1 - The Reverberation Effect
Have you ever heard that awful sound a microphone makes when it reverberates? That is what happens with time travelling too (if you're time travelling to the past). You see, if you're in 2010 and you time travel in 1993, the particles around you are time traveled as well. That is where the reverb begins because since you time traveled your past selves will as well at the exact same time and place so those particles will keep time travelling to the spot, eventually making the world explode... If that was too confusing here's a simpler explanation: If you pour water in a glass and there's more water the glass can contain, the water piles up and eventually spills on the table. With time travel the particles cannot spill because it is happening all in one moment, so you're trying to fill a glass with an infinite amount of water all at the same time; definitely something bad is going to happen.
2 - Through Time Not Space
As most time travelling movies have pointed out, time travelling only allows you to travel through time and not space. So you will be time travelling to the same spot you just came from. The Earth spins, if you're on the equator it spins at 1,038 miles per hour. at mid-latitudes the speed is spinning about 138-338 miles per hour. And at the poles it hardly spins at all, now I think you know where I'm getting to here. So even though you aren't moving, doesn't mean anything else does. But I am not quite done yet, the mentioned speeds are only the Earth spinning. But the Earth's speed revolving around the sun is 67,000 miles per hour. And guess what, the whole universe is moving as well, but you get the point. So with those numbers if you actually traveled through time and not space you would most likely end up in the vacuum of space even if the delay is only a second.
The World is a Sandwich.