1887: Two Down, One to Go - Revision history

Natg19: /* Trivia */ aurora

2026-01-23T20:17:07Z

‎Trivia: aurora

R128: /* Trivia */ i may be daft

2026-01-05T18:06:00Z

‎Trivia: i may be daft

R128: /* Trivia */ add source

2026-01-05T18:05:26Z

‎Trivia: add source

Elektrizikekswerk: Moved some stuff to trivia section

2024-05-22T12:16:43Z

Moved some stuff to trivia section

Poxy6 at 17:34, 3 April 2024

2024-04-03T17:34:03Z

SilverTheTerribleMathematician: Remember that it is currently not unproven that light could travel instantaneously in one direction and half as fast in the other direction. The speed of light is in actuality just an average between the two outliers in speed.

2022-12-22T02:29:52Z

Remember that it is currently not unproven that light could travel instantaneously in one direction and half as fast in the other direction. The speed of light is in actuality just an average between the two outliers in speed.

SilverTheTerribleMathematician: /* Explanation */

2022-12-22T02:28:17Z

‎Explanation

Davidy22: Reverted edits by Explain xkcd server admin (talk) to last revision by Theusaf

2022-05-21T02:54:31Z

Reverted edits by Explain xkcd server admin (talk) to last revision by Theusaf

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Explain xkcd server admin at 21:51, 20 May 2022

2022-05-20T21:51:15Z

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Theusaf: Reverted edits by 👖🔥 (talk) to last revision by Jacky720

2022-05-11T18:45:00Z

Reverted edits by 👖🔥 (talk) to last revision by Jacky720

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@@ Line 42: / Line 42: @@
 [[Category:Total Solar Eclipse 2017]]
-[[Category:Astronomy]]
+[[Category:Aurora]]
 [[Category:Solar eclipses]]

@@ Line 31: / Line 31: @@
 * This particular ''aurora borealis'' happened because the coronal mass ejection (CME) headed directly toward Earth causing Northern Lights spreading more south than common. That solar flare was first detected by the {{w|Solar Dynamics Observatory|Solar Dynamics Observatory (SDO)}} just eight minutes after it happened at the Sun. This [https://www.nasa.gov/feature/goddard/2017/nasa-s-sdo-captures-image-of-mid-level-flare animation] shows what the probe SDO has seen on Sept. 4, 2017 in the early evening. While light, and x-rays as well, travel at light speed the mass ejected did only move at a speed of 500-1,000 km/s. It was [http://www.swpc.noaa.gov/news/shock-arrival-6-sep-2308-utc-4-september-cme first detected] by {{w|Deep Space Climate Observatory|DSCOVR}} two days later, still 1,5 Mio. to reach Earth or just 30 minutes before the --non critical-- impact. And at this [http://www.swpc.noaa.gov/news/g3-watch-7-through-9-september-2017-due-cme-effects aurora forecast] the prediction showed that the northern United States were lucky.
-* Betelgeuse is estimated to be in a range between 613 and 881 {{w|light-year}}s from Earth, which means that its light takes more than 600 years to reach Earth. That incident must have already happened when it should reach us in the next few decades. Since no information can travel {{w|https://en.wikipedia.org/wiki/Faster-than-light|faster than light}}, there is no way to confirm this.
+* Betelgeuse is estimated to be in a range between 613 and 881 {{w|light-year}}s from Earth, which means that its light takes more than 600 years to reach Earth. That incident must have already happened when it should reach us in the next few decades. Since no information can travel {{w|Faster-than-light|faster than light}}, there is no way to confirm this.
 * Something about the brightness of celestial objects:
 ** The Sun is the brightest object at a {{w|Apparent magnitude|magnitude}} of −26.74

@@ Line 31: / Line 31: @@
 * This particular ''aurora borealis'' happened because the coronal mass ejection (CME) headed directly toward Earth causing Northern Lights spreading more south than common. That solar flare was first detected by the {{w|Solar Dynamics Observatory|Solar Dynamics Observatory (SDO)}} just eight minutes after it happened at the Sun. This [https://www.nasa.gov/feature/goddard/2017/nasa-s-sdo-captures-image-of-mid-level-flare animation] shows what the probe SDO has seen on Sept. 4, 2017 in the early evening. While light, and x-rays as well, travel at light speed the mass ejected did only move at a speed of 500-1,000 km/s. It was [http://www.swpc.noaa.gov/news/shock-arrival-6-sep-2308-utc-4-september-cme first detected] by {{w|Deep Space Climate Observatory|DSCOVR}} two days later, still 1,5 Mio. to reach Earth or just 30 minutes before the --non critical-- impact. And at this [http://www.swpc.noaa.gov/news/g3-watch-7-through-9-september-2017-due-cme-effects aurora forecast] the prediction showed that the northern United States were lucky.
-* Betelgeuse is estimated to be in a range between 613 and 881 {{w|light-year}}s from Earth, which means that its light takes more than 600 years to reach Earth. That incident must have already happened when it should reach us in the next few decades. But since all information cannot travel faster than light{{Actual citation needed}} there is no way to find this out.
+* Betelgeuse is estimated to be in a range between 613 and 881 {{w|light-year}}s from Earth, which means that its light takes more than 600 years to reach Earth. That incident must have already happened when it should reach us in the next few decades. Since no information can travel {{w|https://en.wikipedia.org/wiki/Faster-than-light|faster than light}}, there is no way to confirm this.
 * Something about the brightness of celestial objects:
 ** The Sun is the brightest object at a {{w|Apparent magnitude|magnitude}} of −26.74

@@ Line 18: / Line 18: @@
 In the title text, Randall suggests the next meteor storm could be 2034, probably because this is predicted to be [http://adsabs.harvard.edu/full/2007JIMO...35....5M a good year for Leonids].
-Randall then continues by saying that if he manages to see a {{w|supernova}} during the daytime, he will drop the goal for the meteor storm and call it 3 of 3. This is because such an event is so unlikely that he hasn't even included it in his bucket list, and he would be happy to switch between the two types of events if he had the chance. A few stars, when they turn supernova, could be so bright that they can be seen during the day time here  on Earth. The brightest supernova recorded in human history was {{w|SN 1006}} which was sixteen times brighter than {{w|Venus}} but still not bright as the full moon. {{w|SN 1054}} is an other example. When such an extremely rare event might happen is impossible to predict. There is a [http://earthsky.org/brightest-stars/betelgeuse-will-explode-someday (very small) chance]  that the giant star {{w|Betelgeuse}} will go supernova within Randall's lifetime, allowing him to tick this off the list too. Randall even mentioned that this could not happen soon enough in [[1644: Stargazing]]. Note that if you could see it during the day time, it would be one of the brightest objects in the night sky after the Moon.  Also keep in mind that if Betelgeuse were to go supernova in Randall's lifetime, he wouldn't see it since it's over 600 light years away.  For Randall to see it during his lifetime, it must have already gone supernova some 600 odd years ago, and we won't know that until we actually see it 613-881 years after it happened.
+Randall then continues by saying that if he manages to see a {{w|supernova}} during the daytime, he will drop the goal for the meteor storm and call it 3 of 3. This is because such an event is so unlikely that he hasn't even included it in his bucket list, and he would be happy to switch between the two types of events if he had the chance. A few stars, when they turn supernova, could be so bright that they can be seen during the day time here  on Earth. The brightest supernova recorded in human history was {{w|SN 1006}} which was sixteen times brighter than {{w|Venus}} but still not bright as the full moon. {{w|SN 1054}} is an other example. When such an extremely rare event might happen is impossible to predict. There is a [http://earthsky.org/brightest-stars/betelgeuse-will-explode-someday (very small) chance]  that the giant star {{w|Betelgeuse}} will go supernova within Randall's lifetime, allowing him to tick this off the list too. Randall even mentioned that this could not happen soon enough in [[1644: Stargazing]]. Note that if you could see it during the day time, it would be one of the brightest objects in the night sky after the Moon. Also keep in mind that if Betelgeuse were to go supernova in Randall's lifetime, he wouldn't see it since it's over 600 light years away.  For Randall to see it during his lifetime, it must have already gone supernova some 600 odd years ago, and we won't know that until we actually see it 613-881 years after it happened.
 ;Astronomical backgrounds
 * This particular ''aurora borealis'' happened because the coronal mass ejection (CME) headed directly toward Earth causing Northern Lights spreading more south than common. That solar flare was first detected by the {{w|Solar Dynamics Observatory|Solar Dynamics Observatory (SDO)}} just eight minutes after it happened at the Sun. This [https://www.nasa.gov/feature/goddard/2017/nasa-s-sdo-captures-image-of-mid-level-flare animation] shows what the probe SDO has seen on Sept. 4, 2017 in the early evening. While light, and x-rays as well, travel at light speed the mass ejected did only move at a speed of 500-1,000 km/s. It was [http://www.swpc.noaa.gov/news/shock-arrival-6-sep-2308-utc-4-september-cme first detected] by {{w|Deep Space Climate Observatory|DSCOVR}} two days later, still 1,5 Mio. to reach Earth or just 30 minutes before the --non critical-- impact. And at this [http://www.swpc.noaa.gov/news/g3-watch-7-through-9-september-2017-due-cme-effects aurora forecast] the prediction showed that the northern United States were lucky.
@@ Line 30: / Line 38: @@
 ** The mentioned supernovae SN 1006 and SN 1054 were at −7.50 and −6.00 respectively
 ** The brightness of the supernova from Betelgeuse is hard to predict. Because it's closer than both the other supernovae it could become brighter than Venus but definitely not than the full moon.
 {{comic discussion}}

← Older revision		Revision as of 17:34, 3 April 2024
Line 42:		Line 42:
	[[Category:Total Solar Eclipse 2017]]		[[Category:Total Solar Eclipse 2017]]
	[[Category:Astronomy]]		[[Category:Astronomy]]
		+	[[Category:Solar eclipses]]