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Janus

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Everything posted by Janus

  1. Or, the more reason explanation for Mercury and Venus not having satellites and slow rotations is that they are both closer to the Sun and subject to greater tidal forces which has the effect of making it harder to capture and hold on to satellites and results in greater tidal braking which slows rotation. The Earth-Venus alignment is most likely a result of orbital resonance (Earth orbits 8 time for every 13 orbits of Venus). Such orbital resonances are not rare, and result from the fact that the orbits are not independent of each other, because each planet has a small gravitational effect on the other.
  2. I'll give you the values to work it out for yourself. e = 0.0167 a = 1.496e11 meters u = 1.3275e20 m^3/s^2 q ( at the Vernal equinox) = 102.93 degrees
  3. For those interested in the equations used to work out the radial component for an elliptical orbit: Orbital velocity: = V_o = sqrt(u(2/r-1/a) Where: u is the gravitational parameter (GM) for the Sun r is the present radial distance of the orbiting body a is the semi-major axis of the orbit "r" for a chosen point of an orbit is found by r = (a(1-e^2))/(1+e cos(q)) where e is the eccentricity of the orbit q is the angle from perihelion at the chosen point of the orbit. The orbital velocity component perpendicular to the radial line is found by V_p = 2 sqrt(ua(1+e)/(1-e))/r V_r, the radial component can derived from V_o and V_p by applying a bit of trig.
  4. I'll cut to the chase. Just because you personally cannot envision how light waves could travel without the aid of a medium does not equate to it being impossible.
  5. Washing your hands is more about physically removing the virus from their surface than it is about killing the virus.
  6. All three of the motions mentioned here are themselves subject to gravity. The Earth is in orbit around the Sun, the Sun orbits our galaxy, the galaxies in our local group orbit a common center of gravity, etc. This means that these motions are also examples of free-fall. The Earth is in a free-fall trajectory around the Sun due to the Gravitational attraction of the Sun. It undergoes a centripetal acceleration towards the Sun, which, due to its tangential velocity, has it following an orbital path. The object you drop is also attracted to the Sun, has the same centripetal acceleration, and same velocity relative to the Sun that the Earth does. So, since the Sun effects both equally, you only need to consider the force acting between them.* The Earth's force of attraction doesn't have to be any stronger than it would if the Earth were floating free in space far from any other gravitational source. Motion, in of itself is of no consequence, as the Earth and object are already sharing the same motion, and it would take a force acting on one and not the other to change this, The same holds for the Sun orbiting the galaxy, and the galaxies moving due to mutual gravitational attraction. * the caveat here is that if the Sun isn't on the horizon, the object will be slightly closer or further from the Sun than the center of the Earth is, so it will have a slightly different centripetal acceleration. However, even if the Sun is directly overhead, your object is only 1/23456 closer to the Sun. This is pretty insignificant. This difference results in what is known as a "tidal force", and is how the Sun effects tides on the Earth. The tidal effects due to the galaxy and other galaxies are magnitudes smaller than this.
  7. Why is it that "common sense" is so often a conclusion reached by starting with incomplete or incorrect information and applying faulty logic to it?
  8. No. It simply wouldn't be worth the time and effort to sort through the vast quantities of "chaff" to find one grain of wheat that likely doesn't even exist.
  9. That's not what I said. 12 and 11 are dimensionless numbers. 1s and 1s2 involve units of dimension and are not equivalent, in the same way that 1ft and 1ft2 are not equivalent. 1s = 11s1 1s2 =12s2 While the 11 and12 parts of these equations are equal to each other, the s1 and s2 are not.
  10. f=ma does not resolve to f=mv in one sec. Neither are force and momentum equivalent. Reducing to base units of KGS: f(Newtons) = kg-m/s^2, and momentum = kg-m/s. Even over one sec these these are not equivalent. 1kg-1m/1s^2 ≠ 1kg-1m/1s, because 1s^2 = (1s)^2 = 1s x 1s For the two to be equivalent, everything in one equation as to cancel out everything in the other, but this doesn't 1kg-1m/(1s x 1s) ≠ 1kg-1m/1s, or 1= 1/s one of the s's on the left side doesn't cancel out. What you are trying to do is like trying to argue that 1 linear foot is equivalent to one square foot, when one is a linear measure and the other a measure of area.
  11. "Get your hands off me, you damn dirty ape!"
  12. Electromagnetic radiation does not produce an Electromagnetic field, it carries information about changes in the field. Likewise gravitational waves do not produce a gravitational field, but carry information about changes in the field. While you can't have gravitational waves without a field, you can have a field without gravitational waves. The spiral arms of a galaxy have nothing to do with the SMBH at the center. The central BH has almost no effect beyond locally as it only represents a very small fraction of the total mass of a galaxy. It is the combined mass of the rest of the galaxy that dominates.
  13. Again, I don't think you actually understand what gravitational waves are and what produces them. It might be that you are under the common misconception that it is gravitational waves that mediate gravitational attraction; that masses naturally radiate gravitational waves and these waves are the mechanism by which masses attract each other. This is not the case. Gravitational attraction is the result of a field that exists whether or not there are any gravitational waves produced. Gravitational waves represent ripples in that field that are produced under certain circumstances. They are very, very, very weak; much too weak to produce those kinds of visible effects in a ring system. And again, in order to produce wavelengths of that size, you would require a mass oscillating at a few thousand hz, at the very least. The spiral arms of galaxies are produced by waves, but not gravitational waves. They are compression waves passing through the galaxy and are more like sound waves passing through a medium. Also, these waves are not as intense as the visible appearance would lead you to believe. The bright spiral arms are not bright because they contain that much more material, it is because this is where most of the new stars are being born. The "gaps" between the arms aren't that devoid of matter, they just contain more older, dimmer stars than bright young ones.
  14. There is nothing about Jupiter that would produce gravitational waves of a high enough frequency to have wavelengths that short. To generate gravitational waves you need an accelerating mass. In this case, the only acceleration would be due to Jupiter's rotation. Any gravitational waves produced by this would have a frequency equal to Jupiter's rotational rate on 1 cycle per 10 hrs. Traveling at c, this gives a wavelength of roughly 10^10 km.
  15. "Speed" doesn't have negative or positive values, as it is just a measure of magnitude. "velocity" is magnitude and direction, and thus can take on negative and positive values. So, if you assume that Bob measures a velocity for Alice of +0.983c , then using the same velocity convention, Alice would measure a velocity of -0.983c for Bob. However, the +/- in these velocities have no bearing on gamma factor each measures effecting the other. This is because gamma contains v^2/c^2. and v^2 is v x v. so if v= +0.983c, you have (+0.983c) x (+0.983c)/c^2 = 0.966...* , and if v = -0.983, you have ( -0.983c) x (-0.983c)/c^2 = 0.996... , since a negative times a negative yields a positive. You get the same answer if v is positive or negative. * (+0.983c) x (+0.983c)/c^2 = (+0.983)x(+0.983) c^2/c^2. The c^2 cancels out.
  16. You are assuming that there is such a thing as absolute motion, and that there is a way to tell who is really "moving" and who isn't. This is not the case. Motion is only relative. Thus, you can only say that something is moving relative to some chosen reference frame frame. In this case, there are two reference frames to choose from:* 1. The one Bob and the Planet are at rest with respect to 2. The One Alice is at rest with respect to. If you are working from the Bob/planet frame, then Alice is moving and this frame measures Alice as length contracted. If you are working from Alice's frame, then it is Bob and the Planet that are moving, and it is they and the distance between them that is measured as being length contracted.** * There are an infinite number of reference frames we could use, it is just that these two are the most convenient to work from in this scenario. ** in addition, Bob would measure Alice's clock as ticking slower than his own, while Alice would measure clocks on Earth and the Planet as ticking slow compared to hers.
  17. While this "Wall of Fire: has a high temp, you have to understand the difference between temperature and heat content. Temperature is a measure of the average kinetic energy of the particles. Heat content is the total of the KE of the particles in a given volume. Thus a volume that contains a lot of low temp particles can have a larger heat content than an equal volume with higher temp, but fewer particles. Now while articles have described this wall as being of a "high density", this is meant relative to the normal solar wind density of a few particles per cubic centimeter. This a much better vacuum that can be achieved by man on Earth by several magnitudes. This "thick wall" off plasma is a not that much less of a vacuum. To melt a comet you need to add a fair amount of heat energy to it, and even at such a high temperature, this plasma has nowhere near the total heat content per cubic meter to do this.
  18. In d = vt, all three are measured by Bob. v = 0.986c and t = 5 y, so d = 4.93 LY Alice would measure 'd = vt', for her v = 0.986c and t' equals 0.833 y, so d' ( the distance between planets) is ~0.822 ly To use length contraction, Alice would use d/y = d' or 4.93/y = 0.822 LY, which is the same answer.
  19. If you by this you mean that Bob can measure Alice as being length contracted, but Alice can't measure Bob as being length contracted, then you're wrong. Or let's put it this way: Assume there is a planet 4.93 ly from Bob as measured by Bob, to which Alice is traveling. Then, as measured by Alice, this planet and Bob are only ~0.822 ly apart. Bob and this planet is traveling at 0.986c relative to Alice, and thus Alice measures 0.822 ly/0.986 = ~0.834 yr between Bob passing and the planet passing.
  20. But since the OP specifically used "BC" and "AD", which are not used in the Hindu calendar, that is not relevant here.
  21. I went back and corrected the typo, that 1339 years should have be 4399 years . The Gregorian calendar wasn't introduced until 1582, so it wouldn't have been in effect over this time period. But even if you take the difference between 1399 Julian years and 1399 Gregorian years, it only works out to be ~34 days.
  22. 4399 years. As there is no year 0, there is only 1 year between the start of 1 BC and 1 AD, and between the start of 1AD and the start of 1400 AD, there are just 1399 full years.
  23. No, you were not. You were told that posting a video alone, so that someone has to watch the video in order to participate in the thread is against the rules, as stated in this quote from the rules. "Links, pictures and videos in posts should be relevant to the discussion, and members should be able to participate in the discussion without clicking any links or watching any videos. Videos and pictures should be accompanied by enough text to set the tone for the discussion, and should not be posted alone." You weren't told that you can't post any videos, just that that you didn't follow the proper rules for posting videos.
  24. Any pardon Pence issued could only cover federal crimes, It can't apply to cases being prosecuted at a state level such as those in New York. Oh, And I can make at least one prediction for the Biden Presidency - Obama will finally get his portrait hung in the White House.
  25. I assume that the Dutch version is similar to the Finnish "salmiakki". I've tried two versions. One was soft, a bit salty and quite good. The other was harder and much stronger on the ammonium chloride taste. While I was taken back at first by the second one, and can see why many people wouldn't like it, I kept giving it a chance, ended up finding it oddly addictive, and finished the box.
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