Editing 2413: Pulsar Analogy
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{{w|Pulsar}}s are a kind of old, shrunken, fast-spinning star. They are usually {{w|neutron stars}}. They no longer shine in all directions, but instead produce beams of radiation out of their magnetic poles, which blip by us in rapid pulses as they spin. | {{w|Pulsar}}s are a kind of old, shrunken, fast-spinning star. They are usually {{w|neutron stars}}. They no longer shine in all directions, but instead produce beams of radiation out of their magnetic poles, which blip by us in rapid pulses as they spin. | ||
| − | + | Ponytail, an astronomer in this comic, explains a pulsar's fast rotation with an analogy about a tape measure retracting. The analogies that Ponytail picks are incredibly poor ones. | |
Since the analogy does result in something that spins, the reader might think that, while they don't immediately see how it helps in understanding pulsars, they're willing to reserve judgment to see what is then done with the analogy; Cueball's response may suggest this sort of wait-and-see attitude. However, the analogy is likely to be useless or misleading, as the tape measure starts to rotate because the retracting tape is not moving only in a radial (in/out) direction. As a star collapses into a pulsar, its natural rotation rate is greatly amplified by its shrinking moment of inertia. | Since the analogy does result in something that spins, the reader might think that, while they don't immediately see how it helps in understanding pulsars, they're willing to reserve judgment to see what is then done with the analogy; Cueball's response may suggest this sort of wait-and-see attitude. However, the analogy is likely to be useless or misleading, as the tape measure starts to rotate because the retracting tape is not moving only in a radial (in/out) direction. As a star collapses into a pulsar, its natural rotation rate is greatly amplified by its shrinking moment of inertia. | ||
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While pulsars do demonstrate incredible {{w|Quake_(natural_phenomenon)#Starquake|starquakes}} and rotational {{w|Glitch_(astronomy)|glitches}}, neutron degeneracy is part of the mechanisms in which they are originally formed. During the formation of a neutron star, usually in the form of an initial inward implosion, the neutron degeneracy (basically the impossibility of neutron of occupying the same space because of fundamental constraints in physics that are studied by quantum mechanics) stops the implosion and redirects the shockwave outwards, thus producing a Supernova explosion. The analogy is with a tape measurer that hits a hand (the constraint) during its rapid rotation due to its retracting tape (the implosion) thus redirecting part of the energy towards the hand (the supernova energy is redirected outside). | While pulsars do demonstrate incredible {{w|Quake_(natural_phenomenon)#Starquake|starquakes}} and rotational {{w|Glitch_(astronomy)|glitches}}, neutron degeneracy is part of the mechanisms in which they are originally formed. During the formation of a neutron star, usually in the form of an initial inward implosion, the neutron degeneracy (basically the impossibility of neutron of occupying the same space because of fundamental constraints in physics that are studied by quantum mechanics) stops the implosion and redirects the shockwave outwards, thus producing a Supernova explosion. The analogy is with a tape measurer that hits a hand (the constraint) during its rapid rotation due to its retracting tape (the implosion) thus redirecting part of the energy towards the hand (the supernova energy is redirected outside). | ||
| − | However, astronomers do not usually let go of laser tape measures frequently, so they are probably not the top cause of any type of hand injuries, | + | However, astronomers do not usually let go of laser tape measures frequently, so they are probably not the top cause of any type of hand injuries, as [[Ponytail]] said. |
| − | The title text mentions the {{w|right-hand rule}} in three-dimensional space. In a typical 3D coordinate system the Y-axis will point counterclockwise to the X-axis when looking down from the positive Z-axis. In academia, students are often taught to remember a number of mathematical conventions by using their actual physical right and left hands to align the axes. When the axes are in a different order, the left hand can be used instead of the right, but there are a number of common operations in engineering and physics that use the {{w|cross product}} in systems where the first axis might point in absolutely any direction relative to the viewer. Using the hand rules, the thumb is aimed along the first axis, the forefinger along the second, and the middle finger along the third — all at ninety degrees. So, when the first axis points off to the right, the right wrist is torqued to its full extension to make the thumb point that way while the other two fingers don't. During exams, students can be seen performing this feat. People who learn cross products early in their life may develop other approaches for remembering these things, that don't stretch the hands as much, but then adopt the common approach once taught it | + | The title text mentions the {{w|right-hand rule}} in three-dimensional space. In a typical 3D coordinate system the Y-axis will point counterclockwise to the X-axis when looking down from the positive Z-axis. In academia, students are often taught to remember a number of mathematical conventions by using their actual physical right and left hands to align the axes. When the axes are in a different order, the left hand can be used instead of the right, but there are a number of common operations in engineering and physics that use the {{w|cross product}} in systems where the first axis might point in absolutely any direction relative to the viewer. Using the hand rules, the thumb is aimed along the first axis, the forefinger along the second, and the middle finger along the third — all at ninety degrees. So, when the first axis points off to the right, the right wrist is torqued to its full extension to make the thumb point that way while the other two fingers don't. During exams, students can be seen performing this feat. People who learn cross products early in their life may develop other approaches for remembering these things, that don't stretch the hands as much, but then adopt the common approach once taught it. |
==Transcript== | ==Transcript== | ||
