# How loud was the big bang? **URL:** \ **Category:** Factual Questions\ **Created:** [October 31, 2010, 4:31am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953 "2010-10-31T04:31:32Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![KiLLa\_KAM\_666](https://avatars.discourse-cdn.com/v4/letter/k/a3d4f5/32.png) [@KiLLa\_KAM\_666](https://boards.straightdope.com/u/KiLLa_KAM_666)\ **Post date:** [October 31, 2010, 4:31am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/1 "2010-10-31T04:31:32Z")
The question was originally a joke and used to give Cha Cha, a question answering base by via texting, to confuse them. My curious mind has left me bored and I stumbled upon this website, being a fan of The Straight Dope, I figured to ask. How loud was the Big Bang? ---
**Author:** ![oliversarmy](https://avatars.discourse-cdn.com/v4/letter/o/eb8c5e/32.png) [@oliversarmy](https://boards.straightdope.com/u/oliversarmy)\ **Post date:** [October 31, 2010, 4:35am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/2 "2010-10-31T04:35:18Z")
About as loud as that weird green text. Does that help? You know, since there is no sound in a vacuum. ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [October 31, 2010, 4:41am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/3 "2010-10-31T04:41:22Z")
I think a bigger question is whether the big bang had any space for the sound to propogate to, anyways. Remember, space itself is being created here. ---
**Author:** ![Fubaya](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@Fubaya](https://boards.straightdope.com/u/Fubaya)\ **Post date:** [October 31, 2010, 5:17am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/4 "2010-10-31T05:17:32Z")
I don’t know how loud it was, but there is a [simulation](http://faculty.washington.edu/jcramer/BBSound.html) of what it “sounded” like shortly after the Big Bang (in cosmic terms, 100,000 years is “shortly”). ---
**Author:** ![GuanoLad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guanolad/32/42_2.png) [@GuanoLad](https://boards.straightdope.com/u/GuanoLad)\ **Post date:** [October 31, 2010, 5:24am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/5 "2010-10-31T05:24:47Z")
I read somewhere that you can still hear it. ---
**Author:** ![Dag\_Otto](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@Dag\_Otto](https://boards.straightdope.com/u/Dag_Otto)\ **Post date:** [October 31, 2010, 5:30am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/6 "2010-10-31T05:30:22Z")
It wasn’t as loud as the Big Bang that preceded it, but it was louder than the next Big Bang will be. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [October 31, 2010, 6:26am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/7 "2010-10-31T06:26:08Z")
> [@oliversarmy](#): > > About as loud as that weird green text. Does that help? You know, since there is no sound in a vacuum. Actually space wasn’t a vacuum then; not for a long time.\* As **BigT** says, space was coming into being at that point, so at the very start there wasn’t anything as such to have a “sound”; and immediately after space wasn’t filled with normal matter. Answering the question would require a definition of “sound” in this context that you are willing to accept. And it would require a knowledge of just what kind of turbulence existed during the early universe that I don’t think anyone has yet. \*And in fact it’s arguable if there’s no sound in a vacuum; space is full of charged gases that react to the passage of objects with shockwaves. The mechanism isn’t the same as in atmosphere and an ear could never “hear” it, but it does act rather like ordinary sound does. The right instrumentation would be perfectly capable of “hearing” the “sound” of a satellite or the Moon moving through space. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [October 31, 2010, 9:02am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/8 "2010-10-31T09:02:55Z")
> [@GuanoLad](#): > > I read somewhere that you can still hear it. I suspect you are thinking of the microwave background radiation, that is sometimes referred to pseudo-poetically as an “echo of the Big Bang.” It is electromagnetic radiation, however, not sound. > [@](#): > > And in fact it’s arguable if there’s no sound in a vacuum; space is full of charged gases that react to the passage of objects with shockwaves. A better way to put that would be to say that space is not really a perfect vacuum. In a true vacuum there would be no sound at all. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [October 31, 2010, 9:17am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/9 "2010-10-31T09:17:40Z")
What’s the sound of the universe now? The Big Bang hasn’t ended - we’re still in the middle of it. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [October 31, 2010, 10:50am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/10 "2010-10-31T10:50:16Z")
> [@KiLLa\_KAM\_666](#): > > How loud was the Big Bang? Loud enough at low frequencies that galactic clusters formed at the high points of the pressure waves. [Ducks of Oregon Discuss Cosmic Background Radiation:](http://abyss.uoregon.edu/~js/ast123/lectures/lec23.html) > [@](#): > > Since the COBE discovery, many ground and balloon-based experiments have shown the ripples peak at the degree scale. What CMB experimentalists do is take a power spectrum of the temperature maps, much as you would if you wanted to measure background noise. The angular wavenumber, called a multipole l, of the power spectrum is related to the inverse of the angular scale (l=100 is approximately 1 degree). Recent experiments, notably the Boomerang and Maxima experiments, have show that the power spectrum exhibits a sharp peak of exactly the right form to be the ringing or acoustic phenomena long awaited by cosmologists > … > The density fluctuations at recombination, as measured in the CMB, are too large and too low in amplitude to form galaxy sized clumps. Instead, they are the seeds for galaxy cluster-sized clouds that will then later break up into galaxies. However, in order to form cluster-sized lumps, they must grow in amplitude (and therefore mass) by gravitational instability, where the self-gravity of the fluctuation overcomes the gas pressure. Similar things have been known to happen at Grateful Dead concerts, but the mechanism there does not strictly rely on the intensity of the sound waves. If we are lucky we will never hear a sound loud enough to precipitate galactic cluster formation. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [October 31, 2010, 10:58am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/11 "2010-10-31T10:58:26Z")
I guess you could argue that sound is a change is pressure. Thus we could use the change in pressure of the early time of the big bang to derive a SPL. However if we consider that the universe started from a singularity we have an infinite/undefined pressure at the absolute start, and thus infinite or undefined loudness. After that the pressure just keeps dropping and dropping. The inflationary period should make for a pretty big pressure drop too. You could argue that that that was pretty loud. ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [October 31, 2010, 3:47pm UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/12 "2010-10-31T15:47:25Z")
I would hazard a guess the early universe had a sonic squelcher that limited noise beyond 55 decibels. Otherwise it would be possible to hear you scream. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [October 31, 2010, 3:49pm UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/13 "2010-10-31T15:49:40Z")
It sounded as if a hundred thousand people had said “whop.” ---
**Author:** ![The\_Flying\_Dutchman](https://avatars.discourse-cdn.com/v4/letter/t/9fc348/32.png) [@The\_Flying\_Dutchman](https://boards.straightdope.com/u/The_Flying_Dutchman)\ **Post date:** [October 31, 2010, 4:13pm UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/14 "2010-10-31T16:13:07Z")
Given that the speed of sound is miniscule compared the c plus expansion during the big bang… I’ve got nothing. ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [October 31, 2010, 4:19pm UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/15 "2010-10-31T16:19:53Z")
If a universe explodes into existence and there’s no-one there to hear, does it make a big bang? ---
**Author:** ![KiLLa\_KAM\_666](https://avatars.discourse-cdn.com/v4/letter/k/a3d4f5/32.png) [@KiLLa\_KAM\_666](https://boards.straightdope.com/u/KiLLa_KAM_666)\ **Post date:** [October 31, 2010, 8:48pm UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/16 "2010-10-31T20:48:18Z")
Hypothetically speaking, if it were audible some way, how loud would it be? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 31, 2010, 10:07pm UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/17 "2010-10-31T22:07:20Z")
> [@](#): > > Given that the speed of sound is miniscule compared the c plus expansion during the big bang… > > I’ve got nothing. Not minuscule. In a radiation-dominated gas like we had shortly after the Bang, the speed of sound is 1/3 the speed of light. ---
**Author:** ![Morgenstern](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@Morgenstern](https://boards.straightdope.com/u/Morgenstern)\ **Post date:** [October 31, 2010, 10:17pm UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/18 "2010-10-31T22:17:00Z")
I wonder if the “tone deaf” heard it? ---
**Author:** ![RaftPeople](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@RaftPeople](https://boards.straightdope.com/u/RaftPeople)\ **Post date:** [November 1, 2010, 1:32am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/19 "2010-11-01T01:32:41Z")
> [@KiLLa\_KAM\_666](#): > > Hypothetically speaking, if it were audible some way, how loud would it be? The big bang was almost as loud as a Spinal Tap concert. ---
**Author:** ![MichaelEmouse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/michaelemouse/32/101_2.png) [@MichaelEmouse](https://boards.straightdope.com/u/MichaelEmouse)\ **Post date:** [November 1, 2010, 2:40am UTC](https://boards.straightdope.com/t/how-loud-was-the-big-bang/558953/20 "2010-11-01T02:40:47Z")
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