TheVat Posted June 18 Share Posted June 18 7 hours ago, Sensei said: Such delay is used to triangulate a person, vehicle, etc. So, when you know that Japan has a small ping to Korea, and Korea has a small ping to China, and China has a small ping to India, Generally, a small ping to China will return a small pong. 1 Link to comment Share on other sites More sharing options...
zapatos Posted June 18 Share Posted June 18 14 minutes ago, TheVat said: Generally, a small ping to China will return a small pong. 😂 Link to comment Share on other sites More sharing options...
Janus Posted June 18 Share Posted June 18 On 6/17/2024 at 6:24 AM, TheVat said: The sun meandering back and forth across the celestial equator seems like a good refutation for those without cellphones, spyglasses, lasers, ocean views, etc. All you need is a couple weeks and a long stick for shadow generating. Trace out the path of the end of the shadow on different dates of the year. With the flat Earth model, with the Sun circling over the disk and shifting between the two Tropics, you would always get arcs of concentric circles. With the globe model, you get series of hyperbolas starting with a maximum curve in one direction for one Solstice, to a maximum curve in the opposite direction on the other Solstice, and which flatten out to straight lines on the dates of the Equinoxes 1 Link to comment Share on other sites More sharing options...
studiot Posted June 18 Share Posted June 18 (edited) On 6/15/2024 at 11:39 PM, mark1966 said: So far I have heard replies suggesting that I try something else (All of what I am already aware of except for the seeing of France from Dover). Thank you all for your comments but the sort of comments I am interested in are about the proposed experiment. What are the problems with it (i.e. the proposed area for the experiment is not sufficiently large enough to detect the divergence in the data sets without extremely precise equipment rendering the experiment unrealistic for an individual or small group to conduct. -- or -- both water and light are equally affected but earths gravitational influence so even if there is curvature, that curvature will not be reflected in the data due to a divergence between the sets -- or any other criticism that breaks the experiment as being possible. It does not matter to me if instead of doing the experiment, you would do something different. Thank you If you ever return to discuss your proposal I take your point "So far I have heard replies suggesting that I try something else" To deal with this enquiry, please note that this is not a new method of demonstrating (and measuring) the curvature. The Romans knew about it, as did they about the difference between using a water level and a line of sight. So let us fast forward to modern times when this difference was not appreciated, causing major disruption to a giant construction project I havd direct experience of. Over your distance of 1 km the a level line is approximately 79mm below straight sight line. however sight lines, including lasers, are not perfectly straight and refraction causes the line to dip below the straight by about 12mm over 1 km This has the combined effect of reducing the difference between a level line and a sightline to about 67mm. Another way to look at it would be to note that you would have to depress your laser sight line by nearly 2 seconds of arc to align on the level spot 1km away If you have the interest we can discuss this further. Edited June 18 by studiot Link to comment Share on other sites More sharing options...
exchemist Posted June 18 Share Posted June 18 34 minutes ago, studiot said: If you ever return to discuss your proposal I take your point "So far I have heard replies suggesting that I try something else" To deal with this enquiry, please note that this is not a new method of demonstrating (and measuring) the curvature. The Romans knew about it, as did they about the difference between using a water level and a line of sight. So let us fast forward to modern times when this difference was not appreciated, causing major disruption to a giant construction project I havd direct experience of. Over your distance of 1 km the a level line is approximately 79mm below straight sight line. however sight lines, including lasers, are not perfectly straight and refraction causes the line to dip below the straight by about 12mm over 1 km This has the combined effect of reducing the difference between a level line and a sightline to about 67mm. If you have the interest we can discuss this further. Good point about refraction. That occurred to me too, after I had posted, but I wasn't sure how significant it would be, if the laser and the reflectors were all at the same height above the ground. Link to comment Share on other sites More sharing options...
studiot Posted June 18 Share Posted June 18 4 hours ago, studiot said: Another way to look at it would be to note that you would have to depress your laser sight line by nearly 2 seconds of arc to align on the level spot 1km away My apologies make that 14 seconds of arc Link to comment Share on other sites More sharing options...
TheVat Posted June 19 Share Posted June 19 21 hours ago, Janus said: Trace out the path of the end of the shadow on different dates of the year. With the flat Earth model, with the Sun circling over the disk and shifting between the two Tropics, you would always get arcs of concentric circles. With the globe model, you get series of hyperbolas starting with a maximum curve in one direction for one Solstice, to a maximum curve in the opposite direction on the other Solstice, and which flatten out to straight lines on the dates of the Equinoxes Beautiful. It took me longer than I care to admit to visualize this, but I got there. Thank you! Link to comment Share on other sites More sharing options...
StringJunky Posted June 19 Share Posted June 19 Is that the annalemma? 1 Link to comment Share on other sites More sharing options...
TheVat Posted June 19 Share Posted June 19 I would guess the lobe difference is due to eccentricity of orbit. Here is a tutulemma: (tutulma is the Turkish word for eclipse) Link to comment Share on other sites More sharing options...
swansont Posted June 19 Share Posted June 19 4 minutes ago, TheVat said: I would guess the lobe difference is due to eccentricity of orbit. Here is a tutulemma: The eccentricity makes it elliptical. The axial tilt gives us the figure-8 shape https://bigthink.com/starts-with-a-bang/this-is-how-the-sun-moves-in-the-sky-throughout-the-year/ “If we only had axial tilt to contend with, and our orbit was a perfect circle, the path the Sun traced out in the sky would be a truly perfect figure-8: symmetryic about both the horizontal and vertical axes. If we lived on an untilted planet that had an elliptical orbit, the Sun’s path through the sky would simply be an ellipse: where the eccentricity would be the only contributor to how the Sun moves.” Link to comment Share on other sites More sharing options...
John Cuthber Posted June 19 Share Posted June 19 This is interesting; it's a step by step guide to triangulating the Moon, and the source might help to convince some people. https://www.vaticanobservatory.org/sacred-space-astronomy/knowing-the-moons-distance/ Link to comment Share on other sites More sharing options...
Bufofrog Posted June 20 Share Posted June 20 19 hours ago, John Cuthber said: This is interesting; it's a step by step guide to triangulating the Moon, and the source might help to convince some people. These people are either insane or morons, no amount of actual evidence will ever convince them. It's a complete waste of time to try IMO. Link to comment Share on other sites More sharing options...
John Cuthber Posted June 20 Share Posted June 20 47 minutes ago, Bufofrog said: These people are either insane or morons, no amount of actual evidence will ever convince them. It's a complete waste of time to try IMO. Quite possibly. But we might be able to convince the "undecided" and I don't want the nutters to have the last word. 1 Link to comment Share on other sites More sharing options...
TheVat Posted June 20 Share Posted June 20 (edited) 20 hours ago, John Cuthber said: This is interesting; it's a step by step guide to triangulating the Moon, and the source might help to convince some people. https://www.vaticanobservatory.org/sacred-space-astronomy/knowing-the-moons-distance/ I was all ready to try this out until it got to the bit about bicyling from north North Dakota to south Texas. 😀 57 minutes ago, Bufofrog said: These people are either insane or morons, no amount of actual evidence will ever convince them. It's a complete waste of time to try IMO. Probably. What's disturbing is the stuff that sane people who aren't morons can be led to believe. Edited June 20 by TheVat Link to comment Share on other sites More sharing options...
John Cuthber Posted June 20 Share Posted June 20 Get on eBay and buy a second hand sun dial from the other hemisphere. https://www.alamy.com/sundial-at-noon-in-southern-hemisphere-hobart-royal-botanical-gardens-image4533735.html Try to make it work in your location. Link to comment Share on other sites More sharing options...
TheVat Posted June 20 Share Posted June 20 You would have to reverse it, I reckon. And the hours would be reversed, so the gnomon shadow would count down instead of up? So after noon, the shadow would move forward to 11 AM when it was actually 1 pm, and so on. "second hand sun dial" - didn't know they were that accurate, hehe. Link to comment Share on other sites More sharing options...
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