# Early Explanations For Difference In Velocity of Light and Sound **URL:** \ **Category:** Factual Questions\ **Created:** [February 16, 2015, 7:17pm UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843 "2015-02-16T19:17:25Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![TCMF-2L](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tcmf-2l/32/16553_2.png) [@TCMF-2L](https://boards.straightdope.com/u/TCMF-2L)\ **Post date:** [February 16, 2015, 7:17pm UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843/1 "2015-02-16T19:17:25Z")
I read Aristotle in Ancient Greece mused about whether light moved instantaneously. Which impressed me - I would have thought speed of light came much later. However it posed a question. Did the ancients ever have any pseudo-scientific explanations to explain the disparity between seeing something noisy and actually hearing the noise? There is the obvious cop out of thunder and lightening - suggest they are separate and unrelated. But what about seeing a blacksmith or a stone mason from a distance striking something and noticing the noise only appearing a second or so later? Or even in later periods of history when the general population was uneducated. How did the common man watching, for example, a naval battle a mile or two off shore explain seeing cannons fire but only hearing them a few moments later? Were there no Bad Science of the Flat Earth / Sun Orbits The Earth / Fever is cured by blood letting type explanations? TCMF-2L ---
**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:** [February 17, 2015, 2:30am UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843/2 "2015-02-17T02:30:35Z")
Why wouldn’t they have been able to come up with the correct explanation, that sound moves at a finite speed, while light is either instantaneous or so fast that it might as well be? ---
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [February 17, 2015, 3:05am UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843/3 "2015-02-17T03:05:30Z")
[The speeds of sound and light were determined earlier than you think.](http://www.explorecuriocity.org/Content.aspx?contentid=187) ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [February 17, 2015, 3:21am UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843/4 "2015-02-17T03:21:19Z")
> [@chacoguy](#): > > [The speeds of sound and light were determined earlier than you think.](http://www.explorecuriocity.org/Content.aspx?contentid=187) It was determined even earlier than your link says - [cite](http://en.wikipedia.org/wiki/Sayana) ---
**Author:** ![TCMF-2L](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tcmf-2l/32/16553_2.png) [@TCMF-2L](https://boards.straightdope.com/u/TCMF-2L)\ **Post date:** [February 17, 2015, 9:10am UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843/5 "2015-02-17T09:10:22Z")
> [@Chronos](#): > > Why wouldn’t they have been able to come up with the correct explanation, that sound moves at a finite speed, while light is either instantaneous or so fast that it might as well be? It looks like they did! I just expected that at least some of the ancients, from a pre-scientific era, would have observed the disparity and come up with a more creative, albeit wrong, explanation. TCMF-2L ---
**Author:** ![DrFidelius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drfidelius/32/3447_2.png) [@DrFidelius](https://boards.straightdope.com/u/DrFidelius)\ **Post date:** [February 17, 2015, 12:34pm UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843/6 "2015-02-17T12:34:51Z")
Light and sound are obviously two different things, so why would anyone feel the need to explain why they propagate differently? ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [February 17, 2015, 3:05pm UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843/7 "2015-02-17T15:05:50Z")
> [@am77494](#): > > It was determined even earlier than your link says - [cite](http://en.wikipedia.org/wiki/Sayana) If a student of mine gave a test answer like the one in your link, I’d give them less than half credit and write “show your work!” on the paper. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [February 17, 2015, 3:17pm UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843/8 "2015-02-17T15:17:05Z")
I love how they give the speed of light in m/s considering the meter is defined by the spped of light and seconds. ---
**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:** [February 17, 2015, 3:37pm UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843/9 "2015-02-17T15:37:35Z")
I’m certain I remember one of the classical philosophers determining the speed of sound from echoes, and attempting to determine the speed of light but finding only a lower bound. ---
**Author:** ![mhendo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mhendo/32/3159_2.png) [@mhendo](https://boards.straightdope.com/u/mhendo)\ **Post date:** [February 17, 2015, 4:32pm UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843/10 "2015-02-17T16:32:02Z")
> [@am77494](#): > > It was determined even earlier than your link says - [cite](http://en.wikipedia.org/wiki/Sayana) There’s some bad math going on in that Wikipedia article: > [@](#): > > “[O Sun,] bow to you, who traverses 2,202 yojanas in half a nimesha.” > > Given that a yojana was equivalent to about 5 km and a nimesha to about 106.7 ms, Sayana’s approximation to the speed of light comes to about 330000 km/s, which is only 10% off the actual value of c as determined by modern scientific experiments. I have no particular axe to grind regarding Sayana and his claims about the speed of light but, as far as i can tell, the calculations there are wrong. If a yojana is ~5km, then 2,202 yojanas is 11,010km. So, if light travels 11,010km (2,202 yojanas) in half a nimesha, it must travel 22,020km (4,404 yojanas) in a full nimesha. If a nimesha is 106.7 ms, then there are about 9.37 nimeshas per second. Multiply 22,020 x 9.37 and you get 206,327, which is NOT the 330,000 figure claimed by the article. If i’ve screwed something up here, let me know, but i think that Wikipedia page needs fixing. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [February 17, 2015, 4:49pm UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843/11 "2015-02-17T16:49:03Z")
nm ---
**Author:** ![Nava](https://avatars.discourse-cdn.com/v4/letter/n/da6949/32.png) [@Nava](https://boards.straightdope.com/u/Nava)\ **Post date:** [February 17, 2015, 4:50pm UTC](https://boards.straightdope.com/t/early-explanations-for-difference-in-velocity-of-light-and-sound/712843/12 "2015-02-17T16:50:12Z")
> [@Saint\_Cad](#): > > I love how they give the speed of light in m/s considering the meter is defined by the spped of light and seconds. It’s defined that way now, but that wasn’t the original definition. Do you think it would be practical to change our basic units to be speed ones and our dimensional analysis to match? I don’t.