Where could you touch the firmament?

[parallaxicality]

In 2014, the Civilian Space Exploration Team launched their second GoFast rocket from a site in the Black Rock desert in Nevada, reaching a height of 117 km. Once it reached its maximum altitude, its insane spin, recorded on GoPro cameras, abruptly ceased, which has led flat earthers to assume that it must have hit the firmament. Or as they call it, the dome.

Now here's the question that I have. Leaving aside the fact that the video clearly shows the rocket was still moving after the decelleration, I was wondering if a reductio ad absurdam could determine how far from the edge the firmament would have to be before humans could actually walk under it, assuming:

An even, steady curvature
A height of 117 km at the Black Rock Desert in Nevada
A radius equal to that of the Earth
The standard flat earth geography

[grant hutchison]

Depends on the shape of the firmament dome, doesn't it?

Grant Hutchison

[parallaxicality]

Wouldn't its shape be determined by its width and height?

[grant hutchison]

Well, no. It could, for instance be a roof of constant height supported by a ring-wall at the edge of the world; or it could be a highly eccentric hemi-ellipse in cross section, rising steeply from the edges and then covering the earth in a broad, relatively flat curve; or it could be a shallow spherical cap, rising from the edges much more gradually. The first two would result in a wall you could walk up to and touch; the latter would require you to crouch down under the descending roof as you neared the edge of the disc.

Grant Hutchison

[parallaxicality]

Well, I was thinking mainly of the third option, since the other two don't really fit the definition of "dome".

[showmeonthedollwhere]

Lol wut

Sent from my A502DL using Tapatalk

[Hornblower]

Well, I was thinking mainly of the third option, since the other two don't really fit the definition of "dome".

What to the Flat Earthers say about the shape of this reputed dome?

[Hornblower]

Suppose the dome is spherical and 117 km high at 40 degrees north latitude, about the position of the launch site, and reaches the flat surface 20,000 km from the center. I find a height of 2 meters at a distance of about 157 meters from the edge. That is where someone about 6'7" will need to duck. Of course this is merely a geometric curiosity of an exercise, as in my opinion the Flat Earthers' beliefs are absurd.

[grant hutchison]

Well, I was thinking mainly of the third option, since the other two don't really fit the definition of "dome".

Domes aren't necessarily spherical caps (and usually aren't), and the firmament isn't necessarily a dome. The origin of the word "dome" is the same as "domicile" and "domestic" - a house. And in Isaiah the firmament is a "curtain" or a "tent" - implying that it might be high at the edges and sag in the middle, or low at the edges and supported by a stonking great pole in the middle. I'm not seeing this working as a debunking strategy.

Grant Hutchison

[publiusr]

According to this new theory--the universe may have "borders"
http://www.spacedaily.com/reports/A_...menon_999.html

The idea of branes flapping--of origami in space as per the recent NOVA documentary makes me think of this little thing
https://math.berkeley.edu/~kpmann/thurstonslide.pdf

[tusenfem]

According to this new theory--the universe may have "borders"
http://www.spacedaily.com/reports/A_...menon_999.html

The idea of branes flapping--of origami in space as per the recent NOVA documentary makes me think of this little thing
https://math.berkeley.edu/~kpmann/thurstonslide.pdf

Keeping up with tradition and posting a way off-topic message.
If you don't have anything to say about the topic, then don't post.
Infraction

[Abaddon]

IIRC the usual flat earth model requires both sun and moon circulating above the disc at an altitude of 3000 miles, yet also inside the firmament/dome/whatever so it would be odd to claim a rocket hit it at 117 km altitude.

[marsbug]

I was going to say something similar - there's no need to work out where you could touch the firmament, you just need to work through what such a 'low roof' would mean for the sizes, altitudes, and appearances of the Sun and Moon.

[Abaddon]

I was going to say something similar - there's no need to work out where you could touch the firmament, you just need to work through what such a 'low roof' would mean for the sizes, altitudes, and appearances of the Sun and Moon.

Yeah, it's this nonsense.

https://images.app.goo.gl/UsTwV24mdBsR2URd9

[marsbug]

I think that's actually the 'slightly more in line with daily experience' version with a higher altitude Sun and Moon! If the roof were 117km up (or anything like it) most of the disk would see both Sun and moon as scarcely clearing the horizon, and their apparent sizes would vary hugely over the course of a day, and from place to place on the disk. As a result most of the disk would be in permanent darkness or twilight. It just doesn't work on a common on sense/daily experience' level, never mind physics and properly gathered evidence. Anyway, enough from me, happy new year everyone, I have a drink to attend to!

[janeandr]

I think that's actually the 'slightly more in line with daily experience' version with a higher altitude Sun and Moon! If the roof were 117km up (or anything like it) most of the disk would see both Sun and moon as scarcely clearing the horizon, and their apparent sizes would vary hugely over the course of a day, and from place to place on the disk. As a result most of the disk would be in permanent darkness or twilight. It just doesn't work on a common on sense/daily experience' level, never mind physics and properly gathered evidence. Anyway, enough from me, happy new year everyone, I have a drink to attend to!

I cannot also stop thinking about the gravity force for that matter, in the far end corners of the "flat" earth it could force people into some kind of Michael Jackson lean

[Noclevername]

An even, steady curvature
A height of 117 km at the Black Rock Desert in Nevada
A radius equal to that of the Earth
The standard flat earth geography

I suppose it depends on where you put the highest point of the dome. Most modern FE beliefs say it's above one of the poles, but IIRC before we knew about those it was centered on either Jerusalem or Bethlehem. I assume other faiths and cultures had their own centers of the world.

[21st Century Schizoid Man]

I think you could get just about any answer you want.

As I understand these flat-earth theories, the usual one is the world is a flat disc, with the North Pole at the centre, and Antarctica being a ring going all the way around, at the outside edge. So lines of latitude are concentric rings.

So assuming the lines of latitude are equally spaced (are they in flat-earth topology), what is the angle of the "firmament" when it touches down at 90 degrees south in Antarctica? (I assume that's where it touches down.) If it goes straight up, and the distance from Antartica over the North Pole back to Antarctica on the other side is 40,000 km, then the dome would be 20,000 km high over the North Pole. At 40 degrees north, it should be about 19,200 km high.

But you could assume assume the "firmament" rises up from Antarctica at an angle. In this case, it wouldn't be as high.

What I am getting is, the height of the firmament would be



This is the height in kilometres, where is the angle from which the firmament rises from the south pole (which is a ring in this flat disc earth), so that pi/2 in radians or 90 in degrees would mean it rises vertically, where pi/4 in radians or 45 in degrees means it would be sloping up at a 45 degree angle, etc. is the latitude in degrees, with the equator being 0, positive numbers being northern hemisphere, and negative being Southern Hemisphere.

So to get 117 km at 40 degrees north, it would rise from the South Pole at an angle of about 0.7264 degrees, so almost horizontally. I'm getting that you'd have to be about 145 metres away from the south pole to bump your head on it, but obviously that depends on how tall you are.

ETA - looks like I am in pretty close agreement with Hornblower.

[John Mendenhall]

Doesn't matter. The Earth is round. This has been known to educated people since the time of the ancient Greeks, maybe earlier.

Now if you would like to talk about Fat Earth, you can do the research yourself by going to your local mall and estimating the average obesity. I can give you the data point for me for a start, about 30 pounds or about 20%. The Earth under me isn't flat, it sags a little bit.

[21st Century Schizoid Man]

Doesn't matter. The Earth is round.

Ah, so you’re one of those Round Earthers.

[Jens]

Ah, so you’re one of those Round Earthers.

Actually, recently I've started to wish that the flat earthers were right. My organization recently organized an online conference, and it was OK for Asian and European participants (though it ended at 9 pm in Japan), but for people on the west coast of the US it was like from 3 am to 5 am, not a meeting-friendly hour. If the world was flat, everything would be cool! I wonder if somehow we could stretch it out, like make a fissure somewhere and then make it into a flat dish...

[21st Century Schizoid Man]

Actually, recently I've started to wish that the flat earthers were right. My organization recently organized an online conference, and it was OK for Asian and European participants (though it ended at 9 pm in Japan), but for people on the west coast of the US it was like from 3 am to 5 am, not a meeting-friendly hour. If the world was flat, everything would be cool! I wonder if somehow we could stretch it out, like make a fissure somewhere and then make it into a flat dish...

I am entirely sympathetic with your plight, as I have been dealing with meetings involving people in west coast US, Europe, and east Asia. There is no good time.

But do Flat Earthers believe in time zones? I'm not really sure.

[Noclevername]

A Flat Earther calls on a satellite phone found using GPS to complain about how his SiriusXM service cut out during a show about the ISS....

[21st Century Schizoid Man]

A Flat Earther calls on a satellite phone found using GPS to complain about how his SiriusXM service cut out during a show about the ISS....

Oh, well that one’s easy. The satellites and ISS run along tracks in the firmament.

[KaiYeves]

If only this thread title was meant poetically as I first assumed, and not about people taking such terms literally...

[agassiz]

If only this thread title was meant poetically as I first assumed, and not about people taking such terms literally...

"In lands I never saw, they say,
Immortal Alps look down,
Whose bonnets touch the firmament,
Whose sandals touch the town, —"

[grant hutchison]

"In lands I never saw, they say,
Immortal Alps look down,
Whose bonnets touch the firmament,
Whose sandals touch the town, —"

I've always liked that verse. But then she made it go all weird in the second stanza.

Grant Hutchison

[agassiz]

I've always liked that verse. But then she made it go all weird in the second stanza.

Grant Hutchison

I imagine she'd be a bit embarrassed by the whole thing, though it is a lovely poem.

[NGCHunter]

In 2014, the Civilian Space Exploration Team launched their second GoFast rocket from a site in the Black Rock desert in Nevada, reaching a height of 117 km. Once it reached its maximum altitude, its insane spin, recorded on GoPro cameras, abruptly ceased, which has led flat earthers to assume that it must have hit the firmament. Or as they call it, the dome.

I happened to run into Ky Michaelson (he created that team) at a space museum at the Cape. We talked for a bit about the flat earthers who have harassed him over that video and he kindly allowed me to do a short interview with him right there in the museum. Please feel free to share it with any flat earther who is continuing to use his GoFast rocket as proof of a dome:

[parallaxicality]

Wow. I never knew I was subbed to you on Youtube!