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Could You See the Curvature of the Earth in This Airport?

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Re: Could You See the Curvature of the Earth in This Airport?

#31

Post by dalke »

_archon_ wrote: post #26
dalke wrote: post #20

Earlier quoted context omitted.

It's familiar because it's a not uncommon comment. Well, except that most such comments refer to the Verrazano-Narrows Bridge, which has a longer span than the Golden Gate. For examples: - Guinness Book of World Records (1973) made it with the Verrazano-Narrows Bridge - http://books.google.com/books?ei=93b7U_XoBuT5yQPkqYGIBQ&hl=s... - So did Henry Petroski in Engineers of Dreams: Great Bridge Builders and the Spannin…

What tools are you using to locate these sources?

books.google.com , which is also the domain name for all of those links. The searches were various combinations of "golden gate" "curvature of the earth" and a few other bridge names.

Re: Could You See the Curvature of the Earth in This Airport?

#32

Post by idlewords »

"First get a long East-West terminal and see if we can roll a ball all the way to the end of the hallway. There shouldn’t be any Coriolis deflection in that case"

The author is confused. That statement would only be true on the Equator. In the northern hemisphere, the ball will always deflect to the right. If I put a pencil on a globe, I can intuitively understand why, sometimes for up to five minutes!

Re: Could You See the Curvature of the Earth in This Airport?

#33

Post by lutorm »

harshpotatoes wrote: post #16

I don't like his method of measuring the curvature distance. I think it will be very difficult to align a local to the local tangent of the earth's surface. Over a distance of 700m, the earth's surface deviates by about 4cm. This means we would have to align our laser to within 50 microradians in order to accurately measure the deviation of the earth's surface. Further more, his two beam system is setup using two las…

You don't need to align anything: Point a single laser down the hallway and measure the height of the beam above the floor at the ends and at the midpoint. If the hallway is straight, these will fit a line; if the hallway is level, they will not. You can surely measure the heights to an accuracy much better than 4cm, and that's all that matters.

Re: Could You See the Curvature of the Earth in This Airport?

#34

Post by dredmorbius »

ctdonath wrote: post #17
jsweojtj wrote: post #11

Earlier quoted context omitted.

> And of course, if one also has a scale, the weight of the ball can be used to see whether the floor is level. Can you elaborate on this? Why would the weight be different if non-level? Unless you're meaning that the center-of-mass of the ball would be ~2 centimeters further from the center-of-mass of the Earth and 1/r^2 means a decrease?

The article depicts the difference between "level" (consistent radius from Earth's center) vs "straight" (line tangent to surface). A bowling ball rolled on a very long straight hall would (assuming nearly negligible resistance etc) actually accelerate toward the center, then slow down, reverse, and oscillate until it stopped in the middle (the lowest gravitational position) because relative to the curvature of the E…

Where the ball centered on would depend on how the hall was constructed. The low point could be anywhere, though it would likely be somewhere between the two endpoints.

It would only be at the center of the hall if that's where the floor were tangent with the Earth's circumference.

Re: Could You See the Curvature of the Earth in This Airport?

#36

Post by JadeNB »

richcuteguy34 wrote: post #14
lutusp wrote: post #9

Earlier quoted context omitted.

This is a fact "borrowed" from my Web site without attribution. Here's the original: http://arachnoid.com/carnival/index.html#Vertical In the linked article, we also find this graphic used to make another point -- horizon distance: http://datagenetics.com/blog/june32012/globe.png Here's the original, from my Web site: http://arachnoid.com/carnival/resources/horizon_distance.png Look familiar?

Yes, and also paradoxically the datagenetics article was published in June 2012, and the article you reference is dated March 2014. Next you are going to claim he stole your idea of a time machine. (Oh and your idea about calculus, and the English language).

I pointed out 6 hours after you did that his referenced article was dated 2 years after the article that he said copied it. You pre-stole my comment!
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