This is the context:

On the idea of whether the quantum multiverse is the same as the inflationary multiverse . . . I heard this proposed by Leonard Susskind, one of the inventors of string theory at Stanford. I was talking to Steven Weinberg, who is the father of the standard model of particle physics, probably the greatest physicist living, and he said, “This idea seems crazy to me that Susskind could identify the quantum multiverse with the inflationary multiverse. They are at right angles to each other.”

What is the meaning of the bold part? Does that mean they are very different?

  • Thanks, but please consider waiting longer before accepting. :)
    – Em.
    Commented Nov 10, 2019 at 20:27
  • Oh yes. good point. thank you. I take it back and if nothing better shows up, I would accept your answer again Commented Nov 10, 2019 at 20:28

1 Answer 1


Yes, you have the right idea. I interpret it to imply disagreement, incompatibility, incongruity, etc. I really can't say that this is common expression, at least in everyday language. But it's understandable. The idea of perpendicularity suggesting dissimilarity is not unprecedented:

4 : relating to, uniting, or consisting of individuals of dissimilar type or on different levels

You might be able to say Weinberg's expression is a bit of word play, or simply a mathematical metaphor used to express this idea.

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