The mystery is why only one theory is accepted, while all other are left behind.
For me, it's clear that Universe has no bounds, so objects after Visible Universe is invisible because of geometry - we just cannot see objects which are sending less than 1 photon per hour per square meter, so there was no Big Bang less than nanosecond ago at Universe scale, it's just aging of light, so background microwaves is just aged light from distant objects.
Not exactly. In tired light theory, red shift of light is result of scattering, which is very unlikely, because scattering changes course of photon, so these photons will not be associated with original object after some very short distance.
My own idea is that photon itself has no mass, because it just wave of energy, but vacuum of volume of photon has some non-zero mass.
As analogy, water wave has no mass, but water has, so water, which forms wave, can be affected by external forces, e.g. gravitation of Moon and Sun, thus form of water wave can be disturbed by these forces. LIGO demonstrated that light can be affected by gravitational waves, so these gravitational waves, in form of constant noise, can disturb shape of photon, so photon will lost small fraction of energy to gravitational field.
Moreover, as EM force, photon should be affected by fluctuations of quantum foam, which are happened nearby. In this case, photon will lose small fraction of energy to these virtual particles.
> Because the other theories we leave behind do not make predictions compatible with our measurements of the universe.
It's temporary. With more data, we will have more and more exceptions, which cannot be explained by patches to mainstream theory.
>> so there was no Big Bang less than nanosecond ago at Universe scale
> What is this supposed to mean?
Lifetime of larger objects usually is much larger than lifetime of smaller objects, so, as we increase scale of x,y,z, t axis should be increased proportionally.
> You mean red-shifting or something else here?
Modern version of tired light. A kind of resistance for light, which causes loss of energy proportional to light frequency. See below.
> How do you account for the CMB angular power spectrum[1][2] with your "tired light"?
> With more data, we will have more and more exceptions, which cannot be explained by patches to mainstream theory.
At which point we hopefully come up with a new theory which fits the observations, and leave the current mainstream theory behind. This happened for example when General Relativity was introduced.
Until we find a new theory which fits all the observations, we have a transition period where things are a bit confusing. See for example particle physics before the QCD model tied it back together. Now we're starting to see cracks in the the current standard model of particle physics, so something new is likely needed soon. This is science.
> I see just aged spectrum. IMHO, it's helium. :-/
The power spectrum I linked to is the angular power spectrum of the CMB. It's not the spectral density. The horizontal scale is (in essence) angular separation, not frequency.
How does helium explain the peaks in the angular power spectrum? Link to some calculations please.
I had year long discussion about similar topic by email, so I see nothing exceptional there. If you have sum(sin(x_natscale)), and you will start to play with scale, you will see sinusoidal graphic, freq=asin(scale). Object formations in space usually have round shape, so it's will be same in 3D. :-/
Why? Because our formation exists for very long time. Let's play simple example: we need a 1d function f(x), such as sum(f(x_nat*scale)) newer produces infinite sum or singularity. Physical meaning: Our Universe exists for infinite time, but all matter is not attracted into one single point of infinite mass, so it's not possible.
The simplest such function is sin(x) or cos(x). If we will try to play with scale, we newer be able to make infinite sum, because Pi is irrational number. The closer our scale will be to Pi, the larger peaks of sum we will have.
In real life, this influence diminishes after some point, so, for example, size of nuclei has influence at frequency (distribution) of chemical elements, but it has no influence at macro objects, so function becomes flat and sum must rise (e.g. collapse into a black hole), then next level begins.
So, it looks like at some point, these formations cannot be bigger, or we cannot see light from them, e.g. because they are so massive, so light cannot escape them. If so, we have lower limit of formation size we can see at this distance, dictated by geometry (angular size) and luminosity, and upper limit dictated by nature, e.g. upper mass of formation of such size (upper density).
It's like in our galaxy: we can see stars, but cannot see black holes (too heavy), lone planets and smaller objects (too cold), and far away objects after certain distance (too small luminosity). IMHO, angular power spectrum of visible stars must show distribution similar to CMB or distribution of chemical elements.
> I had year long discussion about similar topic by email, so I see nothing exceptional there.
But the point is we have models which predict quite specific values for the angular power spectrum, and when compared matches observations very well.
This is highly non-trivial. And for any new model to take over, it must do better.
It's not enough that it has potential to have some sinusoidal-like features. Lacking matching model predictions, you'd need to have a plausible explanation for why the features are missing from your model predictions. For example you used some first-order approximation for some term and due to <insert convincing argument here> a higher-order approximation should produce the missing features.
I saw math paper about systems, which can remain stable for unlimited time. As far as I remember, infinity number of solutions exist for 1D, and 2D worlds. Only 3 solutions found for 3D world (named 1, 2, and 42). None found for 4D world, so, if infinite time given, 4D world will collapse into 3D world.
I can't find this paper again yet. (I'm quite busy: revolution, ongoing war, problems with health, my father died, politics, delivery for 1+y long project in less than 2 weeks, etc.)
This paper complimented view I already had in my head (everything is particle, surrounded by spherical wave, and propelled by vibrations/noise), because now I know that Universe is very simple thing in general. Nothing complex can survive in infinite time. This mean that on lower level only extremely stable (simple) systems can survive, because time is very fast on level below. On our level, we can find temporary complex systems (we live at one of them, and we itself are another example). On level above, it unlikely that we will find a complex system, chances are very low, thus what is see around us should continue for very long time and space.
I sometimes ask a similar question about matter/antimatter symmetry, if the “tiny asymmetry” that gets used as an explanation for why any baryonic matter exist at all, could be explained by the antiparticles we should’ve annihilated with being on the other side of our cosmic event horizon.
Seems like a not bad idea. Especially if the antiparticles accelerated away before they could interact. But the two types of particles should be mutually attracted. They’d also have to appear in an organized way to avoid collisions with other particles.
Maybe there wasn’t a Big Bang, but instead a “large shearing”. Ie two “sheets” (like higher dimensional objects) started in contact with one another and moved apart/were pulled apart from one another. Before the shearing, lots of energy existed with little or no opportunity for massive objects to form. During the shearing the particles adhered to one sheet (for whatever reason) and the antiparticles the other.
A question I'm too amateur to resolve on my own is what if the Big Bang simply created two universes? One made primarily of "matter" and the other made of "anti-matter?"
What if the big bang was simply a Casimir event? The particles should have collided and annihilated, but didn't? The result being two new universes pulled into existence by the sudden inversion of entropy?
I've often wondered the same thing. What if the entire universe is finite, but something like 1^(enormously large number) times larger than the observable universe? We could be this tiny speck of a backwater that's completely unrepresentative of the overall universe. The Big Bang itself could have been a minuscule local disturbance that took place in some small part of the overall universe which is trillions of times older.
I think that depends on whether big bang was global event that created matter in the entire universe (then no, because it's too far) or local event that affected observable universe (then we could see the spacetime curvature caused by outside objects and even gravitational waves that are older than the age of observable universe).
could there be an adjacent sphere of expanding matter? a "parallel universe" or universes, not in the sci-fi alternate dimension sense, but in the "physically adjacent big bangs in space" sense where the light has simply never reached us yet, but could one day
My personal (lay) theory is that the global curvature of the universe is flat, but that there are local distortions due to the energy of the big bang/rip.
Two (probably completely inaccurate) thought experiments:
Imagine a sheet of aluminum foil. Crumple it up really tightly into a ball then stretch it back out again. The sheet won't be perfectly flat anymore: it will have ridges and valleys introduced when compressing the sheet. Place objects with mass onto the sheet and those will cause further distortions, but there will be areas without mass that are also distorted.
Imagine a sheet of fabric. Place an object with mass on the sheet, then pull on the sheet (like trying to remove a tablecloth without displacing the tableware). Depending on the velocity of the pull, the mass of the object, and a bunch of other factors, you might introduce ripples into the sheet around the object. Again, distortions in areas without mass. (From my very lay understanding, this would be related to, but independent from, gravitational waves, which are caused by motion of mass in space-time rather than the expansion of space-time itself. But then again, motion is all dependent on the frame of reference, so what do I know?)
We are an ant on a leaf in a bathtub with a fancy tiny telescope. These observations aren't going to make sense until we get far outside of our mono perspective from Earth (eg travel
to Andromeda and take more data).
So there are three numbers: the expected expansion based on Planck measurements of a historical value based on cosmic microwave background, red shift of distant supernovas calibrated to nearby Cepheids, and an independent value obtained from LIGO based purely on gravitational waves, which still has uncertainty that encompasses both of the others, but will sharpen in coming years.
The LIGO measurement is not subject to vagaries of electromagnetic effects that could be introducing anomalous redshift, or to possible systematic changes in supernova brightness, such as might be caused by metal concentration of stars decreasing with distance/age.
So, if we just wait, LIGO will give an answer. Possibly, a third answer. If so, we will then have two problems, or maybe three: explaing why the Planck prediction is off, explaining why supernova brightness and/or redshift is off, and maybe even why LIGO is off.
No, it wasn't in the article, because it wasn't relevant, except as independent confirmation that both are in the ballpark.
I just gurgled LIGO and Hubble relation, and up popped https://arxiv.org/pdf/1710.05835.pdf and 'Dr Stephen Feeney of the Center for Computational Astrophysics at the Flatiron Institute in New York City, “We should be able to detect enough mergers to answer this question within 5-10 years.”'
29 comments
[ 3.1 ms ] story [ 79.2 ms ] threadFor me, it's clear that Universe has no bounds, so objects after Visible Universe is invisible because of geometry - we just cannot see objects which are sending less than 1 photon per hour per square meter, so there was no Big Bang less than nanosecond ago at Universe scale, it's just aging of light, so background microwaves is just aged light from distant objects.
And remember: it’s just that the software produces a “noisy signal” at first.
Because the other theories we leave behind do not make predictions compatible with our measurements of the universe.
> so there was no Big Bang less than nanosecond ago at Universe scale
What is this supposed to mean?
> it's just aging of light
You mean red-shifting or something else here?
> so background microwaves is just aged light from distant objects
How do you account for the CMB angular power spectrum[1][2] with your "tired light"?
[1]: http://background.uchicago.edu/~whu/intermediate/summary.htm...
[2]: http://folk.uio.no/hke/AST5220/v11/AST5220_2_2011.pdf (slide 23 and onwards)
>You mean red-shifting or something else here?
I think they are probably talking about tired light[1]
[1] https://en.wikipedia.org/wiki/Tired_light
[edit] spacing
My own idea is that photon itself has no mass, because it just wave of energy, but vacuum of volume of photon has some non-zero mass.
As analogy, water wave has no mass, but water has, so water, which forms wave, can be affected by external forces, e.g. gravitation of Moon and Sun, thus form of water wave can be disturbed by these forces. LIGO demonstrated that light can be affected by gravitational waves, so these gravitational waves, in form of constant noise, can disturb shape of photon, so photon will lost small fraction of energy to gravitational field.
Moreover, as EM force, photon should be affected by fluctuations of quantum foam, which are happened nearby. In this case, photon will lose small fraction of energy to these virtual particles.
It's temporary. With more data, we will have more and more exceptions, which cannot be explained by patches to mainstream theory.
>> so there was no Big Bang less than nanosecond ago at Universe scale
> What is this supposed to mean?
Lifetime of larger objects usually is much larger than lifetime of smaller objects, so, as we increase scale of x,y,z, t axis should be increased proportionally.
> You mean red-shifting or something else here?
Modern version of tired light. A kind of resistance for light, which causes loss of energy proportional to light frequency. See below.
> How do you account for the CMB angular power spectrum[1][2] with your "tired light"?
I see just aged spectrum. IMHO, it's helium. :-/
Yes, it's called science.
> With more data, we will have more and more exceptions, which cannot be explained by patches to mainstream theory.
At which point we hopefully come up with a new theory which fits the observations, and leave the current mainstream theory behind. This happened for example when General Relativity was introduced.
Until we find a new theory which fits all the observations, we have a transition period where things are a bit confusing. See for example particle physics before the QCD model tied it back together. Now we're starting to see cracks in the the current standard model of particle physics, so something new is likely needed soon. This is science.
> I see just aged spectrum. IMHO, it's helium. :-/
The power spectrum I linked to is the angular power spectrum of the CMB. It's not the spectral density. The horizontal scale is (in essence) angular separation, not frequency.
How does helium explain the peaks in the angular power spectrum? Link to some calculations please.
My bad. I'm not familiar with this.
(Beware, my English is weak).
I had year long discussion about similar topic by email, so I see nothing exceptional there. If you have sum(sin(x_natscale)), and you will start to play with scale, you will see sinusoidal graphic, freq=asin(scale). Object formations in space usually have round shape, so it's will be same in 3D. :-/
Why? Because our formation exists for very long time. Let's play simple example: we need a 1d function f(x), such as sum(f(x_nat*scale)) newer produces infinite sum or singularity. Physical meaning: Our Universe exists for infinite time, but all matter is not attracted into one single point of infinite mass, so it's not possible.
The simplest such function is sin(x) or cos(x). If we will try to play with scale, we newer be able to make infinite sum, because Pi is irrational number. The closer our scale will be to Pi, the larger peaks of sum we will have.
In real life, this influence diminishes after some point, so, for example, size of nuclei has influence at frequency (distribution) of chemical elements, but it has no influence at macro objects, so function becomes flat and sum must rise (e.g. collapse into a black hole), then next level begins.
So, it looks like at some point, these formations cannot be bigger, or we cannot see light from them, e.g. because they are so massive, so light cannot escape them. If so, we have lower limit of formation size we can see at this distance, dictated by geometry (angular size) and luminosity, and upper limit dictated by nature, e.g. upper mass of formation of such size (upper density).
It's like in our galaxy: we can see stars, but cannot see black holes (too heavy), lone planets and smaller objects (too cold), and far away objects after certain distance (too small luminosity). IMHO, angular power spectrum of visible stars must show distribution similar to CMB or distribution of chemical elements.
But the point is we have models which predict quite specific values for the angular power spectrum, and when compared matches observations very well.
This is highly non-trivial. And for any new model to take over, it must do better.
It's not enough that it has potential to have some sinusoidal-like features. Lacking matching model predictions, you'd need to have a plausible explanation for why the features are missing from your model predictions. For example you used some first-order approximation for some term and due to <insert convincing argument here> a higher-order approximation should produce the missing features.
I can't find this paper again yet. (I'm quite busy: revolution, ongoing war, problems with health, my father died, politics, delivery for 1+y long project in less than 2 weeks, etc.)
This paper complimented view I already had in my head (everything is particle, surrounded by spherical wave, and propelled by vibrations/noise), because now I know that Universe is very simple thing in general. Nothing complex can survive in infinite time. This mean that on lower level only extremely stable (simple) systems can survive, because time is very fast on level below. On our level, we can find temporary complex systems (we live at one of them, and we itself are another example). On level above, it unlikely that we will find a complex system, chances are very low, thus what is see around us should continue for very long time and space.
We can't know if whole universe looks as smooth as observable universe.
Maybe there wasn’t a Big Bang, but instead a “large shearing”. Ie two “sheets” (like higher dimensional objects) started in contact with one another and moved apart/were pulled apart from one another. Before the shearing, lots of energy existed with little or no opportunity for massive objects to form. During the shearing the particles adhered to one sheet (for whatever reason) and the antiparticles the other.
(End of my out there positing)
What if the big bang was simply a Casimir event? The particles should have collided and annihilated, but didn't? The result being two new universes pulled into existence by the sudden inversion of entropy?
https://en.wikipedia.org/wiki/Shape_of_the_universe#Curvatur...
Two (probably completely inaccurate) thought experiments:
Imagine a sheet of aluminum foil. Crumple it up really tightly into a ball then stretch it back out again. The sheet won't be perfectly flat anymore: it will have ridges and valleys introduced when compressing the sheet. Place objects with mass onto the sheet and those will cause further distortions, but there will be areas without mass that are also distorted.
Imagine a sheet of fabric. Place an object with mass on the sheet, then pull on the sheet (like trying to remove a tablecloth without displacing the tableware). Depending on the velocity of the pull, the mass of the object, and a bunch of other factors, you might introduce ripples into the sheet around the object. Again, distortions in areas without mass. (From my very lay understanding, this would be related to, but independent from, gravitational waves, which are caused by motion of mass in space-time rather than the expansion of space-time itself. But then again, motion is all dependent on the frame of reference, so what do I know?)
Yes, I realize this requires FTL. :-]
The LIGO measurement is not subject to vagaries of electromagnetic effects that could be introducing anomalous redshift, or to possible systematic changes in supernova brightness, such as might be caused by metal concentration of stars decreasing with distance/age.
So, if we just wait, LIGO will give an answer. Possibly, a third answer. If so, we will then have two problems, or maybe three: explaing why the Planck prediction is off, explaining why supernova brightness and/or redshift is off, and maybe even why LIGO is off.
I just gurgled LIGO and Hubble relation, and up popped https://arxiv.org/pdf/1710.05835.pdf and 'Dr Stephen Feeney of the Center for Computational Astrophysics at the Flatiron Institute in New York City, “We should be able to detect enough mergers to answer this question within 5-10 years.”'