I think I have to chime in now. Having been owning a little bit of old swords of various cultures and playing around with my friend's Glen Parrell "hand and a half sword". And having been learning the Japanese swordsmanship (Toyama Ryu) for a few months I understand a little bit about the swords I think.
<The straight and double-edged blade of the longsword makes agressive sheering cuts and opens up the the possibility of false-edge attacks, as well as being a competent thruster.>
-ever tried to use the long sword for cutting? a 37" blade, 2" wide at the base with continuous distal taper still weight close to 3 lbs. I've tried that, back-cutting(false edge attack) is almost impossible because of the weight and the co-ordinations required between the two hands.
<The katana's single-edged and curved blade can only make true-edged attacks, is most proficient at drawcuts(uneffective against serious armour) due to its thick spine, and the curvature brings the asymetrical point out of line with the handle, giving it an inferior thrusting profile>
- first not every katana are very curve. Most very curved katana called Taichi are used on horseback. After a few months in Toyama Ryu, I understand that Katana are not mean to draw cut, it is meant to chop-cut. For serious armour, can a long sword deal with it? I think it was more efficient to use war-hammer, war-axe or the like. Most katana are not very curve and is very efficient at thrusting too, although most of the kata are cutting strokes
<The wide arms of the hilt of a longsword provide an infinitely superior defense for the hand and wrist than the diminutive tsuba of a katana, and also allow for the trapping and binding of your opponent's blade, a gambit which the disk-like shape and small size of the katana's gaurd prevents>
- I was thinking like this before I learnt the art, thank you very much for all the hollywood films
duellings oftens ends with 1-2 strokes, unless in a large scale battle, there are very few chances of parries, not to mention to used the tsuba for defense....
<The homogenous steel construction and true tempering of the longsword is a product of a more advanced metalurgy than the laminated and differentialy hardened blade of the katana. Katanas continue to be made with a metalurgical process that was obsolete by the end of the Dark Ages in Europe>
For steel to hold an edge, with equal materials, it has to be made hard. If in case of a long sword, with its lengthen, spring through tempering will give the advantage of less easy to be bent, but sacrified some edge holding ability. With the length of a katana, differential tempering maximized the edge holding and at the same time make it tough, it rather band than break in use.... actually edge quenching or differential heat -treating may have the history as long as steel itself and makers of longswords, I think, chose not to do so...
<At two or three pounds, they're both light enough to be used single-handed, but the grips are long enough to accomedate two. The large pommel of the longsword aids in keeping the hand from sliding off the handle, and may also be used for striking. There is no such provision on the katana>
-you obviously never cut with a sword.....you never use the pommel to keep the sword sliding off, the thing you are cutting offer resistance, and pommel in a longsword is more to used first to retained the tang of the blade and second to balance the sword. Try to grip tight when you cut and you will find that you are only beating the target with your sword. Besides, try to weild a 3 lb sword with single hand for say 50 times. I use a katana a little more than 2 lbs and we practice weilding it at least 100 times everyday with 2 hands grip and still it is quite an exercise