Is indefinite exponential economic growth possible?

Economic growth is frequently expressed as a % of GDP. Proponents of a steady-state economy postulate that perpetual exponential economic growth is impossible and that any system relying on it is inherently unstable. Is this true?

Is indefinite exponential economic growth possible?

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The answer, of course, is yes in some models and no in others. If you're asking for a survey of the growth literature, this question is too broad. Otherwise, it should be about a specific model or class of models. – Steven Landsburg Dec 4 '14 at 21:03
@StevenLandsburg - what about real life, instead of models which can be constructed either way? – Deer Hunter Dec 5 '14 at 0:49
@DeerHunter: In real life, the Universe will pretty much die out in another $10^{15}$ years or so, so the answer is no, you can't have exponential growth "forever". If you want to ask a sensible question about this, it needs to be in the context of a model. – Steven Landsburg Dec 5 '14 at 1:10

As Steven Landsburg pointed out, indefinite anything isn't possible given the eventual heat death of the universe.

Von Neumann posited machines capable of indefinite growth in population (and theoretically production and consumption), so in theory, it would be possible for a time.

Sagan's Response however argued if such things existed that we would have already observed them, and that they would destroy whole galaxies en masse.

That's probably the closest answer you can get to a question like this.

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but what if economic growth is in intangibles? If the future growth of the world is all in videogames and philosophy, would it still destroy whole galaxies en masse? – CarrKnight Dec 5 '14 at 6:56
Probably. Generation of intangibles still consumes energy, requiring fuel. Not to mention people do the thinking and appreciating. – Jason Nichols Dec 5 '14 at 13:29