-There is some misunderstanding of the MeissnerEffect (seeHyperPhysics -with a wrong one) . In pure form it occurs below the critical field Hc1 =110Gs for YBCO with Tc=93K. Shown here on the left is a 373K sample stabilized by the attraction with its image (approximately-exact only for a semi-infinite 1.4 T magnet). Evidently it has a first critical magnetic field Hc1 larger then 1.4 T. On the right top photograph small magnets stay similarly in vertical position and orient N-S. If the pellet below the small magnet is slowly turned in a circle the magnets stay along the same direction N-S and do not turn with the pellet. Usually the YBaCuO samples levitation is shown with strong magnets way above the rather small Hc1 =110Gs. The levitation demos for YBaCuO (Tc =93 K) include the effect of the forces arising from a complicated system of currents created by the Abricosov flux lines lattice. The top right photo has small magnets on top of 373K superconductors and one 373K superglass without a magnet with different color. The bottom right photo show 3 superconductors and one superglass pellet demonstrating their reflectivity difference at room temperature ( about 300 K). Reference. arXiv:1603.01482v1 [physics.gen-ph] March, 4, 2016
The video 1-below is a THz waves generation conducted along a 10 meters long cable in front of a police detector-3-loud and long signals repeated near the end after the noise. The second video - 2 is a copper tape in series with a superconductor tape of the same size. The copper tape of thickness 40 microns is blown up by a 137 Amperes current, when the same size tape of 373 K type superconductor in series remains intact.
TTTorching diamagnetic samples on the magnet - VIDEO - DOMINIKA RADEVA