https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&feedformat=atom&user=165.1.131.69 2026-05-15T09:27:31Z User contributions MediaWiki 1.30.0 https://www.explainxkcd.com/wiki/index.php?title=3243:_Crystal_Gazing&diff=412069 2026-05-08T18:29:03Z

<p>165.1.131.69: /* Explanation */ ce</p> <hr /> <div>{{comic<br /> | number = 3243<br /> | date = May 8, 2026<br /> | title = Crystal Gazing<br /> | image = crystal_gazing_2x.png<br /> | imagesize = 281x397px<br /> | noexpand = true<br /> | titletext = 'Beyond that lies a vale of fire through which my vision cannot penetrate' is the kind of fun thing geologists, heliophysicists, and early universe cosmologists have a lot of opportunities to say.<br /> }}<br /> <br /> ==Explanation==<br /> {{incomplete|This page was created over 4.54 billion nanoseconds ago. Don't remove this notice too soon.}}<br /> <br /> A geologist dressed up as a wizard announces - in archaic language befitting his costume - that he has determined the age of the earth by analysing {{w|zircon}}. Zircon is a crystal with the formula ZrSiO4. During its formation it can incorporate Uranium instead of Zirconium in its lattice - but no lead. However Uranium decays (via several intermediates) into lead. Thus a sufficiently old Zircon crystal will contain some lead, allowing geologists to calculate its age. This method is especially reliable since Uranium 238 decays into Lead 208 with a half life of 4.5 billion years while Uranium 235 decays into Lead 207 with a half life of 0.7 billion years. This allows geologists to determine the age even if some lead was lost from the crystal.<br /> <br /> ==Transcript==<br /> {{incomplete transcript|Don't remove this notice too soon.}}<br /> <br /> :[A character in wizard garb with long beard and hair talks to Cueball. To the left of the wizard is a chart with two lines intersecting.]<br /> <br /> :Wizard: By gazing into my crystals of zircon, I have divined the date of the hour of fire marking the limit of this world's existence.<br /> :Wizard: 4.54 billion years ago, the beginning was nigh!<br /> <br /> :[Caption below comic:]<br /> :Geochronologists are just reverse prophets of doom.<br /> <br /> {{comic discussion}}&lt;noinclude&gt;<br /> [[Category:Geology]]<br /> [[Category:Comics featuring Cueball]]</div>

165.1.131.69 https://www.explainxkcd.com/wiki/index.php?title=3243:_Crystal_Gazing&diff=412068 2026-05-08T18:28:09Z

<p>165.1.131.69: /* Transcript */ ce</p> <hr /> <div>{{comic<br /> | number = 3243<br /> | date = May 8, 2026<br /> | title = Crystal Gazing<br /> | image = crystal_gazing_2x.png<br /> | imagesize = 281x397px<br /> | noexpand = true<br /> | titletext = 'Beyond that lies a vale of fire through which my vision cannot penetrate' is the kind of fun thing geologists, heliophysicists, and early universe cosmologists have a lot of opportunities to say.<br /> }}<br /> <br /> ==Explanation==<br /> {{incomplete|This page was created over 4.54 billion nanoseconds ago. Don't remove this notice too soon.}}<br /> <br /> A geologist dressed up as a wizard announces - in archaic language befiting his costume - that he has determined the age of the earth by analysing zircon. Zircon is a crystal with the formula ZrSiO4. During its formation it can incorporate Uranium instead of Zirconium in its lattice - but no lead. However Uranium decays (via several intermediates) into lead. Thus a sufficiently old Zircon crystal will contain some lead, allowing geologists to calculate its age. This method is especially reliable since Uranium 238 decays into Lead 208 with a half life of 4.5 billion years while Uranium 235 decays into Lead 207 with a half life of 0.7 billion years. This allows geologists to determine the age even if some lead was lost from the crystal.<br /> <br /> ==Transcript==<br /> {{incomplete transcript|Don't remove this notice too soon.}}<br /> <br /> :[A character in wizard garb with long beard and hair talks to Cueball. To the left of the wizard is a chart with two lines intersecting.]<br /> <br /> :Wizard: By gazing into my crystals of zircon, I have divined the date of the hour of fire marking the limit of this world's existence.<br /> :Wizard: 4.54 billion years ago, the beginning was nigh!<br /> <br /> :[Caption below comic:]<br /> :Geochronologists are just reverse prophets of doom.<br /> <br /> {{comic discussion}}&lt;noinclude&gt;<br /> [[Category:Geology]]<br /> [[Category:Comics featuring Cueball]]</div>

165.1.131.69 https://www.explainxkcd.com/wiki/index.php?title=3243:_Crystal_Gazing&diff=412067 2026-05-08T18:27:44Z

<p>165.1.131.69: /* Transcript */ actually nvm</p> <hr /> <div>{{comic<br /> | number = 3243<br /> | date = May 8, 2026<br /> | title = Crystal Gazing<br /> | image = crystal_gazing_2x.png<br /> | imagesize = 281x397px<br /> | noexpand = true<br /> | titletext = 'Beyond that lies a vale of fire through which my vision cannot penetrate' is the kind of fun thing geologists, heliophysicists, and early universe cosmologists have a lot of opportunities to say.<br /> }}<br /> <br /> ==Explanation==<br /> {{incomplete|This page was created over 4.54 billion nanoseconds ago. Don't remove this notice too soon.}}<br /> <br /> A geologist dressed up as a wizard announces - in archaic language befiting his costume - that he has determined the age of the earth by analysing zircon. Zircon is a crystal with the formula ZrSiO4. During its formation it can incorporate Uranium instead of Zirconium in its lattice - but no lead. However Uranium decays (via several intermediates) into lead. Thus a sufficiently old Zircon crystal will contain some lead, allowing geologists to calculate its age. This method is especially reliable since Uranium 238 decays into Lead 208 with a half life of 4.5 billion years while Uranium 235 decays into Lead 207 with a half life of 0.7 billion years. This allows geologists to determine the age even if some lead was lost from the crystal.<br /> <br /> ==Transcript==<br /> {{incomplete transcript|Don't remove this notice too soon.}}<br /> <br /> :[A character in wizard garb with long beard and hair talks to Cueball. To the left of the wizard is a chart with two lines intersecting.]<br /> <br /> :By gazing into my crystals of zircon, I have divined the date of the hour of fire marking the limit of this world's existence.<br /> :4.54 billion years ago, the beginning was nigh!<br /> <br /> :[Caption below comic:]<br /> :Geochronologists are just reverse prophets of doom.<br /> <br /> {{comic discussion}}&lt;noinclude&gt;<br /> [[Category:Geology]]<br /> [[Category:Comics featuring Cueball]]</div>

165.1.131.69 https://www.explainxkcd.com/wiki/index.php?title=3243:_Crystal_Gazing&diff=412066 2026-05-08T18:27:19Z

<p>165.1.131.69: /* Transcript */ ce</p> <hr /> <div>{{comic<br /> | number = 3243<br /> | date = May 8, 2026<br /> | title = Crystal Gazing<br /> | image = crystal_gazing_2x.png<br /> | imagesize = 281x397px<br /> | noexpand = true<br /> | titletext = 'Beyond that lies a vale of fire through which my vision cannot penetrate' is the kind of fun thing geologists, heliophysicists, and early universe cosmologists have a lot of opportunities to say.<br /> }}<br /> <br /> ==Explanation==<br /> {{incomplete|This page was created over 4.54 billion nanoseconds ago. Don't remove this notice too soon.}}<br /> <br /> A geologist dressed up as a wizard announces - in archaic language befiting his costume - that he has determined the age of the earth by analysing zircon. Zircon is a crystal with the formula ZrSiO4. During its formation it can incorporate Uranium instead of Zirconium in its lattice - but no lead. However Uranium decays (via several intermediates) into lead. Thus a sufficiently old Zircon crystal will contain some lead, allowing geologists to calculate its age. This method is especially reliable since Uranium 238 decays into Lead 208 with a half life of 4.5 billion years while Uranium 235 decays into Lead 207 with a half life of 0.7 billion years. This allows geologists to determine the age even if some lead was lost from the crystal.<br /> <br /> ==Transcript==<br /> {{incomplete transcript|Don't remove this notice too soon.}}<br /> <br /> :[A character in wizard garb with long beard and hair talks to Cueball. To the left of the wizard is a chart with two lines intersecting.]<br /> <br /> :By gazing into my crystals of zircon, I have divined the date of the hour of fire marking the limit of this world's existence.<br /> :4.54 billion years ago, the beginning was nigh!<br /> <br /> :[Caption below comic:]<br /> :Geochronologists are just reverse prophets of doom.<br /> <br /> {{comic discussion}}&lt;noinclude&gt;<br /> [[Category:Geology]]<br /> [[Category:Cosmology]]<br /> [[Category:Comics featuring Cueball]]</div>

165.1.131.69 https://www.explainxkcd.com/wiki/index.php?title=3243:_Crystal_Gazing&diff=412065 2026-05-08T18:27:06Z

<p>165.1.131.69: /* Transcript */ cats; copyedit</p> <hr /> <div>{{comic<br /> | number = 3243<br /> | date = May 8, 2026<br /> | title = Crystal Gazing<br /> | image = crystal_gazing_2x.png<br /> | imagesize = 281x397px<br /> | noexpand = true<br /> | titletext = 'Beyond that lies a vale of fire through which my vision cannot penetrate' is the kind of fun thing geologists, heliophysicists, and early universe cosmologists have a lot of opportunities to say.<br /> }}<br /> <br /> ==Explanation==<br /> {{incomplete|This page was created over 4.54 billion nanoseconds ago. Don't remove this notice too soon.}}<br /> <br /> A geologist dressed up as a wizard announces - in archaic language befiting his costume - that he has determined the age of the earth by analysing zircon. Zircon is a crystal with the formula ZrSiO4. During its formation it can incorporate Uranium instead of Zirconium in its lattice - but no lead. However Uranium decays (via several intermediates) into lead. Thus a sufficiently old Zircon crystal will contain some lead, allowing geologists to calculate its age. This method is especially reliable since Uranium 238 decays into Lead 208 with a half life of 4.5 billion years while Uranium 235 decays into Lead 207 with a half life of 0.7 billion years. This allows geologists to determine the age even if some lead was lost from the crystal.<br /> <br /> ==Transcript==<br /> {{incomplete transcript|Don't remove this notice too soon.}}<br /> <br /> :[A character in wizard garb with long beard and hair talks to Cueball. To the left of the wizard is a chart with two lines intersecting.]<br /> <br /> :By gazing into my crystals of zircon, I have divined the date of the hour of fire marking the limit of this world's existence.<br /> :4.54 billion years ago, the beginning was nigh!<br /> <br /> :[Caption below comic:]<br /> :Geochronologists are just reverse prophets of doom.<br /> <br /> {{comic discussion}}&lt;noinclude&gt;<br /> [[Category:Geology]]<br /> [[Catgeory:Cosmology]]<br /> [[Category:Comics featuring Cueball]]</div>

165.1.131.69