Faster-than-light communications? Warp drives? Vacuum energy propulsion? Not every idea promising a revolutionary concept actually is feasible. A collection of ideas classified as "non-issues" by the ACT.
Naturally, technological breakthroughs do not come easy. However, it is already helpful to single out approaches that will definitively not work. Settling controversial issues will help us to free resources for other projects which will hopefully be more fruitful. In this way we also make sure that we have not overlooked certain areas just because the ideas did not fit into the mainstream of physical research. On this page some examples of such concepts that have been assessed within the ACT are presented.
Possible couplings between the electromagnetic field and the gravitational field are so weak that they are of no use for technical applications. Read More
Faster-than-light Communications by Tunnelling.
The existence of faster-than-light group velocities has by now become well established. For space communications the tunnelling effect however does not seem to have any technical applications because the required barrier, so that tunnelling can take place, cannot be generated for space communications. Read More
Quantum Vacuum Effectshe idea that energy or momentum could be extracted from the quantum vacuum regularly appears in futuristic propulsion concepts. While most of these ideas are plainly wrong, some actually rely on existing and experimentally proven effects of quantum states under non-trivial external conditions. The by far best-known example is the Casimir effect. Nevertheless none of these effects can yield technologically interesting numbers as they cannot be amplified. One particular suggestion has been looked at more in detail in collaboration with the universities of Cologne and Grenoble.