Time travel has long fascinated scientists and theorists, prompting questions about whether the future can send visitors into its own past and whether individuals could move forward in time in ways that bypass the normal flows of daily life. The general idea of time as a fourth dimension, comparable to spatial dimensions, gained traction when Hermann Minkowski famously stated that “space by itself, and time by itself, are doomed to fade away into mere shadows” (Minkowski, 1908, p. 75). This integrated view of spacetime underlies many physics-based theories of how a traveler might move along the temporal axis.
In relativity, closed timelike curves (CTCs) theoretically allow a path through spacetime that loops back to its origin in time. As Kip Thorne put it, “wormhole physics is at the very forefront of our understanding of the Universe” (Thorne, 1994, pp. 496–497). A wormhole with suitable geometry might permit travel from one point in time to another. However, such scenarios raise paradoxes. One common example is the “grandfather paradox,” which asks how a traveler could exist if they venture into the past and eliminate their own ancestor. David Deutsch offered one possible resolution by suggesting that “quantum mechanics may remove or soften the paradoxes conventionally associated with time travel” (Deutsch, 1991, p. 3198). His reasoning rests on the idea that quantum behavior might allow timelines to branch or otherwise circumvent contradictions.
Researchers at TU Delft and Brown University have developed scalable nanotechnology-based lightsails that could support future advances in space exploration and experimental physics. Their research, published in Nature Communications, introduces new materials and production methods to create the thinnest large-scale reflectors ever made.
Lightsails are ultra-thin, reflective structures that use laser-driven radiation pressure to propel spacecraft at high speeds. Unlike conventional nanotechnology, which miniaturizes devices in all dimensions, lightsails follow a different approach. They are nanoscale in thickness—about 1/1000th the thickness of a human hair—but can extend to sheets with large dimensions.
Fabricating a lightsail as envisioned for the Breakthrough Starshot Initiative would traditionally take 15 years, mainly because it is covered in billions of nanoscale holes. Using advanced techniques, the team, including first author and Ph.D. student Lucas Norder, has reduced this process to a single day.
This compares some of the ringworlds, centrifuges, space stations, and ships that use spin to make gravity. It also try’s to show how the variables of artificial gravity are used to make centripetal acceleration into spin gravity.
▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ REFERENCES 1. Hill, Paul R.; Schnitzer, Emanuel (1962 September). “Rotating Manned Space Stations.” In, Astronautics (vol. 7, no. 9, p. 14 18). Reston, Virginia, USA: American Rocket Society / American Institute of Aeronautics and Astronautics. 2. Gilruth, Robert R. (1969). “Manned Space Stations – Gateway to our Future in Space.” In S. F. Singer (Ed.), Manned. Laboratories in Space (p. 1–10). Berlin, Germany: Springer-Verlag. 3. Gordon, Theodore J.; Gervais, Robert L. (1969). “Critical Engineering Problems of Space Stations.” In S. F. Singer (Ed.). Manned Laboratories in Space (p. 11–32). Berlin, Germany: Springer-Verlag. 4. Stone, Ralph W. (1973). “An Overview of Artificial Gravity.” In A. Graybiel (Ed.), Fifth Symposium on the Role of the. Vestibular Organs in Space Exploration (NASA SP-314, p. 23–33). Pensacola, Florida, USA, 19–21 August 1970. Washington, DC, USA: NASA 5. Cramer, D. Bryant (1985). “Physiological Considerations of Artificial Gravity.” In A. C. Cron (Ed.), Applications of Tethers in. Space (NASA CP-2364, vol. 1, p. 3·95–3·107). Williamsburg, Virginia, USA, 15–17 June 1983. Washington, DC, USA: NASA. 6. Graybiel, Ashton (1977). “Some Physiological Effects of Alternation Between Zero Gravity and One Gravity.” In J. Grey (Ed.). Space Manufacturing Facilities (Space Colonies): Proceedings of the Princeton / AIAA / NASA Conference, May 7–9, 1975 7. Hall, Theodore W. “Artificial Gravity in Theory and Practice.” International Conference on Environmental Systems, 2016, www.artificial-gravity.com/ICES-2016–194.pdf.
The Odysseus spacecraft made a rough landing on the moon last year, toppling over and rendering much of its equipment unusable, but an onboard NASA radio telescope called ROLSES-1 was able to make some observations
NASA’s Artemis project aims to put humans on the moon for the first time in more than half a century. Japan is slated to take part in this program, providing both astronauts and a rover to aid in exploration on the lunar surface. A look at the possibility of a made-in-Japan vehicle on the moon in the next decade.
The goal of enabling extended deep-space exploration is driving NASA, space agencies, and private players to explore nuclear power solutions.
Recently, two Southern California-based startups, Exlabs and Antares Nuclear, announced a partnership to advance deep-space missions with nuclear-powered spacecraft.
SpaceNews reported that the Exlabs’ Science Exploration and Resource Vehicle (SERV) spacecraft will be equipped with Antares microreactors.
Somehow, we all know how a warp drive works. You’re in your spaceship and you need to get to another star. So you press a button or flip a switch or pull a lever and your ship just goes fast. Like really fast. Faster than the speed of light. Fast enough that you can get to your next destination by the end of the next commercial break.
Warp drives are staples of science fiction. And in 1994, they became a part of science fact. That’s when Mexican physicist Miguel Alcubierre, who was inspired by Star Trek, decided to see if it was possible to build a warp drive. Not like actually build one with wrenches and pipes, but to see if it was even possible to be allowed to build a warp drive given our current knowledge of physics.
Physics is just a mathematical exploration of the natural universe, and the natural universe appears to play by certain rules. Certain actions are allowed, and other actions are not allowed. And the actions that are allowed have to proceed in a certain orderly fashion. Physics tries to capture all of those rules and express them in mathematical form. So Alcubierre wondered: does our knowledge of how nature works permit a warp drive or not?
Interstellar objects are among the last unexplored classes of solar system objects, holding tantalizing information about primitive materials from exoplanetary star systems. They pass through our solar system only once in their lifetime at speeds of tens of kilometers per second, making them elusive.
Hiroyasu Tsukamoto, a faculty member in the Department of Aerospace Engineering in the Grainger College of Engineering, University of Illinois Urbana-Champaign, has developed Neural-Rendezvous—a deep-learning-driven guidance and control framework to autonomously encounter these extremely fast-moving objects.
A private lunar lander has captured the first high-definition sunset pictures from the moon.
Firefly Aerospace and NASA released the stunning photos Tuesday, taken before the Blue Ghost lander fell silent over the weekend. One shot included Venus in the distance.
Firefly’s Blue Ghost landed on the moon on March 2, the first private spacecraft to touch down upright and perform its entire mission. It kept taking pictures and collecting science data five hours into the lunar night before it died for lack of solar energy.
