Is the Local Bubble alone in space or is there another bubble similar to the Local Bubble in space, i.e., do we live in a special place or is this a more general phenomenon?
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$\begingroup$ Perhaps you are unclear about what the "local bubble" is. If you edited to describe what you understand "local bubble" to mean, that would clarify the question $\endgroup$ – James K Aug 15 '19 at 8:01
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The "local bubble" is a region of the galaxy where the density of interstellar gas is lower than average. It has about 50 thousand atoms per cubic metre, compared with 500 thousand averaged over the whole of the milky way. It was probably formed by one or more supernova explosions (10-20 million years ago) physically pushing gas away.
There are many such bubbles all over the galaxy, carved out by supernova and other energetic objects. See https://en.wikipedia.org/wiki/Superbubble
