explosions are often described as beginning with a swelling of the water surface, but these descriptions are qualitative in nature (“giant”, “huge”), not quantitative; researchers wanted to put some numbers on those adjectives but obviously, hanging around a volcano and waiting for it to erupt is not exactly a safe idea. Previous research has shown that smaller bubbles produce infrasound when they oscillate, and their size can be calculated based on these oscillations. This is where the microphones kicked in — they picked up the infrasound and based on this, enabled the researchers to calculate how big the bubbles were without actually seeing them.

You can actually hear the bubbles below. The audio has been adjusted for human ears and sped up 300x. Each of the spikes is a signal from a separate bubble.

via Wired.

According to the calculations, volcanic bubbles reached up to 750 feet (228 meters) across, with a volume of over 180 million cubic feet (5 million cubic meters) of gas. The size of the bubble depended on the radius of the crater and the depth at which the bubbles form.

“The range of initial bubble radii thus varies from the vent radius, 25m, to 200m, or slightly smaller than the approximate radius of the crater area around the time of the observed signals. In our model, large bubbles most probably formed at or near the vent in the base of the shallow submerged crater and thus the height of the submerged portion of the bubble is controlled by the depth of the water,” the study concludes.

The study has been published in Nature Geoscience.


Bubble physics can explain why dialects appear and how they evolve

The way language and dialects evolve could be explained using the laws of an unexpected chapter of physics: the behavior of bubbles.

Bubble crowd.

Bubbles: making everything more awesome since forever.
Image in public domain.

Physics and foreign languages have a lot of similarities: they both string up a bunch letters that us regular folk can’t really make sense of, for example. But the similarities seem to extend to our native tongue as well: new research from the University of Portsmouth shows that equations from physics can become very accurate predictors of where and how dialects appear.

And we’re talking about the best part of physics: bubble physics!

“If you want to know where you’ll find dialects and why, a lot can be predicted from the physics of bubbles and our tendency to copy others around us,” says Dr James Burridge from the University of Portsmout.

Bubblingly social

In broad lines, Burridge’s theory goes like this: because we’re social animals and like to fit in, we strive to copy the way others around us speak. Since people tend to “remain geographically local in their everyday lives”, Dr Burridge explains, this creates areas where one certain particularity of speech (what we call a dialect) becomes dominant.

Imagine this early step of dialect formation like a foamy bath. There’s a lot of bubbles, but they’re pretty tiny and all mushed up into each other. So these bubbles/dialects start to interact, and here’s where physics gets involved.

“Where dialect regions meet, you get surface tension. Surface tension causes oil and water to separate out into layers, and also causes small bubbles in a bubble bath to merge into bigger ones,” Dr Burridge adds.

“The bubbles in the bath are like groups of people — they merge into the bigger bubbles because they want to fit in with their neighbours.

As small dialect-dominated bubbles come into contact with the ones around them, they’ll tend to merge (align their dialects) with the ones neighboring them. The same happens with the now-bigger bubbles, leading to ever-larger areas where a single dialect imposes itself over the others.

Dialectologists use the term ‘isogloss’ to describe the boundaries between distinct linguistic features, such as dialects. Under Dr. Burridge’s theory, the isoglosses behave like the thin edges of bubbles and, he says, “the maths used to describe bubbles can also describe dialects.”


Image credits Natalia Kollegova (Наталья Коллегова).

Bubbles merge in your bath because they’re trying to appease surface tension. This is the force of the bulk liquid’s molecules pulling on those forming the surface, trying their best to make the surface/volume ratio as small as possible. Because water molecules tend to stick together (cohesion) much tighter than water and air molecules (adhesion), the liquid’s surface gets put under tension by the force imbalance and gets ‘pulled in’. That’s what makes water in your glass edge up ever so slightly, and why water drops tend to merge.

It’s also why new ways of speaking often spread outwards from a large urban center.

“My model shows that dialects tend to move outwards from population centres, which explains why cities have their own dialects. Big cities like London and Birmingham are pushing on the walls of their own bubbles. This is why many dialects have a big city at their heart — the bigger the city, the greater this effect, he concludes.”

“If people live near a town or city, we assume they experience more frequent interactions with people from the city than with those living outside it, simply because there are more city dwellers to interact with.

This model also suggests that language boundaries get smoother and straighter over time, explaining why dialects stabilize over time.

The paper “Spatial Evolution of Human Dialects” has been published in the journal Physical Review X.