2310: Great Attractor

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Great Attractor
Living in the southern hemisphere was nice because I could jump extra high, but I like it here too. Besides, if I ever want to move back, I can just curl up in a ball and wait!
Title text: Living in the southern hemisphere was nice because I could jump extra high, but I like it here too. Besides, if I ever want to move back, I can just curl up in a ball and wait!


Ambox notice.png This explanation may be incomplete or incorrect: Created by a Greatly Attractive SpaceBOT. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.
If you can address this issue, please edit the page! Thanks.
Cueball comments on the fact that as summer approaches, the sun rises earlier and sets later, a common topic of conversation, especially to complain that it is still light at times of day where you are used to it being dark out. Beret Guy comments that he fell off of the wall this morning, a seemingly unconnected topic.

People will often complain about falling out of bed as an indicator of having slept badly. The later sunset is often linked to worsened sleep [1]. However, Beret Guy didn't fall from the bed, he fell from the wall. While being able to figure out he's talking about his worsened sleep, Cueball is understandably confused, so Beret Guy clarifies.

Beret Guy is strongly affected by the Great Attractor, a large gravitational anomaly that influences the galaxies near it, but is difficult to observe directly. Beret Guy claims that the Great Attractor pulls on him unusually hard, which could be another one of his strange powers. This attraction, while not overpowering the gravity of the earth, (as he states that he can only "Jump extra high" in the Title Text) affects his life greatly, such as allowing him to sleep on walls. While 'normal' people can probably (if uncomfortably) lie down on the top of a boundary wall, for Beret Guy this may, at various times, mean that he can lie on the vertical surface of any wall (external or internal) that is currently orientated in a fortuitous direction.

He fell off of the wall this morning due the Great Attractor being below him during daylight hours and on the horizon during night hours. Because the Day starts earlier in the summer, he fell unexpectedly.

He gives a short explanation of why the Great Attractor affects him, apparently caused by his bones existing in more dimensions than our normal 3 dimensions of space and 1 of time, and the motion of galaxies, which normally has no significant affect on a person.

Beret Guy then says that day-sliding season is near, due to the Great Attractor being at the horizon in the day, and offers to run errands for Cueball in the South, implying that he will be pulled towards the south during day-sliding season.

Beret Guy is not standing straight up during this comic, he has one knee slightly bent; and walks with a strange gait and movement lines around him. This is presumably due to the extra downwards force that the Great Attractor is currently exerting on him, so he has to exert more effort to hold himself upright and seems quite content, in the titletext, to entirely stop bracing himself against the pull by crouching into a more spherical shape and rolling down the 'sloping' ground to some place with lower net gravitational potential.

A prior example of an xkcd character with alternate gravitational susceptibility is 417: The Man Who Fell Sideways, where a consistent off-vertical pull somehow applies (rather than one linked to a spot on the stellar sphere) while other fictional examples of 'personalised' gravitational susceptibilities also exist, in various forms.


Some of the humor of the comic has to do with the immense differences in scale between Beret Guy and the Great Attractor.

In very round numbers our own Milky Way galaxy is 200,000 light years across. It is just one of several galaxies in something called the Local Group, which is around 10,000,000 light years across. And the Local Group is itself in something called the Local Supercluster (also called the Virgo Supercluster), around 110,000,000 light years across. Each galaxy, each group, and each supercluster is not just a chance alignment, but is a gravitationally coherent structure.

Something unpredicted (hence "anomalous") is going on with the galaxies in the Local Supercluster (including our own). These galaxies are indeed accelerating away from one another as seen by their red shift. Hubble's Law predicts the expansion should be uniformly proportional to their distance from Earth and from one another. But for the Local Supercluster something is restricting the expansion. That something is, as "viewed" from Earth, somewhere in the direction of the Southern Triangle constellation but 250,000,000 light years distant, and has (but only since 1988) been termed the Great Attractor. The Great Attractor can't conveniently be seen at visible wavelengths, because that direction is the so-called Zone of Avoidance: the area of the night sky obscured by our own Milky Way.

Boiling this all down: something a quarter of a billion light years away that makes an anomalous blip in the local rate of expansion of the universe, and whose existence astronomers deduce only by X-ray observations of stellar red-shift, has large-scale effects on everyday gravitational forces uniquely experienced by Beret Guy. OK, now you can smile.


Ambox notice.png This transcript is incomplete. Please help editing it! Thanks.
[Cueball and Beret Guy stand next to each other, talking.]
Cueball: I can't believe it's still light out. It's 8:00 PM!
Beret Guy: Seriously! This morning I fell off the wall.
[In a frameless panel, Cueball and Beret Guy are still standing and talking. Beret Guy is gesturing to the right.]
Cueball: Wait, why were you sleeping on the wall?
Beret Guy: The Great Attractor is near the horizon at night right now.
[A regular panel, zoomed in on Beret Guy, who is gesturing to the left.]
Cueball (off screen): The Great Attractor?
Beret Guy: Yeah! The space one.
Beret Guy: It pulls on me extra hard. Doctors said it's something to do with galactic motion and how many dimensions my bones have.
[Zoomed back out to show Cueball, standing still, and Beret Guy, who is sliding away to the right.]
Beret Guy: This time of year, it's below us all day, so I stand vertically. But day-sliding season is near!
Beret Guy: Let me know if you have any errands to run to the south!
Beret Guy: Goodniiighttt

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Is Beret Guy talking about the Great Attractor? or simply about the Sun? It would fit in Beret Guy's quirkiness to call the Sun "the Great Attractor". Also, I didn't even know there was actually something called the Great Attractor... 23:42, 22 May 2020 (UTC)

Well, given that it's "below him all day" and on the horizion at night, it's probably not the Sun. Argis13 (talk) 23:58, 22 May 2020 (UTC)

Has anyone (inc Randall) done an analyses on TGA similar to https://what-if.xkcd.com/25/ does for other things? 01:44, 23 May 2020 (UTC)

"The unexpected onset of summer daylight patterns may be further commentary on the ongoing COVID-19 measures and how they have affected perception of time." <-- what the heck is this even supposed to mean?

It's not there any more, but it sounds like it might be a comment on how the sun is not really rising much earlier yet, and our sense of that is warped because we're staying inside so much 23:27, 24 May 2020 (UTC)

"Pull harder, Mom. I miss you." 08:07, 23 May 2020 (UTC)

I have added 502: Dark Flow as it has some similarities, but it was not the great attractor in that comic. But also the first I though about. ;-) --Kynde (talk) 08:22, 25 May 2020 (UTC)

It currently says “Beret Guy is not standing straight up [...]. This is presumably due to the extra downwards force that the Great Attractor is currently exerting on him, so he has to exert more effort to hold himself upright and seems quite content”. Am I the only one who thinks this makes no sense? Beret Guy is going to sleep because the Great Attractor starts pulling him sideways. And if there was more force downwards, instead of sidewars, it would not help to bend the knee and stand tilted. If you have to carry heavy things, the easiest way is to put them on your head and stand as much vertical as possible (although this method is unpopular in some countries). 19:31, 23 May 2020 (UTC)

It's not just you. I interpreted the final frame as him being dragged sideways. This fits with the movement lines along the side covering most of his body, and the "drag lines" left by his feet. His stance makes more sense if he's resisting a sideways force. It also fits better with the time, since the Great Attractor is said to currently be on the horizon at night, and it's 8PM when they are talking. 21:19, 23 May 2020 (UTC)
I guess the one who wrote that part of the explanation forgot that it was evening. I have corrected the explanation to indicate that the pull is to the right - i.e. south --Kynde (talk) 08:22, 25 May 2020 (UTC)

Whenever I am standing on a moving Bus or Train, I always bend the knee on my leading leg in order to counteract the inertia trying to force me forwards if the vehicle rapidly slows or stops [adjusting or resisting changes to my center of gravity]. If I tried to lead with a stiff leg I would topple forward. Beret Guy's stance would only work if he intends to slide on his feet. These Are Not The Comments You Are Looking For (talk) 04:26, 24 May 2020 (UTC)

But why does the Great Attractor pin Berret Guy to the wall, while it won't make him fly?Gunterkoenigsmann (talk) 07:07, 24 May 2020 (UTC)

There is friction so if it is pulling hard enough the the south he could stay on a wall facing south. But it is also Beret Guy so maybe not think too much. --Kynde (talk) 08:22, 25 May 2020 (UTC)
I just changed this, BTW. Obviously a wall with a south-facing side normally also has a north-facing side (if not infilled in some way, or built into a hillside) but it's definitely the latter you'd be reclining against with a southerly attraction in force. Unless I'm confused and you're going to tell me why. 19:38, 25 May 2020 (UTC)

I'm pretty sure the local Supercluster is called Laniakea, and Virgo is just a smaller supercluster within it. https://en.wikipedia.org/wiki/Laniakea_Supercluster

True has added this to the extra explanation. Great Attractor is withing than. --Kynde (talk) 08:22, 25 May 2020 (UTC)

The mysterious analyses of Dark Flow near the great attractor are consistent with Beret Guy's strange experience. Scientists have said it looks like the universe functions by different laws over there. 23:27, 24 May 2020 (UTC)

Although the location of the Great Attractor should not be linked directly to daylight here on Earth.: Literally, no; but like everything else above Luna's orbit, the GA appears to circle the groundpounding observer at about the same rate as Sol. What's really meant by this sentence is obscure.
But it is also Beret Guy so maybe not think too much.: Absolutely! Is our purpose to explain XKCD or only to lecture science with "just enough" pedantry? If the former, which implies the reader may not count such a rare character as a personal friend, it might be well to drop a word or two about Beret Guy's fantastic nature.
Xiong (talk) 17:05, 25 May 2020 (UTC)