5 ms·

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 thi

by hugh3 15y ago

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 heat conducted away more efficiently than the sand far from the pyramid, so it'll show up as slightly cooler when imaged with the infra-red satellite.

pbhjpbhj 15y ago
Do they look at day-night differential images? That would a priori seem to confirm your hypothesis and also provide a better imaging result. No I didn't read the article.
- hugh3 15y ago
  That would a priori seem to confirm your hypothesis I'm not sure that a priori means what you think it means.
  - pbhjpbhj 15y ago
    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 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?
    - hugh3 15y ago
      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.
      - pbhjpbhj 15y ago
        >asking a question that could have been answered by reading the article. Except I read the article and watched the video and neither answered the question ... so if any of these people had read it they would have known the article didn't answer the point. So it's just pettiness? IMO part of the benefit of social media such as this site is that others are willing to digest news and information to enable one to get a quick overview of a topic.
lutorm 15y ago
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.
- Plimsoll 15y ago
  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.
mturmon 15y ago
Alternate theory: the material scooped and dumped to cover the pyramid has different thermal characteristics than the pre-existing soil surrounding the site. That is, it's not the pyramid that stands out, it's the covering. I don't know, just formulating another hypothesis for the fun of it.
- Groxx 15y ago
  alternate alternate theory: the ancient pyramids, created and dropped there by aliens, are superconducting - they cool the ground above them in a characteristic square gradient.

by hugh3 15y ago

pbhjpbhj 15y ago

Do they look at day-night differential images? That would a priori seem to confirm your hypothesis and also provide a better imaging result. No I didn't read the article.

hugh3 15y ago
That would a priori seem to confirm your hypothesis I'm not sure that a priori means what you think it means.
- pbhjpbhj 15y ago
  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 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?
  - hugh3 15y ago
    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.
    - pbhjpbhj 15y ago
      >asking a question that could have been answered by reading the article. Except I read the article and watched the video and neither answered the question ... so if any of these people had read it they would have known the article didn't answer the point. So it's just pettiness? IMO part of the benefit of social media such as this site is that others are willing to digest news and information to enable one to get a quick overview of a topic.

lutorm 15y ago

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.

Plimsoll 15y ago
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.

mturmon 15y ago

Alternate theory: the material scooped and dumped to cover the pyramid has different thermal characteristics than the pre-existing soil surrounding the site. That is, it's not the pyramid that stands out, it's the covering. I don't know, just formulating another hypothesis for the fun of it.

Groxx 15y ago
alternate alternate theory: the ancient pyramids, created and dropped there by aliens, are superconducting - they cool the ground above them in a characteristic square gradient.