Yes, the wavelength of photons will be preserved if they travel through non-expanding space. If the photon is emitted by a source that’s in motion with respect to a detector, there could still be redshift or blueshift from the relativistic Doppler effect. This would only depend on the relative velocity between the emitter and observer, and not on the distance the photon traveled between them.
Haha it’s in the title: “Cosmological Particle Production: A Review”. Also the journal it was published in is for review articles: Reports on Progress in Physics. Mostly though the abstract promises to give a review of the subject.
Another indication is its lengthy (28 pages) with tons of citations throughout. If someone is doing new work, citations will mostly be in the introduction and discussion sections.
So unfortunately the article they reference by Parker is paywalled. I have access but can’t share it easily. The article is essentially the foundation of quantum field theory in curved space time - in other words the genesis of the standard cosmological model. Cosmological particle production in an expanding universe isn’t an alternative to the Big Bang, it’s an essential part of it.
Leonard Parker’s work is summarized on his Wikipedia page. You can also read an interview with him on the arxiv
There isn’t a link in your post, but it looks like you’re referring to this preprint. The article has been published in a peer reviewed journal paywall warning.
This is a review article, so it isn’t proposing anything new and is instead giving a summary of the current state of the field. These sorts of articles are typically written by someone who is deeply familiar with the subject. They’re also super useful if you’re learning about a new area - think of them as a short, relatively up-to-date textbook.
I’m not sure how you’re interpreting this review as an alternative to the standard model of cosmology and the Big Bang. Everything is pretty standard quantum field theory. The only mention of the CMB is in regards to the possibility that gravitons in the early universe would leave detectable signatures (anisotropies and polarization). They aren’t proposing an alternative production mechanism for the CMB.
Certainly! You can see discrete emission lines from the ionized air molecules, which only occurs because of quantum physics. I realize that’s not what you’re asking though.
I did a quick calculation and for a plasma torch (~27000 Kelvin) and assuming air molecules, the average velocity of the plasma ions would only be like 6000 m/s. That’s 0.001% the speed of light, so you aren’t going to see any relativistic effects.
First a caveat: An object with mass can’t move at the speed of light, but it could move at speeds arbitrarily close to that.
The most successful model of gravity isGeneral Relativity, which treats gravity as a curvature of 4-dimensional space time. Gravity’s influence travels at the speed of light. There’s a classic thought experiment that sort of answers your question: what would happen if the sun was teleported away? The answer is the earth would continue to orbit around the spot the sun was for 8 minutes, and we would continue to see sunlight for that same amount of time since that’s how long it takes light to travel that distance. Then after 8 minutes the sun would disappear and the first “lack of gravity” would reach us, and things would be bad for earth :(
The fact that gravity travels at the speed of light actually leads to an interesting phenomenon: Gravitational waves If a massive object rapidly accelerates (or decelerates), for example a star sized mass moving quickly and then coming to an abrupt stop, it will emit a ripple in space time called a gravitational wave that will travel outward at the speed of light.
It was big news about a decade ago when gravitational waves were first detected by LIGO, a series of large interferometers that look for expansion/contraction in spacetime. Their first detection was the collision of 2 black holes; as the black holes spiral around each other and eventually merge, they emit oscillating waves with increasing frequency. They made a cool video showing how the frequency increases by converting it to sound.
Since then LIGO and VIRGO (similar European collaboration) have detected multiple gravitational waves from the collision of black holes and neutron stars. So not only are gravitational waves a neat validation of general relativity, they’re actually being used to do astronomy.
lmk if there's a better community to ask this in
Shameless plug: you could try !askscience@lemmy.world
The Milwaukee Protocol is a treatment plan that is essentially a more advanced version of what you’re asking. The patient is put in a medically induced coma and then given antivirals and IV fluids, which avoids the issue of hydrophobia.
It got a lot of press because one person survived on it (a big deal given that rabies is a death sentence once symptoms appear) but this success hasn’t been reproduced with other patients. A paper on the protocol has a remarkably blunt title: Critical Appraisal of the Milwaukee Protocol for Rabies: This Failed Approach Should Be Abandoned.
But in order to do that photon actually needs to be created and travel from one particle to another.
The electromagnetic force is mediated by virtual photons. These don’t exist as free particles, such as a photon emitted by a light source, but only as an intermediate particle. Because they’re only intermediate states, virtual photons can have non-physical energies (so long as they’re within the uncertainty principle), resulting in some having an effective mass. Suffice it to say virtual photons are quite distinct from real ones! Technically, I believe you could have some of the basic features of the em force (namely attraction/repulsion by 2 point charges) with just virtual photons. Things get tricky once charges begin accelerating though, as this leads to the emission of real photons.
If Higgs works in a similar way also being a boson
The short answer is, it doesn’t. The Higgs Field gives mass to fundamental particles. Existing in that field causes certain particles to have mass due to their coupling to the field. The W and Z weak gauge bosons gain mass through electroweak symmetry breaking, quarks and leptons gain mass through a different coupling. I realize this is a very unsatisfying answer as to “how” the Higgs field creates mass, but the mechanism involves some complex math (group theory and non-abelian gauge theory), so it kind of defies a simpler explanation. Regardless, it’s through interactions with the Higgs field (which can exist without any Higgs bosons around) that fundamental particles gain mass. The search for the Higgs boson was just to confirm the existence of the field, because while the field can exist without Higgs bosons present it must be possible to excite it sufficiently to create them.
Going back to your original question: these particles have almost certainly been created “naturally” in high energy collisions between particles and matter. Nature can achieve much higher energies than our particle accelerators. The highest energy particle ever observed was a cosmic ray. However, Higgs bosons are extremely short lived, with a lifetime of 10^-22 seconds. So whenever they’re created, they don’t stick around for a meaningful amount of time.
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.
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.”
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.
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There are no valid inertial frames for an object moving at the speed of light. The idea that “a photon doesn’t experience time” is a common, but misleadingly incorrect statement, since we can’t define a reference frame for it. Sometimes this misconception can be useful for conveying some qualitative ideas (photons don’t decay), but often it leads to contradictions like your question about Hawking Radiation for black holes.