Attached to the target bridge and the railway bridge?
How about if the targets had flashing lights on them, differently coloured for each distance?
That's a nice idea. Do you think the railway bridge in the right place for that? What about the suggestion that a minimum of three targets would be best?Yeah fixed poles with poles attached that can move up and down with water level. Float at the bottom and marks at the top.
I wouldn't let that stop you. In part this is a historical recreation. There's already vastly better version of the experiment out there, fixed in place, with scores of markers, like the Ponchartrain causeway. Various views of which (and other similar structures) can be seen here:What about the suggestion that a minimum of three targets would be best?
That's a nice idea. Do you think the railway bridge in the right place for that? What about the suggestion that a minimum of three targets would be best?
It's clear the canal has silted up, the banks have grown and the waterway is narrower, has grown choked with "cott weed," etc. These are impediments to your project, but may be an opportunity to fold your project into a larger restoration project.AWA arranges work-parties for waterway restoration, improvement and maintenance and offers advice, support and funding to local organisations with similar aims.
So how about the original, with the addition of posts/targets at 1.5 and 4.5 miles?Personally I'd like to see the [Wallace] experiment repeated as closely to the original as possible.
I could see it being a problem if that section of the river is currently used for navigation - i.e., canal boats are travelling it.Activity like this is bound to catch the attention of whatever government agency.
Watching this makes me somewhat doubtful that a P900 would be powerful enough to pick up on one-metre targets 6 miles away.FYI a YouTube video using a P900, both directions from Welney Bridge.
Watching this makes me somewhat doubtful that a P900 would be powerful enough to pick up on one-metre targets 6 miles away.
Yes, I did originally add something about the English gloom and haze - but didn't want to cast aspersions on our fair isle, nor tempt fate, nor reflect unfairly, when there are also a good number of sunny clear days (some years).The limit is not the camera, it's the atmospheric conditions. The video has significant haze and turbulence. Early morning would probably be best.
While that bridge resembles the illustration, I don't think it necessarily means it's the bridge in question. Number one, as already pointed out, it's on a different waterway. And, number two, the bridge known as 'Old Bedford Sluice' - on the right waterway - looks much more modern than 1870.I was just searching Google Images for 'Old Bedford Bridge', in the hope of identifying the 'target' bridge in the Wallace experiment. It is not entirely clear from Wallace's own account where his observations were made. He says that they were between Welney Bridge and Old Bedford Bridge, six miles distant. There is only one bridge at Welney, but I have not yet been able to identify Old Bedford Bridge.
However, Wallace does refer to the town of Downham Market, which is just over six miles to the north-east of Welney, which perhaps makes it more likely that the view was from Welney to the north-east, the target bridge (OBB) being at the hamlet of Salters Lode, just outside Downham Market.
Photographs of the bridge at Salters Lode, e.g. here http://www.geograph.org.uk/photo/685667 seem a fair match for Wallace's illustration of the target bridge.
Schedule 40 is the type of PVC tubing used for household pressure water lines in garden irrigation. It's stiff, you can cut it to size, and it has couplings that let you just push pieces together to make longer pieces, or structures like bases. It comes in different diameters, but 1" diameter should work.
There's a variety of sizes and wall thicknesses. I picked 1" SCH40 as something that will stand up without bending (at least for an 8 foot length, and probably for two of them fitted together).Wickes looks like a good place to buy PVC pipe. There's a 40mm x 3m pipe for £4.39.
I'm doubtful about its ability to stand up straight, though. But maybe filling them with a cement mix might be a way to ensure rigidity, as well as constructing a tripod at the base for stability and verticalness.
Their 1" Sch40 pipe sells at £24.44 for 10 feet - though they also advertise white, "display grade" Sch40 at £9.29 for 10 feet (i.e., for furniture, etc).What is different about Schedule 40 pipe and fittings?
Schedule 40 (sometimes abbreviated to Sch40) is a North American pipe standard similar to the European classification system. In the European system, however, the pipe is grouped into "classes" of the same pressure rating. The ASTM Schedule system works in a different way in that it relates to the wall thickness and bore of the pipe and has inherited its measurements from steel pipe systems. The result is that unlike the Classification of European pipe, in which everything in class C has an operating pressure of 9 bar, the pressure rating of Schedule 40 pipe changes for each size, although the minimum working pressure is still 9 bar - for example 1" pipe has a pressure rating of 31bar, 1 1/4" pipe a rating of 25.5bar, with working pressures only reaching 9 bar at sizes of 12" and over.
In North America (as well as some other parts of the world) the colour of standard PVC pressure pipe is white. Hence, when this range of pipe and fittings are imported to the UK, they come in as white pipe and fittings rather than grey.
When I check on the mapometer link I posted above - same data as google - it's showing that 12-mile stretch of the Old Bedford as being 2-3 metres above sea level.Another point I've belatedly noticed: most of the land in the relevant area is very low-lying. If Google Earth is to be believed (and in this case I don't see any reason to doubt it) much of it is actually below sea level.
‘The telescope inverts the picture presented to the eye, so that, in each case, the sky is at th bottom of the picture. But there are the three points in a regular series, so nearly equidistant that the sharpest vision could not detect a fault, one slightly above the other in each case ... To see these views is to see a never-to-be-forgotten sight, and if Mr. WALLACE is not convinced now, he never will be!’
You seem to be attempting to satirically turn Carpenter's objection on it's side, but I think you are probably just adding more confusion.I am now going to tackle the arguments of Straight Riverists, who claim that rivers are not bendy, as the Thames is claimed to be by scientists, but dead straight. So I have devised an experiment to determine the answer.
Do you think so? It seems to me that these really are just the same objections, except to the horizontal case, rather than the vertical one. And it's psychologically interesting. The vertical case does genuinely seem more difficult than the horizontal one.You seem to be attempting to satirically turn Carpenter's objection on it's side, but I think you are probably just adding more confusion.
Perhaps you should address them directly, or at least quote the objections.The rest are genuine objections I have from other Flatearthers.
Things our gene's survival depends on (food, threats, mates, shelter) generally occur on the ground, which is usually fairly flat, and gravity is vertical. Our field of view is wider than it is tall, our eyes and ears are side by side, not one above the other. So our bodies (and to a degree our minds) handle up/down vastly differently to left/right and in/out or near/far. As matter of interest, what are these evolutionary reasons?
4.4 miles would do, but not an expert on what we would expect to see. Can't locate the stretch you are talking about, however.
I just discovered that Downham mkt is 1 1/2 hours by train from Kings X, and I am thinking of buying a telescope similar to the one used by Wallace, and checking it out for myself.
The height difference is between the center marker and the line between the end markers. So it's the same as the "bulge" distance in a curve calculator. 'Bulge' b = r-sqrt(4*r*r - d*d)/2I wonder does anyone have a view on the minimum distance needed for a viable Wallace-type experiment?
This seems a much better experiment, and if we can assume his honesty, it is slightly more difficult to explain.
His description only really covers the end flags, and does not explicitly state that the intermediate flags were all lined up. All he says about what he SAW is "the line of sight fell on the lower part of the larger flag at B."