QUESTION: Why is space travel such a bust?

ANSWER: The Future used to be so much better. Johnny Quest had his own personal jetpack, George Jetson had a moving sidewalk in his house, and James Bond's car could turn into a submarine with the flick of a switch. The transportation options were staggering!And of course there was Space Travel. Kirk and Spock used to visit unexplored planets the way most people go around the corner to pick up some cat litter.

These dreams have been dashed. As we stare into a new millennium, the most exciting transportation vision on the horizon is . . . the Honda Accord. We checked the dealerships and we can't find ANYTHING powered by anti-matter.

Now for the painful truth. Space travel has never been a viable, realistic option for humans. Star trekking will probably never happen - not even in the distant, unforeseeable future. "Never" might seem too strong, given the tendency of history to come up with surprises, but in this case the obstacle to space travel is not a lack of technological prowess but rather a structural flaw with the universe. It's too empty. There's too much void. Even the closest stars are so far away that, sorry, you can't get there from here.

Consider that Proxima Centauri, the nearest star, is more than four light years away. That means a spaceship traveling at 186,000 miles per second - thousands of times faster than anything we possess - would need four years to get there. That doesn't count the time it would take to accelerate to light speed and then decelerate prior to arrival.

Even the most visionary propulsion engineers see no way to achieve such speeds, not even theoretically. Although Capt. Kirk routinely ordered Scotty to take the engines up to Warp 7 and Warp 8 - multiples of light speed - such tricks are ruled out by Einstein's discovery that nothing in the universe can go faster than light. (OK, so there are tachy-ons, which are theoretical particles that go faster than light, but even if they do exist they never actually perform the feat of accelerating up to light speed and then crossing the barrier.)

Another problem is that our neighborhood is awfully dead. Mars is a desert, Jupiter is a ball of gas. A few once-promising moons in the outer planets are little more than exotic snowballs. As far as we can tell, life is the most abberant of abberations.

If we could freeze some astronauts for a long time, they could explore distant worlds. but it's hard to imagine what civilization would pay for a voyage of discovery that wouldn't be completed until thousands of years after everyone was dead. And frozen astronauts would be hard-pressed to have enough adventures to fill up a weekly TV show.

The only realistic way to explore the cosmos is through machines. This has already started. The Pioneer 10 spacecraft has left the Solar System, hurtling through the void, complete with a gold plate containing messages and recordings from Earthlings. It will reach the nearest star in 80,000 years. And chances are, no one will be home.

QUESTION: Why is the chicken-crossing-the-road joke funny?

ANSWER: Write this down on your palm so you don't forget: Humor is funny because of overlapping, conflicting frames of reference.

Let's tweeze apart the subtleties within the Henny Youngman joke, "Take my wife, please." The joke has a humor hinge on either end: The word "take" has the dual but incompatible meanings of "for an example" and "get her outta my face." The word "please" has the simultaneous attributes of politeness and desperation. Recognition of the irony - that the surface of marital bliss hides a subterranean agony - provokes a tension release that manifests itself as powerful convulsions of laughter.

The chicken joke has its own internal conflict, of an even more subtle nature. When we are asked the initial question - "Why did the chicken cross the road?" - we expect to hear a "punch line." We expect, an actual joke. We don't get it. All we get is a factual, lame, dull answer - "to get to the other side" - the most straightforward response imaginable. Yet we still bend over double with mirth, because this non-joke answer is so wildly inappropriate to the joke format in which it is delivered.

All of this should go on your palm.