In all probability, without any other planets, the chances of the Earth forming in the first instance, would be zero.
Even if Earth DID form, then it would have been unlikely to have any significant life on it, as any "intelligent" life would have been eradicated fairly early on from an asteroidal impact. That asteroid that would have been "devoured" had Jupiter existed.
There are too many possibilities to consider in such a short area, but needless to say, the Earth would not be as we know it without the other planets.
The planets would slowly start to randomly go in directions, eventually colliding into the sun, or other planets.
If the planets did not move in their fixed orbits they may dash each other.
Probably nothing much would 'happen', we would just be even more isolated than we are now.
nothing would happen to other planets if the world ended because the planets are so far apart that the explosion wouldnt reach too other planets and take my advise. the world wont end right now because since when humans exist, the world is still young.
If there was no gravity, the Sun and and the planets would never have formed.
This question would not exist!
If planets did not move in a fixed orbit, their paths would become unpredictable and chaotic. This would likely result in collisions between planets or ejections from the solar system. Ultimately, the stability of the entire solar system would be compromised.
There would be no life because with out the planets and the sun pulling on each other they would spin out of control and possibly crash into each other.
Absolutely nothing
They would have banged into each other, split up, gone off in different directions and regrouped into planets with different orbits.
i do not this answer that's why i am asking you this answer.
Your question is unclear. Nothing would happen if it remains the same temperature it presently is. It would mean some other planets would have to cool.