He hath made the earth by his power,
he hath established the world by his wisdom,
and hath stretched out the heaven by his understanding.
Jeremiah 51:15
"Claims of a major breakthrough about the big bang are swirling in the news: is it inflation, or inflating the evidence?In “Stop the presses!” style, the science news are simultaneously announcing that gravitational waves have been discovered that reveal evidence for inflation. Cosmic inflation stems from Alan Guth’s proposal in the 1980s that the universe underwent an unbelievable expansion (much faster than light) for just a few billionths of a trillionth of a trillionth of a trillionth of a second immediately after the big bang.
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| BICEP2 |
What really happened is that a team with a sensitive detector dubbed BICEP2 in Antarctica found (they claim) some signals of B-mode polarization in the cosmic microwave background (CMB) – a very weak signal that leans on various models and the ability to identify noise to subtract out. They are interpreting swirls on a chart as evidence of gravitational waves (extremely weak and difficult to detect), which they infer were caused by inflation after the big bang, since producing those artifacts would have required very high energy according to theory.
First of all,
the experiments are highly theory-laden. It’s a bit like reasoning, “Major premise: If space aliens visited Mars, they would have left faces. Minor premise: a face has been found on Mars. Conclusion: Space aliens visited Mars.” Only if cosmologists assume certain things about what inflation might do to the cosmic microwave background can they claim inflation caused what they think they see. Confirmation bias is a common problem in science and in everyday life (that’s why Karl Popper proposed falsification as a criterion for science.)
Second,
the data are extremely tenuous. Gravitational waves are notoriously weak. Additional support may come from data now being crunched by the ESA’s Planck telescope’s team. But again, interpretations of the reduced data set after signals considered uninformative are tossed out are not free of theory bias.
Third,
even the “discoverers” of the ripples admit it is premature to conclude their favored interpretation (inflation) is correct. Mr. Inflation himself, Alan Guth, warned in the New Scientist article, “No experiment should be taken too seriously until there’s more than one that can vouch for it.”
Fourth,
the announcement does not claim to bring understanding of any physical cause for the signal. Harvard cosmologist Avi Loeb gives this admission at the end of the Space.com article:
"Still, there is much more to learn about our universe’s first few moments. For example, astronomers still have no idea what the substance that propelled inflation — dubbed the “inflaton” — actually is, Loeb said.
“It’s not yet a victory of theoretical physics that we see evidence for a process that took place early on,” he said. “We really need to understand what this substance — this inflaton — is. And until we do that, it’s just like dark matter or dark energy — we give it a name, but we don’t know what it is.”
Perhaps it is best to summarize the announcement thus: A very tiny signal of uncertain origin might have been detected from the Earth’s surface in microwaves that might have originated in gravitational waves from deep space, but confirmation is needed. Some cosmologists have pet theories, but nobody understands what they mean." CEH
