Final answer:
Physical travel between stars is highly unlikely due to the vast distances, the limitations imposed by the speed of light, and the immense energy cost involved. Even if we could achieve high speeds, time dilation would result in drastic differences in time between space travelers and Earth.
Step-by-step explanation:
Physical travel between stars is highly unlikely due to the vast distances involved and the limitations imposed by the speed of light. The fastest spacecraft humans have built so far would take almost 80,000 years to reach the nearest star. To travel to neighboring stars within a human lifespan, we would need to achieve speeds close to the speed of light, which would require immense amounts of energy and become astronomically expensive.
According to special relativity, as an object reaches closer to the speed of light, its mass increases and the energy required to further accelerate it becomes infinite. Thus, the energy cost involved in attaining such high velocities is a significant hurdle to interstellar space travel.
Additionally, even if we were able to achieve high velocities and cover large distances, the time dilation effect would come into play. As an object travels at high speeds, time will pass more slowly for that object relative to observers on Earth. So, even if space travelers return to Earth after their journey, thousands to millions of years will have passed on Earth, obliterating most of what currently exists.