Your eyes probably weren’t quick enough to notice – the slow-mo camera helps. Slinky’s are magic!  Not really, it’s awesome physics but it’s still pretty magic.

Physicist Rod Cross of the University of Sydney demonstrates the magic and then explains it.  Turns out the tension at the top of the suspended slinky and the gravity pulling at its bottom completely cancel one another out perfectly – until the top comes crashing down.  Awesome.