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Ken Fabian

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Everything posted by Ken Fabian

  1. There will be enough oxygen and energy already present as a buffer in a body to run for ten seconds without breathing. You will need to catch your breath after. The oxygen you take in now takes time to reach hard working muscles but you have enough reserve to cope with that.
  2. I had a good mathematics teacher for a year at high school and for a brief time calculus was a joy. I haven't used it much since and so, have mostly forgotten. I do recall deriving the equation for the area of a circle using calculus - I think it was a test question - and that it seemed to be seamless in it's logic. Made a Pi starting from square one! I couldn't do it now but it was kind of reassuring. It may have contributed more to my trusting established knowledge rather than sparking great determination to personally confirm everything. I cannot work out the equation for area of a cir
  3. Currently sea level rise from thermal expansion is greater than that from ice sheet/glacier sources. However my understanding is the proportion from melting ice is expected to rise significantly. Between now and 2100 the rate of sea level rise is not much different between low emissions scenarios and high - mostly thermal expansion - but slows with low and accelerates due to ice sheet contributions with high emissions, with much higher rates of rise over the subsequent couple of centuries. There is also potential for ice sheet collapse that could result in surges in ice loss and sea level rise
  4. It is all a bit too speculative or something for my liking. That some planets might be more likely than Earth for life - and for complex life - to develop seems a reasonable proposition. Knowing exactly what conditions those might be is going to be difficult, but even the assumption of milder, warmer, less extremes being "better" looks like overreaching. I don't think we know what "better" is. Could not extreme conditions and variability be more - not less - significant to evolution?
  5. Not knowing anything about it I thought fish probably wouldn't have bone density problems in zero gee - but I was wrong. From studying fish raised on the ISS - Osteoclasts are a type of bone cell that triggers bone breakdown and re-absorption - and are essential to maintaining, repairing and remodeling bone. Microgravity appears to inappropriately activate osteoclasts. I don't think there is going to be much difference between cetaceans and humans in how bones grow; many human bones aren't weight bearing and are equally "buoyed up" within the human body, as much as cetaceans woul
  6. Lots of subjects of scientific inquiry won't conflict with a lot of versions of religious faith. A sense of wonder that has religious aspect has been a significant motivation for scientific inquiry, often without leading to false conclusions despite the overlap. But there are those who's religious beliefs lead them to attempt to disprove the science that appears to conflict with their faith, sometimes honestly applying scientific methodology but often not. Those may well put their conclusion first and will dismiss the validity of science outright should that conflict look unresolvable. It shou
  7. I'm not sure tree climbing machinery is a major user of energy. Using bicycles more conventionally isn't so much significant for direct energy generation as significant for avoided generation elsewhere, in this case motor vehicle energy use. It is genuinely significant in that regard. Tends to be good for the people using them, so long as car drivers don't run over them. Ancient dead stuff from the deep bowels of the Earth, that burns with a foul brimstone stench - and with poisonous fumes, that adds about 100x more heat to the world at large when mixed in atmosphere than the "useful"
  8. I expect complex engineering projects are not even possible, let alone done better by individual engineers. Teams are essential. Selection and management of that team will be crucial. As an aside I think the gratuitous derision of camels, as being a "badly designed horse" makes for a good joke - for horse lovers. Meanwhile camels are superior (better "designed") to horses - for wild survival and as a beast of burden - in many circumstances.
  9. It is not as simple as less trees equals less fire risk; mostly it is the grass and undergrowth and leaf litter that burns most readily in forest fires, not usually trees. Fires are extreme when forest canopy (trees) burns - and that is more likely when the intensity of lower level fires is enough to carry the fire to tree tops. Eliminating "ladders" of fuel from ground to canopies is often a priority for fire hazard reduction. Taking out trees usually results in an increase in fuel, from the treetops - the branches and leaves that are not usually harvested - as well as increased growth o
  10. People in positions of trust and responsibility in the US (and Australia where opinion like Trump's also runs deep through conservative politics, conservative commentary) got the same science based reports on climate as everyone else; they are not rejecting it because some scientists seemed arrogant or said things that were exaggerated or wrong, they are rejecting it because it is almost certainly true and they don't want it to be true - because being true demands an appropriate response. These are people in high places who mostly know better - who are expected and relied on to read the report
  11. It seems much more likely there is an unknown non-biological process making Phosphine than unknown biological processes. But news programs I've seen are hyping the "could be life" story - some with inclusion of appropriate skepticism but mostly not.
  12. "Feminist" is a broad category - in many cases it just means wanting things like equal opportunity of wages, legal rights, freedom from sexual harassment. It is not going to determine sexual preferences beyond being likely to make men who do not support such equal opportunity less compatible as life partners. I would not call men supporting such things "feminine".
  13. Such settlements in wilderness have no expectation of becoming self sufficient. They import almost everything (apart from air and water) from the greater Canadian and global economy and don't even directly use the minerals they mine. Were that greater economy to vanish or be out of reach they would be in serious trouble, even with foreknowledge and prepperation; an ability to survive, maybe, because there are natural, if limited, food resources and ancient experience to draw on. Sustaining advanced technology and a lifestyle dependent on it? A lot harder. Such outposts can be steps on the way
  14. I don't think Stephen Hawking was ever a reliable source on how long humanity has left on Earth, no matter his brilliance with respect to black holes and cosmology. I think the reality of moving to space is not anywhere even close to being a viable option - and without a healthy wealthy Earth economy, not likely to ever be one. Failing to go all out to fix our problems here will ensure failure to establish a reliable, colonial foothold in space; space colonisation is not an alternative to Earth, it depends absolutely on Earth. If it achieves true self sufficiency, that will be an emergent outc
  15. The line between spacecraft and space station/habitat blurs but I can't see even attempting terraforming without an existing full capability of living in artificial space habitats, using asteroid/cometary - ie non-planetary- resources; ie that if we are capable of doing so we will not need to. So terraforming planets is going to be optional. I think terraforming lifeless planets will be extremely unlikely and candidates are more likely to be planets with simple life and atmosphere's not too different; ie kill off what is there and supplant it with selected/engineered terrestrial life. And
  16. Studiot - I said - You say - I think pressure would approach equilibrium - and become effectively static, barring transient variations from pressure difference based air movements. And those would average out, even if they don't maintain a perfect equilibrium. With respect to the initial question I think heat is only relevant to pressure at the centre by changing the density of the air column and by that, the weight of the air column. Heat flow within a (not insulated) borehole/tunnel? Yes, it must, through conduction, convection and radiation but I think heat profile alon
  17. I think the question is pressure for a lined borehole, a tunnel with walls that hold back the pressure. Or else the question reverts to what is the pressure at Earth's core, sans borehole.
  18. I don't think that would be true; there is no source of air at the core to support a plume. Nor for flinging air out. I think it would reach pressure and temperature equilibrium and become effectively static. Air movement from convection can occur within the tunnel and changing weather based pressure differences at each end would generate air movements. Given the distances those air movements might be more like sloshing waves along the tunnel, generating their own small transient pressure variations.
  19. If all the ice sheets melt, about 70m of average sea level rise. Counter-intuitively the sea level closest to where the ice loss occurs will drop, with the highest average rise at the greatest distance. The sources would include Greenland and other glacial ice that is not at the poles - but if Antarctica can melt entirely the world will be too warm to support ice sheets or glaciers. Predicting the rate of sea level rise - and therefore pin down when a specific location would be inundated - is difficult. We don't know how global warming will progress because we don't know what emissions wi
  20. I admit this one does have me scratching my head. I wouldn't expect heat to change the pressure once temperature equilibrium is reached but I'm not sure of it. But if you have an imaginary borehole you can imagine it being insulated and then consider the heat separately. On reflection it is likely the heat does matter - by changing the density of the air (or plasma), which changes the weight of the air column. My first impressions left me thinking the pressure would be the same as surface air pressure but on reflection it would be SAP plus the pressure from the weight of the air column wi
  21. I think in the case of interstellar colonisation - with or without autonomous, self replicating probes - incredulity is entirely appropriate and persuasive. I think the onus is on those doing the proposing to provide extraordinary proof or at least sound reasoning for their extraordinary claims.
  22. Sorry Area54 but your excess credulity that technological progress will overcome all obstacles is naive. We will hit hard limits for what technology is possible, along with economic ones where great things are possible but unaffordable. Some grand space dreams, like Mars colonies, are - I believe - possible, but unaffordable; orders of magnitude too expensive. Hypothesising a high tech solution to every problem isn't going to do it and sometimes throwing more money at a problem just wastes money. My remark about what the humans are for if the mission is run and done by AI and robots may h
  23. I don't think anyone should ever do that to any children. Bad enough to raise generation after generation of kids by adult choice - or indoctrination - aboard a "generation ship". Makes me wonder what they will be for if the mission is being undertaken by AI with robots? Pets? Leave aside how complex the technological capabilities would have to be and how difficult to sustain in the absolute physical isolation of a multi-generational voyage and distance from the economy that designed and made it, that this will be a much diminished branch of humanity for a lot of generations - narrowed options
  24. More than one wave of migration seems possible, even likely. That every wave was successful and thrived... maybe not. I recall reading about New Zealand, that the Polynesians that settled there, that modern Maori know as ancestors, found people already there, from prior visits. Hawaii likewise. Those people were not thriving and had lost their sea going capabilities. Possibly marooned? Certainly supplanted by later arrivals, possibly violently.
  25. The kids that didn't get rickets would do better and go on to have more and healthier kids as adults - bigger families - than those that did get rickets. That sounds like natural selection, not sexual selection yet mate selection would be part of it. I'm not sure how obvious any connection with skin colour would be; there will be different susceptibility to deficiency illness according to lifestyle and dietary differences as well. The more obvious mate selection criteria might be the unattractiveness of bow legged sick youths - choosing for health, not skin colour - but I suppose an endur
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