Jump to content

granpa

Senior Members
  • Posts

    894
  • Joined

  • Last visited

Everything posted by granpa

  1. do we know the sun will rise tomorrow? why? Because we have seen it rise so many times before? you also have to consider the difference between a doubt and a reasonable doubt. the laws of physics could conceivably change tomorrow but I have no reason to doubt them.
  2. Language
  3. http://en.wikipedia.org/wiki/Microtubule http://en.wikipedia.org/wiki/Microtubule_organizing_center http://en.wikipedia.org/wiki/Undulipodia
  4. 4D space has an up and a down just like 3d 4d space has a forward and back just like 3d 4d space has (as it were) 2 rights and 2 lefts. use time to represent the new dimension. start at the new right and take a 3d slice of the 4d object. then move over time to the new left.
  5. maybe you should stop worrying about winning and worry more about being right.
  6. the ideal gas law is for a container of known volume a stars volume depends on its gravitational field which in tern depends on its volume adding energy results in the star expanding which weakens its gravitational field which causes it to expand further. the net result is that the star cools
  7. I have wondered the same thing http://www.physicsforums.com/showthread.php?t=261728 http://www.physicsforums.com/showthread.php?p=2881210#post2881210
  8. the article you quoted was about Arthropleura. Arthropleura is a millipede. I gave it as an example of how big myriapods (millipedes and centipedes) got at that time. (And as an example of how big land arthropods can get) It may well have been omnivorous. We simply dont know. I would have liked to have given a link to a giant prehistoric centipede but at that time I didnt know of any. Euphoberia is the giant centipede and it was carnivorous and poisonous. There are no centipedes today that get anywhere near as large as Euphoberia. There is no reason to suppose that if centipedes were that big today that insects would be able to compete with them. (I dont mean that they would be driven to extinction by centipedes but rather that the insects would be prevented from evolving large size by them just as dinosaurs kept mammals from evolving large size during the time of the dinosaurs) I think the giant centipedes prevented insects from evolving large size during the time they existed. Today of course vertebrates keep both insects and centipedes from evolving large size. If insects had evolved a way to out-compete centipedes (as mammals eventually found a way to out-compete dinosaurs) then maybe they would have grown as large as humans. The cube square law is certainly true. There is a size that insects cant grow beyond. I never said otherwise. I just said that I dont believe that that size limit is as small as it is commonly thought. I see no reason to suppose that insects couldnt grow nearly as large as humans. (If vertebrates with big heavy ribcages and skulls can grow to the size of dinosaurs then I see no reason why the idea of a nearly human sized insect should be so shocking) If so then there is no reason they couldnt evolve large brains. Molting would be an issue but not so much for social insects. I see no reason social insects couldnt grow very large as larvae then pupate into near human sized animals. vertebrates, arthropods, & molluscs correspond to the 3 modes of moving used by worms:wriggling, walking, & sliding. This is suficiently basic that I would assume that it would evolve on any planet. Since arthropods are generally going to be the first to leave the ocean and colonize land on any planet then I suspect that most alien species will turn out to be insects (especially social insects).
  9. As everyone knows millipedes are for the most part herbivorous. centipedes, which evolved 10 million years after millipedes, are carnivorous. http://en.wikipedia.org/wiki/Millipede#Diet http://en.wikipedia.org/wiki/Centipede they were plant eaters so they shouldn'have stopped insects from getting larger. Arthropleura was a millipede. Arthropleura could have been omnivorous. I gave Arthropleura (a millipede) as an example of how big myriapods (millipedes and centipedes) got at that time. At that time, I would have liked to have given a link to a giant prehistoric centipede but at that time I didnt know of any. if you go back and look at what I actually wrote (rather than spending all your time trying to trip me up) then you will see that I always carefully and deliberately stated 'millipedes and centipedes'. Here is an example of a prehistoric giant centipede: http://animal.discovery.com/tv/lost-tapes/death-crawler/
  10. thats why I stated in post 8 its also why I quoted http://en.wikipedia.org/wiki/Arthropleura
  11. If a vertebrate can get as large as this: then is it really so surprising to suppose that an insect might be able to get nearly as large as a human? (and that dinosaur had one hell of a big ribcage and its leg bones were probably nearly as large as its legs) And these guys here were not plodding: http://en.wikipedia.org/wiki/Spinosaurus http://en.wikipedia.org/wiki/Tyrannosaurus
  12. we seem to be talking past one another. I will accept, on your authority, that there might be a little truth to what you say but I do not believe that it would prevent insects from being able to be large enough to have large brains. I also accept that we are never going to see eye to eye on this. (When I say that the insects couldnt have competed with the centipedes I dont mean that they would be driven to extinction by centipedes but rather that the insects would be prevented from evolving large size by them just as dinosaurs prevented mammals from evolving large size during the time of the dinosaurs) Why? Were mammals able to compete with dinosaurs? centipedes and millipedes in those days were much larger than they are today. one millipede was 8.5 feet long. Thats bigger than you. if centipedes and millipedes were as large today as they were then then there is no reason to suppose that insects would be able to compete with them. Moreover, it stands to reason that a centipede with its many legs will always be able to grow much larger than an insect with only 6 legs. edit: http://animal.discovery.com/tv/lost-tapes/death-crawler/
  13. Pardon me but it is external in the sense that it is just below the skin. (As opposed to our arm and leg bones which are in the very center) The ribcage and skull may not support weight but they are still big and heavy (to protect the organs inside) Anyway, external skeletons are actually more efficient at supporting weight. A tube gets stronger as it gets larger. I think that molting is probably the limiting factor in the size of insects. Thats not a problem for social insects so I see no reason they couldnt grow very large as larvae then pupate into near human sized animals. Unfortunately social insects didnt evolve until long after dinosaurs took over. coconut crabs may be clumsy but then so are alligators. Crabs are sea creatures anyway. If we are going to talk about sea creatures then how about eurypterids? http://en.wikipedia.org/wiki/Eurypterid the largest land arthropod ever was the millipede Arthropleura http://en.wikipedia.org/wiki/Arthropleura But Insects are the arthropods that evolved specifically to live on, and move quickly and efficiently over, land. I wonder what the largest insect ever was? Looks like it was a dragonfly. http://en.wikipedia.org/wiki/Meganeura_monyi the largest today is a beetle (which also flies) http://en.wikipedia.org/wiki/Goliathus odd that flying insects get so big but walking insects dont. I think you are right. There has to be a reason that they didnt get large. I'm just not convinced that its because their exoskeleton would have been too heavy. I'll give it some more thought. (something to do with their lungs maybe) edit:I'm thinking that they didnt get big for the same reason that mammals didnt get big during the time of the dinosaurs. There was already a very big predator. (centipedes and maybe millipedes) It stands to reason that centipedes can always get much larger than a 6 legged insect. edit:http://en.wikipedia.org/wiki/Giant_weta
  14. consider a similar case with an orbiting satellite. If you add energy with thrusters then you would expect it to go faster What actually happens is that it goes to a higher orbit where it actually goes slower. so adding energy makes it go slower. its very non-intuitive.
  15. what on earth are you talking about. first off I didnt say arthropods colonized the earth. I said arthropods were the first to colonize the land. second I said that it is bunk that insects cant grow as large as humans. (or at least large enough to hold a large brain) If their exoskeleton would be too big then why isnt our ribcage and skull too big for us to evolve? I think life did evolve on earth from organic molecules deposited from comets produced by living molecules in space. The molecules though alive in space could not survive in such a radically different environment as the earths primitive ocean.
  16. vertebrates, arthropods, & molluscs correspond to the 3 modes of moving used by worms:wriggling, walking, & sliding. This is suficiently basic that I would assume that it would evolve on any planet. trilobites http://www.palaeos.com/Invertebrates/Arthropods/Trilobita/Trilobita.htm lobsters http://www.palaeos.com/Invertebrates/Crustacea/Crustacea.html Arthropod bodies are naturally waterproof so they would tend to be the first to leave the ocean and colonize land on any planet. first land animal (millipede) http://en.wikipedia.org/wiki/Pneumodesmus_newmani millipedes http://www.palaeos.com/Invertebrates/Arthropods/Myriapoda/Myriapoda.html insects http://www.palaeos.com/Invertebrates/Arthropods/Mandibulata.html scorpions and spiders http://www.palaeos.com/Invertebrates/Arthropods/Chelicerata/Chelicerata.html I think social insects (termites, wasps, ants) are most likely to develop higher intelligence first. The idea that their bodies would be too heavy to grow large is bunk. Look at your own ribcage and skull. If anything insect bodies would be lighter. (edit:Yes there is a limit to how big they can get but I see no reason to suppose they cant get nearly as big as a human) I suspect that ecosystems derived from extremely high tech terraforming nanobots are not rare. They may even be the rule rather than the exception. Over time they would eventually evolve into some very impressive highly intelligent half-robot half-animal creatures.
  17. http://ircamera.as.arizona.edu/NatSci102/NatSci102/lectures/jupiter.htm#internalenergy http://www.windows2universe.org/jupiter/interior/J_int_motions_overview.html
  18. granpa

    Monopole

    the distance between the infinite charges may be infinitesimal but its still nonzero. A continuous distribution of such dipoles will still result in a finite separation of the resulting (infinite) monopoles. the monopoles actually used to solve these types of problems are(continuous distributions of) finite monopoles separated by infinitesimal distances.
  19. granpa

    Neutrons

    all nucleons attract all other nucleons
  20. which cell lines made by what what grade are you in how much biology have you studied
  21. granpa

    Monopole

    some problems can be solved by treating the far field as though it were the result of magnetic monopoles but it wont work for the internal field within the magnet itself
  22. I have put you on my ignore list. I will no longer read or respond to your posts.
  23. no. if event A causes event B then all observers must agree on that (and they will). but they dont have to agree on the sequence of all events. As I said in post 3 its all about relativity of simultaneity: http://en.wikipedia.org/wiki/Relativity_of_simultaneity
  24. Yes it does just move the "how did it start" question somewhere else, but it moves it to the vast molecular clouds of interstellar space where there are far more oportunities for just the right molecules to come together in just the right way. if it was just a single self-replicating ribozyme-like molecule then there would be no need for water. Water is the 'medium' in which life processes occur on earth. In space, space itself would be the 'medium'. If these molecules seeded earth with life (or at least with organic molecules) by means of comets then maybe they have seeded all habitable planets in this galaxy. If so then life must be everywhere. It took 5 billion years for intelligent life to evolve on earth and the milky way galaxy is over twice that age. Once one species on a planet becomes advanced enough to genetically engineer animals and they figure out how brains function then it may only be a short time before nearly all large animals on that planet are intelligent. Yeah, i just quoted a hollywood movie. So sue me.
  25. from the point of view of the original frame yes thats obviously true. vuquta asked: He was asking who was younger from the new frame of A and B In that frame it is as I said
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.