IF PRESIDENT CARTER planned his fall trip by any method other than spining a globe, it is not apparent. Eight countries on four continents in 11 days: It is an antic schedule, practically an absurb one. We can already hear the assurances that the President and his staff are iron men, imprevious to jet lag and capable of wolfing down three state meals a day. Nonsense. The travel cannot fail to be exhausting. Mr. Carter will have hardly enough time, in between blurred stops, for consummation along the way - are out of the question. Or, at least, we hope they are. Whether his hosts will feel more honored by his presence than dismayed by his pace is perhaps an open question.

It's no secret, of course, how these things get out of hand. Is there a diplomat who could not give the boss four good reasons to go practically anywhere? But the various explanations offered by the White House for Mr. Carter's particular choices are peculiarly eclectic. Either he will be visiting "countries with which we have significant relations" or those "playing an increasingly important role," Either his trip will "underline traditional ties of alliance, of beliefs, of values" or "symbolize our willingness to cooperate with systems that are different than ours." Three of his stops are non-Arab oil exporters; one is a recent nuclear proliferater, and two others are possible proliferaters; four are democracies; two are accused torturers; two are in NATO, aone in the Warsaw Pact, and so on. Anyone who can detect a theme in this pudding gets to stay home as a reward.

All this is not to say that the President won't generate some goodwill here or there along the way. He may also get some useful, if fleeting, first-hand impressions of people and places as he flashes by. And the sheer diversity of his itinerary may oblige him to come to grips with some of the inconsistencies and contradictions that have emerged in his approach so far to international affairs. Out of it all could come a better understanding at home and abroad of the inherent diversity in his developing design for "the kind of world we all want to live in" and in his "commitment to the promotion of constructive change, worldwide," as National Security Adviser Zbigniew Brzezinski put it the other day.

Finally, the mere announcement of the trip is a timely distraction from the Lance affair and other recent difficulties; undeniably, it presents him to the public, and to the world at large, as a world statesman on the move. And the trip itself, coming as it will at the end of a long, bruising and not necessarily rewarding encounter with the Congress, could give his presidency a needed boost. This is what globe-trotting can do for a President in the age of jets and television. The opportunity for a drama and image-building is something no modern Chief Executive has been able to resist. At the very least, there is the prospect, for Mr. Carter, of several asterisks in the presidential record books. *Longest trip by a President in a nonelection year. *First President to visit black Africa since Franklin Roosevelt passed through Liberia in 1943. *First visit by a President to four continents in one swing. *First President to have breakfast in New Delhi, lunch (or brunch, if there's a tailwind) in Tehran and dinner in Paris - on a Tuesday.

We wish him a pleasant and productive journey, a happy Thanksgiving (airbone, as we calculate it, between Brazilia and Lagos) and a safe return.