# What is the 2nd fastest thing? **URL:** \ **Category:** Factual Questions\ **Created:** [July 18, 2017, 12:39am UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540 "2017-07-18T00:39:55Z")\ **Posts on this page:** 15\ **Page:** 4
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [July 22, 2017, 2:58pm UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/61 "2017-07-22T14:58:34Z")
> [@albino\_manatee](#): > > _“take it as a given”_ … _“fighting ignorance”_ … bit of a paradoxy, wouldn’t you agree? > > anyway … you talk about _“fastest thing”_ … light is not the fastest. as far as humanity currently understands, thought is _(by far)_ the fastest _“thing”_. also time, itself, is faster than light. however … i’m not willing to spend better part of a weekend researching to validate myself. so … y’all enjoy yourselves. That’s pretty much abject nonsense. But it does have pretty colors. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [July 22, 2017, 3:39pm UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/62 "2017-07-22T15:39:55Z")
I like my nonsense abject, if possible. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [July 22, 2017, 11:28pm UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/63 "2017-07-22T23:28:35Z")
> [@Chronos](#): > > Well, it depends on what currents, wire sizes, etc. you consider typical. But there are certainly reasonable choices for those values that get you to **Stranger** ’s result. > > The only set of values I know off the top of my head is that if you attach a foot of copper wire to 1.5 volts, you get a centimeter per second (I was interested in a simple electromagnet experiment, and no, I didn’t account for the internal resistance of the battery, even though I should have). But a foot of copper wire is an extremely low resistance, and thus a very high current. More realistic currents would then give you a much slower velocity. As I recall, HV transmission lines are at 10-20 Km/H, and semi-conductor drift velocities are even faster. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [July 30, 2017, 3:47am UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/64 "2017-07-30T03:47:42Z")
> [@wolfpup](#): > > That proton could not only smash your window, it could also knock your grandmother’s framed family portrait off the mantelpiece and smash it to bits! 😃 So what would have happened if it hit a person? Would it just go through with no ill effect? Somehow leave a bruise? Cause a tiny explosion? ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [July 30, 2017, 4:41am UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/65 "2017-07-30T04:41:18Z")
> [@DesertDog](#): > > But C is 3×10[sup]8[/sup] meters per second only to the first five decimal places. It really is 2.99792458x10[sup]8[/sup] m/s (exactly\*) which would make the calculated speed faster than C. > > This is why keeping track of your significant figures is important; your precision is only as good as the least precise factor. What they’ve done is like somebody saying they drove 255.8 miles on 8.9 gallons so they got 28.74157303 miles per gallon, a precision that cannot be supported. I appreciate what you are on about here but I am the wrong person to ask. You’ll have to take it up with the authors of the article I cited. I’d answer if I could but this is beyond my math abilities (well, more work than I am willing to put in although also probably beyond my math abilities so won’t bother trying). ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [July 30, 2017, 7:42am UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/66 "2017-07-30T07:42:24Z")
> [@Sunspace](#): > > So what would have happened if it hit a person? Would it just go through with no ill effect? Somehow leave a bruise? Cause a tiny explosion? Tiny explosion. Probably too tiny to notice, unless it hit a photoreceptor in your eye, but it would be a bad day for several of your atoms. ---
**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:** [July 30, 2017, 12:28pm UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/67 "2017-07-30T12:28:51Z")
The answer seems to be that a person is a bit too small to have a really good chance of it actually managing to hit anything. (We are to a very good approximation empty space.) If it did mange to bulls eye an atom’s nucleus, you would get a shower of daughter particles, all travelling with insane speed as well, and these would similarly have only a small change of hitting anything else before they reached the other side of you. As the energy in the extending shower of particles decreases they become much more populous, and you are much more likely for one to hit something. However looking into it a bit more, it isn’t that huge a gap. At least for the first collision. Looking at [this page](http://www.cosmic-ray.org/reading/detect.html#SEC3) we find that protons get through about an average of 70g/cm[sup]2[/sup] of matter before their first interaction, and that these distances increase only slowly with the log of the proton’s energy. So, a human is as close to water as needed for this. Which means a proton will go on average thorough about 70cm of human before interacting. After this you get showers of muons and pions, and the shower is pretty much done after making it though 500-700 cm of human equivalent, The OMG making it through 7 odd metres of human equivalent. So there is a passable chance that the OMG particle could have its first collision inside you. If it hit you directly from above the chance is reasonably high. But almost all of the daughter particles are going to stream on and the chances that much energy at all is actually deposited in your body are slim to none. A blue whale OTOH could quite possibly end up adsorbing the entire lot if hit end on. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [July 30, 2017, 12:42pm UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/68 "2017-07-30T12:42:09Z")
> [@Francis\_Vaughan](#): > > …A blue whale OTOH could quite possibly end up adsorbing the entire lot if hit end on. Which ends like this: [https://www.youtube.com/watch?v=GkZottYDpEE](https://www.youtube.com/watch?v=GkZottYDpEE) 😃 I love any excuse to post this link. 😃 ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [July 30, 2017, 1:14pm UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/69 "2017-07-30T13:14:02Z")
> [@Whack-a-Mole](#): > > I appreciate what you are on about here but I am the wrong person to ask. You’ll have to take it up with the authors of the article I cited. > > I’d answer if I could but this is beyond my math abilities (well, more work than I am willing to put in although also probably beyond my math abilities so won’t bother trying). Yes, **WaM** , I agree, which is why I stuck that \ inside the quote attributed to you: So people wouldn’t think it was _your_ work I was criticizing. I think the main take away here is that it might or might not be the fastest particle detected, but if it isn’t the difference is too small to measure, kind of like a dead-heat horse race. ---
**Author:** ![Banksiaman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/banksiaman/32/3334_2.png) [@Banksiaman](https://boards.straightdope.com/u/Banksiaman)\ **Post date:** [July 31, 2017, 5:06am UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/70 "2017-07-31T05:06:44Z")
At the considerable risk of revealing that I am not a brainiac physics type can I ask those of you who clearly are whether along with the speed of light there is also such a thing as the speed of dark? ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [July 31, 2017, 9:39am UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/71 "2017-07-31T09:39:35Z")
> [@Banksiaman](#): > > At the considerable risk of revealing that I am not a brainiac physics type can I ask those of you who clearly are whether along with the speed of light there is also such a thing as the speed of dark? Only on planar worlds with chelo-pachydermian support systems. ---
**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:** [July 31, 2017, 10:20am UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/72 "2017-07-31T10:20:15Z")
Indeed. 😃 For the otherwise mystified\*, dark is just another way of information moving, and it must also be limited by the speed of causality. So dark travels at at most c. - Discworld references not withstanding. ---
**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:** [July 31, 2017, 1:05pm UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/73 "2017-07-31T13:05:42Z")
The speed of dark is exactly the same as the speed of light. If I have a hallway 3e8 meters long, lit by a light bulb on one end, and I turn off the light, then the other end will become dark one second later. ---
**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:** [July 31, 2017, 2:51pm UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/74 "2017-07-31T14:51:41Z")
> [@Banksiaman](#): > > At the considerable risk of revealing that I am not a brainiac physics type can I ask those of you who clearly are whether along with the speed of light there is also such a thing as the speed of dark? Everything you want to know [about that](https://www.youtube.com/watch?v=JTvcpdfGUtQ). ---
**Author:** ![Banksiaman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/banksiaman/32/3334_2.png) [@Banksiaman](https://boards.straightdope.com/u/Banksiaman)\ **Post date:** [July 31, 2017, 6:32pm UTC](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540/75 "2017-07-31T18:32:46Z")
Thanks heaps Darren Garrison, Francis Vaughan, Saint Cad and Chronos. Now I know. [Previous page](https://boards.straightdope.com/t/what-is-the-2nd-fastest-thing/791540.md?page=3)