this post was submitted on 17 Jul 2026
47 points (88.5% liked)

Showerthoughts

42905 readers
600 users here now

A "Showerthought" is a simple term used to describe the thoughts that pop into your head while you're doing everyday things like taking a shower, driving, or just daydreaming. The most popular seem to be lighthearted clever little truths, hidden in daily life.

Here are some examples to inspire your own showerthoughts:

Rules

  1. All posts must be showerthoughts
  2. The entire showerthought must be in the title
  3. No politics
    • If your topic is in a grey area, please phrase it to emphasize the fascinating aspects, not the dramatic aspects. You can do this by avoiding overly politicized terms such as "capitalism" and "communism". If you must make comparisons, you can say something is different without saying something is better/worse.
    • A good place for politics is c/politicaldiscussion
  4. Posts must be original/unique
  5. Adhere to Lemmy's Code of Conduct and the TOS

If you made it this far, showerthoughts is accepting new mods. This community is generally tame so its not a lot of work, but having a few more mods would help reports get addressed a little sooner.

Whats it like to be a mod? Reports just show up as messages in your Lemmy inbox, and if a different mod has already addressed the report, the message goes away and you never worry about it.

founded 3 years ago
MODERATORS
 

We all talk about the big bang as this moment the Universe begins by popping into existence with simple hydrogen and some helium. Hydrogen and Helium are gases that are able to carry sound. Today, space has expanded so much that there is vacume beyond where matter clumps together to form stars/planets, which means the sound couldn't propagate, but the early early Universe wouldn't have clumped like today; there would have been hydrogen everywhere. This means it would have been loud everywhere.

*Edit: I know we call it the Big Bang because of the rapid expansion of spacetime, but I always just pictured the general motion of expansion as the "bang". Never thought of how loud it would have been.

you are viewing a single comment's thread
view the rest of the comments
[–] calcopiritus@lemmy.world 11 points 13 hours ago

The edge of the observable universe is not because of that.

It is because space expands. Therefore everything goes away from everything else. Therefore, everything goes away from us. And the more space there is between us and that other thing, the more space expands, since there is more space. Therefore, things that are farther away from us, get away from us faster than everything else. Only if it is close enough to us that gravity is strong enough would that something not move away from us.

This creates a peculiar situation. Things that are far enough away from us, actually move away from us faster than the speed of light. This means that no photon ever emitted from this far away will ever reach us.

That is the edge of the observable universe. The distance at which a photon emitted in our direction will never reach us, since for every meter the photon travels, there is at least a meter of space "created" between us. Therefore it never progresses in moving towards us, in fact, it moves away from us even though it is traveling in our direction.