I've just been reading this about scientists discovering (or more accurately, deciding) that the last ice age was ended by a huge CO2 'burp', some 17,000 years ago. It never fails to amaze me how confident these experts are when it comes to deciding stuff that happened thousands of years ago, and then present it as fact. Or is that because they know nobody can challenge them, because its not in living memory.
I wouldn't want to form a hypotheses based only on living memory seeing as human beings have only been around for a fraction of the earth's history and the bit that's in living memory is less than the blink of an eyelid. Scientists take some evidence- something that's been observed, measured, catalogued, not just invented- then try to interpret what they've observed. If they don't get challenged it's because few lay people have the same access to the kind of evidence scientists use when they form hypotheses. If it comes over as a 'decision'' it might be because there is a lot of evidence that has convinced a lot if people.
Looking at the report i don't see the word 'decided' anywhere. However, discovered, found, study, tested, results, measurement explain, findings, understand etc are the kind of language used. I'd be far more likely to be convinced by that than a story about what someone's grandad can dimly recall.
They normally do their calculations from core samples. Don't know whether they have done it in this case. It's inanimate objects that puzzle me. For instance, take a vacuum flask. It can be used to keep drinks hot or cold. How does it know which to do? It always seems to get it right!!!
