Conditions have a huge impact on whether bubbles can be formed and how long they last. The larger the bubble, the more vulnerable it is, and the more reliant on good conditions. Ideal bubble conditions are hard to precisely detail because while many important factors are known (such as humidity, temperature, particulates, and wind), there are as yet unknown factors that play a big role.
Bubbles are only a few molecules thick so they are subject to quick evaporation/thinning in dry air. Turbulence and wind pop stiff bubbles or break flexible bubbles into smaller bubbles. Particles in the air (dust, bugs, smoke, etc.) can pop bubbles.
Humidity, temperature, air movement (wind), and particulates are the most obvious factors. Understanding how the environment impacts bubble making can help you adjust your expectations and figure out what might be going wrong or right.
Important to know! There are mysterious factors that can result in bubbles not working at all on days when the conditions seem (on paper) to be ideal. It sometimes happens that you cannot form a bubble or the bubbles are especially short-lived even though the humidity and temperature are good. You may think that your juice has gone bad or that the recipe is not a good one and then try that same juice a few days later with great results.
General Environment & GroundEdit
It is generally agreed that bubbling over grass tends to work better than bubbling over pavement or dry ground. Even on a hot, dry day, you can sometimes make decent bubbles in a grassy area even when a paved area a few hundred feet away does not work at all.
Tree cover is sometimes helpful but sometimes problematic. Edward Spiegel reported that on a very hot, dry day (95F and 20% humidity) that he made nice bubbles in a meadow with a 48" top-string loop but that in an adjacent grove, he could not make bubbles at all.
Humidity is often mentioned as THE critical factor, and it is very important. All things being equal, higher humidity is generally better. However, other environmental factors -- some of which are still unknown -- can have just as big an impact and may make it hard to bubble even if the humidity is great.
Good humidity by itself is not enough. Even with great humidity, there are times when it is hard to make bubbles. High temperatures, especially when combined with high wind, often mitigate the benefits of high humidity. When it is very hot, it can be hard to make bubbles that last more than an instant even when the humidity is very high.
Generally speaking, for long-lasting bubbles 2 meters in diameter or larger, cool conditions (let's say roughly 45F to 60F or 7C to 15C ) and high humidity (80% RH or higher) and little or no air movement are generally required. Under these conditions, a 2 meter diameter (and larger) bubble might last 30 seconds or more while the same bubble might last 10 seconds or less with less humidity or a higher temperature.
Low Humidity. If you are bubbling in humidity below 50%, you might want to also take a look at the article Low Humidity.
Here is a rough guide as to what to expect at different humidity ranges and reasonable temperatures (let's say 45F to 75F or 7.2C to 24C) with bubbles more than 1/2 meter (20 inches) with most decent bubble juice.
<20%. It is very hard to make a bubble at all. If you are successful at these humidities, please post your recipe!
20%-30%. It is very hard to make a bubble that lasts more than a few seconds and big bubbles are hard to make. Unclosed tubes will be noticeably limited compared to higher humidity. You can see the bubbles quickly go from being colorful to colorless as the bubble quickly thins. [EDWARD: add link to the tubes on a hot day].
30%-40%. If the wind and temperature are reasonable, you can make 1 meter bubbles that occasionally last 15 seconds or more -- though most will break sooner. Making a 2 meter diameter bubble that lasts more than a fraction of a second is tricky but gets easier as the humidity rises.
50%-70%. Things start to improve when the humidity is over 50% and improve as it gets higher and higher. This is a pretty good but not great range. You can make big bubbles but not massive giants. The length of unclosed tubes and closed giants goes up noticeably as does the longevity of closed bubbles of all sizes.
>75%. When the temperatures are cool, humidity over 75% seems to be almost magical. Again, things get dramatically better as the humidity increases (as long as temperatures aren't too hot. The very very biggest bubbles require very clean air and humidity over 90%.
Do keep in mind that humidity is not everything. You can have good humidity and occasionally have problems due to particles and gases and other unknown factors.
SEE ALSO: Low Humidity
When temperatures approach freezing or rise above about 75F (24C), bubble longevity is adversely affected. It can still be fun to make bubbles but you won't get the same longevity that you do in other temperature ranges.
Judging wind speed. Go here for a guide to determining wind speed.
Knowing Local ConditionsEdit
It is a good idea to know the conditions in your area. In areas where the air tends to be dry, early morning or just before or after it rains generally has higher humidity. Early morning also offers nice soft light that brings out the color in bubbles.
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