Orders of magnitude

Strangely, the phrase “orders of magnitude” featured in a visitor’s search efforts while browsing the sciencebase site. Unfortunately, other than using the phrase myself in the context of, for instance: “the amount of greenhouse gases emitted by human activities is several orders of magnitude smaller than those emitted by natural processes”. I did not actually have a definition of orders of magnitude on the site. Until now. So here goes:

The order of magnitude is the scale of any given amount where each class contains values of a fixed ratio to the class preceding it. The ratio most commonly used is 10. For example, a kilogram is three orders of magnitude bigger than a gram.

In the greenhouse gas instance cited above, the phrase “orders of magnitude” is simply being used colloquially and can apply in many situations, such as the volume of water in the Pacific Ocean is many orders of magnitude greater than that contained in Lake Michigan. To give a more solid example, one might say “An order of magnitude difference between two values is a factor of 10. For example, the mass of the planet Saturn is almost 100 times that of Earth, so Saturn is two orders of magnitude more massive than Earth.

Orders of magnitude are not always on the decimal scale. For instance, the difference in size between a megabyte and a gigabyte is three orders of magnitude, but the multiplier is 1024 rather than 1000. Please correct me if I’m wrong on that, I guess you could define a single order of magnitude her as being based on 1024 rather than “10″.

More on order of magnitude here.

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4 thoughts on “Orders of magnitude

  1. No insult was taken; I fancy myself a bit of a raconteur, and that opening sentence was just the segue to an off topic story

  2. Hi DV82XL, never meant to insult anyone with that post, there are lots of young science students and homeschoolers who drop by the Sciencebase site, as revealed by some of the phrases they search for, such as orders of magnitude, so I like to do the occasional “educational” post, just to keep up the teaching spirit.

    That story is classic. I’ve got a friend who sells desktop magnifiers and other scientific instruments and he had a call from a customer (head of a QC/QA lab) who actually asked if the 14X magnifier would be stronger than the 8X magnifier he already owned! Unbelievable. I cover a lot of these kinds of story on the ScienceText.com site in the Significant Figures category, check it out if you have a moment, I try to make it informative and entertaining as well as extracting the urine 0.457884 mills at a time.

  3. Two days ago I would have been mildly insulted by this post – I mean really we’re all of a scientific bent here, aren’t we?

    However since then I had a disturbing encounter with the child of one of my neighbors.

    She is about seventeen and wants to go into nursing, while finishing high school she works as a cashier at a local market. I went there to pick up some finger-food for a small gathering we were having that night, and noticed that the bags in question were on sale at six dollars for three. Picking up three of them I went to her checkout and watched as she passed my items through the bar-code reader. My three bags rung up as two-fifty each.

    I stopped her and pointed out the error. After fumbling through the weekly flier, she saw that indeed they were on sale. Now she had to make a manual correction to my bill. “So,” she said, “that’s one-thirty-three each then.”

    One day when I am old and infirm, this shining product of the education system is going to be in charge of my medication.

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