Janus

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Everything posted by Janus

  1. Natural response of RC and RL Circuits?

    You have to understand what the transistors do in the circuit. Here, they are acting lie switches. The three connections to the transistors are as follows; At the top we have the collector, at the bottom is the emitter and out the side is the base. Basic operating principle is this: If a small current flows between emitter and base, then a larger current will flow between emitter and collector. Current will not flow between emitter and base unless the base-emitter voltage is above a certain threshold call the bias voltage. So let's assume that Q1 is presently conducting. At this point, C1 has been charged to a positive voltage at the plus sign. With Q1 conducting, this end is pulled to zero, which pulls the other end negative, which in turn drives the voltage at the base of Q1 negative and below cut off. Q2 does not conduct. This means that C2 will now now start to charge Through R4. Meanwhile, C1 is discharging, which causes the voltage at the base of Q2 to go more positive. Eventually it reaches the point where Q2 starts conducting. This drives the positive end of C2 to zero and the base of Q1 negative, shutting off Q1. C1 now begins to charge through R1 while C2 discharges. Eventually C2 discharges enough to turn Q1 back on and we are back to where we started. The speed at which the capacitors go through their cycles depends on the the time constants of C1-R2 and C2-R3. (its possible to use different time constants so that one LED remains on for a larger percentage of a whole cycle than the other does.)
  2. Truth About Corners

    https://en.wikipedia.org/wiki/Time_Cube
  3. How do I learn to design and make my own electronics

    If you really want to know the "why", there are no shortcuts. Right now, you are learning about passive components. You have yet to learn about semiconductor components such as diodes and transistors. For example, a circuit that causes a LED to blink on and off using a battery as a power source can be made with two transistors and some resistors and capacitors. To understand the why of which resistors and capacitors are used and why they are arranged the way they are requires you to understand what the transistors do in the circuit. So even such a simple circuit involves the use of components you have yet to learn about. And while it doesn't seem like you are getting closer to your goal now, what you are learning now will become useful later.
  4. Swallowing spider silk dangerous?

    And even if it weren't digested, it would just pass through your digestive system and be eliminated as waste.
  5. Why does this ball go faster than c?

    if the ether the M&M experiment was trying to measure the Earth's drift with respect to existed, then, yes there would have been a slight offset in the perpendicular light. (with the 11 m path length, and a "drift velocity of 30 km/sec, it would have only amounted to a bit over 1 mm.) This would not however have effected the time it took for the perpendicular light to travel it path, and it was the timing or phase difference the experiment was designed to measure. However, the M&M experiment, and those following it, failed to detect said ether. No ether, no drift. Thus "moving" or "stationary" the beam travels at a 90 degree angle to the apparatus. If I'm playing catch with someone across the width of a railway car traveling at 60 mph relative to the tracks, I don't have to "lead" him with my toss. I toss the ball directly at him. Light in a vacuum behaves the same way, as long as the target has no velocity relative to me, I just aim my light at the object.
  6. Simple question?

    So for example, starting at the surface of the Earth, a graph of escape velocity would look like this:
  7. Which is exactly what people have been doing here; Entertaining your idea, but then ultimately rejecting it.
  8. The Moons Atomosphere

    When there is a wind the pressure is greater on one side (windward ), than it is on the other. Air pressure is just the sum of collisions of air molecules. With a wind, the particles are hitting with more force on the windward side. This also causes a wind shadow effect which lowers the air pressure a bit on the leeward side. Gravity does not "hold you in place", it pulls down on you. It is the friction between the object and the surface it is resting on that keeps it in place. If you to remove the friction, an object on a level surface would start sliding around at the slightest touch, regardless of how strong the gravity was. Gravity only fights efforts to raise the object against its pull. Gravity on the moon is determined by the same considerations as gravity everywhere: the mass of the objects involved and the distance between them. For a body like the Earth, your effective weight at different points of the surface are mainly effect by the fact that it's surface is not a perfect sphere, which alters the distance from the center, and the slight centrifugal effect caused by it rotation. But both of these only result in small variations. For the moon, these same variations would apply. But being both a smaller body, and spinning 1/27 as fast as the Earth, the centrifugal effect will be much smaller, and you would get a smaller variation between pole and equator.
  9. The Moons Atomosphere

    But this is true of something sitting in a vacuum also. It will stay there unless something acts on it. Air pressure from all sides doesn't change this. Since it pushes equally from all sides, the various forces cancel each other out. The 14 psi air pressure does not "hold" the object in place.
  10. Why should they? What keeps planets in their orbits is their orbital speeds around the Sun. The Sun stopping its rotation wouldn't alter this. The Sun rotation does not "drag" the planets around with it. They would maintain their orbital velocities with or without the Sun rotating.
  11. The Moons Atomosphere

    Core, magma layer, anything below the crust. Mon Olympus is a giant shield volcano that is evidence that Mars was much more geologically (areologically) active in its past, producing the type of lava flows needed to build such a volcano, which in turns suggests a past magma layer beneath under the crust.
  12. The Moons Atomosphere

    It is believed that Mars once had a thicker atmosphere. But because of it smaller mass, Mars has a lower escape velocity than the Earth does. (less than 1/2) and this made it easier for Mars to lose its atmosphere over time, especially once its geological processes slowed the venting of gasses to replace it. (Again, at just 1/10 the mass of the Earth, Mars' interior cooled faster.) The loss of of an active interior also could have resulted in a severe weakening of its magnetic field which protected its atmosphere from being stripped away by the solar wind. Whether the loss of the majority of it atmosphere is just due to a slow bleeding/stripping away over time, or could have been helped by a catastrophic collision with a another body is still an open question.
  13. black holes do not have infinite gravity!

    That's due to a concept known as "escape velocity". It the velocity something would have to be moving in order never fall back to the object. For example, the escape velocity from the surface of the Earth is ~11 km/sec. If you were able to launch something from the surface of the Earth at that speed, and didn't have to worry about air resistance, it would never fall back to Earth. Escape velocity can be found by the formula Vesc = sqrt(2GM/d) Where G is the universal gravitational constant, M is the mass of the body, and d is the distance from the center of the body you are starting from. For comparison, the acceleration due to gravity, which at the surface of the Earth is ~9.8m/sec2, is found by a8= GM/d2 So for example, if you were starting from a point 1/2 again as far away from the center of the Earth than the surface is, the escape velocity from that point would be ~82% of that at the surface and would be ~9 km/sec. the acceleration due to gravity would fall to ~44% of the Earth surface value So what if you moved closer to the center of the Earth? That becomes a bit more complicated. As you move inward, more and more of the Earth's body is overhead and no longer contributes to the gravity you feel. So even though d is getting smaller, M decreases even faster. If we were to assume that the Earth was of uniform density, the acceleration due to gravity would steadily decrease to zero, while the escape velocity would continue to slowly increase until it reaches a value some bit less than twice that at the surface. But what if, instead of boring into the Earth, we jut kept compacting it into a smaller and smaller size. That way, we can get closer to its center, while still keeping all of its mass "under" us. Compacting the Earth by to 1/2 its radius raises the escape velocity by a factor of 1.414 and the surface gravity by a factor of 4. Compacting it to 1/10 it present radius raises the escape velocity by ~3.2 and surface gravity by 10. Decrease the radius to just under 9mm, and the escape velocity exceeds c, the speed of light. Meaning even light can't escape this small object, and we've created a black hole. But this has no effect on the gravity felt at other distances from the black hole. At the original Earth radius distance, the acceleration due to gravity is still 9.8m/s2 , and the escape velocity would still be ~11 km/sec. If the Earth was a thin hollow shell surrounding an Earth-mass black hole at its center, in terms of the gravity we experience on the surface, we would not notice a difference. A black hole does not need infinite mass to prevent the escape of light. And that's basically what a black hole is; a mass that is so compact that its surface is closer to its center than the distance at which the escape velocity for that mass equals c. (While we actually don't know what happens inside this radius (marked out by an imaginary surface of a sphere called the event horizon.) We also don't know of anything that will stop any object inside it from continuing to compact under the crushing local force of gravity until it becomes a mathematical point called a singularity. This is one of the, as of yet, unsolved questions in science. )
  14. And which also rules out the other offered explanation of "Aether Drag", where it is suggested that the Earth carries a bubble of aether around with it as it orbits the Sun.
  15. It showed that there was no detectable ether. The "aether wind" it was looking would have been the result of the Earth moving with respect to the aether. Of course, there would have been no wind if the Earth was at rest with respect to the aether. However, the Earth orbits the Sun in a circle, and thus it would only be possible for it to be at rest with respect to the aether at one particular time of the year. Since the experiment gives the same result no matter what time of the year it is performed, this is not an option. As to accuracy, it was accurate enough to detect the expected motion with respect to the aether, if it existed. But the accuracy of the original experiment is moot as it has been repeated since to much higher degrees of accuracy without giving any different results. I know that there are some out there that seem to think that if they could just find some flaw in the original M&M experiment, the whole of Relativity would come crashing down to its foundations. This simply is not the case. Relativity is supported by so many various and independent experiments and observations that it is far too late to put that particular genie back into its bottle. For instance, It has been suggested that Mendel "fudged" some the result for his Pea breeding experiments, as they were just a bit too perfect. But even if he had, it wouldn't have changed the validity of the Laws of genetics he discovered.
  16. A multi-meter will tell you. what the current, voltage, or resistance is. Circuit analysis tells you what it should be. If I'm testing a circuit with a multi-meter and get a different reading than what circuit analysis tells me I should be getting, then I know that there is a flaw in the circuit. (an open, a short, or bad component.) Often knowing the what the the reading should be vs. what you get can lead you to the probable fault.
  17. A 0.1 solar mass red dwarf could burn for 10 trillion years or so. A planet orbiting around such a small star and still be in the Goldilocks zone would be almost assuredly tidally locked.
  18. There might be some small amount of tidal acceleration ( we get this between Earth and Moon where tidal interaction between the two transfers angular momentum from Earth to Moon), But since tidal forces decrease by the cube of the distance, and the distances between the Sun and the planets are pretty great, this is not going to very significant. Besides, this is well understood by present Physics. Any significant additional effect would have been noticed by now, and since our present theories are very good at predicting the motion of the planets, there isn't really much room for any unknown effect caused by the Sun's rotation.
  19. Generating Gravity

    Probes have landed on Venus, put in orbit around it and Venus has been used "sling shot" spacecraft to other planets. To land a probe requires you to have a good knowledge of its surface gravity, Putting an object into an given orbit around it requires knowing its gravity over-all as does using it for a sling shot. So yes, we have lots of direct evidence as to what Venus' gravity is. None of which has anything to do with generating gravity. Can moving air produce forces on objects? yes. But unless you are dealing with tornado or hurricane force winds, They come nowhere near the the magnitude of the force of gravity on say a human body. And these forces depend heavily on the shape and orientation of the object. A sheet of paper will feel a much greater force if held facing a wind vs, being held edge on. Yet the same sheet feels the same force of gravity whether being held horizontally vs. vertically. Because they are not being negated. Newton's laws are being perfectly followed. It is your claim that they are being negated that in error. If I hold a cup 3 ft above the floor. Newton says that if I let go, it will fall. But if it were sitting on a countertop at that same height while I was holding it and I let go, it would not. does this "violate" Newton?. No. Without the countertop , the cup falls due to the downward force of gravity. With the countertop, the countertop exerts an upwards force on the cup opposite that of gravity. With the atmosphere at the equator, three effects are in play: Gravity, pulling down on the air Centrifugal effect, acting to lift the air Force by the ground acting upwards on the air. Gravity is much, much stronger than the centrifugal effect, so when you combine the two, you still get a net downward force on the Air which is then counter-acted by the upward force exerted by the ground on the air. If you were to remove the supporting ground (while still keeping gravity the same), the air would fall inwards, (just like the cup does if I let go of it when there is no countertop beneath it.) All this is in accord with the proper application of Newton's laws. The problem with the "basics" you are using to explain your idea is that they are based on misconceptions.
  20. Generating Gravity

    Let's see, the Moon makes 1 rotation every 27.25 days and has a radius of 1738 km. This puts the speed at it's equator at 4.64 m/sec or ~10 mph. 1/100th that of the speed at the Earth's equator, so gravity on the surface of the Moon should be 1/100 of that of the Earths. But it isn't, it is 1/6th of that. So let's try another track. Venus is pretty close to the same size as the Earth (6052 km radius vs. Earth's 6378 km) it is just slightly less dense. But it also rotates very slowly. taking 243 days to make one rotation. This give the surface speed at the equator of 4 mph. Even slower than the Moon's. Yet it has a surface gravity of 90% of the Earth's. It also has a thick atmosphere, but if it is the speed of the planet that holds the atmosphere to the planet, Venus shouldn't be able to hold on to it atmosphere. But now I guess you are going to argue that its Venus' thick atmosphere that gives it its higher gravity. But then we get back to the Moon which still has a much higher gravity than your idea would predict, and yet has no atmosphere. You seem to keep bouncing around as what you claim causes gravity, changing the cause depending on the situation. In reality, all you've ever offered is a bunch of hand-waving. No actual predictions as to what your hypothesis would predict what should happen under certain given conditions. For example, here's a simple one: exactly how much difference would there be in the weight of a 130 lb person if the Earth had no atmosphere? Since you have of yet offered no numbers, I'll assume you have no idea. Compare this to the present model of gravity. One that we understand so well that we can launch a spacecraft have it pass by a moving planet at just the right speed distance and angle so that that planet's gravity changes its speed and direction in just the right way so that it passes by a second moving planet in just the right way such that the spacecraft's speed and direction is altered in just the right way to reach a third planet, and then after this flyby reach yet a forth planet. Without being able to predict with very high precision exactly how that craft responds to gravity along its entire trip. And that requires a very accurate model for gravity. And yet you expect us to take seriously a bunch of vague suppositions made by someone who couldn't even work out how Newton's Laws of motion applied to the atmosphere at the Equator.
  21. Generating Gravity

    The air doesn't leave at the equator because the centrifugal effect is too small to overcome gravity, as per the link you gave. 4.39 cm/sec2 for the centrifugal effect and 980.665 cm/sec2 for gravity. Thus in this "tug of war", gravity wins overwhelmingly. The statement of gravity having to increase in order to maintain the same path refers to an object that in a free-fall trajectory. This is not the case for the atmosphere. The air at the equator is actually moving too slow to maintain an orbit. If it wasn't for the body of the Earth being in the way, it would fall inward. As it is, the ground supports the lowest level of air and each layer of air supports the layer above it. ( and since air is compressible, This causes air density and pressure to vary with altitude.) The shuttle maintained it's orbit due to the fact that it was traveling fast enough at its altitude for gravity and the centrifugal effect to balance out (on average*). So at 400 km above the Earth, acceleration due to gravity is 8.678 m/ss The shuttle has an average speed of 7.669.6 m/s . Which, if traveling in a circle with a radius of 6778 km (earth radius +400 km), creates a centrifugal effect of 8.778 m/s2. * I say on average because I don't want to imply that this is some delicate balancing act where if the Shuttle were to lose a bit of speed it would come crashing into the Earth or if it gained a bit it would go flying off into space. This is not the case. A reasonable increase or decrease of speed would just put the shuttle in a different type of orbit, one that swings in closer to the Earth and then moves out further away. This elliptical orbital is actually the norm as perfectly circular orbits are just not practical to maintain. To fling the Shuttle way from the Earth completely would require a velocity increase of 3175 m/s, and to bring the low point of its orbit down to the point where the vast majority of the Earths atmosphere is would require losing 98.4 m/s.
  22. Generating Gravity

    It might help if you actually read what I wrote. I said the the Earth's gravity at Moon distance drops to 0.0028% of the value it has at the Earth's surface, not that it has dropped by 0.0028% In contrast, the pull of gravity at the equator drops to ~99.81% of the value it has at the poles. (though you'd actually only weigh ~ 99.47% as much at the Equator. That extra reduction is due to the the centrifugal effect caused by the Earth' rotation.)
  23. Generating Gravity

    99.999997% of the Earth's atmosphere is below that 62 mile altitude. If it the air above us that holds us to the planet then that force should drop to about 0.000003% of the surface value at that height, and it doesn't. Even at the distance of the Moon, nearly a quarter of a million miles away, gravity has only dropped to 0.0028% of the value it is at the surface of the Earth. At the distance the ISS orbits (254 miles) it is still 88.5% of what it is at the surface, even though it is well beyond the vast majority of the atmosphere.
  24. Generating Gravity

    You've made this same statement about objects on the surface of the Earth as moving at ~1k mph before. You do realize that this figure only holds near the equator? Where I live the number is closer to 700 mph, at the arctic circle it is ~390 mph, and at either pole you are slowly rotating at 0.0007 rpm.
  25. It is not true that you have added KE in every frame. There will be frames in which the the magnitude of the object's velocity has decreased after the acceleration ( the acceleration can be negative or positive depending on the frame) and thus it lost KE in that frame. Even the magnitude of the KE change is not constant across all frames. In the frame where a 1 Kg mass accelerates from 0 to 1m/s, it gains 0.5 joules of KE. But in the frame where is is seen as accelerating from 1 m/s to 2 m/s, it gains 1.5 joules of KE.