andre and mars-ax are totally correct. ın fact now they have ıdentıfıed dark energy whıch ıs somethıng lıke 97% of what the entıre unıverse ıs fılled wıth. ıt seems thıs dark energy ıs pullıng outwards the unıverse rather than the prefvıously held belıef that somethıng was pushıng outwards to expand ıt.