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| ==Explanation== | | ==Explanation== |
| + | {{incomplete|Created by a MUON ON SALE- Please change this comment when editing this page. Do NOT delete this tag too soon.}} |
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− | This comic shows a box labeled to indicate that it contains 30,000 fresh {{w|neutrino}}s and four zeptograms of {{w|dark matter}}. The box is intended as an inexpensive gift for a {{w|cosmologist}}. The gift giver didn't put those things in the box—both are simply passing through it, so the "gift" consists of exactly what was in the empty space it occupies. While the caption suggests this would be a good gift for a cosmologist, what they or anyone else would do with such a box is uncertain.
| + | According to this comic, "Cosmologists are easy to shop for because you can just get them a box." The example box allegedly contains 30,000 fresh neutrinos and 8 zeptograms of dark matter. The gift giver didn't put these things in the box; both are simply passing through it. There are about a billion {{w|neutrino}}s per cubic meter throughout space, produced during the {{w|Big Bang}}.[https://physics.mit.edu/news/journal/physicsatmit_14_conrad/] However, the flux of "freshly produced" {{w|solar neutrino}}s at Earth is around 7.1×10<sup>10</sup>/cm<sup>2</sup>/s. |
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− | There are about a billion neutrinos per cubic meter throughout space, produced during the {{w|Big Bang}}.[https://physics.mit.edu/news/journal/physicsatmit_14_conrad/] However, the flux of "freshly produced" {{w|solar neutrino}}s at Earth is around 6.5×10<sup>10</sup>/cm<sup>2</sup>/s, yielding about 2.1 million per cubic meter, and implying the box is around 12 liters, three quarters as big as a typical {{w|breadbox}}.
| + | Eight zeptograms is an infinitesimal amount equal to eight sextillionths of a gram. For comparison, Wolfram Alpha says it's equivalent to approximately 4800 daltons, which works out to the weight of about 400 carbon-12 atoms. |
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− | Four zeptograms is a minuscule mass, equal to four sextillionths of a gram, the mass of about 200 carbon-12 atoms or around 20 to 23 {{w|amino acid}}s. There is an estimated 0.011 to 0.016 {{w|solar mass}}es of dark matter per cubic {{w|parsec}} local to the solar system,[https://iopscience.iop.org/article/10.1088/1361-6633/ac24e7/meta] or about 900 zeptograms per cubic meter, suggesting the box is closer to 4 liters. This discrepancy [[2035: Dark Matter Candidates|could imply Randall agrees]] with cosmologists who believe dark matter is partially composed of {{w|primordial black hole}}s,[https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.120.121301][https://www.sciencedirect.com/science/article/abs/pii/S2212686418301250?via%3Dihub][https://news.yale.edu/2021/12/16/black-holes-and-dark-matter-are-they-one-and-same][https://iopscience.iop.org/article/10.3847/2041-8205/823/2/L25][https://iopscience.iop.org/article/10.1088/1475-7516/2010/04/023] instead of being composed entirely of ubiquitous subatomic particles. This comic coincided with the [https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-delivers-deepest-infrared-image-of-universe-yet first James Webb Space Telescope science image release to the public] containing {{w|gravitational lens|gravitationally lensed}} very distant {{w|quasar}}s and {{w|population III star}}s, the spectra of which can be used to test [https://twitter.com/SheerPriya/status/1546576050976870400/photo/1 certain hypotheses associated with dark matter being black holes.] A billion neutrinos have a mass of only about 2×10<sup>-12</sup> zeptograms, at about 0.1 {{w|electron volt}}s each.
| + | The "local source" mentioned in the title text is the Sun; it takes light (and neutrinos) 8 minutes to reach Earth once they're emitted. |
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− | The "local source" mentioned in the title text is a joke about the commercial value of fresh, locally produced items, but the comic means that the neutrinos come from the Sun. It takes solar neutrinos slightly more than 8 minutes to reach Earth once they're emitted, roughly the same time as photons take to make the trip. (While [https://en.wikipedia.org/wiki/Radiative_zone energy takes approximately 170,000 years to reach the Sun's surface from its core,] where the fusion reactions occur, the neutrinos are not slowed down inside the Sun and travel at about 99.9999999999% of the speed of light. Thus, they will have aged by less than a millisecond,[https://www.omnicalculator.com/physics/time-dilation] and so are technically even fresher than indicated.)
| + | Randall suggests that the neutrinos and dark matter in an empty box would make a good gift for a {{w|cosmologist}}. What anyone would ''do'' with 80,000 fresh neutrinos and 8 zeptograms of dark matter is open to speculation. |
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| ==Transcript== | | ==Transcript== |
| + | {{incomplete transcript|Do NOT delete this tag too soon.}} |
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− | :[A picture of a box with writing on one side. The box's lid is slightly hanging off the right edge of the box so you can see inside. The inside of the box is black.] | + | :[A picture of a box with writing on one side] |
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| + | :Box: |
| :30,000 neutrinos | | :30,000 neutrinos |
− | :<small>Freshly produced</small> | + | :Freshly produced |
− | :Plus 4 zeptograms | + | :Plus 4 zetograms of dark matter |
− | :of dark matter
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| :[Caption below the panel]: | | :[Caption below the panel]: |
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| {{comic discussion}} | | {{comic discussion}} |
− | [[Category:Cosmology]] | + | [[Category:Astronomy]] |