Jump to content

Edtharan

Senior Members
  • Posts

    1623
  • Joined

  • Last visited

Everything posted by Edtharan

  1. Ok, it is known that a bullet from a gun travels at lest 330m/s. This is enough to kill someone. So if I have a bullet on train going at 330m/s down the tracks, then according to you, that bullet is travelling at 330 m/s. If I then get a friend to slowly (1m/s) throws the bullet towards me and hits me with it, then I should be killed as we know that a bullet travelling at 330 m/s can kill you. However, I understand relativity and know that motion is relative. I know that although the Bullet is travelling at around 330 m/s (+/- 1 m/s), that I too am travelling at that 330/ms and our relative speed is only around 1m/s. A bullet travelling at 1m/s is not enough to kill me and so I know that I won't be killed by it. This is what is meant by relative motion. In the case of the bullet, it doesn't matter if both it and me are travelling at 300m/s or 100,000km/s so long as the difference between our speeds is not that great, I'll survive. Now, lets consider a poor bystander on the platform. My friend seeing that a slowly moving bullet doesn't kill me, decides to chuck that bullet out the window of the train. He doesn't throw it very fast. Just the same 1m/s that he hit me with. He saw that 1m/s can't kill someone, so he concludes that the bullet chucked out of the train at 1m/s won't hurt any one. However, as the train is moving at 330m/s relative to the person on the platform, the bullet hits them at a high enough speed to kill them. Because although the bullet was only moving 1m/s relative to me and my friend at all times, it was moving at a different speed relative to someone standing on the platform. Of course we could try this experiment again but this time the train is moving slowly, only 1m/s. This time the bullet hits the person on the platform at only 2m/s and they survive. But what if instead my friend chucked it out the other window as another train was passing at 330m/s? The bullet is only travelling at 1m/s according to my friend and me and 2 m/s according to the person on the station. So at most, according to the thinking you are doing, that bullet can not kill someone on that other train. However, according to relativity, that other person is moving at around 330m/s relative to us and so that bullet will hit them at around 330m/s and kill them. Can you now see your mistake? According to you, the bullet could never kill any one in the last examples because it is only travelling at most 2m/s. But under relative motion, you have to compare the speeds of the observer to work out the situation relative to them. In the last example, the relative motion of the bullet gave 1m/s, 2m/s and 330m/s. All observers were observing the same bullet, there was no illusion as this is the difference between someone getting killed or not getting killed which can be directly measured. It can't be a case of the delay of the light takes to reach me that I see them live and another person sees them killed. It is why there are laws that make it illegal to throw things out of moving vehicles. People can be and are hurt be these kinds of events. If you gently chuck an apple core in a car travelling at 100km/s to the person sitting next to you, you are not going to bruise them, but if you such that same apple core with the same force out of that moving car moving at 100km/s at a person sitting on the side of the road you will bruise them. The reason is that motion is relative. Your motion relative to the person sitting next to you is 0. But the motion relative to the person on the side of the road is 100km/h. So, your science is wrong. All motion is relative. There is no absolute motion. I just proved it (several times).
  2. You are mixing frames of reference here. The Pilot (one frame of reference) travels 5 light years (from the frame of reference of Earth). This is what is wrong. The people on Earth see the Pilot travel 5 light years in just over 5 year. However, form the Pilots from of reference he does not travel 5 light years and it takes significantly less time than 5 years. Because the Pilot is in a different frame of reference to the people of Earth. What we have been (very patiently) trying to explain is that when you have accelerated you are in a different frame of reference to someone who is in the initial frame of reference and hasn't accelerated. Well assuming that the pilot is quite fit and has a hear beat around 60 beats per minute this would mean his heart beats around 2231.4 times during the trip. However, the people left of Earth, their heart would beat around 30,693,600 times (for around 5 years). This means that the Time for the pilot has slowed down. The Pilot sees everybody else as moving faster. And everybody else sees the Pilot moving slowly (inside the ship - not that the ship is moving slowly through space, just that time for the ship has slowed down). no. You are not exceeding the speed of light and your acceleration is not infinite. We are talking Physics, not the engineering requirements to send rockets to a distant star (or even just to get them into orbit). Whether you could design an engine to withstand the pressures to generate this kind of acceleration is an engineering problem, not a physics problem (although you would use physics to solve the engineering problem). We did not specify a particular rate of acceleration. We specified an initial speed (0c) and a target speed (0.9999999999c) and a period of time (almost instantaneously). We did not say that once we reached that speed we kept on accelerating. Actually to achieve a constant rate of acceleration over the specified period of time, we would need to have an increasing amount of thrust. The faster you go the more mass (not rest mass which is a slightly different thing) according to the E=MC^2 equation (moved around to be M = E / C^2). The more mass you have the more thrust is needed to accelerate you at the same rate according to A = F/M (Acceleration = Force / Mass ). So the faster the ship goes the more massive it becomes, but the more massive it becomes the more force is needed to achieve the same rate of acceleration. If you work these out for accelerating a ship up to the speed of light, it turns out you need an infinite amount of energy to accelerate something up to the speed of light (interestingly this only applies to accelerating something to the speed of light, if you create something moving at the speed of light - like a photon - this is different and does not take an infinite amount of energy, but the object must have 0 rest mass, and that if you have 0 rest mass you can only be created travelling at the speed of light ). So, back to the example... Even though our "hypothetical" ship accelerated to near light speed almost instantaneously, this rate of acceleration was either non uniform (that is our rate of acceleration reduced as we got faster) or we increased the amount of thrust to compensate for the increase in mass. But, if we were to try to continue to increase our thrust and keep accelerating, then the amount of mass increase continues exponentially to the point where we would need an infinite amount of thrust to go faster. As infinities are non physical (they break the laws of physics) we can't use them and we can not accelerate to the speed of light. Oh, and if you think that we can't know this because we have never accelerated anything up to that kind of speed, well... We have. In particle accelerators, these kinds of velocities are achieved every day. They use magnetic and electric forces to push and pull the particles like electrons up to these phenomenal speeds. We know that the particle is gaining mass, as we can detect that in the amount of energy needed to increase it's speed further (as I was saying the faster you go the more mass, the more mass the more energy needed to accelerate at the same rate) and also in that the accelerators are curved (usually) and we can detect the amount of force needed to make the particle turn around the corners. So through these direct experiments, we absolutely know that when you accelerate an object it gains mass and as it gains mass it requires more energy to keep the same rate of acceleration. We can measure these and draw a graph. When you plot that graph we can see that to achieve a velocity of light speed you would need an infinite amount of energy to do so.
  3. You are right. And this is also why we have a "flavour of the week" situation with the different theories. Something will be discovered that will make one theory more likely (say knowing what types of chemicals were in the atmosphere, or that a type of clay can catalyse certain reactions) than another. But as new discoveries are made all the time, this leads to one theory being replaced as the most likely by another (only to be replaced when another discovery is made). This makes it easy to construct the strawman argument that "Scientists have no idea how life got started". It is not that we don't have an idea, it is exactly the oposite, it is that we have so many.
  4. Simple answer: "Turbulence". The more complex answer follows (and explains why turbulence is the reason): Well different minerals have different Densities, Melting Temperatures, and many other factors. So in one case a mineral might melt, but a nearby mineral might still be solid. One might be more dense and the other less dense. The less dense will rise to the surface just like ice (which is less dense than water) will rise and float on water, even though they are made of the same stuff (H2O). So differences in temperature in one location might have a mineral either solid or liquid. Differences in density might make parts of those areas sink lower or rise up. This creates regions where certain minerals and elements will encounter different environments (pressures, temperatures nearby minerals and elements to react with, etc). These different environments mean that the results of matter in one location will be different from the results in another location. So something like Iron might encounter sulphur and be come Iron(II) sulfide, where as the iron in another location might encounter oxygen and become Iron Oxide. But why might the environments be different? Well if an asteroid that originated near the sun hit Earth at one location, then it will have more heavier elements (like sulphur), but an asteroid that originated from further out (say the Oort cloud) hit the Earth, it will have more ices and lighter elements (like oxygen). It was the gravity of the collapsing dust cloud, and the spinning disk that formed because of it, that formed the sun, the planets, asteroids comets, etc (the solar system), that sorted out the elements into masses and distributed them. However, it was not a completely ordered place and there was turbulence. As the dust swirled around in this disk, the particles of the dust collided and stuck together, a bit like the dust bunnies that form under furniture. These Solar System Dust Bunnies grew bigger (just like the house hold variety does - and there was no one around to clean them up in the early solar system), and bigger. Now all objects that have mass have a gravitational field. So these Obese Solar Dust Bunnies grew so big that they started pulling in more dust and even other Dust Bunnies. Eventually the gravity of the Dust Bunnies was so big that the stiffness of the dust was unable to support itself. These Dust Bunnies collapsed and formed Micro Meteorites. these Micro Meteorites still have gravity, so they pulled in more stuff (dust, dust bunnies and micro meteorites) and grew bigger and got more massive so pulled in more and more stuff. Eventually these grew so big that the speed that they pulled in the other stuff was so fast that when it hit it released that energy as heat, melting the dust. Welcome to the era of planetesimals. The gravity from these planitisimals was enough to "stir" up the gasses, dust, dust bunnies, micro meteorites and even other planetisimals and send them to places all over the solar system. This is the Turbulence I was talking about. The planetisimals collided and stuck together and eventually grew big enough to be classed as planets (as well as dwarf planets and plutoids :-p ). There was actually many more of these planets in the early solar system than there are today. It is quite likely that one of these (about the size of Mars) was knocked out of place by another planet passing near by it, and sending it hurtling on a collision course with the forming Earth. Now you don't have to worry about this doomsday planet hitting us because it already has. The debris kicked up form this collision was flung into orbit and eventually when through the same accretion that formed the planets and we now call it the Moon. We know this because we have gone to the Moon and looked at the Moon rocks and they are remarkably similar to the Earth (if the Moon had formed elsewhere and been captured by the Earth, then the composition of the Moon would be very different from the Earth). There is one difference though. The Moon does not have much water in its rocks (unlike the Earth). If it had just formed around the Earth right from the start, its rocks would be identical to the Earth's rocks. The most plausible explanation is that something heated the Rocks so much that the Water broke down into Hydrogen and Oxygen. Which could be done by a planet the size of Mars hitting the Earth. So we have objects from all over the Solar system careening around it. This means the composition of any two asteroids hitting Earth will likely be different. This means that the initial distribution of minerals will not be ordered and even. There will be pockets where an asteroid that was high in sulphur will have hit and there will be locations where asteroids high in oxygen (most like as water) will hit. We now have, due to turbulence (and a long rambling post ) an explanation of why the distribution of minerals on a planet are clumped.
  5. Edtharan

    need help!!

    yes. The fibres in the flag will rub against each other and produce heat through friction. This will slow the motion of the flag down. In fact, this proves that the Moon Landing actually took place. The motion of the flag (the way it is moving) and the duration of that movement could only occur that way in a vacuum and a gravity 1/6th of our own. The motion could not be replicated by slowing down the film (as is often claimed by those that think the moon landing was faked). So either they sent someone to them Moon to get that exact shot so they could fake the Moon landing, or they actually landed on the Moon. Ok, now think hard and re-read that sentence. Yes, either they landed someone on the Moon so that they could fake it, or they Landed someone on the Moon. Today we could fake easily with computer animation. But they didn't have that technology when the Moon landings took place.
  6. You are right. At low relative velocities this discrepancy between classical mechanics and relativity is not noticeable (it does exist however). But when you get to high speeds the discrepancy is much more noticeable. It is like a speedo that is 10% out. At 10km/h it will only be 1 km wrong. This is not too much of a concern as the size of the needle usually gives a greater error to the reading. But at 100km/h, you will now have an error of +/-10km, far bigger than the needle and much more noticeable. Now the error with Relativity is not linear like this speedo example. It is instead geometrical, so that at the relay high speeds it has so much error, our experience with the unnoticeable error at low speeds make it look like nonsense. First Andromeda is far more than 2.5 light years away. Andromeda is a galaxy of billions of stars. The closest star to Earth is the Sun at 8 light minutes away. The next closest is Proxima Centauri at around 4.22 light years. A whole galaxy of billions of stars can not fit between us and Proxima. I think you meant 2.5 million light years. That would depend on the rate of acceleration... Oh wait this was given by DH: "I'm assume the spacecraft has an inertialess drive so it can change velocity nearly instantaneously without destroying the ship or crushing the pilot." So your answer then would be: Almost Instantaneously. Well if you know the rate of acceleration and know the time you accelerated for, then you can work out the speed. Or you would just compare your velocity to your starting frame of reference (Earth). It was measured from Earth before the space ship set off. We can do this by several methods, but for a star so close, the best way is probably by Parallax That 5 light year distance is only valid for the reference frame that the measurement was made in. If you change your reference frame then you have to take the measurement again, or using Relativity calculate it from the original measurement and your new reference frame. Yes, and he said: "Almost Instantly". So that was a Strawman. It is currently imposible for us to build a space ship that could take us to another star and return. So does this mean that we should stop talking about space ships too? Stop being pedantic for the sake of being pedantic. These are Thought Experiments. They are theoretical situations designed to demonstrate the principles being discussed. We are not Rocket Scientists (well some of us might be ). In Fact, most Rocket Scientists would not have to use much Relativity in their day to day work. We are talking Physics, not the engineering requirements to send rockets to a distant star (or even just to get them into orbit). Hang on! You just computed the acceleration and then just asked us to compute it. So are you just asking us to check you maths?
  7. Exactly what it said: space that is empty. It was a thought experiment. That is a simplified experiment done in your head to test or demonstrate a particular argument. The bounds of the thought experiment did not include you getting to that speed. I was using the Thought Experiment to demonstrate relative motion at a constant speed. Acceleration is a completely different frame of reference and is not covered by special relativity (as in certain circumstances). For that you need General Relativity (as in it is applicable to a more situations that special relativity). Actually, Einstein came up with Special Relativity first, but he knew that it didn't cover all situations. He released that theory knowing that it was incomplete and that he was going to work on a more General theory later. He them developed General Relativity to cover the holes in the Special Theory of Relativity. You seem to be arguing that Special Relativity is incomplete. Well you are write. However General Relativity covers and explains all those holes. You see, many people here have been getting frustrated because you point to a hole in Special relativity. However, they then say that that situation is not covered by Special relativity and that it is instead covered by General Relativity. You then ignore the fact that they situation is supposed to be covered in General Relativity and then keep pointing to the hole in the Special Theory. It is a bit like how someone might point to the theory of gravity and claim that it doesn't explain how stars get their heat. Then someone responding to that by saying that stars don't get their heat from gravity, but get it instead by fusion. Then that first person jumping up and down saying that fusion is not part of the theory of gravity so it doesn't actually explain it. So to reiterate: Acceleration is part of the General Theory of Relativity. I was talking about constant motion which is part of the Special Theory of Relativity. Ok, Intergalactic space in the middle of one of the voids between galactic clusters. What is specifically meant was that there was no points of reference (as they would indicate relative motion) and you were far enough away from gravitational fields so that we didn't have to consider these into our reference frames (they complicated the situation a bit but they do act like an acceleration - and as we are not using General Relativity, these are unnecessary). Ok, if you really wan to be pedantic... Empty except for you. You were launched billions of billions of billions of years ago by linear acceleration with a counter weight sent in the opposite direction. You were in cryogenic sleep for the duration and you are wanting to determine where you came from or if you started here and everyone else left. Also if you are moving you want to know which direction you are moving in because then you will know how to get back. There is no trace exhaust and no engines on the ship that might give you a hint at which direction you came from (you could always take a guess that the direction the ship came form is in the direction that the main engines are facing). The ship has no power to operate its sci-fi like sensors so you can only rely on you own eyes and simple sensors (like optical telescopes and computers). Because it has been so long, all the stars have used up their fuel and have grown dim. So you can't use the light of the stars to determine you motion either. In fact the expansion of the universe has also accelerated and light beyond a few billion light years will never reach you. Also this expansion has reduced the the density of matter (other than you space ship) so that there would not be a single atom of any matter to be within that billion light years. So, no matter, no light, no gravity, nothing except your ship (oh and mine, but you didn't see me at first as the window in you ship restricted your field of vision). Is that clear enough for you?
  8. I am not saying that people don't think of it as one. But that if they do they are incorrect. Someone may want to see an avalanche coming at them as just a figment of their imagination, but if they are about to be flattened by one, that does not make it disappear. Reality is not determined by how we wish it to be. Evolution may be seen by some as a "Force" but it is definitely not a "Force" in the scientific sense.
  9. You can only determine what the velocity of something is by comparing it to another object. So compared to the pilot, the ship is travelling at 0 km/s, but compared to the Earth the ship would be travelling at some fraction of the speed of light. According to the pilot (in this example), the time taken will be less. This means that he must (according to his frame of reference), the distance must also be less. Remember Velocity is Distance divided by Time. 300 / 100 gives the same result as 30 / 10.
  10. I think it is more the case of that there a re many different and plausible methods of how life could begin, but it is that we just don't know which if them is the one that actually happened.
  11. Well if we had the ability to change things like Eye colour or Hair colour, then we could always change them back. Or, we might introduce new variations that could not have evolved naturally in the same span of time (they might have eventually been able to evolve, but it would have taken a far longer time).
  12. Ahh. Ok. I see this is where the source of your confusion lies. Here is a question: Imagine that you are in empty space and nothing else exists. Can you tell me how fast you are travelling? Against what can you measure how far you have moved? Without something to compare your position with there is no way you can tell if you are moving (you can still tell if you are accelerating - but not if you are getting faster or getting slower). Under constant velocity, without any point of reference, it is the same as if you are not moving at all. Or think about this one: Sitting at your computer, how fast are you moving? Well compared to the seat, you are not moving at all. Compared to the Moon you are moving at around 1.022 km/s. Hang on. But you aren't moving compared to the Seat. How can you be simultaneously sitting (literally) still and also moving far faster than the speed of sound? May be it is the Moon that is moving not us? But, what if there was someone on the Moon that was also sitting at a computer? Compared to the Moon they would not be moving, and compared to the Earth (you) they would be moving around 1.022 km/s. How can you both be sitting still and both be moving? Simple. All motion is Relative. What does this mean? Well it means that there is no absolute measure of motion. There is nothing that all objects in the universe can compare their motion against and determine exactly how fast they are moving. In relativity speak it is stated as: There is no preferred Frame of Reference. Finally. Imagine you are in a space ship in empty space. Except now you see another space ship heading towards you. But wait, is it, or are you heading towards it? Which is it? The other ship sees the same thing. Are you heading towards it or are they heading towards you? Again, motion is relative so it means that both views are actually the same thing. Under the laws of Physics, it does not matter who is the one moving, only that there is motion relative to the other. So, what does this mean? In your statement I quoted: "I don't measure my second compared to HIS MOTION." The reality is that you do. Remember all motion is relative, including motion through Time. But why should that be? Well, there is one thing about relativity: In all frames of reference the speed of light must remain constant. Now, as Velocity is Distance divided by Time, then these must change for it to be true. So either Distance, or Time or Both must change. So if I was travelling at 99% of the speed of light (or around 297,000km/s), I must still see light travelling at 300,000km/s. But if you were sitting at your computer as I whizzed by you and made the same measurement of the speed of light at the same time, you would also conclude that light travels at 300,000km/s.
  13. It seems that we might be able to start filling in some of the numbers for the Drake Equation. There is still a lot of uncertainty, but this should help narrow down the limits.
  14. Actually, surprisingly not. If you eliminate someone because of a small amount of genetic faults (disease), then you are eliminating the rest of their genome as well. It is a case of throwing the baby out with the bathwater (as the saying goes). However, if instead you genetically modify that person's genome to eliminate that disease, then you still have the rest of that person's genome (you have kept the baby but thrown the bathwater out).
  15. Motor Daddy, you seem to have a problem with understanding Frames of Reference. A Frame of Reference is essentially How you are moving and The Gravitational Field around you. (however as in these examples we are not taking into account gravity, we can leave that out for now) If you are moving the same as something else, then you are both in the same frame of reference. If you are moving differently, then you are in a different frame of reference. Now anything in your frame of reference experiences the same effects you do. So if you have a watch, no matter how accurate, then if your frame of reference has time slowing down, then your watch will also experience that slowdown. Because you have slowed down and everything around you in your frame of reference has slowed down, you are not aware of this. Everything seems normal to you. However when you look at the outside world (that is everything else that is not in your frame of reference), it will appear to be sped up. You will see clocks moving faster, people ageing faster and so forth. However, someone in the outside frame of reference where time hasn't slowed down, will still see everything running normally (because everything is in their frame of reference so it experiences the same effects as that observer). But, they will see you slowed down and your watch running slowly. This is not and illusion. Processes (like chemical reactions and subatomic reactions - like the decay of a lone neutron into a proton and electron) also experience this effect. If this effect was only an illusion, then such processes would be unaffected, but they are (and have been measured). Atomic clocks work on a process within an atom (Caesium) where by it will regularly emit a photon. It does this so regularly that they are the most accurate clocks that currently exist. It is also not dependant on Distance for its operation. However, when such clocks are accelerated (put into another frame of reference), they clearly show dilations of time. Remember, if the dilation of time was an illusion, then such a process should go unaffected. If it was dependent of Distance, it should be unaffected. But it is effected by it. Therefore this time dilation must be real and not an illusion. The atomic clocks are not measuring time by having a distance analogue (as it is with a watch), but are measuring events where the only separation is in time (they are even emitted form the same object). Therefore the only effect on this is changes in Time. So, if all we are measuring is separations in time, and we see changes in time, then it really must be change in time, not some illusion where distance or some other factor is confusing us.
  16. Seismographs. These measure the vibrations of the Earth. Sound is just vibrations in a medium. So these seismographs act like the reciever in a Ultrasound machine. Then using the same knowledge of how sounds waves are effected by different materials, we can work out what materials the vibrations that have travelled through the core of the Earth have passed through. We can determine the density, temperature, state of matter (solid liquid or gas), moments (if it is moving there will be a predictable distortion in the sound waves), and many other aspects. You can even determine where one material stops and another begins. Vibration can give us a lot of information about an object. So using such techniques we can determine the composition of the core of the Earth, and it is made of a solid iron inner core with a liquid iron outer core. It is no more alive that the steel (an alloy of iron) in your car. Actually it is quite smooth (see my last post). If the Earth was shrunk down to the size of a tennis ball, then the largest height differences would be far smaller than any on a tennis ball. As I said in my last post, if you shrink the Earth to the size of a Basket ball (much larger than a tennis ball), then the bumps used to give a basketball its grip would be around the same height as the largest height differences of the Earth. So you are right, according to accretion the Earth should be fairly smooth, and it is. The reason we have mountains is that the surface of the Earth is not all one piece and these pieces are able to move around. When two pieces collide, one will slide on top and the other will be pushed under. This is because the crust of the Earth is not all the same. There is some lighter material that we call the Continental Crust and Heavier Material that we call the Oceanic Crust. As the Oceanic Crust and Continental Crust is pushed around, the Oceanic Crusts will, being more dense, slid under the Continental Crust. However, and Continental Crust that is sitting on top of the Oceanic Crust that is sliding under the other Continental Crust will collide and accumulate together. When these Continental Crusts collide the oceanic crust is still moving. This keeps the pressure on the continental crusts. This pressure has to be released some how and it is usually in the form of buckling. It is this buckling that we call mountains.
  17. Most will be, but remember there will be some that the world is better with (and you can only tell after the fact). People like Steven Hawking. Actually, No. Variation within a population is a good measure of that species "strength". Species that are limited in their genetic diversity tend to be quite "weak". Reduction in genetic diversity within a species leads to inbreeding and this brings out many recessive genetic problems. With a large variation in genes within a population, this "future proofs" the species against changes in the environment. A new disease might arise and a varied population is more likely to have individuals that are immune (or have a reduced effect from it), or if the climate changes, some individuals will be better adapted in the more varied populations. We are facing this problem at the moment with some crop species. Most Banana plants are virtually identical genetically. This means that certain diseases that they can get will have an equal effect through out the population. So when disease does strike (as it has in many places), whole plantations can get wiped out.
  18. Natural Selection is not a force, but a process. A process can involve many different forces (all of them completely physical and known), but can also be very complex (to the point where it is far easier to refer to the process as an entity/force than to list all the real forces going on). This is what we do with Natural Selection.
  19. As I said, you can have the "information" stored in the radiative emissions. The thing is you are forgetting Relativity. When you plot the events in space time, that "apparatus", at the point it takes the reading is in the past of the information deletion event. It is not recovering the information it is storing it when it is still there. So in effect, you don't actually erase the information (only one copy of it). It is no different than if I write something on a piece of paper, photocopy the paper, burn the original and then claim that I was able to retrieve the information from the burnt paper (when I haven't, I have just made a copy before I destroyed the original). It is all about Simultaneity.
  20. They have some pimped out wheels on those goal posts. It makes them much easier to shift
  21. Sorry, I meant mutation. Thanks for the catch.
  22. When you take pressure off a species, like say a large predator goes extinct, the species does not stop evolving. What happens is that because of the less pressure, the genome has more freedom to explore the possibilities. A good example is after any mass extinction. The species would rapidly develop new "designs" as the level of fitness selection was relaxed enough for "non-optimal" mutations to survive where in a high pressure environment they would not have allowed the individuals to survive. Humans are experiencing this at the moment. We, due to our technology, have been able to remove a lot of selection pressure from us as a species. Now mutations are occuring that would, without our technology, be below the survival threshold. WHen, or if, the selection pressures return the human genome will have diversified enough that some of us are likely to survive (and they will be different pressures that existed before technology). As there will be many solution to these pressures and many different types of pressure, you would expect that humans will separate into several subspecies at that point. This is probably the best argument against any form of Eugenics. Eugenics tries to reduce variation in the gene pool, where as variety in the gene pool is essential for a species to be able to survive variations in their environment. For instance: Genes that increases the likelihood for obesity might be a bad thing when there is a lot of food available, but if there was a major disruption in food supply, these people would be more likely to survive as they have more fuel reserves to call upon.
  23. Actually there is very few fundamental constant that slight changes would cause life to be impossible. It might make us as we currently are impossible but not other forms of life. We have evolved in this universe with these fundamental constants. The universe as we see it is a point where various forces cancel out. Take for instance Stars. They are a balance of forces between Gravity and the outward forces created by fusion. But what if gravity was weaker, shouldn't stars just blow themselves up? Well, no. The process of star formation means that the gasses will contract unbder gravity until the amount of outwards push form the processes of fusion cancel out the pull of gravity. If you were to transport a star from this universe straight into that other universe, then the star would blow it's self to pieces, but in that other universe, star formation means that a balance will be achieved. And such as it would be with many of the other fundamental constants. There are limits, but the processes are quite robust in the face of change in the fundamental constants. Also, even if the fundamental constants are changed so radically that life as we know it is impossible, who is to say that other kinds of life are not impossible under those circumstances. Even in our universe, life as we know it (chemical reactions of oxygen, hydrogen, carbon and trace amounts of others) might not be the only form of life possible. So under examination, this argument is actually quite thin. In concept, yes. However, do to the history fossil record) if there was an intelligent designer, then they would have to be doing so in a way indistinguishable from pure randomness. At which point asking if there is an intelligent designer is moot as it would be indistinguishable from randomness (and Occam's razor says to take the simplest one).
  24. We can used vibrations to examine what lies inside the Earth. This is not conceptually different from using something like an Ultrasound machine to examine inside a patient (in fact it is the same physics - so if you can accept that ultrasound machines can tell us about a developing foetus, then you also have to accept that this technology can tell us about the insides of the Earth). Using these vibrations (caused by earthquakes or powerful explosions) we know what is inside the Earth and we can also know that it is not a living organism. Just because we have not dug down further than 12 or so km, doe snot mean we have no idea about what lies below that depth. Again read: Equivocation. Just because something appears to resemble another thing, doe snot mean that they share any properties at all. However, surprisingly, the surface of the Earht is actually quite smooth. If you were to shrink the Earth down to the size of a basket ball, the largest difference in height (that is the height of mount Everest to the bottom of the Mariana Trench) is less than the bumps used for grip on an actual basket ball. So, using you logic of "if it resembles it then it must share the properties", Earth is actually a basket ball. A frozen lake. It has a "crust" of ice. Also the deeper you go the warmer it can get (to around 4 degrees C ). Actually the reason that the inside of the Earth is hot is mainly because the Heat has nowhere else to go. Once the Earth had a molten surface because it was being bombarded with asteroids and meteors so often that it didn't have time to cool down before the next one hit. SO it just got hotter and hotter. Also because there was so much in falling material, the size and mass of the Earth got bigger (over a long period of time). This occurred around 5 billion years ago (that is 5,000,000,000,000 years ago). It took around 500,000,000 (5 hundred million years) for the surface to cool sufficiently that organic molecules could exist in complex reactions (and then a bit longer for life to actually get started). Now the only way that the Earth can cool down is to radiate the heat into space. SO the cooling of the surface would occur quite quickly. However, Rocks are not good conductors of heat, so any heat below the surface would not radiate away nearly as quick. So we started off with a molten surface (because it was so hot), and then the Earth started to cool. This created a solid layer of Rock (a poor conductor of heat) which trapped the heat from the still molten rocks inside the Earth. Now as this heat (and molten rock) is trapped inside the Earth, any heat it radiates is also trapped in there, and, due to the insulating layer of rocks on the surface that heat can't escape. It is a bit like in winter when you have several blankets on. The outside of the blankets might feel cool, but underneath them they can be quite warm (which is really good on these cold winter nights). the other thing is that the Earth is a sphere. This is a good shape for retaining heat as there is very little surface area for the volume (in fact it is the best shape for that). As the only way the Earth can loose heat is to radiate it out into space, the less surface there is to radiate as compared to the volume of it the slower it will loose that heat. Now for the difference between living creatures and the Earth. The temperature of the Earth's core is a relic from it's formation. It is the kinetic energy of the in falling asteroids converted into thermal energy. However, in living organisms, the heat generated by them is due to chemical reactions, not from in falling asteroids. So although they both can be warm in the inside, the process about how this came about is completely different. Also, the process as to which the acquired their "skin" is also completely different (solidified molten rock for the Earth and chemical reactions for the organisms).
×
×
  • 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.