Detecting Faster Than Light Travel By Extraterrestrials

August 4, 2024 by Maya Posch 73 Comments

The idea of traveling faster than the speed of light (FTL) has been a popular idea long before [Alcubierre] came up with the first plausible theoretical underpinnings for such a technology. Yet even if such an FTL drive is possible, it may be hundreds of years before humanity manages to develop its first prototype. This does however not prevent us from for looking for possible FTL drive signatures in the spacetime around us. Such a concept was recently proposed by [Katy Clough] and colleagues in a recent article (Arxiv preprint).

For a friendly but detailed explanation the PBS Space Time video (embedded below) on the paper comes highly recommended. The gotcha with detecting an FTL warp drive is that it is undetectable until it collapses in some fashion. By simulating what this collapse might look like, the researchers were able to speculate about the properties to look for. These include gravitational waves, which would not be detectable by an existing gravitational wave detector like LIGO, but we might be able to build one that can.

Ultimately we’d be acting on conjecture on what a warp bubble would look like and how it would behave when it collapses so we might just as well mistake something far less intelligent for Vulcans passing through our solar system. It might also be our first sign of extraterrestrial life, possibly ogling some primitive civilization on a Class M planet until it’s ready for First Contact.

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Developing Warp Drive Might Take Antifreeze

February 8, 2023 by Al Williams 63 Comments

In Star Trek, dilithium crystals — whatever those are — are critical to the operation of a starship’s warp drives. But a Texas professor thinks he can make a baby step towards a warp drive using ethylene glycol, which is commonly found in antifreeze.

While superluminal travel has been regarded as impossible for many years, recent work has suggested ways we might be able to circumvent the light-speed barrier. Unfortunately, all of these mathematical theories require energy and types of matter that we don’t know how to create yet. But [Dr. Chance Glen] believes that by shaping the energy in a specific way through a dielectric, the math can work out so that there’s no exotic negative energy required.

The experiment involves shooting RF energy into an antifreeze container and using a laser interferometer to detect gravity waves. Of course, that will involve some very sensitive measurements to account for other tiny perturbations that might give false readings. As we’ve seen in the past, that’s a task easier said than done.

Does this make sense? Beats us. Our physics and math are too out of date to make a good guess about how much of this is real and how much is hype. Of course, if he does detect gravity waves, that will get us as close to warp drive as the invention of the telegraph got us to cell phones. Then again, you have to start somewhere.

If you want to know more about the state of rocket engines, including the nascent possibility of warp drives, we’ve discussed that before. Incidentally, if you think the experiment sounds a bit like the the Laser Interferometer Gravitational-wave Observatory (LIGO), you aren’t wrong.

Keynote Video: Dr. Keith Thorne Explains The Extreme Engineering Of The LIGO Hardware

December 9, 2021 by Mike Szczys 18 Comments

The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a huge installation measured in kilometers that is listening for wrinkles in space-time. Pulling this off is a true story of hardware and software hacking, and we were lucky to have Dr. Keith Thorne dive into those details with his newly published “Extreme Instruments for Extreme Astrophysics” keynote from the 2021 Hackaday Remoticon.

Gravity causes space-time to stretch — think back to the diagrams you’ve seen of a massive orb (a star or planet) sitting on a plane with grid lines drawn on it, the fabric of that plane being stretch downward from the mass of the orb. If you have two massive entities like black holes orbiting each other, they give off gravitational waves. When they collide and merge, they create a brief but very strong train of waves. Evidence of these events are what LIGO is looking for.

Rai Weiss had the idea to look for gravitational waves using laser interferometers in about 1967, but the available laser technology was too new to accomplish the feat. In an interferometer, a laser is shot through a beam splitter and one beam reflects out and back over a distance, and is then recombined with the other half using a photodetector to measure the intensity of light. As the distance in the long leg changes, the relative phase of the lasers shift, and the power detected will vary.

LIGO is not your desktop interferometer. It uses a 5 kW laser input. The 4 km legs of the interferometer bounce the light back and forth 1,000 times for an effective 4,000 km travel distance. These legs are kept under extreme vacuum and the mirrors are held exceptionally still. It’s worth it; the instrument can measure at a precision of 1/10,000 the diameter of a proton!

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How The LIGO Observatory Detects Gravitational Waves

March 24, 2021 by Lewin Day 43 Comments

Gravity is one of the more obvious forces in the universe, generally regarded as easily noticeable by the way apples fall from trees. However, the underlying mechanisms behind gravity are inordinately complex, and the subject of much study to this day.

A major component of this study is around the concept of gravitational waves. First posited by Henri Poincaré in 1905, and later a major component of Einstein’s general theory of relativity, they’re a phenomena hunted for by generations of physicists ever since. For the team at the Laser Interferometer Gravitational-wave Observatory, or LIGO, finding direct evidence of gravitational waves is all in a day’s work.

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About Those Gravitational Waves

February 17, 2016 by Will Sweatman 306 Comments

It was the year of 1687 when Isaac Newton published “The Principia“, which revealed the first mathematical description of gravity. Newton’s laws of motion along with his description of gravity laid before the world a revolutionary concept that could be used to describe everything from the motions of heavenly bodies to a falling apple. Newton would remain the unequivocal king of gravity for the next several hundred years. But that would all change at the dawn of the 20th century when a young man working at a Swiss patent office began to ask some profound questions. Einstein had come to the conclusion that Newtonian physics was not adequate to describe the findings of the emerging electromagnetic field theories. In 1905, he published a paper entitled “On the Electrodynamics of Moving Bodies” which corrects Newton’s laws so they work when describing the motions of objects near the speed of light. This new description became known as Special Relativity.

It was ‘Special’ because it didn’t deal with gravity or acceleration. It would take Einstein another 10 years to work these two concepts into his relativity theory. He called it General Relativity – an understanding of which is necessary to fully grasp the significance of gravitational waves.

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