How do tunnels meet

How long would such a tunnel have to be? Look it up on a map or do some Internet research to find out how far it is from New York City to Paris. How much money do you think such a tunnel would cost? Would it be worth it?

Would people really be willing to drive under the Atlantic Ocean rather than sailing or flying across it? Why or why not? Would you? Ready to be amazed? Underwater tunnels are only some of the incredible engineering feats that have been accomplished. Did you get it? Test your knowledge. Wonder Words trench laser mole beaver excavate underwater tunnel boring ferry shutter humongous circular experimental ultrasonic avenue commerce Take the Wonder Word Challenge.

Join the Discussion. Sam Dec 18, Can I just be the first to point out that is more than 9 years Dec 19, You're right, Sam. It's 18 years. Good catch! Lu May 17, May 24, We think that's easier said than done, Lu! Just imagine owning a tunnel underwater. It would be really cool! Dec 4, It would be pretty neat! Nov 7, Nov 5, Wonderopolis Jan 15, Hi william! Nicholasa Aug 13, The video was very cool. I never knew you could travel under water in a tunnel.

It was a hard thing to build. The workers had to be brave because they had to go under water and build. It had to be dangerous! I hope they do build a tunnel to New York to England!

I would travel on it! Wonderopolis Aug 14, Morgan Jul 14, I think tomorrow's wonder will be about mountains. But I still can't imagine how people think of these ideas! Melaka Sep 30, Oct 3, Wonderopolis Jul 15, Spencer Apr 16, This is a very interesting wonder. It has a lot of good information. Wonderopolis Apr 16, Great, Spencer! Wonderopolis May 28, I love that they took the time to do that and I think it's crazy how that machine is so big I hope I can drive in an under water tunnel soon.

Wonderopolis Jan 14, John Nov 29, I have to write reports on 5 wonderopolis wonders per week, reading the wonders are really fun I can't say the same about writing it!!!!! Wonderopolis Nov 30, Squary11 May 8, So cool!!!!!!! I wish I can go to an underground tunnel! Wonderopolis May 9, I think this one was awesome!!!!!!!!!!!!!!!!!!!! It is really cool to know that this takes a long time to do.

I never knew there was the Three Gorges Dam in China!!!!! Wonderopolis May 7, Wonderopolis Apr 26, Thanks for letting us know! Blake Dec 16, Wonderopolis Dec 16, Laura Dec 6, Hello from New Jersey! Our 5th grade class thought this was very "clutch" and cool! Wonderopolis Dec 6, Amber Nov 30, Do you know how long It would take to ake a underwater tunnel? Wonderopolis Dec 1, Mira Nov 22, I have always wanted to go through an underwater tunnel, and I actually wish there was an underwater roller coaster, too.

I wonder if that's possible? To avoid such a catastrophe, Eupalinos arranged for the two straight shafts to zig-zag slightly near the centre point, to ensure a successful juncture even if the cuts were initially misaligned.

As it turned out, the construction was so accurate that if the diggers had continued along straight lines they would have made an almost perfect connection. Eupalinos also needed to ensure that the cuts were vertically aligned. He constructed a continuous duct, like a gutter, around the mountain between the two openings.

When filled with water, this enabled him to locate the two openings at the same altitude. Similar arrangements ensured that the shafts remained horizontal as they were bored. No one knows exactly how Eupalinos determined the directions of boring. Several methods of triangulation have been suggested. He may have set up a line of marker poles over the mountain-top between the openings. Alternatively, by laying off a series of short segments in the cardinal directions, he could determine the nett north-south and east-west displacements.

The theorem of Pythagoras would then give the length of the tunnel. It would also enable the direction of the bores to be determined. Pythagoras was born in Samos around BC. It is tempting to speculate that he had a role in the design of the tunnel, but we have no evidence of this.

The ancient Greeks had no laser-guided boring machines. Neither had they magnetic compasses, topographic maps or survey instruments. The tunnel was built in the sixth century BC, years before the principles of geometry were formalised by Euclid.

It was one of the greatest engineering achievements of ancient times and is a testament to the power of mathematics and the ingenuity of the ancient Greeks. Peter Lynch is emeritus professor at the school of mathematics and statistics, University College Dublin.

He blogs at thatsmaths. It is denied as a serious problem but could cause reputational damage. The starting point for reverse maths is a base theory that is strong enough to state the theorems of interest, but not strong enough to prove them. Further global warming will cause more trouble, but there is much we can still do. Italian example shows how investment in rail can drastically cut traffic on air routes.

Science fiction writers give us a glimpse into the possible worlds that await us. Stuart Mathieson: International efforts can have an effect within our lifetimes. Please update your payment details to keep enjoying your Irish Times subscription. The fascinating world of boring tunnels That's Maths: Laser-guided machines are today used to drill tunnels from both ends, but how did the ancient Greeks do it?

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By using our site, you acknowledge that you have read and understand our Privacy Policy and Terms of Use. A composite image of the Western hemisphere of the Earth. Credit: NASA. Source: Universe Today. Citation : What if we dug a tunnel through the Earth? This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission.

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