The most important walls in western history aren't even in the West.
They surround the modern city of Istanbul, Constantinople as the Romans called it.
And for a thousand years, the fate of Europe depended on them.
Constantinople was designed to be the center of the world.
When the frontiers of the Roman Empire began to crumble in the 4th Century, the capital was moved to the cultured, wealthy, and still stable East.
There, at the crossroads between Europe and Asia, the hub of the major trade routes of the ancient world, the Emperor Constantine built his city.
This was the city of libraries and universities, 20 times the size of London or Paris at the time.
It contained the priceless knowledge of the classical world which was fading in the West.
To protect this masterpiece from its many enemies, Constantine's successors built the finest defensive fortifications ever made.
The first line of protection was a moat 60 feet wide and 22 feet deep, stretching all four miles from coast to coast.
Pipes from inside the city could fill it at the first sight of the enemy, and a short wall protected archers who could fire at the soaked soldiers trying to swim across.
Those who were lucky enough to clear the moat had to contend with an unceasing barrage from the 27 foot outer wall above.
Arrows, spears, or far worse, Greek fire -- an ancient form of napalm that would ignite on contact and couldn't be extinguished by water -- would rain down on them.
Squads of Roman defenders would carry portable flame throwers, spraying anyone trying to climb out of the moat.
The terrified victims would leap back, only to find that they still burned underwater.
At times, the Romans would also mount siphons onto the ramparts, and launch clay pots full of Greek fire from catapults at an invading army.
The front lines would turn into an inferno, making it appear as if the earth itself was on fire.
If, by some miracle, the outer wall was compromised, attackers would be faced with the final defense: the great inner wall.
These walls were wide enough to have four men ride side by side, allowing troops to be rushed wherever they were needed.
Attilla the Hun, destroyer of civilizations, who named himself the Scourge of God, took one look at them and turned around.
The Avars battled the walls uselessly til their catapults ran out of rocks.
The Turks tried to tunnel under them, but found the foundations too solid.
The Arabs tried to starve the city into submission, but ran out of food themselves and had to resort to cannibalism.
It took the guns of the modern world to finally bring them down.
In 1453, the Turks brought their super weapon: a monster cannon that could fire a 15 hundred pound stone ball over a mile.
Together with more than a hundred smaller guns, they kept up a steady bombardment day and night.
A section of the old walls collapsed, but even in their death throes they proved formidable.
The rubble absorbed the shock of the cannonballs better than the solid wall.
It took a month and a half of continuous blasting to finally open a breach.
The last Roman Emperor, Constantine the 11th, drew his sword and jumped into the gap to stop the onrushing horde, disappearing into legend.
The city was taken, and the Roman Empire finally disappeared.
But those broken walls had one last gift.
As the survivors fled the doomed city, they brought with them their precious books and their ancient traditions.
They traveled west to Italy, reintroduced the Greek language and learning to western Europe, and ignited the Renaissance.
Thanks to Constantinople's walls, that pile of brick and marble that guarded them for so long, we still have our classical past.
Last year, I got a chance to watch the new "Star Wars" movie, which was fantastic, but one thing kept bugging me.
I don't know if you noticed this or not.
In this entirely technically advanced world, I did not see a single AED anywhere, which was totally shocking -- almost as shocking as not knowing what an AED is, which you guys do know.
But for those at home, an AED is an automated external defibrillator.
It's the device you use when your heart goes into cardiac arrest to shock it back into a normal rhythm, or, as one of the guys I was teaching a class to referred to it as: "The shocky-hearty-box thing."
(Laughter) But I really can't blame the Empire, since health and safety regulations aren't really their first order of business.
Though, even if we -- I think worse than not having an AED would be if there was one there, but just, no one knew where to find it.
These devices can drastically increase your chance of survival -- almost like a tauntaun on Hoth.
(Laughter) But I'm pretty sure that stormtrooper is going to be toast, regardless if we have an AED or not, since what happens is the chest plate is going to be quite hard to get off, and like that tauntaun, the AED has a very short window of time at which it's highly effective.
In this case -- basically, we've got to use it within the first 10 minutes.
The Jedi, on the other hand, have no problems with their outfits.
Those robes open straight up, you can place the pads right onto the chest -- so upper-right-hand side of the chest, lower left, wait for the unit to determine if it's a shockable rhythm and get ready to shock.
But, the Jedi do have a problem.
They have a head appendage issue.
And so I can be totally clear, thinking I'm ready to go, but I'm accidentally touching a tentacle and inadvertently shocking myself.
(Laughter) So before you hit that button, make sure you are clear and everyone else is clear.
Going back to that stormtrooper: If I did get that chest plate off in time, what would you do if you suddenly found there was a Wookiee under there, or possibly two Ewoks?
(Laughter) Well, lucky for us, in the kit there's actually a razor, and we can use that to shave the chest on the upper right-hand side and the lower left.
Wookiees also have another problem.
They have an accessory issue.
What we want to do is remove these -- anything between the two pads we want to remove, since it can cause something called "arcing."
For those who don't know what arcing is, do you remember the Emperor, when he shoots electricity out the ends of his fingers -- (Laughter) that would be kind of like arcing.
Another thing that -- Oh!
By the way, he creates that by wearing wool socks under his robes.
(Laughter) We can also get arcing if we have an extremely wet chest.
The electricity travels across the surface instead of through the heart.
We can correct this with the immortal words of Douglas Adams: "Don't panic," which most of us have done today -- and also always having a towel.
So, good words to go by.
The metal bikini -- unfortunately, this is where panic sets in -- like the modern bra, we have to make sure we remove, because this can cause severe arcing along with burns.
But unfortunately this opens up an issue that's almost as controversial as talking about the prequels.
(Laughter) The mere mention of the word "nipples," and people get into a little bit of a tizzy.
By the way, that is not a nipple, that's a cupcake.
(Laughter) Chances are, if you do have to use this, this is going to be on someone you know.
And remember, everyone has nipples, except for Jabba.
(Laughter) But he does love cupcakes.
Speaking about Jabba, if we do have to use an AED on him, remember pad placement is the same, even though he doesn't have nipples.
So it's going to be upper right-hand side, lower left.
If we were going through, we're shocking, getting ready to go -- after we've done the shock, one of the things we need to do is remember to do compression.
The preferred method is 30 compressions and two breaths in the center of the chest, between the nipples, pressing down at least two inches, no more than two and a half, at a rate of at least 100 beats a minute, no more than 120.
Unfortunately, due to the size of Jabba's mouth and also what he puts in said mouth, we may not want to actually do the mouth-to-mouth part.
So instead, we can do compression-only CPR.
The way of remembering the compression-only part is we can actually use the Imperial March.
I would sing it for you -- (Laughter) Unfortunately, that would be more something an interrogation droid would do.
Yoda.
Small little guy, like a baby.
What we do is basically treat him like a baby, in the sense that we're going to place one pad in the center of the chest and one in the back.
If we place them both in the front, they can be too close and cause severe arcing, so we want to avoid that.
Hopefully, this helped to clarify and put some light on some of the darker issues of using an AED in the Star Wars universe, or any universe in total.
I'll leave you with one point.
Remember, if you do find yourself dealing with a Wookiee, do not shave the entire Wookiee.
This takes way too much time, and it only pisses them off.
(Laughter) Thank you very much.
(Applause)