Tag Archives: the uncertainty of science

The oldest fossils ever?

Scientists think they have found the oldest fossils ever in Canada.

Scientists say they have found the world’s oldest fossils, thought to have formed between 3.77bn and 4.28bn years ago. Comprised of tiny tubes and filaments made of an iron oxide known as haematite, the microfossils are believed to be the remains of bacteria that once thrived underwater around hydrothermal vents, relying on chemical reactions involving iron for their energy.

If correct, these fossils offer the oldest direct evidence for life on the planet. And that, the study’s authors say, offers insights into the origins of life on Earth. “If these rocks do indeed turn out to be 4.28 [bn years old] then we are talking about the origins of life developing very soon after the oceans formed 4.4bn years ago,” said Matthew Dodd, the first author of the research from University College, London.

This discovery reminds me of the Mars fossils discovered in the late 1990s. There were enormous uncertainties with that discovery, all of which eventually caused most scientists in the field to reject the result. The same thing could be the case here.

Still in Dallas. I hope to get caught up tomorrow.

MRI software bug invalidates 40,000 research papers

The uncertainty of science: A bug just discovered in the computer software used by MRIs to measure brain activity could invalidate 15 years of research and 40,000 science papers.

They tested the three most popular fMRI software packages for fMRI analysis – SPM, FSL, and AFNI – and while they shouldn’t have found much difference across the groups, the software resulted in false-positive rates of up to 70 percent. And that’s a problem, because as Kate Lunau at Motherboard points out, not only did the team expect to see an average false positive rate of just 5 percent, it also suggests that some results were so inaccurate, they could be indicating brain activity where there was none.

“These results question the validity of some 40,000 fMRI studies and may have a large impact on the interpretation of neuroimaging results,” the team writes in PNAS. The bad news here is that one of the bugs the team identified has been in the system for the past 15 years, which explains why so many papers could now be affected. [emphasis mine]

The research the article described is focused entirely on the problems the software causes for past research. It makes no mention of the problems this software bug might cause for actual medical diagnosis Was the treatment of any patients effected by this bug? It does not say.

New data challenges consensus on galaxy formation

The uncertainty of science: A new study has found that the accepted consensus for the formation of large elliptical galaxies does not work, and that, rather than forming from the merger of smaller spiral galaxies, ellipticals formed in place from the material at hand.

From the press release [pdf].

“We started from the data, available in complete form only for the closer galaxies and in incomplete form for the more distant ones, and we filled the ‘gaps’ by interpreting and extending the data based on a scenario we devised” comments Mancuso. The analysis also took into account the phenomenon of gravitational lensing, which allows us to observe very distant galaxies belonging to ancient cosmic epochs.

In this “direct” manner (i.e., model-independent) the SISSA group obtained an image of the evolution of galaxies even in very ancient epochs (close, in a cosmic timescale, to the epoch of reionization). This reconstruction demonstrates that elliptical galaxies cannot have formed through the merging of other galaxies, “simply because there wasn’t enough time to accumulate the large quantity of stars seen in these galaxies through these processes”, comments Mancuso. “This means that the formation of elliptical galaxies occurs through internal, in situ processes of star formation.

The important take-away of this result is that it shows that the present theory of galaxy formation, where smaller spiral galaxies merge to form larger elliptical galaxies, does not fit the data. And if a theory does not fit the data, it must be abandoned.