Posting Comment for "Alan's Crazy Ideas Episode #1: CT Scanning Khufu with Cosmic Rays"

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27th January 2011 15:00

Alan Yates wrote...


Yes please, I'd like to see any information you have.

Spark chambers give you path information, basically the spark forms along the path of the particle between each plate, so by optical or acoustic means you can recover the vector. It gives you no energy resolution though, beyond knowing the particle was energetic enough to leave a sufficiently dense ion trail right through the detector.

You can build spark chambers in modules and various geometries, good ones use paired coincidence gating detectors to trigger the main chamber when something of interest has crossed through the detector volume. They may have used a pair of spark chambers in a coincidence arrangement, or used them crossed to look in two different directions.



27th January 2011 11:47

GB wrote...


If I am interpreting the photo of the apparatus correctly the detector is a cube of side approx. 2m. The text indicates that two spark chambers were used. The photo appears to show that one is on top of the other ie two chambers 2 x 2 x 1m.

Somehow using these detectors and computer analysis a two dimensional map of mass/density of the pyramid has been produced. The computational method is not entered into. How they obtained a 2D map from what essentially appear to be two point detectors, relative to the pyramid size, one above the other is not discussed.

If the coordinates of the scintillations in each spark chamber could be measured, then the angle of the particle arrival could be calculated from the two sets of coordinates. In which case they are not point detectors.

The space between the detectors is attributed as cause of artifacts in the analysis when they ran out of neon.

Can send a copy if you are interested.



26th January 2011 13:02

Alan Yates wrote...


I did not know that someone had tried such an experiment with the pyramids before... Although it is quite a natural and obvious approach.

A spark chamber - wow, I've always wanted to build one myself. The spark chamber is crude and cheap enough that is is feasible to homebrew a working one out of junk. I've been collecting the bits and pieces, but I lack the (ideally) scintillator gating detectors, I guess I could use gas detector modules surrounding the main spark chamber but it would reduce the efficiency dramatically. Let's just say it has been on the geek project bucket list for a long time now.

We have so much better detectors with excellent time and energy resolution now days, I think someone needs to repeat this experiment. Imaging resolution is obviously the big problem, I'd love someone to run the numbers with modern detectors and feasible integration times.



23rd January 2011 16:45

GB wrote...

It may interest you to know that cosmic rays were used in the late '60s, using a detector ("spark chamber") in the central chamber of Kephren's pyramid, in an attempt to detect undiscovered chambers. The corners and faces appear in the figure produced after computer analysis, albeit faintly. The worker was Dr Luis Alverez (Nobel Prize for physics 1968). No hidden chambers were claimed found, but the resolution looks low to me.

This is reported briefly in "Secrets of the Great Pyramids" by Peter Tompkins, 1973, Penguin Books.

It gives very comprehensive coverage of the geometry of the pyramids and the reasons posed for their construction based on measurement of size, proportions and orientation.

Some of the wacky theories are also covered, but overall gives a fascinating insight into these remarkable structures, and showed that their constructors were masters of geometry, astronomy and engineering. The great pyramids were by no means only tombs.

15th January 2011 16:10

Ian wrote...

Alan I enjoyed your video re the CT scanning the pyramids I found it a bit mind boggling I think I will have to rest my head for a while and think about it.



15th January 2011 14:46

Alan Yates wrote...


Nice to see you again the other day. Did you get that NE602 DC receiver front-end tuning up OK? How about the PTO? I checked figure 1.9 in EMRFD, they use 270 pF // 180 pF trimmer to tune the ~1.2 uH front end inductor (20 turns on an T37-6) - which is consistent with my back-of-the-envelope estimate of ~430 pF needed to resonate it on 40 metres.


Indeed, warm-up exercises would be the way to begin. There is a large rock up the street from me and a natural rock tunnel on the shoreline here that would be excellent experimental grounds for trying different techniques. Unfortunately I have no scintillation detectors suitable for the experiment.

Imaging termite mounds is an interesting idea. Not sure cosmic rays would give you the resolution needed to image their fairly small internal structure, at least not very quickly, but it would be a simple matter to build a rotating gantry to image one using conventional CT techniques (X-ray tube or gamma source, etc). I've always wondered about their internal structure, I know the termites are pretty good engineers, building them aligned with the sun to collect heat, etc. I also wonder how quickly they are remodelled internally over time by the termites.


I can't imagine myself as a TV show host. I think I'll leave that for the far more photogenic and eloquent amongst us, like Adam and Jamie of the Mythbusters. But hey if they want another mythturn I'm totally up for it. :)

5.9 Tg is indeed a lot of mass on human scales, but actually fairly light for something masonry that size - it is mostly limestone and isn't completely solid - precision of the block placement inside isn't as great as those at the surfaces, but it is still pretty darn good or else it would have subsided. There are about 2.5 million blocks, so the average block masses ~2.4 Mg (2.4 tonnes), about two average modern-day cars per block. Some blocks, like the really big granite ones inside are 50 tonnes or more. Gives you some appreciation of the engineering involved, no cranes, no hydraulics, just copper, timber, brains and muscle, yet they quarried these 2-car-plus weighing blocks of stone, squared them up with excellent precision, and carried them miles to the site. That's the easy part, they then lifted them up (up to almost 150 metres) and placed them at a rate of better than 350 per-day to hit a 20 year construction period. Just feeding the workers must have been an enormous task, let alone all the other infrastructure needed to undertake an engineering project of this scale. Can you imagine quarrying, squaring-up, lugging, lifting, making and mixing enough mortar, etc for even 35 blocks a day (for 200 years) with no diamond saws, steel, hydraulics, cranes, internal combustion engines? Water, timber, food, and communication must have been massive problems to solve. It just blows me away that they managed to do it.

Of course there are the nutters that say "aliens did it" or helped us or something. I actually had great reservations about documenting this particular crazy idea of mine, lest I become labelled as another "pyramid nut". I think all that alien nonsense takes away from the magnificent achievement of the real humans that designed and built this wonderful artefact of early mega-scale engineering.

14th January 2011 22:02

Claudia wrote...

You need to have a TV show! Totally learnt more watching this than I have in 2 years combined! I'll probably forget all of it when I wake up. My brain is basically like the NOS on a cisco router... Whatever controls my brain keeps forgetting to copy run start and when I wake up in the morning I forget everything I learnt the previous day. Oh well.

Either way. 1. you need a tv show, 2. you need to blow shit up like the mythbusters guys 3. 5.9tg! I cannot even get my head around how heavy that is.


14th January 2011 13:59

Arv - K7HKL wrote...

You have some large termite mounds there in VK-land. Maybe you could start with mapping the tunnels inside a mound using Cosmic Rays. If a suitable resolution could be obtained, then you would be ready to take on a pyramid.

10th January 2011 12:40

Marxy wrote...

The first 30 minutes was scintillating. After that you lost me a little.