Andrew McCalip: "It might be a bust - we may be over"

> Well, I very much enjoyed the ride.

As the saying goes, Don't cry because it's over. Smile because it happened.

In my entire life, I don't think I have ever seen this level of friendly collaboration in the science community (both amateur and professionals) over something.

I like the fact that Andrew is very transparent and honest about his experiments.

Although he didnt explain 1) how did the Fe impurities get localized into certain regions of the overall batch. 2) Were the impurities quantitatively enough in the magnetically susceptible shards to cause the half levitations he demonstrated.

Hope he keeps running and reporting some side experiments, instead of completely going back to his day job.

On the other hand contamination may be necessary. Say if you have the purest water in a lab in ideal vibration free environment, and tried to freeze it, it wouldn’t freeze even way below 0C. What conclusions would we have then?

It's not that straightforward if you have a bunch of samples which may only contain a small fraction of the material which isn't connected together. Firstly it becomes very difficult to probe a small grain that is hopefully pure and secondly you can't just dump an arbitrary amount of current through a superconductor, they only have zero resistance below a critical current level, and for LK-99 even if it was superconducting this was thought to be quite low, so a small sample means a very small voltage drop even for a normal conductor.

No, my understanding is that the problems are

1. Connecting probes to samples the size of a grain of sand

2. Superconducts can only superconduct a finite amount of current. So if you use a bunch of current, you may go past this material's max. And if you use a smaller amount, the limiting factor is the accuracy of your equipment