BLOGS

An unidentified flying object as seen in a declassified Department of Defense video, DoD

Topics: Aerodynamics, Applied Physics, Biology, Exoplanets, General Relativity, SETI

May 17, 2019- No, little green men aren't likely after the conquest of humanity. Boyd's piece for Phys.org highlights the reason why the Pentagon wants to identify UFOs: they're unidentified. If a warfighter on the ground or in the sky can't ID an object, that creates an issue since they don't know if it's friendly, adversarial, or neutral.

U.S. Navy pilots and sailors won't be considered crazy for reporting unidentified flying objects, under new rules meant to encourage them to keep track of what they see writes Iain Boyd for Phys.org.

Why is the Pentagon interested in UFOs? Intelligent Aerospace

The Pentagon refers to them as "transmedium vehicles," meaning vehicles moving through air, water, and space. Carolina Coastline breathlessly uses the term "defying the laws of physics." So I looked at what the paper might have meant. The objects apparently exceed the speed of sound without a sonic boom (signature of breaking the barrier). Even though this is reported by Popular Mechanics, they're quoting John Ratcliffe, whose name somehow sounds like a pejorative. Consider the source.

U.S. Navy F/A-18 flying faster than the speed of sound. The white cloud is formed by decreased air pressure and temperature around the tail of the aircraft.
ENSIGN JOHN GAY, U.S. NAVY

The speed of sound is 343 meters per second (761.21 miles per hour, 1,100 feet per second). Mach 1 is the speed of sound, Mach 2 is 1522.41 mph, Mach 3 is 2283.62 mph. NASA's X-43A scramjet sets the record at Mach 9.6 (7,000 mph), so, it's easy to see where Star Trek: The Next Generation got its Warp Speed analog from. The top speed of the F/A-18 is 1,190 mph. Pilots and astronauts under acceleration experience G Forces, and have suits to keep them from blacking out in a high-speed turn.

A Science Magazine article in 1967 reported the dimensions and speeds for the object were undeterminable. History.com reported an object exceeding 70 knots, or 80.5546 mph underwater (twice the speed of a nuclear submarine, so I can see the US Navy's concern). I found some of the descriptions on the site interesting:

5 UFO traits:

1. Anti-gravity lift (no visible means of propulsion), 2. Sudden and instantaneous acceleration (fast), 3. Hypersonic velocities without signatures (no sonic boom), 4. Low observability, or cloaking (not putting this on Romulans, or Klingons), 5. Trans-medium travel (air, water, space).

When I look at these factors, I don't get "little green men." First caveat: there are a lot of planets between us, and them with resources aplenty. Second caveat: any interest an alien intelligence might have in us is as caretakers of an experiment, or cattle. That's disturbing: ever see a rancher have conversations with a chicken, sow, or steer before slaughter?

My hypothesis (Occam's razor) - these are projections, but of a special kind:

For the first time, a team including scientists from the National Institute of Standards and Technology (NIST - 2016) have used neutron beams to create holograms of large solid objects, revealing details about their interiors in ways that ordinary laser light-based visual holograms cannot.

Holograms -- flat images that change depending on the viewer's perspective, giving the sense that they are three-dimensional objects -- owe their striking capability to what's called an interference pattern. All matter, such as neutrons and photons of light, has the ability to act like rippling waves with peaks and valleys. Like a water wave hitting a gap between the two rocks, a wave can split up and then re-combine to create information-rich interference patterns.

Move over, lasers: Scientists can now create holograms from neutrons, too, Science Daily

This of course doesn't explain the decades of observations, since holograms came into being in a 1948 paper by the Hungarian inventor Denis Gabor: “The purpose of this work is a new method for forming optical images in two stages. In the first stage, the object is lit using a coherent monochrome wave, and the diffraction pattern resulting from the interference of the secondary coherent wave coming from the object with the coherent background is recorded on the photographic plate. If the properly processed photographic plate is placed after its original position and only the coherent background is lit, an image of the object will appear behind it, in the original position.” Gabor won the Nobel Prize in 1971 for "his invention and development of the holographic method." Also: History of Holography

This is purely speculative. I have no intelligence other than what I've shared. It does in my mind, explain the physics-defying five traits described above. It does not explain the previous supposition of sightings since humans started recording history, or trying to hypothesize their sightings in antiquity. Solid objects flying at hypersonic speeds make sonic booms; projections - ball lightning, 3D laser, or solid neutron holograms - likely won't.

If these are projections (adversary, friendly, neutral), who is doing them, and why?

Courtesy: Reaction Engines

Topics: Aerodynamics, ESA, NASA, Space Exploration, Spaceflight

The pursuit, exploration, and utilization of the space environment can be misinterpreted as a luxury. History portrays space as an exclusive domain for global powers looking to demonstrate their prowess through technological marvels, or the stage for far-off exploration and scientific endeavor with little impact on daily life. However, the benefits of space are already woven into our everyday routines and provide utilities and resources on which society has grown dependent. If these were suddenly to disappear and the world was to experience just “a day without space”, the consequences would be evident to all.

The utilization of space is set to become more important still. A new vision for the future is starting to emerge that will feature even more innovative uses of space, ranging from space-based manufacturing and energy production to global Internet connectivity. Space-debris management is also receiving greater focus alongside lunar and Martian exploration, and even space tourism.

While some of these new innovations may sound like they are confined to the realm of science fiction, there are already companies furthering the technology to turn them into reality.

Conventional rocket vehicles are propelled by a fuel (liquid hydrogen, kerosene, or methane) and an oxidizer (liquid oxygen) carried within the vehicle body. When the fuel and oxidizer combust, mass is projected out of the back of the rocket, creating thrust. However, this approach – and especially the use of heavy onboard liquid oxygen – is constrained by Tsiolkovsky’s rocket equation. It basically tells us that everything carried onboard a vehicle has a penalty in the form of the additional propellant, and structural mass of the vehicle needed to get it off the ground. In other words, this approach hampers mission performance, mission payload, and mission time.

A concept image of the Reaction Engine’s Synergetic Air-Breathing Rocket Engine (SABRE).

SABRE, on the other hand, is a hybrid air-breathing rocket engine. During the atmospheric segment of its ascent, it will use oxygen from the atmosphere instead of carrying it inside the vehicle, before switching to onboard oxygen upon leaving the atmosphere. A SABRE-powered launch vehicle will therefore have a lower mass for a given payload than a conventional rocket vehicle. This mass benefit can be traded for systems that will enable reusability and aircraft-like traits, such as wings, undercarriage, and thermal-protection systems – all the features needed to fly the same vehicle over and over again, achieving hundreds of launches.

Air-breathing rocket engines: the future of space flight, Oliver Nailard, Physics World

Image source: Link below ("ride the lightning")

Topics: Aerodynamics, Futurism, Plasma, Propulsion, Spaceflight

Personal note: I've been offline prepping for my preliminary exam presentation, and grieving the loss of a friend I had known for 40 years since our freshman year at NC A&T. I was his best man. He did not die of COVID, but a heart attack. As such, my remarks were read at the funeral in Indiana, as the pandemic and social distancing concerns did not allow me to give my eulogy in-person. I hope you will forgive my absence.

This past autumn, a professor at Wuhan University named Jau Tang was hard at work piecing together a thruster prototype that, at first, sounds too good to be true.

The basic idea, he said in an interview, is that his device turns electricity directly into thrust — no fossil fuels required — by using microwaves to energize compressed air into a plasma state and shooting it out like a jet. Tang suggested, without a hint of self-aggrandizement, that it could likely be scaled up enough to fly large commercial passenger planes. Eventually, he says, it might even power spaceships.

Needless to say, these are grandiose claims. A thruster that doesn’t require tanks of fuel sounds suspiciously like science fiction — like the jets on Iron Man’s suit in the Marvel movies, for instance, or the thrusters that allow Doc Brown’s DeLorean to fly in “Back to the Future.”

But in Tang’s telling, his invention — let’s just call it a Tang Jet, which he worked on with Wuhan University collaborators Dan Ye and Jun Li — could have civilization-shifting potential here in the non-fictional world.

This Scientist Says He’s Built a Jet Engine That Turns Electricity Directly Into Thrust, Dan Robitzski, Futurism