
Long-awaited mathematics proof could help scan Earth's innards - greeneggs
http://www.nature.com/news/long-awaited-mathematics-proof-could-help-scan-earth-s-innards-1.21439
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kurthr
That's too bad... because he's also disproved the cloak of invisibility!

In fact, I suspect this sort of proof may be useful to other fields of
tomography (eg CT / MRI) beyond UltraSound, if it really improves complete
imaging knowing only shortest (eg highest index) paths from the surface. I
guess the sparseness helps minimize errors faster than current techniques,
although it's not clear to me how that necessarily follows from the
mathematical proof.

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_nalply
Interesting idea about invisibility being disproved. Could you flesh out this
idea in more detail?

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XorNot
If time-of-flight is the only necessary information to discover an objects
structure, then all cloaking can be defeated because you can by necessity just
detect that a light pulse took longer then expected to be returned (because it
was bent around the object).

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Houshalter
Well yeah, but you don't need this proof to see that. Invisibility cloaks
should be detectable with Lidar I think.

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BuuQu9hu
The paper:
[https://arxiv.org/abs/1702.03638](https://arxiv.org/abs/1702.03638)

