i've always had a problem with the original trilogy,in star wars darth vader doesn't know who luke skywalker is or even his name,but by empire strikes back he knows who luke is.The problem i have is it's not explained how,and if it happens in the books written between the films i don't think thats fair.anyone got any clues?

In the extended universe, it's said that the Empire caught some Rebels and tortured them for Luke's name. Vader put 2 and 2 together.

This is one of those "Lucas is making it up as he goes along" things discussed in another thread recently.

Yep, there is no satisfying explanation. One theory was that in Star Wars Vader wasn't actually anywhere near Luke, so could not pick up on the whole family connection/force thing, but he was in Empire so he was able to then. That of course doesn't explain how he didn't realize Leia was his daughter when he spent time torturing her on the Death Star... If your looking for things that make sense, Star Wars should be skipped entirely. Like Groucho said, it's a Lucas making it up as he goes along thing.

The Emporer tells him. Once Luke starts training w/ Yoda there must be a "disturbance" in the force, because the emporer hologram tells Vader, "there is a new Jedi." The emporer then tells Vader to go get Luke and bring him to the emporer. I think the emporer knows all.

Plus Vader was "exposed" to Luke in the trench scene. "The force is strong with this one."

Couple that with the emporer's comments posted by Pants, and some other stuff that might have happened that isn't portrayed in the movies, and it's likely Vader just figured it out through the force.

Equally likely -- Vader recognized Luke's face from an episode of "Galaxy's Most Wanted", or maybe from a milk carton.

I don't think this is a big deal. Between the fact that the Emipire should have intelligence reports that would put the current US to shame and the special bond between father, son, and the force, I think you're nitpicking.

Man! What lame answers! you've all got it wrong!

In fact, the year following the destruction of the first Death Star, Vader had managed to return to Coruscant where he went to stay in the Emperor's palace to get some rest before going against those frickin' rebels who blew off his super-weapon.

So here's Vader, sitting confortably in his throne before the holo-screen tv when they he hears :

"Directly from a Galaxy far far away, It's the Lifeday Special featuring : Crazy singin' Princess Leia, Luke Skywalker a bunch of freaky lookni' aliens and the Whole Wookie Family..."

Vader quickly pressed rewind on his Holo-Tivo remote and looked again at the face of Luke.

- See this guy's face your highness?" He asked the Emperor.

- Wasn't he on General Hospital a couple of years ago?

- No, that's the jerk who blew our Death Star.

- Darn Vadey, now I remember. He is your son you know!

-WHATCHU TALKIN' BOUT?

<CUT>

That's aproximately how it happened. Don't listen to those phonies at Lucasfilms. Remember who gave you the only inside scoop kids.

I just hope they'll restore the truth in the new version they'll release on DVD. That and the story telling how Threepio is really the mastermind behind all the mayhem.

nice_skis, you have broken your Non-Disclosure Agreement with Lucasfilms. You are in a lot of trouble.

I always figured The Guy Who Blew Up The First Death Star would be quite famous and that his identity would eventually find his way to the Empire considering they still had control of the galaxy.

After Vader killed OB1 in ANH, didn't he start to walk towards Luke? it was like Darth recongised him before he blasted the door.

Remember, how Vader found out Leia was Luke's sister? By searching his mind. I think Vader did that when he and Obi-Wan saw Luke running to the Falcon. When Obi-Wan glanced to Vader he knew that Vader knew Luke was his son.

But I'm sure this will be all explained in Ep III.

This is exactly what I thought; there really doesn't need to be a more complicated answer than this.

But if you want to get more complicated, everyone always assumes that Vader didn't know that he had a son. Maybe he was just hidden and Vader could never find him. Or maybe he actually didn't know. In which case, he probably became a LITTLE suspicious when the Emperor told him about "Luke Skywalker."

For what it's worth, I never until reading this post thought that Vader knew that Luke was his son in A NEW HOPE.

I wouldn't say he necessarily new Luke was his son in ANH, but I'm sure he had some suspicion, at least some inkling of sensing something familiar in the force.

Read the Marvel comics and they spend about 10 issues of vader looking for the name of the rebel that blow of the death star

To expand on this and counter Renaldow's points, I'd like to (re)offer my theory of the Force, and the non-sensing of other Force users.

My theory is that the Force is a running body of water. When you are not using the Force, you are a stone on the bottom of the riverbed. The Force flows over you, and can affect you without you conciously using it. But to an external observer, you do not cause any disturbances on the surface of the water because you are not actively using it.

When you begin to use the Force, you are like a rock force up to the surface. You break the flow of the water, and cause eddies and currents to form and be changed. These can be detected and tracked to their source by other Force users, ie observing the surface of the water.

It can be extrapolated that the more in tune with the Force you become, the less like a stone you become, and more like the water. This is how Yoda could hide for so many years, especially considering how powerful he is, and also Obi-wan Kenobi. And if you really want to stretch it, you could say Obi-wan was able to hide Luke from anyone directly searching for him by calming the surface over himself and Luke.

Just my two cents.