Questions concerning our understanding of the world

[Unsettomati]

Originally Posted by Heavenese

So when it comes to the oort cloud, is this something that arose from models of solar system formation (like a computer model, which I guess ultimately comes down to mathematics)? What hard evidence do we have to say the oort cloud exist because surely scientists speak on it at times as though it's common knowledge?

The hard evidence is the presence of comets. Analysis of the orbits of very long-term comets shows their source as a point in space. Regardless of a young or old Earth, those comets are coming from a very distant source that is still within the solar system - ie, within that area of space where the Sun's gravitational influence dominates over that of nearby stars or the galaxy as a whole.

We know the much-nearer Kuiper Belt exists from abundant direct evidece, and given basic gravity there is no reason to believe that scattered objects from the disk of the early solar system should not extend out as far as the sun's gravity is more dominant than that of other stars, or the galaxy as a whole. Local or intergalactic gravity perturbations explain why the Oort Cloud regular ejects comets, some of which are flung into the inner solar system.

So comets, unlike a young Earth, comport with the evidence as a whole for a solar system that is about 4.6 billion years old.

Originally Posted by Heavenese

On to the next question, which again many of you probably heard before. Creationists say we have diamonds with c-14 in them. They say this shouldn't be considering it's half life and the age of diamonds. What is science's answer for this?

I had not heard of the 'C-14 in diamonds' claim before. A little digging shows that this assertion originates with the ICR (Institute for Creation Research ).

The problem with the RATE project (that which served up the claim within ICR) is first, contamination. This explains why the RATE project's deep-mine diamonds showed less C-14 than did those samples from alluvial plains - there is less risk for contamination deep underground than above ground (most C-14 being generated in the atmosphere). When this was pointed out to the RATE team (by scientists doing actual science), RATE cleaned up their analysis and came back with a much smaller C-14 sample from diamonds - and that much smaller rate is consistent with normal background detection rate that is due to a variety of sources - none of which are C-14 from the sample itself. As such, there is something in C-14 testing called background subtraction, wherein obtained results are presumed to include a known and consistent amount of detected C-14 atoms that are not there. This presumption arises from the fact that tests can be done on samples known to contain no carbon of any isotope and still receive a small 'measurement' of C-14.

So, there is no C-14 in diamonds themselves, merely a very slight false-positive that is a known issue.

[Heavenese]

Thanks Unsettomati. As I said when it came to the Oort Cloud, creationists present it as scientists' answer for why comets are still around today. Such as "How is it possible comets are still around billions of years later when they all should have been burnt up? Let's plug in this icy cloud around the solar system so comets can be resupplied and that will solve this problem". The reality is actually as you say, the comets have an orbit that extends beyond Pluto, and models of the universe predict it to be there. All of this was in the mix probably before we even knew comets were made up of ice.


Also thanks for clearing that bit up concerning c-14 in diamonds. Again, creationists present it as some diamonds being discovered as having c-14 in them. I didn't know the only claimed discovery came from a creationist group, and no one else found c-14 in non-contaminated diamonds. Now it makes sense to me why this hasn't seen much discussion out there in the world, and yet this claim is still circulating among creationists.