At the 2019 UFOlogy World Conference in Barcelona, Physicist Michio Kaku gave an address, in which he said (21:24): Source: https://www.youtube.com/watch?v=zf4hneVuLmk&t=1284s That video is unfortunately cut short (can anyone find the full-length video?), but he talks more about it here: https://news.yahoo.com/a-turning-po...ference-the-truth-is-out-there-090005631.html The Yahoo quotes seem mostly from this interview: https://news.yahoo.com/a-traffic-ja...is-search-for-the-god-equation-090020986.html Also, during a Q&A, he was asked what brought him to the conference. He responded (21:58) Source: https://youtu.be/5OXC0gdx-ME?t=1318 The problem here is that he is wrong. The three videos do not show anything that is outside the bounds of human science. In fact, they most likely show rather banal things, viewed in an unusual way. There three vides: Flir1, Gimbal, and Go Fast Flir1 (also called Nimitz, or TicTac) is a fuzzy blob in the distance. It does not move (although it jumps around when the camera changes zoom settings or does a gimbal lock correction). There's what looks like a final "zipping away at high speed" at the end of the video, but it's actually just the camera no-longer tracking the object, combined with a change in zoom that gives the illusion of speed. See: https://www.metabunk.org/2004-uss-nimitz-tic-tac-ufo-flir-footage-flir1.t9190/ Gimbal is a saucer-shaped infrared glare. It rotates because the camera is rotating to counter gimbal lock. We can prove this because there are other light patterns in the sky that rotate at the same time the glare rotates. The video is consistent with a jet engine several miles away. it does not have any sudden acceleration. See: https://www.metabunk.org/nyt-gimbal-video-of-u-s-navy-jet-encounter-with-unknown-object.t9333/ Go Fast is what looks like a cool object moving rapidly across the surface of the ocean. However, the angles and range on the screen allow us to triangulate the position and speed of the object. It turns out it's actually moving quite slowly (under 50 knots) and is quite high (13,000 feet). It does not accelerate at all. In fact, it most closely resembles a balloon, or possibly even a large gliding bird. See: https://www.metabunk.org/go-fast-footage-from-tom-delonges-to-the-stars-academy-bird-balloon.t9569/ Kaku describes these videos as "testable evidence", and we can in fact test hypotheses on them to see if they fit. However, Kaku seems not to have tested them himself and is instead relying on the ideas of others. The "To The Stars Academy," for example, still claims that "Go Fast" is going fast, and is close to the water. This is demonstrably wrong. Likewise, others have interpreted the camera movements in Flir1 as object movements, or have interpreted the optical rotation of an infrared glare as a physical rotation of a craft. These are all demonstrable unsupported interpretations that Kaku has somehow been convinced are true. So no, the burden of proof has not shifted. The Navy has no obligation to prove that Mach 20 craft that zigzag at impossibly high g-forces are not aliens. There's no such obligation because no such craft have been demonstrated to exist. We don't know exactly what these videos show, but they don't show anything impossible, and they are well explained by ordinary events. Kaku may be an accomplished physicist and science popularizer, but unless he can present some evidence for his statements, then they carry no more weight than any other UFO fan. The burden of proof is still very much on the person making the extraordinary claim, which in this case is Kaku himself.