Talk:Orders of magnitude (speed)

Human sprinter speed on table
Your listed speed for the maximum a human sprinter would go (11.80 m/s) corresponds to running an ~8.47s 100m race, this is more than a second faster than the world record (Set today, btw at 9.72 5/30/08) Do you mean that the racers "peak" at this speed during the race? or do you mean that this is supposed to be the fastest humans can run 100m? —Preceding unsigned comment added by 70.223.81.19 (talk) 08:28, 1 June 2008 (UTC)

This is certainly false: "90 Speed of a Horse." Yann


 * As a peak speed, I don't think it's that far off: this page claims that the fastest runners can maintain an avererage speed of 72km/h over a mile, with standing start. AxelBoldt 19:49, 27 May 2005 (UTC)

I'm sure that the distance a snail could cover in an hour is closer to 20 cm than 2 cm so I think you're out by at least an order of magnitude, but probably more. Other web resources put the speed of a garden snail at around 0.0085 kph, which would mean they could cover about 8.5 m in an hour.


 * I fixed that using this as a source. --Vedranf 18:10, 17 December 2005 (UTC)

I think the following is wrong (or at least misleading): 70,220	252,792	Speed of the Helios 2 solar probe - Fastest man-made object. I have the 1991 edition of Guinness Book of World Records and it states that the fastest man-made 'solid visible object' was a plastic disc shot in 1980 by US naval research laboratory in Washington which reached a velocity of 150 km/s. It's not self-propelling, but it sure is faster than 70 km/s. - G3, 00:25, 1 February 2006 (UTC)

Doesn't a 1224 km/h speed of sound correspond to 340 m/s, not the 295 listed in the table?128.42.167.229 19:55, 3 February 2006 (UTC)

How about miles/hr equivalents?
What do people think about adding a column with MPH equivalents? Lots of other articles have all the figures in both metric and imperial units, so it seems particularly relavent to an article where the sole purpose is to provide comparisons. —Doug Bell talk•contrib 14:45, 5 April 2006 (UTC)


 * I agree 100% I have absolutely no idea how fast 130 km/h is, and I'd be willing to bet that a large protion of users viewing this page don't either. Johaen 19:01, 16 August 2006 (UTC)


 * Who cares? — Preceding unsigned comment added by 80.232.249.34 (talk) 09:43, 16 January 2014 (UTC)


 * Too many people to ignore, much as we wish we could. The juvenility of the ostrich approach may be illustrated by the following:
 * –OMG, a rabid dog! RUN!
 * –Who cares? Dogs are stupid anyway. --Florian Blaschke (talk) 15:03, 24 January 2014 (UTC)

m·s−1 and km·h−1
I suggest changing the representation of the units to m/s and km/h instead of using −1 for the time. This is an equally precise, and I think more natural, representation. —Doug Bell talk•contrib 18:44, 6 April 2006 (UTC)


 * I entirely agree, it took me a several minutes to work out that m·s−1 is the same as m/s. It wouldn't take away anything from the accuracy of the table to have m/s and km/h, and it would be Much easier to understand.--Hibernian 14:37, 16 August 2006 (UTC)

Hypervelocity
Would it be appropriate to link to Hypervelocity from one of the entries? Somewhere around StarDust? Shenme 03:54, 3 July 2006 (UTC)

snail
I noticed this: 0.0468 (m/s) 	0.013 (km/h)	Speed of a Garden snail [1].

Now the conversion is obviously wrong; it looks backwards. I don't know which is correct, but perhaps somebody who knows could edit it? Alex Klotz 19:53, 8 August 2006 (UTC)


 * Speed of garden snail now uses correct ratio of m/s to hm/h. Also, reference for speed is given. Az7997 18:41, 23 October 2006 (UTC)


 * The snail article gives 1mm/s (with a reference), not 1cm/s as here. Anyone explain this? Robinh (talk) 11:50, 31 March 2009 (UTC)

I have added a dubious tag to the claim that a garden snail's speed is 0.013 metres per second. That is 1.3 centimetres per second. Or one metre in just over a minute. Such an extraordinary claim needs better sourcing than hypertextbook's quoting of an almanac. I added this text to the reason field: "speed five times faster than the world record accepted by Guinness? hypertextbook is an aggregator of other sources, and the one used here may not be reliable or be quoting a simple typo; wikipedia needs better than this; also context needed as to duration of this speed" -84user (talk) 09:42, 4 April 2011 (UTC)

Combine tables
It seems a bit daft to me to have a m/s + km/h table, a m/s table, a mph table, then a km/h table, many sharing information. I'll combine these the next time I have a spare moment if there is no discord. Atropos235 05:09, 20 February 2007 (UTC)
 * I fully support this. As the parent message 4+ years ago, would anyone object? cm&#610;&#671;ee&#9786;&#964;a&#671;&#954; 16:56, 22 May 2011 (UTC)
 * Done! cm&#610;&#671;ee&#9786;&#964;a&#671;&#954; 23:11, 2 August 2011 (UTC)

The speed of light is mistakenly expressed
The speed of light is 299,792,458 (m/s) and not 299,792.458 (m/s). It's about 300 000 km/s and not 300 km/s. Other values are wrong as someone used again a "." where there should be a ",". Guelao 15:03, 7 August 2007 (UTC)

Is it just me or...
does this not make sense.

200,000,000 	720,000,000 	Speed of a signal in a cable.

2,000 	       7,200 	        Estimated speed of a thermal neutron

200,000 	700,000 	Orbital speed of the solar system in the Milky Way galaxy.

My suggestion is "Orbital speed of the solar system in the Milky Way galaxy." in km/h to be changed to 720,000

Anything faster than light?
(Special?) Relativity only states that no INFORMATION may travel faster than light. It is I think possible for, e.g, the distance between two objects, for example our own galaxy and a sufficiently distant one, to be increasing at a rate faster than the speed of light due to the expansion of the universe. This means that light emitted 'now' from the distant galaxy can never reach us. I think. It's been a while since I studied relativity. 86.21.227.237 (talk) 21:50, 23 July 2008 (UTC)

Relativity states no such thing.

Technically what relativity states is that it would take an infinite amount of energy to accelerate to the speed of light. And thus it's OK to say its impossible for something to "get to" the speed of light. But if you're already there then relativity says that thats OK. Some would argue that the symmetry in the equations would mean that things would just get faster accelerating and accelerating past c. But this is ust one model. But the point remains: Relativity does not specifically state that no INFORMATION (even though in Einstein's equation "m" is for mass not information - at least for special relativity) may travel faster than light.

Source: Schrodinger's Kittens and the Search for Reality which is written by John Gribbin 81.105.252.20 (talk) 17:09, 17 January 2009 (UTC)

Fastest submarine?
Shouldn't it be there as an example? There is one that can reach 'bout 41 knots, dunno know if any other submarine is fasterUndead Herle King (talk) 04:32, 26 August 2009 (UTC)

X-43 incorrectly listed
The speed of the X-43 quoted in the entry:

7,111	25,599.6	Speed of the X-43 rocket/scramjet plane.

...is wrong. Correct speed given here:

http://en.wikipedia.org/wiki/X-43 —Preceding unsigned comment added by 70.181.138.57 (talk) 04:58, 3 October 2010 (UTC)

Hair growth
According to the table, the average speed of the (human?) hair growth is 1.7×10-8 m/s, but that means, from Google Calculator (http://www.google.ro/search?q=1.7*10^-8%20m/s%20in%20cm/year), about 53.6467742 cm/year, which is near impossible (or it is the maximum growth, or it is for an animal, or it is wrong), because at the article Human hair growth, it says: 'The rate or speed of hair growth is about 1.25 centimeters or 0.5 inches per month, or about 15 centimeters or 6 inches per year.' So, please resolve the problem! Or it is true? 78.97.152.14 (talk) 13:06, 29 August 2011 (UTC)
 * I was going to check out the talk page but forgot about it ... I've already fixed that and added a caveat since it varies so much. Actually, it would probably be more honest to write something like in the case of continental drift: 1 to 1 m/s (etc.), as this seems to cover the typical range of growth rates found in the population. That doesn't mean that considerably more slowly or quickly growing hair doesn't exist; judging from what I've heard personal acquaintances report, I have reason to suspect it does very definitely – but those cases are most likely rare. --Florian Blaschke (talk) 22:27, 16 October 2011 (UTC)

Column for speed relative to c, the speed of light
I think it would be nice to see a column showing the speed relative to the speed of light, since it is the natural maximum speed limit of the universe.

It would look something like this for an item:

Factor	| Value (m/s)	| Value (km/h)	| Value (mph)	| Value (c)	| Item

10^4 	| 29,800	| 107,280	| 66,700	| 9.9402X10^-5	| Speed of the Earth in orbit around the Sun.
 * Do you have any rationale for its usefulness? I think it might be only for items a significant fraction (1+%?) of the speed of light &mdash; otherwise, very small numbers e.g. 1 just take up space. cm&#610;&#671;ee&#2927;&#8202;&#865;&#176;&#160;&#814;&#1583;&#8202;&#865;&#176;&#8201;&#2669; 19:45, 16 January 2013 (UTC)

Beta Particles in Water?
I don't know if it is true or not. It is said that Beta particles can exceed c (Speed of light in vacuum) when in water. — Preceding unsigned comment added by 220.238.65.82 (talk) 12:54, 22 September 2013 (UTC)

Layman column
I suggest and additional column using the most usual unit for each entry, expressed in layman number writing : Because few people can "get" things like 4.0×10−4 m/s. --Musaran (talk) 14:51, 24 July 2014 (UTC)
 * m/day for glacier
 * m/s and km/h for winds
 * km/h for most ground vehicles
 * km/h and knots for ships
 * mach for fast airplanes
 * % of c for relativistic speeds

Speed of the tip of an hour hand?
The circumferences of clocks vary very widely, from the wristwatch to the Big Ben of London. So, I suggest that the speed of the tip of an hour hand be taken down from here. It already has a place in the table for magnitude of angular velocities. Daimler Ben (talk) 13:13, 15 November 2016 (UTC)
 * ✅ Noted it's for a 7 cm hand as v = r &omega; = 0.07 m &middot; $2\pi⁄60 s/min &middot; 60 min/hr &middot; 12 hr$ . The linear speed is useful as comparison with other slow objects. Cheers, cm&#610;&#671;ee&#9094;&#964;a&#671;&#954; 18:35, 11 August 2017 (UTC)

Speed of Sun in the Milky Way
828,000 km/h. I am not smart enough to add myself, as my attempts cause more destruction than improvment.
 * Already listed as "Orbital speed of the solar system in the Milky Way galaxy." Cheers, cm&#610;&#671;ee&#9094;&#964;a&#671;&#954; 18:37, 11 August 2017 (UTC)

Speed of rocket ship, way too high?
This can't be right, can it? Nothing on the rocket ship wiki page, and google searching the MPH value shows the speed of solar wind. No rocket ship has gotten close to a tenth of c... Going to remove in a couple days, or switch to solar wind.

Gdryke (talk) 16:18, 30 August 2018 (UTC)

Didn't update to solar wind as there was already an entry below it, just removed it.

Gdryke (talk) 16:32, 31 August 2018 (UTC)

Speed of the 7 TeV protons in the Large Hadron Collider at full power
A reader contacted Wikimedia to note that the entry for the

Speed of the 7 TeV protons in the Large Hadron Collider at full power

In miles per hour, shown as

670,615,282

is incorrect and should be 670,616,623.9 mph

Can someone double check the values?-- S Philbrick (Talk)  13:54, 10 September 2017 (UTC)

Average speed of car
Where did the average speed of a car come from? 80 MPH seems a bit high. EdHayes3 (talk) 19:59, 9 January 2019 (UTC)