![]() ![]() It would be subject to the universal speed limit enforced by general relativity after all, and it would need some kind of conventional propulsion system to make it accelerate. If Bobrick and Martire are right, then a warp drive is just like any other object in motion. That said, the energy requirements would still be immense. “normal” energy) or from a mixture of negative and positive energy. By some estimates, the entire energy in the known universe would be needed (though later work brings the number down a bit).īobrick and Martire show a warp drive could be made from positive energy (i.e. Worse, the negative energy requirements of Alcubierre’s device are immense. To make the equations balance, Alcubierre’s device runs on “negative energy” – but we are yet to discover any viable sources of negative energy in the real world. Their work manages to address one of the core problems for warp drives. This gives us a mathematical key for finding and classifying warp technologies. ![]() Using their simple description, Bobrick and Martire demonstrate a method for using Einstein’s general relativity equations to find spacetimes that allow for arrangements of matter and energy that would act as warp bubbles. That, however, is the kind of thing a warp drive might do. The difference is that getting inside a car does not make you age faster. A car is also a shell of energy (in the form of matter) that encloses a flat region of spacetime. Their work tells us that a warp drive is, somewhat surprisingly, like a car. This might not sound like much of a discovery, but until now it was unclear what warp drives might be, physically speaking. The energy of the shell modifies the properties of the spacetime region inside it. Starship bloopersīobrick and Martire show that any warp drive must be a shell of material in a constant state of motion, enclosing a flat region of spacetime. Bobrick and Martire’s work is set to change all that. There’s just less rug between you and the cup when you switch the drive on.Īlcubierre’s suggestion, while mathematically rigorous, is difficult to understand at an intuitive level. It contracts spacetime to make your path shorter. The warp drive is like tugging on spacetime to bring your destination closer.īut analogies have their limits: a warp drive doesn’t really drag your destination toward you. You could move across the rug, or tug the rug toward you. You’re on the rug and you want to get to the cup. How does Alcubierre’s device work? Here discussion often relies on analogies, because the mathematics is so complex. One could potentially make a round trip into deep space and still be greeted by one’s nearest and dearest at home. Such a drive would also avoid the uncomfortable consequences of time dilation. A flat region is like a part of the mat with nothing on it. Gravity is nothing more than the tendency objects have to roll into the dents created by things like stars and planets. The mat curves in the presence of matter and energy (think of putting a bowling ball on the mat). To get a sense of what “flat” means in this context, note that spacetime is sort of like a rubber mat. He argued that the mathematics of general relativity allowed for “warp bubbles” – regions where matter and energy were arranged in such a way as to bend spacetime in front of the bubble and expand it to the rear in a way that allowed a “flat” area inside the bubble to travel faster than light. ![]() The catch, however, is that upon one’s return more than 300 years will have passed on Earth. One can reach a distant star that is 150 light years away within one’s lifetime. Assuming a constant state of acceleration, this makes it possible to travel the stars. Second, the clock on a spaceship traveling close to the speed of light would slow down relative to a clock on Earth (this is known as time dilation). Even traveling at this dizzying speed it would still take us four years to arrive at Proxima Centauri, the nearest star to our Sun. First, nothing can be accelerated past the speed of light (around 300,000 km per second). General relativity places two constraints on interstellar travel. The equations of general relativity capture the way in which spacetime – the very fabric of reality – bends in response to the presence of matter and energy which, in turn, explains how matter and energy move. The story of warp drives starts with Einstein’s crowning achievement: general relativity. There is, however, a silver lining: warp technology may have radical applications beyond space travel. But while Bobrick and Martire have managed to substantially demystify warp technology, their work actually suggests that faster-than-light travel will remain out of reach for beings like us, at least for the time being. ![]()
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