# Using muons to as dating tool (?) in archaeology? (A pyramid in Egypt) **URL:** \ **Category:** Factual Questions\ **Created:** [January 18, 2016, 3:38pm UTC](https://boards.straightdope.com/t/using-muons-to-as-dating-tool-in-archaeology-a-pyramid-in-egypt/743507 "2016-01-18T15:38:32Z")\ **Posts on this page:** 5\ **Page:** 1
**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:** [January 18, 2016, 3:38pm UTC](https://boards.straightdope.com/t/using-muons-to-as-dating-tool-in-archaeology-a-pyramid-in-egypt/743507/1 "2016-01-18T15:38:32Z")
News report: [http://www.timesofisrael.com/particles-could-reveal-how-egyptian-pyramid-was-built/](http://www.timesofisrael.com/particles-could-reveal-how-egyptian-pyramid-was-built/) According to this near-devoid-of-meaning article, muons remain (?) embedded (?) in materials and their “accretion” – the only verb I got from there relating to the damn things, are/will be used in chronology. I think. Or traces of them, if I know anything about muons, which is a truly mind-boggling amount. Unless statistics of particle size and exposure to them might reveal something about the construction of the barrier, i.e. the pyramid itself. I have no clue. Any help? ---
**Author:** ![OldGuy](https://avatars.discourse-cdn.com/v4/letter/o/3bc359/32.png) [@OldGuy](https://boards.straightdope.com/u/OldGuy)\ **Post date:** [January 18, 2016, 3:44pm UTC](https://boards.straightdope.com/t/using-muons-to-as-dating-tool-in-archaeology-a-pyramid-in-egypt/743507/2 "2016-01-18T15:44:43Z")
I didn’t read it, but they must be using muons as a kind of x-ray or a better analogy would be an electron microscope. The half life of muons is some microseconds so I can’t imagine any are left over from several thousand years ago when the pyramids were built. ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [January 18, 2016, 3:51pm UTC](https://boards.straightdope.com/t/using-muons-to-as-dating-tool-in-archaeology-a-pyramid-in-egypt/743507/3 "2016-01-18T15:51:35Z")
> **[Muon tomography](https://en.wikipedia.org/wiki/Muon_tomography)** > > Muon tomography or muography is a technique that uses cosmic ray muons to generate three-dimensional images of volumes using information contained in the Coulomb scattering of the muons. Since muons are much more deeply penetrating than X-rays, muon tomography can be used to image through much thicker material than x-ray based tomography such as CT scanning. The muon flux at the Earth's surface is such that a single muon passes through an area the size of a human hand per second. > Since its devel... ---
**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:** [January 18, 2016, 3:58pm UTC](https://boards.straightdope.com/t/using-muons-to-as-dating-tool-in-archaeology-a-pyramid-in-egypt/743507/4 "2016-01-18T15:58:02Z")
They’re not looking at muons that have accumulated over the course of thousands of years: They’re looking for muons that are detected as they arrive at their instruments. The word “accumulated” is an unfortunate one to use, here: They’re accumulating data, not the muons themselves (they last for only a small fraction of a second). This tells you about the current structure of the pyramids (things like where there’s different kinds of rock, or where there are empty spaces), not the chronology. Or at least, not directly: They might be able to say “This style of construction is similar to those used during the such-and-such dynasty, based on other archaeological finds”, but there’s no age-o-meter built into their instruments. ---
**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:** [January 18, 2016, 5:15pm UTC](https://boards.straightdope.com/t/using-muons-to-as-dating-tool-in-archaeology-a-pyramid-in-egypt/743507/5 "2016-01-18T17:15:25Z")
> [@Leo\_Bloom](#): > > … Or traces of them, if I know anything about muons, which is a truly mind-boggling amount. Unless statistics of particle size and exposure to them might reveal something about the construction of the barrier, i.e. the pyramid itself… Yes! “ **Leo Bloom** invents muon tomography!” I called it, man. Thanks to **Grey** for the cite. Boo to **Chronos** for not giving me props. And thanks to **Chronos** for affirming that the method per se is not for dating, which is what people – like me – think of first.