That's not a solution, that's another layer of abstraction to try to solve the problems of blockchain/decentralization for money with a new layer of issues.
Eg. The hashed list of emails. It's going to be a hard reality check if some of your "friends" don't have access to their emails anymore or just aren't friends anymore after x years. The amount he suggests is 7, which is insanely much. Even people have issues with their parents with money alone.
It's a nice fantasy though, but not workable in reality.
So it's not that hard to distribute several keys of the multisig to various heirs, who would have to agree on any transfers of funds. Another option is to keep each key in a different safe deposit box, with a will stating who gets access to the boxes.
Even with that, who do you trust to actually do any real transfer of your bitcoin in a fully secure way? Certainly not your lawyer, legal offices carry so many security problems. With a total of $1 billion at stake, there are some very real risks of attack.
I'd educate the people who will get the money. They get access to the safe deposits, and issue the transactions. With a multisig, there's no single point of failure, and with hardware wallets there's little risk of getting hacked.
Maybe I'm just not aware of all of the Opsec things that have been done to make Bitcoin transfer stupid simple, but I have instant goosebumps anytime someone claims they can do something in an operationally secure way, especially when 10 figures of currency are involved. At that point, you need to be training your protocol to be secure enough to survive the team from Ocean's 11 or the Russian government, not just script kiddies with too much time on their hands.
Good question - I worked at the ASDEX Upgrade (AUG), also operated by the IPP but a tokamak instead of a stellarator: At AUG similar images and videos [0] are recorded by IR cameras. These cameras require strong cooling and a magnetic / electric shielding as described in [1]. Per plasma discharge (~10s) around ~8GB of video data is recorded. There are also fast frame cameras for dust tracking [2] and similar things. I assume the same techniques are applied at Wendelstein.
The 3+1 dimensional spacetime is not embedded in a higher dimensional space [1]. If there are additional dimensions, they have to be "rolled up" and tiny.
I wish I could read a paper like this one! My takeaway is that is no leak, but this doesn't prove that there are not higher dimensions in space, just that the gravitational waves can't get through it (if exists).
[1] https://vitalik.ca/general/2021/01/11/recovery.html