Editing 2707: Astronomy Numbers
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[[Ponytail]], apparently a scientist researching something related to Earth's orbit, finds that on a particular date, Earth will be approaching the sun at a velocity of 65 miles per hour. To American ears, this is a very normal sounding value (i.e. the speed of a fast-moving vehicle, often used as a speed limit on highways in the US). As Ponytail is accustomed to astronomical values, she is thrown off by this, and remarks that she finds it "suspicious" when reasonably human-scaled numbers come up in astronomy. | [[Ponytail]], apparently a scientist researching something related to Earth's orbit, finds that on a particular date, Earth will be approaching the sun at a velocity of 65 miles per hour. To American ears, this is a very normal sounding value (i.e. the speed of a fast-moving vehicle, often used as a speed limit on highways in the US). As Ponytail is accustomed to astronomical values, she is thrown off by this, and remarks that she finds it "suspicious" when reasonably human-scaled numbers come up in astronomy. | ||
| β | However, Ponytail seems to take this philosophy to an absurd degree by insisting that ''all'' scales should be as incomprehensible as astronomical ones, even those used for human-scale measurements, such as the weight of cats. In the third panel, the vet, [[Megan]], is seemingly used to this problem (perhaps she gets a lot of astronomers, or Ponytail has a hypochondriac cat), so she restates the 12-lb weight of Ponytail's cat in solar masses. Since using this unit yields an ''incredibly'' small number, 3Γ10<sup>-30</sup> (a three preceded by a decimal point and 29 zeroes), it satisfies Ponytail's need for incomprehensibly-scaled values. This weight is in fact about 13 lb 2 oz (about 5.5 kilograms), slightly heavier than the initial figure given for the cat, but within [[2585: Rounding|rounding error]] for the single digit of precision that Megan uses. | + | However, Ponytail seems to take this philosophy to an absurd degree by insisting that ''all'' scales should be as incomprehensible as astronomical ones, even those used for human-scale measurements, such as the weight of cats. In the third panel, the vet, [[Megan]], is seemingly used to this problem (perhaps she gets a lot of astronomers, or Ponytail has a hypochondriac cat), so she restates the 12-lb weight of Ponytail's cat in solar masses. Since using this unit yields an ''incredibly'' small number, 3Γ10<sup>-30</sup> (a three preceded by a decimal point and 29 zeroes), it satisfies Ponytail's need for incomprehensibly-scaled values. This weight is in fact about 13 lb 2 oz (about 5.5 kilograms), slightly heavier than the initial figure given for the cat, but within [[2585: Rounding|rounding error]] for the single digit of precision that Megan uses. According to [[2205:_Types_of_Approximation | 2205: Types of Approximation]] that rounding error is unusually small for an astronomer, though. |
The Earth's orbital velocity around the Sun is far above normal human scales (around 30 kilometers per second or 108,000 kilometers per hour). However, Earth has a fairly circular orbit around the Sun, so most of this speed ends up being tangential (sideways) rather than radial (towards or away from) the Sun, which is the value relevant for Ponytail's calculations. On January 1 (the date being discussed in the comic), Earth's radial velocity is close to its smallest value because we reach our closest point to the Sun in the first few days of January each year (in 2023, {{w|Perihelion|perihelion}} happens on January 4). Thus, by January 1, the Earth's velocity toward the Sun is nearly zero before it starts traveling away from the Sun again. This is how Ponytail ended up with the "suspiciously" small value of 65 miles per hour. | The Earth's orbital velocity around the Sun is far above normal human scales (around 30 kilometers per second or 108,000 kilometers per hour). However, Earth has a fairly circular orbit around the Sun, so most of this speed ends up being tangential (sideways) rather than radial (towards or away from) the Sun, which is the value relevant for Ponytail's calculations. On January 1 (the date being discussed in the comic), Earth's radial velocity is close to its smallest value because we reach our closest point to the Sun in the first few days of January each year (in 2023, {{w|Perihelion|perihelion}} happens on January 4). Thus, by January 1, the Earth's velocity toward the Sun is nearly zero before it starts traveling away from the Sun again. This is how Ponytail ended up with the "suspiciously" small value of 65 miles per hour. | ||
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The title text makes a joke by reversing the typical cat behavior of [[729: Laser Pointer|chasing laser pointer dots]] by envisioning a cat with a mass equivalent to 12 solar masses. The {{w|Schwarzschild radius}} for an object of that mass would be around 36 kilometers, so a cat-sized object of that mass would be a black hole, and would therefore bend all nearby light (including that from the laser) inwards towards its singularity. But then it should also draw in the physical laser pointer device itself, if it is neither very far away nor in orbit. | The title text makes a joke by reversing the typical cat behavior of [[729: Laser Pointer|chasing laser pointer dots]] by envisioning a cat with a mass equivalent to 12 solar masses. The {{w|Schwarzschild radius}} for an object of that mass would be around 36 kilometers, so a cat-sized object of that mass would be a black hole, and would therefore bend all nearby light (including that from the laser) inwards towards its singularity. But then it should also draw in the physical laser pointer device itself, if it is neither very far away nor in orbit. | ||
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| + | An alternative explanation to the title text is that such a large cat would be incredibly alarming and would draw attention from law enforcement agencies, who would aim their guns (and consequently laser pointers) at the cat. | ||
==Transcript== | ==Transcript== | ||
