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arc

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Everything posted by arc

  1. You call it a dead horse – I call it convection; That’s strange . . . . . . . I’ve looked the whole thread over, can’t find even one moderator admonishing me for not answering all the criticisms, not even one mod note addressed to me. I don’t think they would have allowed me to get away with that. Are you accusing them of dereliction of their duties? Maybe it’s because you haven’t directly answered to those problems I raised about the Standard Model. I do remember I had insisted several times that you should address those three criticisms of the Standard Model and convection’s inability to actually work. Here they are again; 1. How does the material in the mantle actually convect in regards to Doglioni et al? http://www.dst.uniro...antle_Dynamics_ MANTLE DYNAMICS AND PLATE KINEMATICS Carlo Doglioni, La Sapienza University, Rome, Italy Roberto Sabadini, University of Milan, Italy ". . . . . none of the proposed models of mantle convection can account for the simpler pattern in plate motion we observe at the surface, nor has a unique solution been proposed for how material in the mantle convects. At the moment there is no way to link mantle dynamics and plate kinematics at the surface, considering that the mantle and lithosphere are detached. The Atlantic and Indian ridges are in fact moving apart with respect to Africa, proving not to be fixed both relative to each other and relative to any fixed point in the mantle. This evidence confirms that ocean ridges are decoupled from the underlying mantle." 1. How does the material in the mantle convect in regards to Doglioni et al? 2. How are mantle dynamics and plate kinematics linked at the surface in regards to Doglioni et al? 3. How does mantle convection produce the required levels of GPE in the crust in regards to Ghosh et al?
  2. If the final result is not to your satisfaction and you are thinking of replacing the glass. You might try etching the entire surface area with an even acid etching. You may get a surprisingly pleasant result. Years ago we did some work in a new retail storefront where the new wood casement surrounding the area we were working had not been sealed yet. We had used a damp cloth to wipe down the neon sign we installed and inadvertently dripped water on the exposed wood below. The general contractor made quite the scene over the fact that it would leave permanent water stains that would show through the final finish. I waited until he was gone on an errand and wiped down the entire casement with the same damp cloth with an even pressure and speed. By the time he had returned it had dried and looked as good as it did before . . . . . . . I water stained the entire surface.
  3. Mirrored time universe big bang! Dammit Moon! You scared the crap out of me!! >>>>>>>>>> dual universe time mirror black hole theory Started by PureGenius , 04 Jul 2013
  4. The most important function of a model is to make accurate predictions of observations. Many researchers build models towards solving specific phenomena in a “build to suite” fashion where the problem is known, and through diligent hard work and using all of the resources available, including the investigator’s own experience and education - a creative solution is prescribed. These models, though, are usually dependent on the Standard Model, and reflect a heavy reliance on it to support the solution’s functionality in solving the observed and targeted phenomena. When an alternate to the Standard Model such as this one proposes a solution in the same “build to suite” manner it will need to outperform the accepted Standard Model in providing predictions that extend beyond the current body of known phenomena. That is, the alternate model should, or really, must describe, or predict, in a detailed way a process that has not yet been observed or described, preferably by others, to have occurred in nature. And, also preferably, this discovery should be made at some appreciable time in the future after it was described and predicted by the model. This predictability is the optimum criteria for science. That it not only describes what is currently being observed, but will describe in detail a solution to various phenomena observed at a later date that are currently unknown to the science at hand. This model has offered an alternate solution to many geologic phenomena; http://www.scienceforums.net/topic/73730-plate-tectonic-mechanism/page-22#entry891454 This model has made some very accurate predictions of observations, some in the manner described above, where a substantial lead-time was given between the model’s description of the phenomena and the actual discovery of the predicted observation. http://www.scienceforums.net/topic/73730-plate-tectonic-mechanism/page-18#entry843598 In the post above this model described solutions for and made many predictions of observations of existing phenomena besides directly and completely answering the original problem raised and described by billiards. That post presented a complete, yet compact model of the Earth’s crustal development from plate tectonics’ earliest beginning to the development and formation of current plate dynamics. I now would like to show some research that was received for review June 20, 2016 and approved October 11, 2016. http://www.pnas.org/content/113/47/E7359 Rapid conversion of an oceanic spreading center to a subduction zone inferred from high-precision geochronology Timothy E. Keenan, John Encarnación, Robert Buchwaldt, Dan Fernandez, James Mattinson, Christine Rasoazanamparany, and P. Benjamin Luetkemeyer Significance “Subduction, the process by which tectonic plates sink into the mantle, is a fundamental tectonic process on Earth, yet the question of where and how new subduction zones form remains a matter of debate. In this study, we find that a divergent plate boundary, where two plates move apart, was forcefully and rapidly turned into a convergent boundary where one plate eventually began subducting. This finding is surprising because, although the plate material at a divergent boundary is weak, it is also buoyant and resists subduction. This study suggests that buoyant, but weak, plate material at a divergent boundary can be forced to converge until eventually older and denser plate material enters the nascent subduction zone, which then becomes self-sustaining.” Abstract “Where and how subduction zones initiate is a fundamental tectonic problem, yet there are few well-constrained geologic tests that address the tectonic settings and dynamics of the process. Numerical modeling has shown that oceanic spreading centers are some of the weakest parts of the plate tectonic system [Gurnis M, Hall C, Lavier L (2004) Geochem Geophys Geosys 5:Q07001], but previous studies have not favored them for subduction initiation because of the positive buoyancy of young lithosphere. Instead, other weak zones, such as fracture zones, have been invoked. Because these models differ in terms of the ages of crust that are juxtaposed at the site of subduction initiation, they can be tested by dating the protoliths of metamorphosed oceanic crust that is formed by underthrusting at the beginning of subduction and comparing that age with the age of the overlying lithosphere and the timing of subduction initiation itself. In the western Philippines, we find that oceanic crust was less than ∼1 My old when it was underthrust and metamorphosed at the onset of subduction in Palawan, Philippines, implying forced subduction initiation at a spreading center. This result shows that young and positively buoyant, but weak, lithosphere was the preferred site for subduction nucleation despite the proximity of other potential weak zones with older, denser lithosphere and that plate motion rapidly changed from divergence to convergence.” The above research involves many of the same questions raised by billiards and raises many new ones that strain the Standard Model even further than just the subduction initiation problem posed by billiards. The limitations that the Standard Model imposes on these problems include that subduction and divergent boundaries are considered to be caused by separate phenomena. That oceanic crust must be old and heavy (less buoyant) to subduct, and newer (bouyant) oceanic crust cannot become or even initiate a subduction regime. Divergent boundaries are then assumed to be initiated by continental break-up (Atlantic) and then perpetuated by ridge push and/or slab-pull at the corresponding convergent boundary. The Standard Model is thus left with a “chicken or egg first” quandary. The Atlantic has no convergent boundaries, yet the oceanic crust is connected to the N. American plate that moves without the slab pull of a convergent boundary pulling it. It is in all actuality, driving or being driven over the Pacific plate, this would then require the source to be ridge push at the Atlantic divergent boundary. At some point though it is assumed the Atlantic plate sections will separate from their adjoining continents and develop into convergent boundaries. But wouldn't an outward shear force to the plate from below provide that separation? And wouldn't a following opposing shear force from below change that new divergent boundary into a convergent boundary? Nowhere in the Standard Model are there solutions for the problems posed by billiards or Keenan, et al. Fortunately, this model had described and predicted the exact scenario observed and described by the Keenan, et al paper of October 11, 2016 over a year and a half earlier on 25 December 2014. http://www.scienceforums.net/topic/73730-plate-tectonic-mechanism/page-18#entry843598 This model described in great detail the formation of divergent boundaries that were then converted to convergent boundaries long before Keenan, et al suggested that such a situation could exist. The Standard Model on the other hand is unable to resolve this dichotomy or even the much simpler subduction initiation problem that billiards had posed earlier.
  5. Not wanting to derail the thread any further, please move or delete if needed. Several years ago we had a nice gal come in to check out our particular occupation (electrical with additional sub categories of expertise) as a possible career choice. They had her spend the day with one of our apprentices (Eddie) who was about to graduate, or turnout as we call it. When they came back at the end of the day Eddie mentioned that she had a degree in biology. Of course I was delighted that she could end up working with us. We talked a little about her degree and how difficult it was to find work in that field around here, she was married with children and looking at several of the state supervised apprenticeships as a possible career choice. I told her it would be great if she came to work with us, and due to her background, how much I would welcome the possible conversational subject matter. Alas, she never came back. It would have been really great if she had. I'm not much into the typical "sports" conversations that the other guys carry on so much about here. So it would have been a welcome change. A REEEEALY welcomed change!
  6. I recently viewed a wonderful documentary on George Westinghouse by Mark Bussler. It really captures the era and the social dynamics between Tesla and his relations with both Westinghouse and Edison. They mention that Edison required all of his employees to sign an agreement to forfeit any claim to their creative work. Westinghouse on the other hand actually helped his employees in securing their rights to their ideas. They mention the discrepancy between the sizable number of patents held by Westinghouse employees as compared to Edison's, and this of course explains rather pointedly why Edison personally held so many more patents than George Westinghouse. I think much of Tesla's cult status relates to his misjudgment of his own abilities. His extraordinary ability to develop and "bench test" designs such as his poly-phase system in his mind before ever building any actual physically examples makes him appear super human. He unfortunately later in life exceeded these extraordinary limits of his mind's abilities without building the resultant, and more important, fully working examples that would have maybe humbled his estimations of these creative abilities. Most of the current woo woo about him relates to these extraordinary imaginary creations of a once very productive and creative mind that had entered its post professional era of simply speculating some rather super extraordinary possibilities.
  7. I borrowed this from http://www.mantleplumes.org/index.html :: Quote of the week :: "In 399 B.C. Socrates was accused of introducing new gods and questioning accepted gods. He was sentenced to death by a jury of 500 of his peers. His philosophy did not pass peer review." Don L. Anderson

    1. arc

      arc

      And I thought SFN was a tough crowd :)

  8. arc

    Boulder Mystery

    Acme, I look forward to their opinion. I have been thinking a bit about this and have concluded; For your specimen to have gravitated to the surface through granular convection it would have require the sub-straight to be as thoroughly mixed as a container of nuts would be when raising a Brazil nut to the surface. In other words, for that scenario to be true; a former stratified or time layered sub-straight could not exist currently beneath that boulder due to the requirement that the same materials would have to be, according to granular convection, vigorously shaken, resulting in their rotational mixing of lower and upper layer materials together as the specimen was simultaneously moved upwards. Frost heave would have also left a tell tale trail to follow. Since the process of frost heaving stones is a group activity engaging any number of other stones in the same area to some degree, at the very least some other stones that reside there would no doubt have been lifted during the process. A freeze cycle regimen capable of lifting that immense specimen would have little difficulty with smaller varieties. There should be many other rocks of more common dimensions laying about the surface in that area. Field stones that are commonly seen made into the walls that line so many Old World and N.E American rural roads and farm fields attest to these "crops" being elevated continuously to the surface over seasonal periods of time. The lack of any sign of appreciable field stone quantity at the subject site would suggest frost heave is not the agent at work here. This rather temperate region does not attain the lower temperature that those seasonally colder field stone regions do. New England winters we do not have. Interestingly though, the loss of top soil is almost universally observed in modern farming practices, this lends to the probability that many of these smaller drop stones around this area that were excavated by farming equipment in the last century are possibly not only due to frost heave but the fact that the surface is being lowered from soil loss while farming equipment has gradually increased in size and strength, thus they have over the last century gradually increased there till depth. These factors alone have assured for the continuous removal of these stones whether or not the stones themselves were rising from frost heave. Although, as you mentioned, graph B indicates most iceberg erratics reside to the south across the Columbia, the two examples I did furnish shows that the one to the east is completely above ground while the other being to the northwest is just breaking the ground's surface. These appear to reside where they initially landed, carried within their parental iceberg to where it had grounded and melted away. The example to the northwest was no doubt buried by the tremendous amount of silt of the Missoula Floods and the Columbia's changing river coarse as it silted up and overran its older channels. These erratics are most easily and most likely explained as erratics that lie where they dropped out of the melting iceberg and either stayed above grade or were covered over based on the local geologic conditions. Occam's Razor would place your example with all the others, all from the same circumstances that were then mediated by various local geologic conditions. But none very far beyond the ordinary circumstances of the others. In other words: If your example was shaken to the surface than many others should have also done the same.
  9. Someone is missing from here. It took me a few minutes to figure it out. Where is ajb? I just checked - he's been gone since Oct, I miss seeing that infinite patience of his chipping away at the . . . . err . . aah . . .problem :)

    1. arc

      arc

      Ok, I read the thread. Us kids hate it when the grown-ups fight:) Well I hope he comes back soon- I'll just miss him till then.

    2. DrP

      DrP

      He was awesome with mathematical problems and explanations.

    3. imatfaal

      imatfaal

      I think he was moving job and country of residence so will have had a lot of extra-curricular work going on. Like others I do hope he returns

    4. Show next comments  9 more
  10. arc

    Boulder Mystery

    An interesting feature of these flood events (maybe around 40 of them) was the icebergs. From your link; https://en.wikipedia.org/wiki/Missoula_Floods "As the water emerged from the Columbia River gorge, it backed up again at the 1 mile (1.6 km) wide narrows near Kalama, Washington. Some temporary lakes rose to an elevation of more than 400 ft (120 m), flooding the Willamette Valley to Eugene, Oregon and beyond. Iceberg rafted glacial erratics and erosion features are evidence of these events." This map at the site below allows you to zoom in to amazingly close resolution. http://www.oregongeology.org/pubs/ims/IMS-036_print.pdf This is a screen shot of that map I made as an example of the range that the flood water could carry these icebergs that in turn were carrying the erratics. That is the Columbia River with the entire Vancouver metropolitan area within the flood zone that extends to Kalama 47 km to the north. This site below chronicles the location of erratics around this region within the range of the flood carried Icebergs. http://www.waymarking.com/cat/details.aspx?f=1&guid=a4f0434e-37f7-4bf9-b13e-d3d0824b86ea&lat=45.13745&lon=-123.290867&t=6&wo=True&p=2&gid=3&sg=c17d366f-f627-497e-b248-6a40cee476ff&st=2 http://www.waymarking.com/waymarks/WMCT67_Erratic_Ridgefield_National_Wildlife_Refuge_Ridgefield_Washington It is located at the Ridgefield National Wildlife Refuge just north of Vancouver. It looks very similar to Acme's example. Here's another erratic located farther to the east; http://www.waymarking.com/waymarks/WM36CY_Round_Lake_Erratic_Camas_Washington And here's a nice video about the Lower Columbia Floods Chapter; http://iafi.org/local-chapters/lower-columbia-chapter/ They chronicle and educate about the floods around this region. http://iafi.org/grants-getaways-oregons-erratic-rocks/ /
  11. Why must we conclude that if this was a Neanderthal construct, or for that matter, built by any others, that it must have been a successful design? The more recent human history (you know, the one we have record of) shows a vast array of trial and error as modus operandi. Why would we assume the Neanderthal would operate any different? That image to me shows a campsite far enough within a cave to ward off the deepest cold of that glacial period. They constructed a campfire to stay warm and slept and ate near their fires. Past experience in other campsites inside and outside of caves showed them that naturally positioned rocks at an appreciable distance around the fire became warmer due to the fire and made occupying, and more importantly, sleeping in the area more enjoyable. This would likely lead them to build such a structure you see in the image. The height is just enough to block the draft that comes in the cave entrance and travels along the floor where they would have lain to sleep. The materials would radiate the expected heat that the other campsite rocks had done in the past while the clay or dirt compacted against it would block that cold air that is drawn inward along the floor by the fire and keep it from going through the openings between the materials of the constructed wall. All was done and worked well until the water started to build up behind the wall, as can be seen in the image. Alas, success meets with failure once again.
  12. arc

    Boulder Mystery

    I do not know exactly how far your specimen is from Mt. St. Helens. You did say in your first post it was 5 miles from the Columbia River and also St. Helens was 50 miles (30km) north. This rock could be from any of the Pleistocene glaciations and the earlier glacial episodes may have been very much different in their direction of travel than the more recent due to the amount of volcanic activity that drastically changes the surrounding landscape with each eruption. As you can see St. Helens has been a very active player. So, if the 30km distance you provided is correct or the distance is even double that, the tremendous volume of material that the mountain has laid out around its range of discharge in the past could send in the following glacial periods, glaciers in any number of directions and distances within the stated ranges listed. This would seem the most likely source considering the evidence so far.
  13. I would really like to understand how this terrain was shaped from the last glacial period. Was this area just caped with ice and all that we see here is the debris of this process? How did those "towers" of rock survive this period?They look rather delicate to have resisted a mile of ice bearing down on them. My guess would be the huge amounts of ground down rock material filled this whole area and these towers were buried in it to quite a depth.Think sand and powdered rock. As the glaciers melted most of this fine material was transported out through normal erosion processes revealing the still fixed and hardest to move materials that we see now.
  14. arc

    Boulder Mystery

    I had a thread previously on this subject; http://www.scienceforums.net/topic/98478-mysterious-little-rock/#entry944470 And also mentioned this situation is not reliant on the Larentide Ice Sheet to distribute these materials during the last glacial. http://www.scienceforums.net/topic/98478-mysterious-little-rock/#entry943609 "I was not referring to the Laurentide Ice Sheet of the last glaciation period but the Cascade glaciation that occurred during the same time period. There is some good accounts of them by Porter et al. Many of these papers unfortunately are now it seems behind paywalls." A nice study by Porter that is available for free is this paper; https://notendur.hi....QuatSci2004.pdf Quaternary alpine glaciation in Alaska, the Pacific Northwest, Sierra Nevada, and Hawaii Darrell S. Kaufman1, Stephen C. Porter2 and Alan R. Gillespie2 1 Department of Geology, Northern Arizona University, Flagstaff, AZ 86001, USA; Darrell.Kaufman@nau.edu 2 Quaternary Research Center, University of Washington, Seattle, WA 98195, USA; scporter@u.washington.edu, alan@ess.washington.edu "During their greatest Pleistocene advance, alpine glaciers in the Washington Cascade Range and Olympic Mountains terminated as much as 70–80 km from their sources. During the last glaciation, the largest glaciers were only half as long. In the Oregon Cascades, glacier tongues terminated 10–30 km from ice fields that mantled the range crest" The 70-80 km estimate is within range to derive this specimen from Mt. St. Helens. "St. Helens which is ~50 miles(30km) north."
  15. Oops, somehow I completely missed imatfaal's entire post. Those rings reminded me of when we were in Montana and saw the ancient shoreline "Bath tub rings" down the sides of the valley that were left by Glacial Lake Missoula. Nice job imatfaal, +1. I withdraw my supposition.
  16. I believe what you are seeing in that image is this area looks to be limestone or similar soluble rock and this feature is the result of the underlying limestone slowly subsiding and creating a depression that collected water. https://en.wikipedia.org/wiki/Karst Karst topography is a landscape formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. What you see as rings surrounding this feature are where waves have left evidence of the changing shoreline of the original lake that had formed in the slowly developing shallow depression as the subterranean limestone subsided. As the ground slowly sank the water's depth and diameter slowly increased until this basin, which is called a Polje, reached an area where the seasonal high water could over top the basin's edge, eroding the terrain and draining to a still lower area. You can see these in the image. Area A is likely the first to over-top the outer edge due to its advanced erosion and substantial size compared to the other smaller erosional features D that all appear to drain assorted regions of the basin to the main branch of the Kotuy river system B1 to the S.W of the basin. Area A's drainage channel C runs to the N.E. into a separate branch B of the Kotuy river and likely emptied the vast majority of the basin's water. https://en.wikipedia.org/wiki/Polje A polje, in geological terminology, is a large, flat-floored depression within karst limestone, whose long axis develops in parallel with major structural trends and can become several miles (tens of kilometers) long. Superficial deposits tend to accumulate along the floor. Drainage may be either by surface watercourses (as an open polje) or by swallow holes (as a closed polje) or ponors. Usually, the ponors cannot transmit entire flood flows, so many poljes become wet-season lakes. The structure of some poljes is related to the geological structure, but others are purely the result of lateral dissolution and planation. The development of poljes is fostered by any blockage in the karst drainage. A polje or karst polje covers the flatbottomed lands of closed basins which may extend over large areas, up to 1,000 km². The flat floor of a polje may consist of bare limestone, of a nonsoluble formation (as with rolling topography), or of soil.
  17. It's called a siphon. https://en.wikipedia.org/wiki/Siphon Your device is called a siphon mixer injector that uses the moving water to create a vacuum (lower pressure) in the coolant siphon tube which is at a lower atmospheric pressure then what is in the coolant's reservoir. This lower pressure in the siphon tube is what draws, or more properly, allows the higher atmospheric pressure to force the coolant out of its reservoir and into the stream of passing water at the T fitting.
  18. arc

    Boulder Mystery

    Acme, what you have found is a tephra that is probably from the Smith Creek Eruptive Period that occurred between 3.9 - 3.3 thousand years ago. As the link below testifies, these tephra materials have been found "as far away as 950 km (590 mi) from source." https://volcanoes.usgs.gov/volcanoes/st_helens/st_helens_geo_hist_108.html Smith Creek Eruptive Period (3.9 to 3.3 ka) "During the Smith Creek period, two periods of highly explosive activity (3.90 to 3.85 ka and 3.5 to 3.3 ka) deposited large amounts of tephra (set "Y") and pyroclastic flows. The second period was initiated with a highly explosive eruption ("Yn") that was about four times larger than the one in 1980, making it the most voluminous eruption in Mount St. Helens' history. These tephras have been identified as far away as 950 km (590 mi) from source. During late Smith Creek time, a lava dome was extruded and huge lahars swept down the Toutle River and probably reached the Columbia River." Tephra Any type and size of rock fragment that is forcibly ejected from the volcano and travels an airborne path during an eruption (including ash, bombs, and scoria). "As in earlier stages, Spirit Lake volcanism erupted mostly dacite, but significant amounts of basalt and andesite were also erupted. The Spirit Lake Stage is subdivided into six eruptive periods—the Smith Creek, Pine Creek, Castle Creek, Sugar Bowl, Kalama, Goat Rocks, and the Modern period of activity that began in 1980." http://www.geo.mtu.edu/volcanoes/hazards/primer/tephra.html "When a volcano erupts it will sometimes eject material such as rock fragments into the atmosphere. This material is known as tephra. The largest pieces of tephra (greater than 64 mm) are called blocks and bombs. Blocks and bombs are normally shot ballistically from the volcano (refer to the gas thrust zone described in the direct blast section). Because these fragments are so large they fall out near their source. Blocks and bombs as large as 8-30 tons have fallen as far away as 1 km from their source (Bryant, 1991). Small blocks and bombs have been known to travel as far away as 20-80 km (Scott, 1989)! Some of these blocks and bombs can have velocities of 75-200 m/s (Bryant, 1991). Smaller ejecta such as lapilli (2-64 mm) and ash (<2 mm) which are convected upward by the heat of the eruption will fall out farther from the volcano. Most particles greater than a millimeter in size will fall out within 30 minutes of the time they are erupted (W.I. Rose personal communication). The smallest particles which are less then .01 mm can stay in the atmosphere for two or three years after a volcanic eruption." That is a nice find I hope you kept a souvenir er I mean sample.
  19. One time on a camping trip in Montana we decided to BBQ some hamburgers . . . . . . . . BAAAAAD IDEA!!!
  20. Plus 1 bender. The original post probably gives the greatest clue as to the reason for the difficult disassembly. Bold mine. Aluminum is a much softer metal than the high carbon steel of the bearing raceway, and assemblies consisting of steel races pressed into a steel or aluminum housing require extremely accurate alignment during the insertion and removal processes. This process is properly done on a press designed to provide gradual and more important, aligned force, to remove and install press fit components together. Aluminum is very easily misaligned with the bearing race when it is subjected to blunt forces at angles beyond dead center to the parts axis. In other words do not use a hammer! This causes galling of the aluminum's machined surfaces which lead to the need of even more increase of forces to dislodge the raceway and many times to the permanent damage of the part through fracturing. Many smaller procedures involving aluminum require the use of an arbor press which allow for a very subtle and direct control of the ram where the operator can feel through the direct mechanical linkage the movement and forces that result. Whereby a hydraulic press could easily overload the aluminum part before the operator can respond in time to prevent damage. I have replaced many bearings over the last 40 some years. I do my own automotive repair in my own very well equipped shop which includes a 20 ton hydraulic press that I would not use to disassemble an aluminum assembly that shows signs of the corrosion or contamination mentioned without first preheating it. Any degree of the corrosion that Acme mentioned or the contamination as I suggested will only compound the difficulties in doing this process correctly with even the proper equipment let alone a hammer.
  21. And in certain situations, they are a sanctuary in an ever increasing hostile world. Aircraft carriers, as already alluded to, extend the nation's boarder to wherever those task force groups are located. In other words, they become mobile islands of national territory, a technological solution to the fluid and sometimes fickle difficulties involved in a world where a land based facility in a host country could be lost within a single regime change cycle, possibly leaving an entire region less accessible. For this reason alone they are unlikely to become obsolete anytime in the foreseeable future. Even if they are found to be more vulnerable to developing weapon systems the retaliatory response should deter all but the most suicidal regime.
  22. To add to Acme's good analysis; The two metals also have quite different coefficients of thermal expansion between them. And when exposed to cycles of heating and cooling, such as through friction from braking during deceleration, and forces from dynamic loading during cornering for example, these changes can allow moisture from the weather and condensation from thermal cycling to penetrate more easily between the dissimilar materials. This can accelerate the galvanic corrosion, or on their own, bring enough microscopic foreign material into the part's contact surface area to make them difficult to remove years later. The greater the difference in the coefficient the greater the space for water and foreign material to occupy. So, if your part's contact areas are still smooth and do not have the visible corrosion from electrolysis it is probably the thermal cycling alone and/or foreign material. Some manufactures actually preheat some parts before the assemblies are combined and use negative thermal expansion to hold the parts together. This, of course would require you to heat the proper part to disassemble the components. https://en.wikipedia.org/wiki/Thermal_expansion "The coefficient of thermal expansion describes how the size of an object changes with a change in temperature. Specifically, it measures the fractional change in size per degree change in temperature at a constant pressure. Several types of coefficients have been developed: volumetric, area, and linear. Which is used depends on the particular application and which dimensions are considered important. For solids, one might only be concerned with the change along a length, or over some area."
  23. 15!!! THAT'S OUTRIGHT ROBBERY!!! (so nice to have an easy way to dump the iron pyrite)
  24. Sure, but you will first need to send the material to me for closer examination . . . . . . . .
  25. A swing . . . . . . . . . . . and a miss.
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