Photonics? / frequency multiplier,

[Ken S. Tucker]

Suppose one views a photonic (ElectroMagnetic Radiation) image,
I'm thinking in the microwave range. Can said images frequency
be multiplied, such as frequency x multiplier = Frequency
up to a visual range?

The application might be interesting to read.
Astronomers have found that as distance of an objects image
increases, the light from said object is "Red Shifted".
That effect creates a kind of *Information Barrier* at
~14 Giga Light years (14GLy), as the EMR is shifted to what
appears as the CMBR (Cosmic Microwave Background Radiation).

The effect is arguably a Doppler Shifting or a General Relativistic
effect, either takes an emission Frequency and divides it as
Frequency / multiplier = frequency.

If photonic multiplication can restore frequency to Frequency,
then we might be able to image beyond the Information Barrier.
Regards
Ken S. Tucker

 

[Tim Williams]

Be interesting to make, perhaps a metamaterial, which doubles or multiplies
the frequency of fields in space. A lens or dish could be made out of this
material, to transmit or reflect light generated by the interaction with
incident radio waves, perhaps THz radiation. Bias could be incorporated to
provide amplification; this would be the bulk equivalent of the
zero-dimensional frequency tripler (which distorts the original signal,
producing 2nd harmonic, which gets implicitly mixed with the original,
making a fairly linear tripler).

Such material can probably be fabricated today from layers of SiO2,
amorphous silicon and aluminum interconnects -- amorphous transistors suck,
but it would be an interesting proof-of-concept that might work into the
GHz. I don't know if schottky diodes can be made with any performance with
amorphous silicon, but regular MOS structures should still do fine. Good
enough for TFTs.

Can Al2O3 be grown by epitaxy on Si? I know the opposite way works.
Annealing probably isn't possible; growth from solution (Al2O3 is soluble in
Na3AlF6 and similar salt 'alloys') is probably necessary. Hmm, making
reliable MOS gates after soaking in a sodium ion bath would be...
interesting?

Tim

 

[Jeroen Belleman]

The information barrier is literally the edge of the universe. The
red-shifted things you see at around 14G light-years were created at
the birth of this universe.

The 'edge', if there is one, seems to be found by linearly
extrapolating the recession velocity described by Hubble's
constant to where it reaches c. That's just silly.

There is no need to have EM energy in the visible range to
make images, either. We can make images using infrared and
radio waves just fine. Of course, we need huge apertures
to get interesting resolution, but that's needed for raw
sensitivity too, anyway.

Jeroen Belleman

 

[Jeroen Belleman]

Well, it appears that there are two things going on.
1. As the Universe is expanding, the galaxies and all are flying out. So
the optical Doppler Effect or 'Red
Shift'
2. Light coming in from from the
extremities of the Universe are 'bent'
from their straight paths by massive
galaxies and 'dark matter' and this
is 'gravitational lensing'.
Very fascinating stuff.

It's the other way around, actually: Remote objects have
their observed spectra increasingly red-shifted, which is
explained by positing they are moving away.

One problem with this is that when you extrapolate that
sufficiently far backwards, you end up with something
that present-day physics cannot explain.

Then again, there are quite a few things in the universe
that present-day physics has trouble with, and most
'explanations' are merely unbridled fantasy.

Jeroen Belleman

 

[Ken S. Tucker]

Well, it appears that there are two things going on.
1. As the Universe is expanding, the galaxies and all are flying out. So
the optical Doppler Effect or 'Red
Shift'
2. Light coming in from from the
extremities of the Universe are 'bent'
from their straight paths by massive
galaxies and 'dark matter' and this
is 'gravitational lensing'.
Very fascinating stuff.

In cosmology, like religion, I agree with everybody else,
the model is your choice.

A standard telescope can increase the brightness, which is
actually increasing the Number of photons in an image.

Total Energy = Number x (Plancks h) x frequency

My curiosity is to boost the Total Energy by

Total Energy = Number x (Plancks h) x Frequency

where Frequency = frequency x multiplier.

Not quite the same as 'heterodyning' or a photo multiplier,
which increases Number.
Regards
Ken

 

[[email protected]]

Suppose one views a photonic (ElectroMagnetic Radiation) image,
I'm thinking in the microwave range. Can said images frequency
be multiplied, such as frequency x multiplier = Frequency
up to a visual range?

At sufficient power densities, some materials will behave in a
non-linear way and produce sum and difference frequencies. Even a
"transparent" fiber might do this at sufficient (close to melting)
power levels.

Of course, this is unusable for image generation purposes, in which
the power levels are _far_ too low.

 

[Ken S. Tucker]

Well let say you have such frequency multiplier, and you travel to get
close to the information barrier (let say 2 feet away) what happens
then? will you see multiple universes ?

I'll ask you, what if we can see more of the universe, perhaps
out to 15GLys, what would that mean?

The 'device' theorized, would have applications to earthly
photonics, (cosmology was just an example).
Ken

 

[Ken S. Tucker]

Well allow me to be incremental, and start with Doppler Shifted Audio.
Of course we've all experienced that.
One has a spectrum of audio ranging from 0-10Khz, and then simulates
approaching that source to Doppler shift to 0-20Khz, linearly, so that
would be frequency x2, and one can select x3 x4 ...
Off hand, I haven't done that using either analog or digital computer,
so that's where I'd need to start.
Regards
Ken

 

[Martin Brown]

Not quite. We actually see back to the surface of last scattering where
the universe first became transparent to electromagnetic radiation which
corresponds to the inevitable 4K background radiation noise in radio and
microwave receiver electronics that will not go away.

The patterns in that region reflect the tiny perturbations from perfect
uniformity that will eventually lead to the formation of stars, galaxies
and clusters of galaxies.

The surface of last scattering is still well before the position where
our observable part of the universe runs out. And you do have to be very
careful how you define the horizon of our universe too...

The Big Bang is silly, too.

Yet another thing that John doesn't understand so it must be wrong.

But you can't make very good images of something that doesn't exist.
It's redshifted to zero Hertz.

You can make very good aperture synthesis images at radio wavelengths.
All it takes is a load of dishes and some very low noise front ends,
phase compensators, correlators and associated electronics. Aperture
synthesis has been done down to tens of MHz. The VLA surveyed ground is
currently retrofitted to do aperture synthesis at 74MHz see for example.

http://lwa.nrl.navy.mil/VLSS/

The tricky bit is in compensating for the atmospheric and ionospheric
distortions in these low frequency wavebands. Resolution isn't exactly
great at 4m wavelength even with a 27km baseline.

The most interesting detectors in astronomy at the moment are in the
largely unexplored terahertz band. I have seen some preliminary results.

 

[Jeroen Belleman]

On 2012-03-12 01:29, John Larkin wrote: [...]
The information barrier is literally the edge of the universe. The
red-shifted things you see at around 14G light-years were created at
the birth of this universe.

Not quite. We actually see back to the surface of last scattering where
the universe first became transparent to electromagnetic radiation which
corresponds to the inevitable 4K background radiation noise in radio and
microwave receiver electronics that will not go away.

The patterns in that region reflect the tiny perturbations from perfect
uniformity that will eventually lead to the formation of stars, galaxies
and clusters of galaxies.

The surface of last scattering is still well before the position where
our observable part of the universe runs out. And you do have to be very
careful how you define the horizon of our universe too...

The Big Bang is silly, too.

Yet another thing that John doesn't understand so it must be wrong.

I don't understand it either. It has too many ad-hoc patches.
What would an infinitely deep background of red-shifted galaxies
at the observed average density look like? Any chance it might
look like a uniform 3K background? Like Olbers thought it should,
but after correction by Hubble or Lemaitre and Einstein?

Jeroen Belleman

 

[Martin Brown]

On Mon, 12 Mar 2012 09:21:55 +0100, Jeroen Belleman

On 2012-03-12 01:29, John Larkin wrote: [...]
The information barrier is literally the edge of the universe. The
red-shifted things you see at around 14G light-years were created at
the birth of this universe.

Not quite. We actually see back to the surface of last scattering where
the universe first became transparent to electromagnetic radiation which
corresponds to the inevitable 4K background radiation noise in radio and
microwave receiver electronics that will not go away.

The patterns in that region reflect the tiny perturbations from perfect
uniformity that will eventually lead to the formation of stars, galaxies
and clusters of galaxies.

The surface of last scattering is still well before the position where
our observable part of the universe runs out. And you do have to be very
careful how you define the horizon of our universe too...

The 'edge', if there is one, seems to be found by linearly
extrapolating the recession velocity described by Hubble's
constant to where it reaches c. That's just silly.

The Big Bang is silly, too.

Yet another thing that John doesn't understand so it must be wrong.

I don't understand it either. It has too many ad-hoc patches.

Why do you think that? It has good observation evidence that actually
found a theoretical prediction of the model much to Penzias & Wilsons
surprise. They spent a lot of time removing pigeon droppings from their
feed horn (dielectric material as they referred to it in their paper)
before concluding that the noise really was uniform and from the sky.

It also neatly explains the relative cosmic abundances of the elements.

The only ad hoc patch that I can see is the Guth's inflation hypothesis
which is required to make the universe sufficiently uniform.

You might find Martin Rees book "Just 6 Numbers" interesting.

What would an infinitely deep background of red-shifted galaxies
at the observed average density look like? Any chance it might
look like a uniform 3K background? Like Olbers thought it should,
but after correction by Hubble or Lemaitre and Einstein?

No. Nothing like right. Tired light theories are completely discredited
and you would then have to figure out some way through the what happened
14bn years ago when based on our observations everything was pretty much
in the same place. And light from further away than 14bn light years
hasn't had time to reach us yet so an infinite universe cannot help you
unless it has also been there for infinite time as well.

One of the fatal nails in the coffin of steady state theories in the
1960's was the discovery that looking at the early universe in radio
wavelengths found far more very bright radio sources the deeper they
looked. The early universe was a much more exciting and dangerous place
to be with a lot more going on. It is quite benign near us now.

 

[Martin Brown]

Do you understand the Big Bang? Explain it to us.

Typical that you quote the whole thing to add your trivial tag line.

I won't bother because I don't think you have the wit to understand.
However, for the benefit of other interested readers I will refer you to
the DAMPT website which explains the four observational pillars of the
hot big bang cosmology without any detailed mathematics.

http://www.damtp.cam.ac.uk/research/gr/public/bb_home.html

It always loses something put into words and without the mathematics.

We actually live in a golden era of observational cosmology where new
instruments can now survey and image the sky at high resolution in
wavelengths ranging from X-rays down to long wave radio. Even the gaps
like terahertz are now being filled in by metamaterial based sensors.

Theoretical models are now very well constrained by the observational
data. When I was a student you could still hide "cold dark matter" as
old biros, chair legs and sticks of rhubarb - but not any more.

 

[Martin Brown]

Of course. I have it around here somewhere, old and yellow by now.
They teach that stuff in high school these days.

Perhaps you would like to share with the rest of us your great insight
that tells you that Big Bang Cosmology is incorrect?

The original question remains, can we build better radio telescopes to
see 30-billion year old galaxies?

Of course not. The universe has only been around for at most 14bn years
so looking for 30bn year galaxies would be like digging a big pit on the
Earth to look for 10bn year old fossils (Earth is 4.5bn years old).

Radio telescopes are now down to deciding what new experiments will help
distinguish between the various competing theories by finding additional
observational constraints. Deep radio surveys at ever lower frequencies
and longer baselines have been done to death already.

The answer is already known the "Steady State Universe" is dead and had
curled up its toes in the late 1960's though it took a while for its
main proponents to accept this and/or die off. The battle royal between
Hoyle vs Ryle (radio astronomy) in Cambridge was particularly brutal.

Observational data from the most distant regions of the universe are
limited to objects that are intrinsically *very* bright and/or imaged
for us by gravitational lensing of an intervening galactic cluster.

http://www.sdss.org/news/releases/20031217.lensing.html

And in case you are wondering how they know the views are images of the
same quasar there are two pieces of evidence. Spectroscopy and temporal
variations in light output. It is an annoying property of quasars that
their output varies rather rapidly (also implying small physical size
and/or relativistic beaming).

The furthest back a galaxy or quasar has been seen is about Z=8 and one
or two really bright ones have been found suitable for further study.

http://www.eso.org/public/news/eso1122/

 

[Ken S. Tucker]

Incorrect? It sounds pretty good to me, at least after the first
femtoseconds, which seem to be in some doubt.

People sometimes pontificate as tho they have god on speed dial,
((I've never received a call from Marty ;-)).
10 GLys away are galaxies requiring 10 Gigayears to form, setting back
it's early formation to 20G years ago....hmmm....
so Big Bangers (BBs) merely modify (speed up) galactic evolution.
OTOH GRists (General Relativity specialists), can provide the same
observations using an *infinite universe* model.
BBs sell more books, and pop-sci, so that's in it's favor.
Regards
Ken

 

[John S]

Well, she's very busy.

You're getting help on these replies from your wife, I think.

 

[Tim Williams]

If that's true then, just look at the acceleration of the red shift in
galaxies far away, and it becomes apparent that the closer they get to
the wall the faster they hurtle toward it because of the inverse
square law of attraction that gravitation seems to exert, and the
massive gravity on the other side of the wall.

Gauss must be rolling in his grave...

Tim

 

[Les Cargill]

---
Indeed.

It makes much more sense to consider our universe as having come into
existence in much the same way as the matter in the inside of a bubble
caused by cavitation comes into being; from the outgassing of material
on the other side of the bubble's wall.

If that's true then, just look at the acceleration of the red shift in
galaxies far away, and it becomes apparent that the closer they get to
the wall the faster they hurtle toward it because of the inverse
square law of attraction that gravitation seems to exert, and the
massive gravity on the other side of the wall.

So what's holding it back, then? In a soap bubble, it's
the shear in density between the air and the soap. I'm
thinking it's electrostatically maintained. Why
is there an edge to a bubble in the dense soup? The radii
of attractio/repulsion seem off.

I do like the poetry of the image of a child blowing a bubble,
and that bubble is our universe. That's way cool.

None of that can be attributed to the big bang, since once a
projectile reaches the end of the barrel it can only decelerate.

So think relativistically; the timebase
is different at the edges than it is in the middle.

I think I read that somewhere, can't remember. But in relativity,
time is not an independent variable.

Dark matter and dark energy, which were invented for the purpose of
upholding the big bang theory are, in my opinion, just dodges designed
to try to maintain the status quo.

I like the origin myths of aboriginal peoples better. They've
had longer to polish them.

 

[Martin Brown]

---
Indeed.

It makes much more sense to consider our universe as having come into
existence in much the same way as the matter in the inside of a bubble
caused by cavitation comes into being; from the outgassing of material
on the other side of the bubble's wall.

You are still thinking in semi-classical terms of there being something
outside our universe. That is not required at all although it is not
excluded as a possibility in modern cosmology.

If that's true then, just look at the acceleration of the red shift in
galaxies far away, and it becomes apparent that the closer they get to
the wall the faster they hurtle toward it because of the inverse
square law of attraction that gravitation seems to exert, and the
massive gravity on the other side of the wall.

I think you will find a gentleman by the name of Gauss proved a long
time ago that inside a uniform spherical shell of mass or charge you
will feel no attractive force from it at all.

None of that can be attributed to the big bang, since once a
projectile reaches the end of the barrel it can only decelerate.

Dark matter and dark energy, which were invented for the purpose of
upholding the big bang theory are, in my opinion, just dodges designed
to try to maintain the status quo.

Not true. Dark matter was proposed by Oort in 1932 to explain the
anamolous motion of stars in the Milky Way. That is nearly 3 decades
before the huge fight over Big Bang vs Steady State in the 1960's.

Dark matter was proposed to explain why galaxies don't fly apart. If you
look at the speed the stars and gas in the spiral arms are doing and yet
they are held together by gravity. The initial idea was that there was
dark matter that is non-luminous in the form of rocks and dust to make
up the balance. Modern observational techniques are now sensitive enough
to rule that out so cold dark matter has to be some form of mass that
doesn't interact in other ways with ordinary matter or with
electromagnetic radiation.

It is reassuring that ab initio computer simulations of CDM universes
now produce very good agreement with the observations of the microwave
background, elemental abundances and galaxy cluster formation that we
observe.

Dark energy is actually the name that has been given to the constant of
integration that Einstein inserted into his field equations to
facilitate a steady state universe solution. Without it he had proved
that universes had to either expand or contract. It is ironic that it
seems now from observations that the value is not quite exactly zero
although its influence only really makes a difference at very great
distances.

 

[josephkk]

Well allow me to be incremental, and start with Doppler Shifted Audio.
Of course we've all experienced that.
One has a spectrum of audio ranging from 0-10Khz, and then simulates
approaching that source to Doppler shift to 0-20Khz, linearly, so that
would be frequency x2, and one can select x3 x4 ...
Off hand, I haven't done that using either analog or digital computer,
so that's where I'd need to start.
Regards
Ken

Actually that is done in music, with a DSP, even in realtime for karaoke.
As for whether the techniques are relevant to your use is rather
questionable.Actually Al2O3 is much more readily soluable/etchable than Si. What would
be really cool is SOI processes on BN.

?-)