The Time Suspension Phenomenon is tied to the unique relationship between Earth and Sonic's world. Long ago, the planets were once one, but then split in two and ended up in different dimensions with their own timelines. As such, when elements from Sonic's world ended up on Earth, the planets and their timelines began coming together, bringing about the Time Suspension Phenomenon. Theoretically, this phenomenon would cause the two worlds to meld completely. And when they do, the two timelines would cancel each other out, bringing time to a stand-still. The rejoined planets would be frozen in time while billions of years past in the rest of the universe. Once the timelines are fused, the effects will then be irreversible, so people will be stuck in time forever. However, this does not mean death in the conventional sense. Rather, it means people will not age or change, every day will be the same, and no progress can be made, hence there would be no such thing as the future or the past. Any pursuits will thus be meaningless.
When world records were being broken by the day, many people simply associated this to the Freedom Movement and people's admiration for Sonic. In reality, this was in fact due to the fluctuation of time due to the Time Suspension Phenomenon.
It was soon confirmed by the government that if all the things from Sonic's world did not return to their world, the two worlds would merge and time would stand still forever. However, despite the signs of the phenomenon taking hold, Sonic and his cohorts were successful in returning to their own world, avoiding the phenomenon safely.