Love the sound that is coming out of cup… plus the leidenfrost-like effect the ball creates when it enters the water.
Can some genius out there explain what just happened? Where are all the bubbles. I would have pictured a lot more violent reaction? Then again, I’m not a physicist.
I’ll guess but I don’t know if I’m even close. The heat quickly created a bubble of steam around the ball of nickel that kept any more water from being able to reach the ball, and the water’s surface tension was balanced with the pressure from the steam and so nothing really happened until the ball cooled enough and more water was able to collapse in and steam was able to bubble its way up.
It might help to google, “leidenfrost effect”.
and someone just used this to pad there sound effect library
That’s not just Leidenfrost-like, that *IS* the Leidenfrost effect! (and a fine example, if I say so myself… xP)
Briefly, for those who don’t know, the Leidenfrost effect occurs when a liquid comes into contact with a surface significantly above its boiling point (I believe it’s a minimum of about 120 degrees C *above* boiling for water). The water which initially hits the surface vaporizes almost instantly, creating a thin layer of steam (the “bubble” seen around the sphere in the video). The steam acts as a thin layer of insulation, since no water actually touches the sphere, it can only transfer heat to the liquid through radiation heat transfer (which is much slower than the convection/conduction that direct contact brings). When the object is really hot (or just actively heated), this can be enough to keep the steam layer vaporized. In this case, once the sphere cools enough, the water outside the steam layer isn’t boiling fast enough to keep the “bubble” from collapsing, which is what you see at the end of the video…the rapid onset of regular boling as the bubble collapses.
Yay for college heat-transfer courses! xD
The bubbles came from the water because when it gets 100 degrees water will become steam by the hot red ball. Then because gas is lighter than the rest of the water, it comes up and gone to the air. :)