[horsawlarway]

Ok, but at the risk of being pedantic...

They are "placeholders" because our models are wrong. Which is fine: all models are wrong, but some models are useful.

And astronomy is particularly vulnerable to this - its models are being applied to make predications at extremes of both time and scale.

But I PROMISE you, we're wrong. We know we're wrong, and we don't know why (and recently there's even been some fair criticism of our models that we use to gauge distance, so no, I'd argue we have not reasonably "detected" anything other than that our models are wrong - STILL USEFUL but wrong)