This discussion centers on the challenges of avoiding collisions while traveling at near-light speeds (0.99c) in space. Participants highlight that at such high velocities, even small particles become hazardous due to their relative speed. Traditional detection methods like RADAR become ineffective, as the return signal does not reach the traveler in time to avoid an object. The conversation also touches on potential solutions, such as using deflection technologies, including a mist of water to absorb or deflect debris.
PREREQUISITESAerospace engineers, physicists, and science fiction writers interested in the implications of near-light-speed travel and collision avoidance strategies in space.
Drakkith said:Not very easily. At high velocities approaching c, even dust starts to become extremely hazardous. Depending on how fast you are going you may or may not have any way to see what you're traveling towards. When objects are approaching you at near the speed of light, you start to lose the ability to detect them at significant ranges unless they are brightly illuminated or sending out some EM signal. Using something like RADAR to bounce a signal off of them becomes near useless, as the return signal is barely traveling faster than the object it bounced off of.
Diego Fernandez said:Wouldn't the reflected RADAR signal travel along with the object? Or are we assuming the object is traveling only at a percentage of the speed of light?
Drakkith said:Well, you in your ship are the one who accelerated to near c. But from your frame, everything in front of you appears to be approaching at near c. So if you send out your radar signal, once it reflects off of the object it barely manages to reach you before the object does.
Drakkith said:Not very easily. At high velocities approaching c, even dust starts to become extremely hazardous. Depending on how fast you are going you may or may not have any way to see what you're traveling towards. When objects are approaching you at near the speed of light, you start to lose the ability to detect them at significant ranges unless they are brightly illuminated or sending out some EM signal. Using something like RADAR to bounce a signal off of them becomes near useless, as the return signal is barely traveling faster than the object it bounced off of.
Khashishi said:Space is very nearly empty, so your chances of hitting something are pretty small. It's probably a good idea to map out your trajectory to avoid any particularly dense regions, but then just hope you don't run into some stray asteroid.
DHF said:I would work on the assumption that if your hypothetical crew has the technical know how and resources to travel at near the speed of light, they would also have some method of deflection. Traveling at such speeds would require a level of engineering hundreds of years ahead of our own, perhaps thousands. a Technology like near light travel would not develop in a vacuum so the ship would have access to some manner of shields. One possible system I read about involved the ship spraying a mist of water ahead of the ship. Any dust or small debris would impact the water molecules and their kinetic energy would be absorbed or deflected by the mist.
bballwaterboy said:Very interesting. By "EM," do you mean electromagnetic? How fast could that signal travel (say compared to RADAR that you mentioned)? Non-science major here.
bballwaterboy said:One thought I had would be what if you mapped out all the "stuff" in front of you beforehand and plotted a course based on that mapping? Would that safely get you through space at high speeds? Or would mapping it all out be too tough or impossible?