I think that this is what most bothered me, the whole thing is so contrarian, stupid (and shallow) that surely all the flat-earth bollocks is just a front or outer layer for a “deeper” world view*****. That is, just where does it end when you think that so much science, education and decades of media coverage is lies?
If these twat-wits are back this week I’ll hang around a bit and try to get a Patrick Jane like feel for what the underlying vibe is. If I don’t bottle it, I may ask the “What’s on the other side” question (avoiding the video-cam bloke) and I will try to find out how Newton fits in.
***** Such as - the whole universe is a “Fall/Dodge in Hell” type simulation (which at least would be somewhat rational).
The caption should certainly have something to do with the picture and vice versa but I’m happy to give a little leeway (just like I did when you got it wrong yourself). All I know is that a perfectly correct sentence was set next to a picture that you interpret as terribly misleading. I haven’t seen the picture so I have no way of knowing.
By the standards of Xema’s own complaint that statement is wrong.
I’m gently teasing because I don’t think it actually matters that much. If the picture did show a spaceman in earth orbit then the caption with it was, at worst, not a full explantion. Xema’s quote above was just a slip of the keyboard and shows how easy it is to apply “weightless” to a body in orbit.
In any case, A slight quibble over a slightly misleading picture with a completely accurate statement is absolutely nothing compared to the bollocks of a flat earth.
On the contrary, there is nothing wrong with Xema’s statement. An object in orbit is in freefall. Objects in freefall (defined as any motion of a body where gravity is the only force acting upon it) are weightless. This is true whether you are talking about an astronaut in orbit, or a person in a plummeting elevator. I’d cite a physics book if I had one handy, but this will have to do.
You seem to have this idea that “weightlessness is the absence of gravity,” which is a common misconception addressed in this same link.
The point that Xema and I have been repeatedly making is the reason that astronauts in space are weightless is NOT because they are far from the center of the Earth where there is an absence of gravity. Because this is such a common misconception, I’d say that the picture is more than just “slightly misleading.”
There are other ways to get across the point that the force of gravity decreases with distance, but the quoted caption with the photo of an astronaut in orbit is not one of them. As I stated upthread, the force of gravity at the orbit of the International Space Station is something like 90% as strong as it is at the surface of the Earth.
Of course I don’t think that, I’m fully aware of the various reasons for weightlessness and stated the inverse square law for gravity upthread. I know how it works.
And my point is that it is entirely possible for an astronaut in space to be weightless for exactly that reason. Take them far enough away from the earth, away from large gravitational influences and that would indeed be the case. It may be that the image in question doesn’t show such a situation, it may be that we’ve never attempted such a thing but that doesn’t make the statement wrong. Xema seemed to be suggesting that the statement was wrong to same degree as the flat-earth bollocks. I don’t think it is anywhere near it.
Well we don’t actually know if the image is misleading or not, having not seen it, but the statement is absolutely accurate by itself and it is that which I believed Xema to be complaining about. If I’ve misunderstood their beef then fair enough but I think that just makes their complaint even more hyperbolic.
Nor do I - I’d hoped (perhaps naively) it would be evident that some exaggeration involved when I said “Not quite as bad as embracing a flat Earth …”
The image wasn’t misleading at all - it was a bog-standard photo of an astronaut doing a spacewalk. Which has only ever happened in earth orbit. When paired with this photo, the caption, by contrast, was not so much misleading as flat-out wrong.
I disagree.
The statement was “As you get further from the center of the Earth, gravity decreases - until, in outer space, you’re weightless!” Outer space is widely held to be all that space further than 100 km from the surface of the earth, which includes space where the earth’s gravity is more than 90% of that at the earth’s surface. The only way to be weightless there is to be in freefall.
IIRC, this is pretty much the conclusion which the book’s hero comes to, after getting a look at the eccentric mariners’ charts; I not being genned-up on such things, had forgotten the details. I had just been taken with the the fancy – before the hero susses things out – of the ship, with these twits doing the navigating, setting out for Jeddah and ending up making landfall in Fiji or somewhere.
Well I took you to be serious, apologies for that. Nuance can get lost on the interwebs.
Of course we’ve now ended up doing the flat-earthers work for them to some extent. They’d point to our back-and-forth and say “look, even those putting forward the spherical earth theory can’t agree, so much for conventional science”
Well, I agree that it’s certainly not wrong to the same degree as the “flat-earth bollocks,” but my point is that no actual astronaut, spacecraft, or space probe has ever been weightless because it was “far enough away from the Earth.” On the contrary, in every case, it is because the object in question is or was on a free-fall trajectory. Even the Voyager space probes, which are on an escape trajectories away from the Sun, are on free fall trajectories and are still influenced by gravity. For one, despite being on escape trajectories from our solar system, they are still being slowed down by the Sun. For another, they are not going fast enough to be on an escape trajectory from the Milky Way galaxy. Both probes will ultimately end up in orbits around the center of our galaxy.
In short, due to the inverse square nature of the force of gravity, it is not actually possible in any practical sense to get far enough away from all gravitational influences such that an astronaut would thereby be weightless.
What you are talking about (i.e. “Take them far enough away from the earth, away from large gravitational influences…”) is something that is not actually possible and is best described as a thought experiment. You’re basically talking about a hypothetical astronaut in the intergalactic void far enough away from everything such that the force of gravity acting upon the astronaut is negligible (though never zero).
That’s not what Xema’s picture showed, though. It showed a photo of an astronaut in low-Earth orbit. This astronaut is weightless for a completely different reason, that reason being because the astronaut is in free fall, and very much affected by gravity.
Let me be perfectly clear. My nitpicking of subtle aspects of orbital mechanics and gravity is not meant to encourage the delusions of flat-Earthers. As to your point, check out this famous essay by Isaac Asimov entitled The Relativity of Wrong.
Apologies Robby, I thought I’d responded to you on this, a digital dog appears to have eaten my homework.
I agree completely. That is exactly how I’d read that sentence, something akin to a thought experiment. Science literature is absolutely full of such things. Asking you to consider a situation that has not happened or even could practically not happen.
Let me use a famous and apt example to explain how I see it. Take the sentence.
Now put that next to a picture of a standard cannon. Would we complain that it isn’t possible to get such a standard cannon to shoot a ball at over 17,000 mph? would we complain that it isn’t actually possible to place a cannon on a tower that takes it beyond atmospheric interference? Would we say that such a thing has never been done and that the cannon in the picture doesn’t depict such a thing?
I think the astronaut picture is just a man in space because the caption mentions it. Just like the cannon example above is just a picture of a cannon because the caption mentions it.
If a caption talking about manned space exploration showed a Soyuz rocket taking off I wouldn’t pick holes in it and point out that only Saturn V vehicles had put people on other worlds or that the particular model didn’t have the lift capability to ever do so.
Like I said previously. If the caption had said that an astronaut in orbit around the earth was weightless because of their distance from the earth, that is a different matter and a clear error. It didn’t say that. I’m happy that the picture is mere illustration and not intended as a comprehensive and accurate expression of the concepts involved.
I watched (a bit) (so you didn’t have to) of content from videos of one of the sites broken-linked to in the OP. I quote as carefully as I can, given that I had a couple of glasses of Shiraz to brave the frontiers of stupidity.
Well, you haven’t been looking very hard, (strike that) at all. I’ve seen them under construction at (XXX redacted) and the ISS is quite often clearly visible in the (night) sky, without optical aids.
I dunno, just what the frak?* Just go talk to a sailor.**
I would like to add some swear-y descriptions at these points, feel free to add your own.
** I’m not a sailor, but I grew up close the Thames, I am pretty sure the tides are pretty damn*** regular.
I like your cannon example, but don’t feel it works all that well as an analogy to the spacewalking astronaut. The possible complaints you list are all valid, but the caption seems sufficiently hypothetical to get by.
Suppose instead the picture was of the original Sputnik satellite (which was more or less cannonball-shaped) and the caption said “Many satellites are launched by rockets, but it’s also possible to launch them with a sufficiently large and powerful cannon.” I think this is both more objectionable and closer to my example.
The essential point is that the picture showed a weightless astronaut and its caption gave an explanation for weightlessness in outer space - which had nothing whatever to do with what was going on in the picture.
In the early days of space travel, which I remember, people often said that astronauts were weightless because of a condition of zero gravity, and took those descriptions as equivalent. Which they aren’t for any place we’ve ever been. (Or will go, as has been noted.) A textbook implying that weightlessness in orbit is due to zero gravity because of distance from the earth is playing to this misconception not refuting it.
