Eris' size resulted in its discoverers and NASA labelling it the solar system's tenth planet. This, along with the prospect of other similarly sized objects being discovered in the future, stimulated the International Astronomical Union (IAU) to define the term planet more precisely. Under a new definition approved on August 24, 2006, Eris was designated a dwarf planet along with Pluto and Ceres.
Best Answer: it depends on a few things~...but the longest time a human can stay upside down is 2 days.. If your heart is reasonably healthy and you aren't restricted, then you shouldn't pass out at all, any more than you would laying down or standing up.
The aforementioned Dr. Fink believed the brain might remain conscious as long as 15 seconds; that's how long cardiac arrest victims last before blacking out. (Dr. Fink's colleague put the window of awareness at 5 seconds.) He also pointed out that people have remained alert after having had their spinal cords severed.his was proven when a scientist condemned to the guillotine in the 1700s told his assistant to watch and that he would blink as many times as he could. The assistant counted fifteen to twenty blinks after the head was severed, the blinks coming at intervals of about one second. So the head does remain briefly alive.