Thanks! I forgot to put the exclamation mark at the front of the link. Hopefully it works now

lmk if there’s a better community to ask this in

Shameless plug: you could try !askscience@lemmy.world

I believe the idea is that a single bright star in the frame (the guide star) is used for selecting the frames. The point spread function (PSF) is just going to be some function that describes the blurred shape you would observe with the detector for an input point source. You then select frames in which the guide star is well centered, compared to its overall distribution.

I think your guess on “sync-resampled” is correct. They increased the “resolution” by a factor of 4, so that when they realign the chosen frames to center the guide star, they can do so at a sub-pixel precision.

You may want to check out chapter 3 in the thesis, particularly section 3.5.3. The give a lot more detail on the process than you’ll be able to find in the paper. A well-written PhD thesis can be 1000x more valuable than the journal article it ultimately produces, because it contains all the specific details that can be glossed over in the final paper.

This isn’t exactly my area of expertise, but I have some information that might be helpful. Here’s the description of the frame selection from a paper on a lucky imaging system:

The frame selection algorithm, implemented (currently) as a post-processing step, is summarised below:

1. A Point Spread Function (PSF) guide star is selected as a reference to the turbulence induced blurring of each frame.

2. The guide star image in each frame is sinc-resampled by a factor of 4 to give a sub-pixel estimate of the position of the brightest speckle.

3. A quality factor (currently the fraction of light concentrated in the brightest pixel of the PSF) is calculated for each frame.

4. A fraction of the frames are then selected according to their quality factors. The fraction is chosen to optimise the trade- off between the resolution and the target signal-to-noise ra- tio required.

5. The selected frames are shifted-and-added to align their brightest speckle positions.

If you want all the gory details, the best place to look is probably the thesis the same author wrote on this work. That’s available here PDF warning.

I’m glad to see this question has sparked a lot of discussion, but I’d like to remind everyone to please include a credible source for your answer.

Rule 9: Source required for answers.

Provide credible sources for answers. Failure to include a source may result in the removal of the answer to ensure information reliability.

Does Thorlabs still package random snacks in their orders? Some lab snacks would offset the sting of a $30k pricetag by a tiny bit.

That’s not really how quantum entanglement works. When particles are entangled, their quantum mechanical states cannot be described independently. So you couldn’t write down a waveform for just one particle and have it correctly describe reality, you would need the waveform of the entire state and therefore all entangled particles.

As a consequence, certain physical observables can be highly correlated between the particles. For example, if the spin of the overall entangled state of 2 particles is 0, then the spin of 1 particle will be exactly opposite the spin of the other. But these spins are only defined upon measurement (interaction with a system that is deterministic), and at that point the entangled state is collapsed. There’s no mechanism for transporting information while maintaining an entangled state.

Ignoring this fundamental issue, it still wouldn’t be possible to maintain an entangled state between particles in a pair of twins for any practical amount of time. Maintaining coherence in qubits (entailed bits) is one of the big challenges in quantum computing. If the qubits interact with the environment it breaks their entanglement. Even just thermal vibrations will destroy the state. So typically qubits are held at near absolute 0 in a dilution refrigerator. Even still, the longest a qubit has been kept coherent is 5 seconds.

Alternative theories of gravity are like alternative theories of medicine, they tend to be thoroughly invalidated and none are anywhere near as effective as the mainstream theory. As the wiki article you linked notes:

However, such models are no longer regarded as viable theories within the mainstream scientific community and general relativity is now the standard model to describe gravitation without the use of actions at a distance.

General relativitiy is one of the most tested, validated theories in physics. It is incredibly successful, not just describing the attraction of massive bodies but also describing frame dragging (solving a longstanding mystery on the retrograde motion of Mercury that Newtonian gravitation couldn’t explain), and predicting gravitational lensing and gravitational waves, both of which have been observed since and are perfectly described by GR.

An alternate model should attempt to solve a problem in the current leading one, for example giving a more fundamental explanation, or working at different scales where the current model fails (quantum gravity theories, for example). A good alternative model will also give results that are consistent with all existing observations, which is one area that every alternative theory of gravity I’m aware of fails. What problems in GR are you looking to resolve with an alternate gravitational model?

The other answer is correct, it’s not really accurate to say that gravity is made of waves.

In physics, a field is a physical quantity that has a value for each point in space and time The most accurate model for the gravitational field is general relativity, however for many cases it’s sufficient to just use Newtonian Dynamics. In GR, changes to the gravitational field propagate at the speed of light in a vacuum, c. It’s possible to create gravitational waves by rapidly accelerating a massive object, which occurs in inspiralling black holes or neutron stars. But the gravitational force pulling the pair of black holes together isn’t made of waves; the black holes are minimizing their gravitational potential energy as defined by the gravitational field.

force fields are made up of waves (as is everything?),

I wanted to address this since I think you might have a common misconception. Particles (photons, electrons, quarks, protons, neutrons, etc) are described in quantum mechanics using a wavefunction. But this doesn’t make these particles “waves”, they are still quantum mechanical particles. They simply don’t have a defined location (if using a spatial wavefunction, you can also work in an alternative basis like energy or momentum). If the particle interacts with something on the classical scale, it’s wavefunction will collapse to a single point where the location is defined.

If you try to model a quantum mechanical particle as either a classical point-like particle (single point in space) or a classical wave you will fail. Before quantum mechanics was discovered lots of very smart people tried and failed to use just waves or point-like particles. Quantum mechanics, using wavefunctions, is consistent with the fundamental nature of reality as far as we can tell.

Assuming a spherical earth, if you doubled its mass but kept the radius the same then the gravitational force on the earths surface would be twice that of the current earth.

As long as you keep the earths mass reasonable, you’re in the realm of Newtonian gravitation. Newton’s law of gravitation depends linearly on the mass of the attracting source. So doubling the mass doubles the gravitational force.

At 1 billion solar masses (firmly in the not-reasonable mass range for the earth), you’d need to consider the formation of a black hole. The Schwarzschild Radius for a 1 billion solar mass black hole (aka the event horizon) is almost 20 astronomical units or 2 billion miles. So in that case you wouldn’t be able to measure the change in gravity as you’d be within the event horizon of a black hole.

At an intermediate mass there might be some general relativity effects that could alter the linear relationship between earth mass and gravitational force as measured on the earths surface, but I’m not sure what that would be. If you were to measure earths mass from a large distance, then it should follow Newtonian dynamics and behave linearly with mass.

The gravitational wave background you linked is extremely weak, it took decades of measurements of pulsar timing and complex signal processing to even see hints of it. In general, the gravitational force is so much weaker than the other forces that it can be ignored except on very large scales. So I’m not seeing how a rogue gravitational wave would produce sufficient energy density for creating matter via pair production or some other mechanism. You would need extremely large amplitude gravitational waves, which would require some even more energetic mechanism for generating them. Maybe this is something you can work into your model?

I was most impressed by a single fact of physics that all energy in ordinary matter is equal to the negative potential gravitational energy of that matter.

I’m not sure what you mean by this, could you point me to a reference where you saw this statement?

I will come back here to answer your questions one at a time … )

Great! I look forward to it.

Thanks for responding!

Photons emitted from radioactive decays have specific wavelengths. Even with Doppler broadening blurring it out, I don’t see how integrating over all decays at all distances would produce a black body spectrum.

The black body spectrum shape is actually really hard to produce through another mechanism. In fact, before the discovery of quantum mechanics attempts to calculate a black body spectrum with classical mechanics failed at short wavelengths. This problem was called the ultraviolet catastrophe.

I’m trying to understand what you’re proposing here, so I have a few questions.

3d interference pattern of gravitational waves would create rogue waves at specific points in SpaceTime that would create matter and the CMB.

What is the source of these gravitational waves? Binary black hole mergers, neutron star mergers, something else?

How would rogue gravitational waves create matter?

How would rogue gravitational waves produce the cosmic microwave background?

Creation of matter and gravity fields, at net zero energy would increase the expansion of the universe.

What do you mean by “net zero energy”? Is it that this process of creating matter and gravitational waves would also conserve energy somehow? How would this increase the expansion of the universe?

The perfect black body curve of the CMB would result from the exponential expansion of the universe.

How does the exponential expansion of the universe produce the black body CMB? In the standard big bang model, photons are emitted during the recombination epoch and have a very uniform black body temperature since the matter that emitted them had been in thermal equilibrium prior to expansion. These photons are then extremely redshifted by the expansion of the universe.

I might be missing something, but how would this new model reproduce the CMB? The cosmic microwave background is a black body spectrum with an extremely uniform temperature in all directions. The localized fluctuations in temperature are only a very small shift to the average.

I’ll try to address your questions in reverse. For the second question, the formation and structure of hadronic particles such as baryons or mesons is dictated by the fundamental forces. Specifically, the weak, strong and electromagnetic interactions between the quarks that make up the hadron. Gravity is too weak to play a role on this scale.

It’s important to remember that protons and neutrons aren’t elementary particles, they’re composed of quarks. A particle composed of 2 up quarks and a down quark in its lowest energy state is a proton. 2 downs and an up in the lowest energy state is a neutron. Elementary particles such as quarks are identical to other quarks of the same type - every up quark could be swapped for another up quark with no effect on the system. So a proton, composed of quarks in a specific energy state, will be indistinguishable from another proton. There doesn’t need to be a blueprint somewhere to define a “proton”, it just emerges naturally from the fundamental forces and elementary particles.

For an example on a more familiar scale, consider chemical reactions. By making or breaking atomic and molecular bonds you can have an oxidation reaction like fire, or generate electricity in a battery, change the color of a substance, etc. All of those distinct emergent reactions are governed by the electrons in atoms, whose energy levels and interactions emerge from quantum electromagnetism.

These forces also dictate how the composite particles can be reorganized, for example allowing a decay to occur. A free neutron will eventually undergo beta decay into a proton, an electron, and an anti-electron neutrino. This is allowed because the mass of the proton and electron (and neutrino, though it’s mass is currently unknown and experimentally consistent with 0 for this case) is less than that of the neutron. So the beta decay produces a lower energy state. The Feynman diagram for the leading order term in the decay mechanism describes it as being mediated by a W- boson.

This segues into your first question. It sounds like you’re thinking of high energy colliders like the LCH, where beams of protons or even lead nuclei are collided at high energy. These collisions produce a quark gluon plasma where quarks are no longer confined by color charge. It’s basically a superfluid soup of quarks and gluons. As it expands and cools, quarks become color confined again and consolidate into composite particles (hadrons), including some exotic and very unstable ones that quickly decay into more stable configurations. Some of these initial hadrons or their decay products will be formed from antimatter quarks. However, any reaction mechanism that creates or destroys antimatter will create or destroy the same amount of matter. This statement ignores CP violation, which is a small effect in this case, though essential for creating the matter dominated universe we live in.

The strong force between quarks is so strong that the energy needed to “separate” the quarks exceeds the energy needed to produce a quark-antiquark pair. This mechanism converts energy into matter, but the only “blueprint” is “minimize the energy of the system”, and creating a pair of quarks to stick to the initial pair that’s being pulled apart achieves this.

Yeah, that’s fair. I don’t think any lines have been crossed (yet) but the tone in the thread is certainly veering close to it. It’s also possible I missed a comment. Please don’t hesitate to report any uncivil or otherwise rule breaking comments.

Hi there. In the future please report any answers that don’t provide credible sources, as they’re in violation of rule 9.

Per rule 9, can you provide a credible source for your answer?

Any data is sent at or below the speed of light. Solar storms are charged particles (mostly protons) being ejected from the sun and eventually hitting the earth’s magnetic field, causing disruptions in the field (and potentially cool auroras).

Since these storms are just particles traveling from the sun to the earth, they travel slower than light speed, so our distant sensors can warn us in advance at/near the speed of light. This won’t work if the sun were to instantly disappear or change color though, that information would travel at light speed and the probe signals would arrive at the same time.

Not exactly a scientific debate, but among the general public there was strong opposition to the idea that rocket engines would work in space, where there’s “nothing to push against.” Famously, the New York Times editorial board mocked Robert Goddard (the rocket scientist that now has a NASA space flight center named after him) in a 1920 article:

“That Professor Goddard, with his ‘chair’ in Clark College and the countenancing of the Smithsonian Institution, does not know the relation of action to reaction, and of the need to have something better than a vacuum against which to react — to say that would be absurd. Of course he only seems to lack the knowledge ladled out daily in high schools.”

Image of the editorial

The New York Times eventually formally retracted that op ed, on July 17th, 1969 - while the Apollo 11 crew was already en route to the moon. The retraction is pretty funny:

Further investigation and experimentation have confirmed the findings of Isaac Newton in the 17th century and it is now definitely established that a rocket can function in a vacuum as well as in an atmosphere. The Times regrets the error.

Retraction source