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Originally Posted by PhysBang
If by "mild" you mean "delusional", then yes.
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Careful, your use of words is borderline ad hom. Attack the subject, not the person.
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Originally Posted by PhysBang
Unfortunately, the Scientific American author (if that is really the origin of the quote...
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You sound surprised...The origin of the quote is Scientific American.
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Originally Posted by PhysBang
...--there seems to be some typos involved) also makes some basic mistakes in his or her description.
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The fact is, an accelerated expansion was not predicted by the standard model (which was based on the FLRW metric, the three Friedmann models).
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Originally Posted by PhysBang
The positive value of the cosmological constant was not taken seriously because there was no measurement of it. Now there is a measurement of it, so it is taken seriously.
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If the measurement of the value of lambda was pending then all possibilities should have been considered seriously as potentially operational.
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Originally Posted by PhysBang
Except that this description of the history of cosmology is pure fantasy.
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It is rather pure fantasy that 96% of the mass-energy density is thought to be "dark" stuff.
Theories make predictions. When those predictions turn out to be erroneous, the theory is either modified or abandoned. In this case the theory (the old pre-1998 standard model) was modified (lambda-CDM). My contention (opinion) is that is should have been discarded unilaterally.
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Originally Posted by PhysBang
Lemaitre came up with the mathematics to describe the current model in the 1920s.
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Neither Lemaître nor his disciples predicted an accelerated expansion. The idea was just too kooky. Why, because something outside of physics (dark energy and nonbaryonic dark matter, in profuse quantities) would be required to justify the otherwise linear regime.
The favored possibility described a universe in which omega is precisely equal to one, the critical density, with a one-to-one relation between the density of the cosmos and its spatial curvature, i.e., this model was a flat, Euclidean (with zero curvature). The velocity of expansion tends to zero as its radius approaches infinity.
That prediction obviously failed.
But then again, there were two other possibilities (on the back burner just in case): one with a closed spherical geometry; it expands and collapses to infinite density in a finite time. There is enough gravitating mass to halt the expansion and reverse it, leading to a big crunch.
And finally, one with a hyperbolic geometry that expands for ever, tending to infinity with a finite velocity. The galaxies are undecelerated as there is not enough gravitating mass to stop expansion or to slow it down.
The new findings reflect none of the above.
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Originally Posted by PhysBang
People had been analyzing the models involved for decades...
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True, and prediction were made. It would have been sweet had predictions coincided with what is observed in nature.
That is the scientific method...
CC
