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Egyptian pyramids found by infra-red satellite images

bbc.co.uk

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Re: Egyptian pyramids found by infra-red satellite images

#31

Post by kbutler »

hugh3 wrote: post #21
ra wrote: post #12

It's fascinating how many relics of ancient civilisation are concentrated in that part of the world. Many presenting puzzles yet to be solved.

It's fascinating how many relics of ancient civilisation are concentrated in that part of the world Not really. It'd be much more fascinating if you found relics of ancient civilisation which weren't concentrated in that part of the world.

> It'd be much more fascinating if you found relics of ancient civilisation which weren't concentrated in that part of the world.

The earliest egyptian pyramids were ~2600BC, corresponding with the rise of civilizations in China (http://en.wikipedia.org/wiki/Yellow_Emperor) and Peru (http://en.wikipedia.org/wiki/Caral). We've found a lot more iconic relics of Egyptian civilization from that time period, however.

Re: Egyptian pyramids found by infra-red satellite images

#32

Post by Plimsoll »

lutorm wrote: post #24
hugh3 wrote: post #15

Earlier quoted context omitted.

I am a physicist, and I'm afraid that the page on infra-red spectroscopy isn't really relevant due to (as you say) the very different length scales. What I think is really going on is thermodynamics. Suppose I bury a big stone pyramid under the sand. Stone is (I assume) a much better conductor of heat than sand. When the sun comes up after a cold night, it heats the sand, but the sand on top of the pyramid has its he…

This was what I was wondering, too. But how deep down does the heat actually go? Unless these structures are just a few inches below the ground, it seems the difference would be very small. Just empirically, you don't have to dig down more than a few inches until even desert sand is cold.

The article reads, these pyramids were close to surface and therefore were found so early on.

As for how deep does heat actually go, I would say, that if earth wouldn't have any temperature of its own, it would go all the way down. The process just takes extreme amounts of time. Empirically it takes time for earth to freeze at winter (if you live north enough) and likewise one cannot dig the ground has melted at the late of spring. Other empirical example would be rock near a campfire, they will stay warm long time after the fire goes down. Earth is just a very big rock.

While the ground doesn't freeze at Egypt, they certainly have some seasons, with different average temperatures, to warm up or cool down the deep ground temperature. So within time they should be able to see temperature differences of objects buried deep into ground. Assuming the resolution of satellites is good enough.

Other question would be how much interference does the warm sand over these objects cause. As the sand is somewhat flat, it probably has black body like radiation curve and removing it should be easy, but there always will be some static from these processes reducing the total resolution.

Well all in all, I really don't know how they do all this.

Re: Egyptian pyramids found by infra-red satellite images

#34

Post by awj »

Jun8 wrote: post #19

Is it me or does news like this throw anyone else into a frenzy of daydreaming for a short while: using my computer expertise to enhance infrared images to reveal hitherto unknown pyramids (combining images from multiple spectral bands, SIFT object detection), battling with corrupt local authorities and looters, digging for the pyramid (and unfortunately losing a few of the team when the tunnel gives in), deciphering…

FWIW, the puppet book [1] was pretty good. Didn't end up using it for the project, but it seemed readable/informative.

[1] http://www.amazon.com/Pulling-Strings-Puppet-Automated-Admin...

Re: Egyptian pyramids found by infra-red satellite images

#35

Post by shii »

ra wrote: post #12

It's fascinating how many relics of ancient civilisation are concentrated in that part of the world. Many presenting puzzles yet to be solved.

On that line, by far the most intriguing and fascinating structure or relic from ancient human history is the site at Göbekli Tepe[1], in modern day Turkey. Shakes up pretty much every theory and timeline we have constructed on how humans probably developed over time and is much too early to fit in anywhere.

[1]: http://en.wikipedia.org/wiki/G%C3%B6bekli_Tepe

Re: Egyptian pyramids found by infra-red satellite images

#36

Post by Jun8 »

awj wrote: post #34
Jun8 wrote: post #19

Is it me or does news like this throw anyone else into a frenzy of daydreaming for a short while: using my computer expertise to enhance infrared images to reveal hitherto unknown pyramids (combining images from multiple spectral bands, SIFT object detection), battling with corrupt local authorities and looters, digging for the pyramid (and unfortunately losing a few of the team when the tunnel gives in), deciphering…

FWIW, the puppet book [1] was pretty good. Didn't end up using it for the project, but it seemed readable/informative. [1] http://www.amazon.com/Pulling-Strings-Puppet-Automated-Admin...

Thanks a lot for the link. I've started to read Pro Puppet by the same guy.

Re: Egyptian pyramids found by infra-red satellite images

#37

Post by hugh3 »

pbhjpbhj wrote: post #30
hugh3 wrote: post #20

Earlier quoted context omitted.

That would a priori seem to confirm your hypothesis I'm not sure that a priori means what you think it means.

a priori - from before, not based on prior study I use it here in the same sense as "an a priori estimate" as opposed to the more common logical use of something being apparent without requiring study but only the application of reason. I take it you're more a logician than a Latin student. If the later then I guess you'll probably correct me? Are you sure now, let me know. -- Aside I've had chance to read teh articl…

Aside I've had chance to read teh article and there was no mention of taking near-IR images at day and night. So presumably it's my language use that's getting me heavily downmodded?

Actually I think you were downmodded for not reading the article and then asking a question that could have been answered by reading the article.

Re: Egyptian pyramids found by infra-red satellite images

#38

Post by NickPollard »

Jun8 wrote: post #19

Is it me or does news like this throw anyone else into a frenzy of daydreaming for a short while: using my computer expertise to enhance infrared images to reveal hitherto unknown pyramids (combining images from multiple spectral bands, SIFT object detection), battling with corrupt local authorities and looters, digging for the pyramid (and unfortunately losing a few of the team when the tunnel gives in), deciphering…

Obligatory xkcd:

http://xkcd.com/208/

It seems we've reached the point where there's an xkcd for every situation (on HN at least) now. Maybe a corollary to rule 34[1] is needed.

[1] http://xkcd.com/305/

Re: Egyptian pyramids found by infra-red satellite images

#39

Post by xbryanx »

ars wrote: post #33

Where does the soil to cover the pyramids come from? Those are not small structures, and you aren't just covering them - you are covering a huge area of land. That soil has to come from somewhere, anyone know where?

Most of the soils in this area are Nile delta deposits.

Re: Egyptian pyramids found by infra-red satellite images

#40

Post by mturmon »

xbryanx wrote: post #14

My searching on this topic turned up this interesting book - http://www.amazon.com/Remote-Sensing-Archaeology-Interdiscip... Seems like these techniques are going to radically change how we find new archaeological sites. Tech. project idea: Build some tools to help archaeologists learn and share from each other with this data. Build a world wide database of IR imagery just a few meters below the surface?

Yes, the idea in the OP is not new.

To my knowledge, the first people to use remote sensing data in an archeological context used radar (SRTM, a synthetic aperture radar mapping mission that flew on the space shuttle). Radar can penetrate the land to a depth of ~meters depending on lots of factors.

They discovered the lost city of Ubar, which was a trading city (ca. 3000 BC) in the Arabian peninsula that had been lost to the desert.

They discovered it because trails that had formerly led into Ubar gave off stronger radar reflections.

Later on-site digs confirmed actual ruins. This was in 1992. A link:

http://photojournal.jpl.nasa.gov/catalog/PIA01721

The person who blurbed the book you found, Charles Elachi, was a key member of the team that designed the radar instrument that found Ubar.

All of the SRTM data is online somewhere. The desert turns out to be a really good place to look for stuff. Less clutter.

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