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edpell
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What is inflation (in big bang theory not economics)?
I think that is essentially right! It's often said that inflation scenarios merely replace one kind of problem by another.edpell said:Is it the case that having inflation happen makes explaining the current (or 12.9 billion years ago) state of the universe easier but we have no theory or experimental data on inflation? i.e what caused it, how fast it was, how long it took, how far it went, why is stopped, etc...
CosmologyHobbyist said:I find it very suspicious, that "coincidentally", just as as the universe cooled enough for some of the intense gravity to condense into nuclear strong force, that is when the inflationary epoch ran its course.
I am in a minority camp, definitely not mainstream, that considers that nuclear strong force may have spacetime bending properties:
That the creation of matter should cause space to expand, and conversion of matter to energy should cause spacetime to contract. I would very much like to hear any evidence decoupling spacetime inflation from nuclear strong force creation.
twofish-quant said:There's a family of Kaluza-Klein and string theory models that model the strong force as geometric bends in space time.
Inflation (of the cosmos) is the contemporary belief that the red shift noted while observing distant galaxies is Doppler related and that they are ballooning away from us into space at an ever accelerating pace. The more distant the galaxy, the faster it is receding.edpell said:What is inflation (in big bang theory not economics)?
Einbeermug said:Inflation (of the cosmos) is the contemporary belief that the red shift noted while observing distant galaxies is Doppler related and that they are ballooning away from us into space at an ever accelerating pace. The more distant the galaxy, the faster it is receding.
cepheid said:So...what is an "inflaton?"
Einbeermug said:Inflation (of the cosmos) is the contemporary belief that the red shift noted while observing distant galaxies is Doppler related and that they are ballooning away from us into space at an ever accelerating pace.
There are several hypotheses to the effect that the red shift is not Doppler related, but stems from the nature of light as it traverses enormous distances.
How many gravitational lenses are there between Earth and the stars of deep space?
And when we observe those stars, why would we NOT expect to see some kind of color shift that increases with distance?
And not just a mystery particle, but some mystery mechanisms.twofish-quant said:It's the mystery energy field that causes inflation. Since in quantum mechanics every field has an associated particle, the mystery energy field should have an associated particle, we now have a mystery particle.
turbo-1 said:And not just a mystery particle, but some mystery mechanisms.
Obviously, the degeneration of inflatons into ordinary matter is a highly exothermic process. See? All fixed! :tongue:twofish-quant said:And also there is the problem with reheating. If the universe expanded really, really fast it should have cooled, right? So how did the universe get hot again?
Reheating occurred when the energy in the inflaton field which drove the expansion was released into thermal energy.twofish-quant said:And also there is the problem with reheating. If the universe expanded really, really fast it should have cooled, right? So how did the universe get hot again?
My misunderstanding. I was equating inflation w/expansion. I've been away from astronomy/cosmology for some 35 years and have not kept up with the current vernacular.twofish-quant said:Nope. Inflation involves early universe.
So if you look at a light source while standing in the red 'shadow' of its spectrum it appears fuzzy? What about someone observing that source from its violet 'shadow'? Do they assume the galaxy is approaching? I would rest easier if cosmologists didn't use the expansion of the universe to explain away velocities greater than C. What is the current data on distant galaxies when observed in frequencies above/below the visible spectrum. Is the Doppler effect apparent there, also?Yup, and after thinking about it between roughly 1950 and 1970 those theories were abandoned by most people. The trouble is that if light is getting scattered, then distant galaxies ought to look blurry. If it is getting absorbed then the energy should get re-emitted at other frequencies, and you should see a warm glow. Also it's pretty easy to think of something that blocks blue light,
Presumably the ratio of matter to aether in local space is 1 atom/m3 - and there are a lot of 'm's btween here and the more remote galaxies. We don't know what elemental gasses occupy deep space and even with that minute density, the more distant light sources may appear red for much the same reason that the sky is blue....it's pretty hard to think of something that *shifts* light and keeps all of those spectral lines nice and sharp.
If there were lots of gravitational lens then looking at the universe would be like looking through a dense fog.
If there was a BigBang, then we should be able to determine an epicenter somewhere in the known universe. If galaxies appear to be receding at a relatively even pace at 360° originating at our point of view, the matter of BB is HIGHLY suspect.Couldn't that cause the cosmic microwave background? Maybe. Again, people thought about that during the 1960's. The problem is that if the CMB was caused by scattered sources, you run into the opposite problem with things being too smooth.
The trouble with gravitational lens is that its a lens and doesn't shift frequencies. There are lots of things that change light. There is absorption, scattering, lensing. The trouble is that you have to pick one.
Einbeermug said:So if you look at a light source while standing in the red 'shadow' of its spectrum it appears fuzzy? What about someone observing that source from its violet 'shadow'?
What is the current data on distant galaxies when observed in frequencies above/below the visible spectrum. Is the Doppler effect apparent there, also?
Presumably the ratio of matter to aether in local space is 1 atom/m3 - and there are a lot of 'm's btween here and the more remote galaxies.
We don't know what elemental gasses occupy deep space and even with that minute density, the more distant light sources may appear red for much the same reason that the sky is blue.
If there was a BigBang, then we should be able to determine an epicenter somewhere in the known universe. If galaxies appear to be receding at a relatively even pace at 360° originating at our point of view, the matter of BB is HIGHLY suspect.
It is my understanding that signature absorption lines can be shifted by differentials in the temperatures of the media traversed by a beam before it is observed. Discounting the possibility that the effect of space is neutral (actually its properties may be so subtle as to not be detectable by current methodology) then over vast distances wouldn't a material density of even 1 atom per CuM be enough to result in the same shift as a 'cloud' would render in a local venue? Wouldn't each photon suffer multiple resonant scatterings.twofish-quant said:Lyman alpha is a very strong line in the ultraviolet, and you start detecting tons of quasars and hydrogen gas clouds. There are things like the Lyman alpha forest and the Gunn-Peterson trough. You have a sharp emission line by a quasar. And then you have a bunch of absorption lines on one side of that line. The standard interpretation is that you have a highly redshifted emission line, and then in between the galaxy and the Earth you have a bunch of gas clouds at smaller redshift whose shadow you can see.
And you can calculate cross sections and absorption coefficients. If you shine a beam of light through hydrogen/helium gas, there are only about a dozen or so known things that can happen to them.
A simple axiom, implication and conclusion:Big bang happened everywhere?
The frequencies of absorption lines are almost completely unaffected by the intervening medium. What you've written here only holds true for continuous spectra, where, for instance, a cool intervening medium will absorb some higher-frequency light and emit more low-frequency light, lowering the average frequency of the spectrum as a whole. But since the entire process is a process of absorption and reemission of light, it just doesn't affect the frequencies of emission lines.Einbeermug said:It is my understanding that signature absorption lines can be shifted by differentials in the temperatures of the media traversed by a beam before it is observed. Discounting the possibility that the effect of space is neutral (actually its properties may be so subtle as to not be detectable by current methodology) then over vast distances wouldn't a material density of even 1 atom per CuM be enough to result in the same shift as a 'cloud' would render in a local venue? Wouldn't each photon suffer multiple resonant scatterings.
If galaxies are in motion, they have trajectories. Although complicated by the possibility of the expansion/inflation (I hope you are not inferring creation) of space between celestial bodies, from any point of reference each trajectory ought to be tracable back in time to produce at least some approximation of its position 14B years ago. And even if the point of observation is not fixed, compensating calculations can be derived to accommodate those dynamics.twofish-quant said:Big bang happened everywhere.
Einbeermug said:If space, itself, is expanding, why is it not measurable locally but only at enormous distances?
Einbeermug said:It is my understanding that signature absorption lines can be shifted by differentials in the temperatures of the media traversed by a beam before it is observed.
Discounting the possibility that the effect of space is neutral (actually its properties may be so subtle as to not be detectable by current methodology) then over vast distances wouldn't a material density of even 1 atom per CuM be enough to result in the same shift as a 'cloud' would render in a local venue? Wouldn't each photon suffer multiple resonant scatterings.
A simple axiom, implication and conclusion
Axiom: Something must exist before it can change or be changed.
:Distance is a measurement - a quantitative assessment or comparison of something(s) with physical presence in the universe. Does the definition in GR propose that a distance can increase without either expanding or adding to that which is being measured?marcus said:What can be viewed as the cumulative effect of many small local expansions is large enough to detect and is, in fact, measured.
I will try to answer your question carefully, please tell me anything that doesn't make sense to you.
The current rate of expansion of distances is 1/140 of one percent every million years. Given limited time and the limited accuracy of distance measurements, the local detection of expansion is not practical. You can do some numbers and see for yourself.
And there is a deeper problem. Our context is General Relativity, and since there is nothing in General Relativity called "space, itself" it must not be "space, itself" that is expanding. What expands, in this context, are distances (defined a certain way) between observers who are at rest with respect to the ancient matter that gave off the cosmic microwave background.
Are you saying that within the frame of reference of GR, the past trajectory of a very distant object cannot be calculated or even approximated with any degree of certainty? Any idea how fast the error factor grows in relation to distance?You are at rest relative to the CMB if your microwave sky is approximately all the same temperature, with no doppler hotspot. At rest can only be determined with finite accuracy. Another reason local measurements are a limited option.
It has been determined that the solar system is moving about 370 km/s in the direction of Leo. This motion relative CMB can be taken out of observational data, so that our corrected observations are then from the standpoint of an observer at rest relative to the CMB.
We see the universe, in this case, from the standpoint of an observer at rest with respect to the hot ionized gas of the early universe, and relative to the ancient light which that gas emitted.
The Hubble law v = Hd is valid for distances between stationary observers. By definition the distances are as if measured by freezing the expansion process and timing light signals.
When you see v = Hd, remember that d is such a distance, and v is the current rate that distance d is expanding.
In a universe where geometry is governed by General Relativity none of us have the right to assume that the distance between stationary observers will not change, will not increase or decrease. Gen Rel says that Euclidean geometry can't be taken for granted. Euclid may be approximated in some situations, but is not to be relied on. Same with Special Rel geometry. When and where it applies, there will be some reason that causes a standard flat non-expanding geometry to be (approximately) applicable.
Einbeermug said::Distance is a measurement - a quantitative assessment or comparison of something(s) with physical presence in the universe.
Does the definition in GR propose that a distance can increase without either expanding or adding to that which is being measured?
Are you saying that within the frame of reference of GR, the past trajectory of a very distant object cannot be calculated or even approximated with any degree of certainty?
If I read you correctly, Doppler is the ONLY known cause of a frequency shift that would not alter the position of elemental signature lines. Correct?twofish-quant said:that's different from my understanding. It's very hard to shift an absorption line, because any sort of change involves an interaction with the medium which causes something much more complex than a simple frequency shift from happening.originally posted by einbeermug
it is my understanding that signature absorption lines can be shifted by differentials in the temperatures of the media traversed by a beam before it is observed.
discounting the possibility that the effect of space is neutral (actually its properties may be so subtle as to not be detectable by current methodology) then over vast distances wouldn't a material density of even 1 atom per cum be enough to result in the same shift as a 'cloud' would render in a local venue? Wouldn't each photon suffer multiple resonant scatterings.
if it's made up of ionized hydrogen then no, since cross sections for interactions are really low. Now if the photons are moving through neutral hydrogen, then yes the light will interact with the medium, and we see this happening with the most distant quasars (the lyman alpha forest and the gunn-peterson trough). But when it goes through a cloud, what happens is that you get new absorption lines, you don't get previous lines shifting.
Also the cross sections for light moving through hydrogen is pretty well studied, since you can pass light through hydrogen on Earth and see how it behaves. There aren't any known effects that would case frequency shifts. Scattering, yes. Absorption, yes. Shifting, no.
I would define an existence as an irreducable (not comprised of independent components) physical presence (not necessarily material) within the comos. Qualifications would necessitate it having quality (even inertness is a quality), quantity (no matter how small) and location in space. Unfortunately 'exist' has another connotation. The English language does us a disservice when it allows us to say conditions 'exist'. Conditions OCCUR. Physical presences EXIST.A simple axiom, implication and conclusion
I'm very dubious about using "word logic" to say things about physics because it turns out that words tend not to be precise enough to allow for clear thinking. When you say something "exists" what are you saying? It turns out that when you use words, you are saying something quite complex and fuzzy. Does a vacuum exist?
If you are referring to observations of the microcosm that are interpreted as "two things occupying the same space" and "things moving from point A to point B without traversing the points in between", or "something that appears to be partially in one location and the rest in another", yes mother nature is a master of legerdemain. There are viable natural explanations for those phenomena, interpretations stemming from a different perspective of the standard model that probably classify as conjecture not suitable for scientific discussion.Axiom: Something must exist before it can change or be changed.
I've seen stranger things happen so I don't trust "word logic" when it comes to these sorts of things. In any case, we are talking about physics and not math, and axioms don't work in physics.
Or a gravitational redshift.Einbeermug said:If I read you correctly, Doppler is the ONLY known cause of a frequency shift that would not alter the position of elemental signature lines. Correct?
Inflation is a general increase in the prices of goods and services in an economy over a period of time. It is usually measured as a percentage increase in the price level in a given economy.
Inflation can be caused by a variety of factors, but the most common cause is an increase in the money supply. This can happen when the government prints more money, or when banks lend out more money than they have in reserves, leading to an increase in demand for goods and services.
Inflation can have both positive and negative effects on the economy. A moderate level of inflation (around 2-3%) can stimulate economic growth by encouraging consumer spending and investment. However, high levels of inflation can lead to a decrease in the value of money, which can cause economic instability and negatively impact businesses and consumers.
Inflation is typically measured using a price index, such as the Consumer Price Index (CPI) or the Producer Price Index (PPI). These indexes track the changes in prices of a basket of goods and services over time.
Governments and central banks use various monetary policies to control inflation. This can include adjusting interest rates, regulating the money supply, and implementing fiscal policies such as taxes and government spending. The goal is to maintain a stable and moderate level of inflation to support economic growth and stability.