[Disclaimer: I'm not a physicist] I thought that due to relativity, if the elements are travelling close to the speed of light then they could still travel for

[Disclaimer: I'm not a physicist] I thought that due to relativity, if the elements are travelling close to the speed of light then they could still travel for thousands of years even if their their half lives are much shorter. That's because the element only appears to be thousands of years old from our frame of reference; their age is much less when viewed from their own reference frame. Though given the size and mass of these elements that might be a moot point since it's unlikely they could be travelling at near light speed anyway, due to the enormous energy it would require for them to do so?