What is Bubbles: Definition and 112 Discussions

An economic bubble or asset bubble (sometimes also referred to as a speculative bubble, a market bubble, a price bubble, a financial bubble, a speculative mania, or a balloon) is a situation in which asset prices appear to be based on implausible or inconsistent views about the future. It could also be described as trade in an asset at a price or price range that strongly exceeds the asset's intrinsic value.
While some economists deny that bubbles occur, the causes of bubbles remain disputed by those who are convinced that asset prices often deviate strongly from intrinsic values.
Many explanations have been suggested, and research has recently shown that bubbles may appear even without uncertainty, speculation, or bounded rationality, in which case they can be called non-speculative bubbles or sunspot equilibria. In such cases, the bubbles may be argued to be rational, where investors at every point are fully compensated for the possibility that the bubble might collapse by higher returns. These approaches require that the timing of the bubble collapse can only be forecast probabilistically and the bubble process is often modelled using a Markov switching model. Similar explanations suggest that bubbles might ultimately be caused by processes of price coordination.
More recent theories of asset bubble formation suggest that these events are sociologically driven. For instance, explanations have focused on emerging social norms and the role that culturally-situated stories or narratives play in these events.
Because it is often difficult to observe intrinsic values in real-life markets, bubbles are often conclusively identified only in retrospect, once a sudden drop in prices has occurred. Such a drop is known as a crash or a bubble burst. In an economic bubble, prices can fluctuate erratically and become impossible to predict from supply and demand alone.
Asset bubbles are now widely regarded as a recurrent feature of modern economic history dating back as far as the 1600s. The Dutch Golden Age's tulip mania (in the mid-1630s) is often considered the first recorded economic bubble in history.
Both the boom and the bust phases of the bubble are examples of a positive feedback mechanism (in contrast to the negative feedback mechanism that determines the equilibrium price under normal market circumstances).

View More On Wikipedia.org
  1. tellmesomething

    How are bubbles formed?

    The solution manual says that before water enters the hollow So here an air bubble of radius R will escape from the sphere. The excess of pressure inside the bubble is 2T/R. The excess of pressure prevents the penetration of water into the sphere. Water begins to penetrate when the excess of...
  2. mastermechanic

    I Vertical acceleration of the water bubbles in a kettle?

    Question is simple, as we all know water boils at the bottom surface and it forms tiny bubbles. These bubbles grow up and rise in the water until they detach. What is the acceleration of these bubbles compared to gravitational acceleration? - Is it constant velocity? - Is it approximately...
  3. H

    B Rice Field Bubbles: Gotcha! Why?

    Bubbles of air were rising in some water in a rice field. The bubbles would float around at random for a while. If two bubbles got within a certain distance of one another they would very quickly merge. It looked like a predatory larger bubble pouncing on the smaller prey. Gotcha! Why is...
  4. EddieP

    Thermal expansion of air bubbles in plastic

    I am interested in the potential for air bubbles in a plastic structure to expand with heat, and put pressure on the plastic surrounding the air bubble. In this case the plastic structure is formed by melting a thermoplastic powder. In between the grains of powder are voids with air in them. As...
  5. I

    Bubbles in buret experimental error

    When bubbles are not removed from a buret before a titration, the measured volume of titrant used is more than the actual volume used. Then the analyte concentration will be greater than the actual concentration, and the mass of the analyte will be greater as well. Instead, it will actually...
  6. ZdMh

    Viscous fluid with air bubbles

    Is a high viscosity fluid(liquid), filled with air bubbles, more or less vicious than without air? Please provide the scientific principle behind that
  7. G

    Eliminating Air Bubbles in a pressure vessel under testing

    Hi, What can be done to avoid trupped bubble air at the top of a pressure vessel without upper hole during hydraulic testing? Also, once the bubble exist what can be done to release it? Thanks
  8. G

    Bubbles in a falling glass of champagne

    Suppose you just poured a glass of champagne, then you drop the glass straight down (so that there is no tilting). Do the bubbles: (1) Continue to rise with respect to the glass. (2) Remain in place with respect to the glass. (3) Sink with respect to the glass.My intuition is telling me that...
  9. R

    Need help- calculating clearing of bubbles from a microfluidic channel

    Hi All, I need some help to figure out how to best go about setting-up and analyzing a micro-fluidics design problem I ran across in my research. It's not the typical single-surface contact angle adhesion kind of analysis. Basically, I have a wide micro-fluidic channel that's formed by a...
  10. fresh_42

    B Missing bubbles in a pipette

    I have observed the following phenomenon: Step 1: Dunk the pipette into the solution. Step 2: Press it and hold it pressed. Step 3: Pull out the pipette, until the lower end is in the air. Step 4: Release the pressure. Now one would expect that the solution in the pipette sucks bubbles of air...
  11. hagopbul

    Using the forth flotation technique to mass produce SARS-CoV-2 serum

    Hello All: i remember (and saw ) that the SARS-ncov-2 layers have hydrophobic and hydrophilic properties few weeks ago i was reading about forth flotation and it is a method to separate metals , but on low temperature could we use it to separate the spike protein and mix it with immune cells...
  12. T

    I Why do Bubbles oscillate sinusoidally?

    I understand why bubbles come from the same spot (nucleation sites) -- not the issue. My issue is WHY does THIS happen? I open a bottle of carbonated water, pour a bit and then close the top. Why does the trail of bubbles oscillate sinusoidally, on the way up? (Now, here is the problem: I do...
  13. C

    I Why do bubbles coalesce in liquids?

    I noticed whilst watching the tiny bubbles rising up in a glass of tonic that if they are close enough to each other they come together and coalesce. I tried to note the distance and my best guess was that at 8 times the bubble diameter the bubble attracts others. Sometimes they get attracted...
  14. Buzz Bloom

    I Large Bipolar radio bubbles in the Galactic Centre

    I confess that I am unable to understand the technical presentation in this article. I am hoping that someone at PF will be able to respond with a simplified summary about what this article is describing. Quote from Abstract The Galactic Centre contains a supermassive black hole with a mass of...
  15. bob012345

    B Black Holes & Warp Bubbles - Event Horizon Considerations

    Last night PBS showed two shows on Black Holes. In the shows the host traveled on a supposed warp drive spaceship. A question occurred to me. Suppose for the argument that the Alcubierre drive were possible. Then suppose you were in a ship contained in a warp bubble moving through space at say...
  16. R

    I Back to basics: bubbles in a syringe

    Please could someone give me some idea of what is happening when you pull back on a syringe filled with fluid and the bubbles in the fluid (in the syring) expand? Let's assume it's water. How do the bubbles grow? I am assuming it is a rectified diffusion process where gas in the fluid is drawn...
  17. L

    Why do bubbles of air in water move up?

    What I am confused about is why do bubbles of air in water move up. I understand why solids and liquids would move up in water if they are less dense. I get the idea that the deeper you go in water the more pressure there is because of the more water weighing down on the water and so there would...
  18. FallenApple

    How often do economic bubbles happen?

    There was the dot.com bubble, the housing bubble etc where lots of people became really rich. Seems there is potentially a bitcoin bubble going on currently. So I suppose in my lifetime, there will be more of these opportunities to cash in on.
  19. Irl495

    Minimum gas pressure to measure its volume with an eudiometer

    Hello, As you can see in the attached hand drawing+calculation, my question concerns the typical method of evolved gas volume measurement by water displacement in an inverted graduated cylinder or "eudiometer". Once a bubble (cavity to be precise) of gas leaves the end of the tube through...
  20. Aniket13

    Area of common surface of two bubbles

    What will be the area of common surface of two identical bubbles of radius R , i know there common surface will be flat as the radius of curvature of comman surface will tends to Infinity , but how do i relate with area of flat surface I tried to use Energy = Surface tension * area And then...
  21. T

    I Expansion Rate of Cosmic Bubbles

    I’ve understood that within the theory of Eternal Inflation the Bubble Universes that form from a drop of “vacuum” energy expand at the Speed of Light. My question is: Why would expansion be at the speed of light and not at a speed proportional to the level of vacuum energy still present in...
  22. M

    Alternatively, if you want a more concise title: What causes bubbles to merge?

    Why do bubbles coalesce? I imagine it has to do with surface tension and pressure. The Young-Laplace equation states a bubbles pressure is inversely proportional to its radii. Higher pressure implies higher potential energy, so maybe bubbles coalesce to form a bigger bubble with bigger radii...
  23. A

    Blue air bubbles on sand

    Hi all, Not sure it's the right place to ask but I found these while walking on the beach, they seemed to have come from the sea. They "explode" if you walk on them. Any ideas what this could be? https://ibb.co/fuL0gF https://ibb.co/ikrUaa https://ibb.co/hj3LgF Thanks, Audry
  24. Tomimo

    Making bubbles and trying to use Trompe

    Hi, I am trying to create a device that would "simply" make a bubble under the water. What I am aiming for is production of small bubble but continuously and under the water. When I say continuously, it doeant have to be for extended periods of time, could be just for ~2 hours but the longer...
  25. O

    Minimum radius of bubbles in a soda bottle (surface tension)

    Homework Statement [/B] The question is from chapter 9 of "Exercises in Introductory Physics" by Leighton and Vogt. The answer given in the book is ##R = 4.9 \times 10^{-5} \rm{cm}##. Homework Equations $$\sigma = \frac{\Delta P \cdot R}{4}$$ Where, ##\sigma## is the surface tension...
  26. davenn

    How do freezing bubbles form and why are they so mesmerizing?

    this is pretty cool ( pun intended) Dave
  27. spareine

    Do soap bubbles reflect sound?

    Bats in my garden do not seem to notice soap bubbles. Do soap bubbles reflect sound?
  28. S

    Both pressure and vacuum eliminate bubbles ?

    To get bubbles out of plastic resin that's to be used in casting, the uncured resin can be put in a vacuum chamber. However, I notice that a pressure chamber is also advocated for getting out bubbles (e.g. http://www.smooth-on.com/faq_display.php?faq_id=81 ). Are bubbles in a plastic resin...
  29. G

    Why are there still bubbles after the pump?

    Hi everyone, Got a question I'm trying to solve here. It is for an experiment I'm running at achool. I got a pipe system with a centrifugal pump. There is cavitation in front of the pump due to the pressure falling below the water Vapor pressure. When the water flow enters to the...
  30. Jaime ortega

    I Bubbles travelling through viscous liquids

    Hi, Im doing a Invesitgation of bubbles traveling through liquids. I am blowing bubbles of fixed volume up different viscous liquids. I seem to have got a anomaly but I can't explain it When recording one of the repeats in the foam bath I saw that the bubble rushed up the liquid. It took 1.4...
  31. F

    Creating controlled cavitation underwater (bubbles)

    Hello all- First post. I am curious if it is possible to create cavitation underwater with these specific criteria. I am basically using a venturi device that will be pulled underwater in saltwater. Is it possible to get the vapor pressure down low enough to boil water (make bubbles). I have...
  32. klotza

    Opening the blood-brain barrier with collapsing bubbles

    There have been some stories in the news lately about using focused ultrasound and collapsing bubbles to open the blood-brain barrier and deliver drugs to treat a brain tumour. e.g. here I was actually involved in the early stages of this project, working on theory and simulations. I wrote a...
  33. _Anthony_

    Variations in bubble persistance

    The apparatus consisted of a one gallon air tight clear plastic jug one quarter filled with ferrous chloride (uh, Fe(II)Cl ?), water and sufficient hydrochloric acid to complete the transformation. The remaining space was filled with oxygen at atmospheric pressure. When triggered a mechanism...
  34. klotza

    Insights Explosion-Generated Collapsing Vacuum Bubbles Reach 20K Kelvin - Comments

    klotza submitted a new PF Insights post Explosion-Generated Collapsing Vacuum Bubbles Reach 20,000 Kelvin Continue reading the Original PF Insights Post.
  35. G

    Effect of air bubbles in a paste when subjected to spinning

    I hope this isn't too simple for this site. I have had a challenge at work trying to eliminate air bubbles from a paste in a 20oz cartridge. The cartridge has a piston in one end to push the material out and the other end tapers to a small threaded 3/8" opening. I won't take the time explain...
  36. S

    Sound Generation: From Soap Bubbles to Nukes

    A soap bubble or a nuclear detonation emit a sound created by the sudden release of pressured air? Am I correct? How is the sound of a knock on the door, two billiard balls hitting each other, etc. How is the sound generated in their cases? Thank you.
  37. Y

    How are bubbles removed in a chemical reaction?

    Hi all, I am really confused at how bubbles are removed in a chemical reaction. Generally it is removed by diffusion...But is there any quantitative equation for that like adhesion energy...? I want to go in this direction to quantitatively analyse the conditions that bubbles are attached or...
  38. L

    Bubble in Liquid: Phase Change Under Pressure?

    Anyone , what the bubble in the fluid will be if we compressed the fluid with high pressure? for example the fluid is oil with high viscous. does the bubble change in phase? (condense)
  39. David Carroll

    Results of steam bubbles in the reactor

    When I was in the Navy, we were told of the immense importance of maintaining pressure inside the reactor (all the reactors in the Navy use a hydrogen moderator via water). My teacher discussed that one of the results of loss of pressure could be the formation of steam bubbles collecting on the...
  40. Isaacsname

    Why do dolphins create air rings and how do they defy buoyancy?

    Hello, I apologize in advance if this is the wrong section, it seemed the most appropriate Dolphins are able to produce rings of air which seem to counteract buoyancy by rotating ( I'm assuming rotation ) https://www.youtube.com/watch?v=bT-fctr32pE How and why is this true ? Thanks
  41. A

    Why do bubbles form when we hit the surface of water?

    Recently I went to a pool, and observed that when we hit the water/ create waves on the top layer of it, bubbles emerge. It may sound like a silly question, but it really got stuck in my mind..Why does this happen? Thank you for your answers in advance. P.S: I am new to this forum, I...
  42. H

    Removing Gas Bubbles from Liquid Without Contact

    I am doing an experiment in which I have to remove gas bubbles within a liquid medium. The liquid is contained within a small plastic mould of about 2cm diameter. The conditions of the experiment cannot be changed. My question is, can I practically remove the bubbles. I cannot stir the...
  43. U

    Soap bubbles sticking to each other

    Homework Statement Two soap bubbles of radii 3cm and 2cm come in contact and sticks to each other. Calculate the radius of curvature of common surface. The Attempt at a Solution Excess pressure inside soap bubble = 4T/R Let the radius of common surface be R' \dfrac{4T}{R'} = \dfrac{4T}{r_1}...
  44. M

    Exploring the Big Bang: 5-Dimensional Bubbles Colliding and Expanding

    Say I have two 5-dimensional bubbles moving towards one another in 5-dimensional space. When they touch, at the monent they touch, they meet at a 3-dimensional "point." As they join, the 4-dimensional hyperplane created their by common boundary immediately inflates from that point and expands...
  45. K

    How to extract bubbles gas from gel(Super Absorbent Polymer)

    I have been thinking to extract gases from SAP (the gel is super absorbent polymer(sodium polyacrylate)). The gases are trapped inside the gel in form of bubbles gas. I am thinking of using salt to turn it back to liquid or using vacuum pump to extract gas out. Using salt might be the best way...
  46. N

    Levitating Bubbles Science Experiment - Chemical Reaction Explained

    Hello. When I was on a scientific event, some students show a experiment with a bubbles. They poured into the bottle baking soda and vinegar. Then they blowing bubbles directly into the bottle, where the bubbles levitated. Why they levitated? Can you express a chemical equation? Thank you...
  47. G

    Bubbles Escaping from Submerged Container

    Hi We have a problem at work where we need to store a metal container under water. The container is to have small holes in the lid to ensure that it floods when submerged but we must minimise the size of these holes. Intuitively, if you have more than one hole in the lid then water will enter...
  48. N

    Boiling Water Bubbles: Proportional Rate & Instantaneous Stop Explained

    Just curious, When my mom was boiling water i saw that the rate of bubbles coming out of water was increasing as time passed.But i want what is the rate of bubbles coming out is proportional to? And one thing i noticed is that when the gas is shut off the bubbles stop instantaneously.Why is it?
  49. Abscissas

    Bubbles that collapse = light?

    Hey I heard somewhere that bubbles underwater that are collapsed by sound waves produce light, to me this in no way makes sense can anyone explain is it like swamp gas that the fabled UFOs are
  50. K

    Bubbles in a Pre-Boiling/Boiling pot of water

    How is it that bubbles form on the bottom of a surface of a pot of boiling water? I think that there is probably an elementary answer to this from chemistry. But I am thinking of something more along the lines of kinetics. I think that perhaps there is enough energy on the bottom surface of...