help me experiment to establish curvature

[TheVat]

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.

 

[zapatos]

14 minutes ago, TheVat said:

Generally, a small ping to China will return a small pong.

 

😂

[Janus]

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

[studiot]

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

[exchemist]

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.

[studiot]

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

[TheVat]

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!

[StringJunky]

Is that the annalemma?

[TheVat]

I would guess the lobe difference is due to eccentricity of orbit.

Here is a tutulemma:

 

(tutulma is the Turkish word for eclipse)

[swansont]

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.”

[John Cuthber]

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/
 

[Bufofrog]

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.

[John Cuthber]

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.

 

[TheVat]

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

[John Cuthber]

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.

[TheVat]

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.

 

  

[iu360]

Hi"

This experiment has some interesting potential, especially for making practical measurements to observe curvature. A few key considerations to make it effective:

Precision in Measurements: At a 1-kilometer radius, the curvature difference is small (about 8 cm). Both laser and water levels must be sensitive enough to detect changes on this scale. Choose equipment that can maintain precision over long distances.

Environmental Factors: Light can bend slightly due to atmospheric refraction, so conducting the experiment in calm, stable conditions is essential. Testing over water is sometimes preferred to minimize uneven ground effects.

Comparison: If using both methods, ensure independent measurement techniques, as water-based leveling tends to align closely with gravitational pull, while laser-based methods could show variations if there’s curvature.

Repeatability: For better accuracy, try repeating measurements or experimenting at various distances to ensure consistent data.

This setup could indeed demonstrate curvature, especially if precise and controlled carefully to minimize external influences.