A bubble is a spherical ‘pocket’ of one substance contained completely within another, usually a gas within a liquid. We’re very familiar with bubbles in boiling water, in fizzy drinks like cola and champagne, and even soap bubbles which are a gas inside a liquid inside a gas. Bubbles can be introduced into fluids, but they can also form spontaneously in a process called nucleation.
Bubbles have a different refractive index from the substance they’re within and ‘scatter’ light, which is why the sea looks cloudy and why you can’t see through foam. It’s also why icebergs are white; without any bubbles in them they are blue. The ‘white water’ so beloved of canoeists and rafters is white for the same reason as are the tops of waves. The sound of a wave breaking is actually that of hundreds of millions of air bubbles bursting at the shoreline.
Bubbles vibrate by rapidly expanding and contracting (known as a breathing mode, for obvious reasons), and that means that bubbles behave like bells: big bubbles ring with deeper notes, and small bubbles ring with higher notes. When it pops, a large bubble disperses into a ring of smaller bubbles.
It’s possible that we may owe our very existence to bubbles. One fashionable theory suggests that air bubbles may have concentrated the molecules and nanoparticles necessary for protocells to form and for life as we know it to begin.
Bubbles have a major effect on climate. They transport carbon dioxide and oxygen from the atmosphere down into the ocean. Most bubbles don’t go down much further than 10 meters. The big ones float back to the surface while the smallest ones get squeezed out by the pressure as they sink. Meanwhile, bubbles popping on the surface release gases back into the atmosphere, including dimethyl sulphide created by tiny marine plants (phytoplankton) – and known as ‘plankton farts’ – which helps to form clouds.
A constant exchange of gases occurs both from the atmosphere into the oceans and from the oceans into the atmosphere. 'The oceans make up 70% of the planet and they are its heart and lungs', says oceanographer and physicist Dr Helen Czerski. 'Gas exchange between the air and the sea affects our climate and the quality of the air we breathe.
'Bubbles are really important because the more bubbles there are, more stuff gets spat upwards and more stuff is drawn down from the atmosphere. By measuring them, we can see what impact we’re having.
'We already know that sound is travelling 10% further than it did a few hundred years ago because of the carbon dioxide the ocean has already absorbed since the industrial revolution'.
Humpback whales use bubbles to catch their prey. They work in teams to create bubble nets to corral and contain their prey into a small area so that they can more efficiently scoop them up in their large filter-feeding mouths.
Herring communicate by farting. They emit bubbles from their anuses which sound like a high-pitched raspberry; these sounds are thought to help shoals to stay together in the darkness. The noise is known as a Fast Repetitive Tick or FRT.
Penguins cover their body in little bubbles to reduce drag and allow them to reach the speeds necessary to jump out of the water. One idea for reducing drag in ships is to swarm bubbles under the vessel; such a technique can cut fuel consumption by about 15%.
In all our quest of greatness, like wanton boys, whose pastime is their care, we follow after bubbles, blown in the air.
Antibubbles are globules of liquid surrounded by air – the exact opposite of a bubble. A water drop is an antibubble. If the water is clean, antibubbles will often skitter across the surface of water. You can sometimes see this when water drops roll across a wet car bonnet without being absorbed into the larger amount of water.
In some circumstances, antibubbles can form inside a liquid but they last only for a very short time. When such an antibubble pops, a ring of tiny bubbles rises towards the surface.
Double, double toil and trouble; Fire burn, and cauldron bubble.
No bubble is so iridescent or floats longer than that blown by the successful teacher.
The foam on the sea shore is not caused by pollution, it is usually created by the decaying remains of algae colonies, as well as dead plants, decomposed fish and excretions from seaweed.
Bubbles that rise to the surface of stagnant lakes and ponds can transfer harmful bacteria into the atmosphere.
In 1986, at least 1200 people were killed after a huge bubble of lethal gas escaped from a volcanic lake. The fact that most of the dead belonged to the local ‘Bum’ tribe should not be treated as humorous.
Aphrodite was born of sea-foam that was fertilised after Cronus cut off Uranus's genitals and threw them into the sea.
There are, allegedly, 49 million bubbles in a bottle of a champagne. A man named Bill Lembeck decided he had to know, so set about calculating and came up with this figure. Those of us who like utterly useless facts should raise a glass to him.
By the time a glass of champagne goes flat, about 2 million bubbles have popped.
Researchers at Harvard don't pop their bubble wrap, they use it as test tubes instead.
Gas bubbles travel downwards in a pint glass of Guinness.
In Denmark, the Volkswagen Beetle is called Boblen (the bubble).
The Bubbling kassina is a kind of South American frog.
Froghopper nymphs produce a den of frothed-up plant sap that looks like saliva and is known as cuckoo spit.