Orders of magnitude/Talk

The individual size pages should probably all have a link back to this overview.

A comparison of times would also be nice. And dimensionless numbers, like the number of stars in the Galaxy, the number of cells in the human body, and the largest known prime. --AxelBoldt

And the population of various countries and cities. --LA2

I think the example column should be placed immediately after the column of dimensions that it's an example of. As it is now, it's unclear what dimension things in the example column are an example of; for example, is the Sun an example of something that is 10⁹m in diameter, or is it an example of something with an area of 10¹⁸m²? This gets even more confusing when mass is considered as well. I'll move it over and see if it looks okay.

There, fixed. If everybody hates this, revert it; otherwise I'm going to add empty example columns for the other measurements as well for future expansion. :)

Hmmm, I think having an example for every unit might clutter up the table too much. My intention of lining things up in rows the way I did was to show a general sense of order of magnitude of objects that have "normal" densities (within an order of magnitude of water at 1000 kg/m³). But perhaps this is not appropriate as things like sub-atomic particles and galaxies have densities that are much-much bigger or smaller. So perhaps on reconsideration we should try to keep the table clean and not put examples columns, but just have people link down to the pages to see the examples. --Eob

Hi 129.128.164.xxx, thanks for entering all those examples, but I think that now the table is getting too cluttered up and some of the examples are not in the individual pages. I suggest we do get rid of the examples column and move them to the individual pages. That way they will be more useful in other pages that link to those pages. --Eob

Heh. Sorry, got a bit carried away and wasn't reading Talk updates while I worked. :) I was getting those examples off of http://math.ucr.edu/home/baez/distances.html for the most part, if you want more precice measurements. I think it'd be good to have at least a few examples scattered throughout the range of this table, however; otherwise the measurements are just meaningless numbers. - BD, from a public terminal

Here is my reasons for not including examples in the table:

1. I think the table should be as clean as possible. This will become particularly important if we add columns for time, temperature, pressure, etc.
2. The formatting on this table is tricky because of the use of HTML tables. Many people will have problems editing it if we are going to keep on adding examples. (In fact some of the recent edits had bad HTML which might have caused problems with some browsers.) I think that it should be more like the periodic table which does not get modified very often once it is set up.
3. Having the same info in two places would make it hard to maintain.

Sorry but this bit of Wiki just doesn't do the business for me. I know that I should put the effort in to sort it but I just don't have the confidence to replace all this stuff. Could we get some more views?

What "bit of Wiki" do you mean exactly? What do you think needs sorting? What do you think needs replacing? You solicit views about what exactly? --AxelBoldt

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I generally agree that this page, while already very useful, needs work.

First, why is this list of different units of measurement on a page called "orders of magnitude"? The latter does not mean "units of measurement." Why not put it on a [units of measurement]? (or better, [listing of units of measurement]?) page?

I'm not sure that "listing of units of measurement" would be more appropriate. We already have SI unit and conversion of units, and all units are listed there. "Meter" is a unit of length, but 100m, 1000m, 10000m are not. I believe they are often called "orders of magnitude of length".

What we could do though is to break this list up and put the length part on length, the mass part on mass etc., under a headline of "orders of magnitude of length" or similar. That however would lose the connection between different units, such as the connection between length and time given by the speed of light. Maybe we should do both: put it on length, together with nice examples for every order of magnitude, and keep it here as a general reference table. --AxelBoldt

Second, there are names like 1e-15 m. For someone who wants to know what "1e-15 m" means, in the article, we are told: "To help compare different orders of magnitudes this page lists lengths between 10-15 m and 10-14 m." This isn't very helpful for someone who doesn't know what "1e-15 m" means in the first place. For instance, what does that mean, using decimal places? Yes, any well-educated person knows how to figure it out; but a Wikipedia article about X, remember, is always for the benefit of a (perhaps theoretical) person who doesn't know much at all about X.

Larry, I changed 1e-15 m to be hopefully more informative in this regard. What do you think of that style? Also, these pages are not intended to be linked without an alias to a particular measure like [[1e-15 m|20 millionths of an angstrom]], so I do not think we need worry too much about the page names per se. --Eob

Third, I generally agree with the person who said (somewhere) that the titles of these articles could perhaps be stated in more clearly recognizable words and numbers, without symbols, e.g.: [1,000,000,000 meters]? (or metres, if you insist). What's wrong with that, at least with the magnitudes close to 1?

Fourth, I think the simplest, single examples should be given for each unit of measurement at each order of magnitude. Again, the whole point here is not to make a pretty table but to make concepts clear to people who do not understand them. If we need several tables, grand, let's make them.

In general, try to bear in mind that our task here is to make concepts as simple as possible--it is not to build a merely pretty-and-clever system of webpages. Prettiness and cleverness are good but must be entirely subsumed under the task of making concepts clear to those who do not have them. --LMS