Thanks, @Galu, I won't have to watch Sabine Hossenfelder's "Whiplash" video then... really, I think she is tapping into our worst boyish tendencies.
"Half Tomb Raider, half Mass Effect, but ALL Sabine!" 😍
Tonight's image is f3.5, 18mm, 30s, ISO 800 (up from 400), small format, shortened Tripod on a car roof.
I was quite pleased with this. I can spot magn. 6.5 easily. And it's definitely R CrB, not G. The faster ISO seems to have brought up the twilight quite a lot.
That line is a telephone wire, not the Space Lab. If anything interesting happens, I shall head off to my spot at Southsea Castle for a perfect view.
Not much to add tonight. Really ought to be starting my Sean Carroll book and finish servicing my bike. Best, Steve.
"Half Tomb Raider, half Mass Effect, but ALL Sabine!" 😍
Tonight's image is f3.5, 18mm, 30s, ISO 800 (up from 400), small format, shortened Tripod on a car roof.
I was quite pleased with this. I can spot magn. 6.5 easily. And it's definitely R CrB, not G. The faster ISO seems to have brought up the twilight quite a lot.
That line is a telephone wire, not the Space Lab. If anything interesting happens, I shall head off to my spot at Southsea Castle for a perfect view.
Not much to add tonight. Really ought to be starting my Sean Carroll book and finish servicing my bike. Best, Steve.
I'm seeing more stars in your 'tonight's' image Steve.👍
I find this image from Euclid quite mind boggling:
The image of the Perseus galaxy cluster is said to show 1,000 galaxies and more than 100,000 additional galaxies further away in the background!
That is so humbling!
In the words of the late lamented Mike Pinder of The Moody Blues:
Wonders of a lifetime
Right there, before your eyes
Searching with this life of ours
You've gotta make the journey out and in
I was trying to get my head round what we are looking at here with Euclid images.
It's a fairly widefield infrared Lagrange 2 survey telescope incorporating all the current improvements in technology of sensors and cooling.
Designed to survey a third of the sky on its mission.
The Horsehead Nebula, a dark dust cloud, is a familiar image, and is 1300 Ly away. Its just below the star Alnitak in the belt of Orion, here in a compressed jpeg that doesn't do it justice:
Alnitak is the brightest Type O star in the sky at about the same 1300 Ly, distance and a whopper. It is 21,000 times brighter than the Sun and 20 times its diameter, and due to go Red Giant and then Supernova in a million years time.
https://en.wikipedia.org/wiki/Alnitak
Back to the Horsehead.
https://en.wikipedia.org/wiki/Horsehead_Nebula
This image is with a 15" reflector, AFAIK, and I have rotated it to show the real alignment below Alnitak:
Finally, Euclid, Hubble and James Webb for comparison:
The full uncompressed and huge images are here:
https://webbtelescope.org/contents/media/images/2024/119/01HV6MPV24NH09VKJ4EWHP8Q4E
The equally famous "Pillars of Creation" are 7,500 Ly away and part of the Eagle Nebula M16 in Serpens Cauda near Sagittarius. South of Corona Borealis as it goes.
No Nova shots tonight. It's chucking it down in Portsmouth again.
Best, Steve.
It's a fairly widefield infrared Lagrange 2 survey telescope incorporating all the current improvements in technology of sensors and cooling.
Designed to survey a third of the sky on its mission.
The Horsehead Nebula, a dark dust cloud, is a familiar image, and is 1300 Ly away. Its just below the star Alnitak in the belt of Orion, here in a compressed jpeg that doesn't do it justice:
Alnitak is the brightest Type O star in the sky at about the same 1300 Ly, distance and a whopper. It is 21,000 times brighter than the Sun and 20 times its diameter, and due to go Red Giant and then Supernova in a million years time.
https://en.wikipedia.org/wiki/Alnitak
Back to the Horsehead.
https://en.wikipedia.org/wiki/Horsehead_Nebula
This image is with a 15" reflector, AFAIK, and I have rotated it to show the real alignment below Alnitak:
Finally, Euclid, Hubble and James Webb for comparison:
The full uncompressed and huge images are here:
https://webbtelescope.org/contents/media/images/2024/119/01HV6MPV24NH09VKJ4EWHP8Q4E
The equally famous "Pillars of Creation" are 7,500 Ly away and part of the Eagle Nebula M16 in Serpens Cauda near Sagittarius. South of Corona Borealis as it goes.
No Nova shots tonight. It's chucking it down in Portsmouth again.
Best, Steve.
Last edited:
Of course, Euclid is not in competition with Hubble and Webb in terms of such images.
The Horsehead Nebula of Barnard 33 as seen by Euclid
As you say, its mission is to use its wide field of view to track "billions of galaxies across 10 billion years of cosmic history".
Euclid's image of the Horsehead Nebula is more for public consumption than for science.
This image from Wikipedia by a certain StephanH is described as Ha RGB on a refractor astro camera:
I think this means visible light with a Hydrogen Alpha red filter. The filter brings up the contrast with the Horsehead dust cloud. We are probably seeing a bit of bluish Hydrogen Beta too.
In fact the whole red field is illuminated with Hydrogen Alpha excitations by nearby Type B Sigma Orionis which is the bright (multiple) star above the Nebula.
Chemists will remember the Hydrogen Lines: Lyman, Balmer, Paschen, Brackett, Pfund and even Humphreys from the Bohr atomic model.
The Balmer series in the visible looks like this:
You are up against the atmospheric window with Earth based observations:
Hubble can do better in the near Infrared:
Depends what you want to see, of course.
JWST can see into Mid Infared as far as 25um due to near absolute zero temperature sensors.
In fact, rattlesnakes can see IR too. In the dark! So let's be careful out there.
Best, Steve.
I think this means visible light with a Hydrogen Alpha red filter. The filter brings up the contrast with the Horsehead dust cloud. We are probably seeing a bit of bluish Hydrogen Beta too.
In fact the whole red field is illuminated with Hydrogen Alpha excitations by nearby Type B Sigma Orionis which is the bright (multiple) star above the Nebula.
Chemists will remember the Hydrogen Lines: Lyman, Balmer, Paschen, Brackett, Pfund and even Humphreys from the Bohr atomic model.
The Balmer series in the visible looks like this:
You are up against the atmospheric window with Earth based observations:
Hubble can do better in the near Infrared:
Depends what you want to see, of course.
JWST can see into Mid Infared as far as 25um due to near absolute zero temperature sensors.
In fact, rattlesnakes can see IR too. In the dark! So let's be careful out there.
Best, Steve.
Last edited:
Ah! The Balmer Series. That brings back memories of my 1st year, 2-term chemistry course.
I was BALMY wasting time on that course when I should have been concentrating on my mathematics course!
Balmer's formula:
v bar is the wave number, which is the reciprocal of the wavelength, and n is the number corresponding to the energy level.
109677 has the unit cm^-1
Thank you Johann Balmer for helping me fail my maths exam at my first attempt! 🙁
While we're covering the spectrum, here's an extreme ultraviolet image of the solar surface that's been captured by the ESA's Solar Orbiter spacecraft:
"Solar Orbiter captured outbursts, jets and rivers of plasma beneath the arch of a glowing coronal loop."
There's a video and description here: https://www.space.com/sun-fluffy-solar-corona-video-orbiter
"Solar Orbiter captured outbursts, jets and rivers of plasma beneath the arch of a glowing coronal loop."
There's a video and description here: https://www.space.com/sun-fluffy-solar-corona-video-orbiter
^ Some extraction of information from the article is required, don't you think brianco?
Galaxy JADES-GS-z14-0 has been observed by the JWST as it was a mere 290 million years after the Big Bang.
The discovery by JWST of an abundance of luminous galaxies in the very early Universe suggests that galaxies developed rapidly, in apparent tension with many standard models. However, most of these galaxies lack spectroscopic confirmation, so their distances and properties are uncertain.
Now, spectroscopic analysis of this unexpectedly luminous galaxy lying at redshift z = 14 reveals copious ultraviolet emission.
The conclusion is that the luminosity of the galaxy is dominated by the emission of light from stars and cannot be entirely explained by accretion onto black holes. Galaxy formation models will need to address the existence of such large and luminous galaxies so early in cosmic history.
Galaxy JADES-GS-z14-0 has been observed by the JWST as it was a mere 290 million years after the Big Bang.
The discovery by JWST of an abundance of luminous galaxies in the very early Universe suggests that galaxies developed rapidly, in apparent tension with many standard models. However, most of these galaxies lack spectroscopic confirmation, so their distances and properties are uncertain.
Now, spectroscopic analysis of this unexpectedly luminous galaxy lying at redshift z = 14 reveals copious ultraviolet emission.
The conclusion is that the luminosity of the galaxy is dominated by the emission of light from stars and cannot be entirely explained by accretion onto black holes. Galaxy formation models will need to address the existence of such large and luminous galaxies so early in cosmic history.
Quite right. I detest the posting of links without comment. What is a forum for? Informed discussion, surely? 🙁
I would have posted the link with some explanation of the spectograph:
As @Galu now knows, a child of ten can calculate the Hydrogen Lyman alpha line. It is 13.6eV x ( 1 - 1/4) in energy.
Unlike the wretched Chemists, Physicists use MKS units. Not an Angstrom or centimeter or gram in sight! 😎
Frequencies higher are absorbed by interstellar hydrogen. This technique is common with all distant objects, including Quasars.
Lyman alpha corresponds to 0.121567 um in the ultraviolet. Multiply by a redshift of z = 14.32 (+ 1 strictly), and I get 1.86 um. Consistent with NASA's result.
We can now estimate how old this Galaxy is by comparing with the previous record holder, z13 (z = 13):
https://en.wikipedia.org/wiki/Redshift
I see < 300 Million Years after the Big Bang.
I would have posted the link with some explanation of the spectograph:
As @Galu now knows, a child of ten can calculate the Hydrogen Lyman alpha line. It is 13.6eV x ( 1 - 1/4) in energy.
Unlike the wretched Chemists, Physicists use MKS units. Not an Angstrom or centimeter or gram in sight! 😎
Frequencies higher are absorbed by interstellar hydrogen. This technique is common with all distant objects, including Quasars.
Lyman alpha corresponds to 0.121567 um in the ultraviolet. Multiply by a redshift of z = 14.32 (+ 1 strictly), and I get 1.86 um. Consistent with NASA's result.
We can now estimate how old this Galaxy is by comparing with the previous record holder, z13 (z = 13):
https://en.wikipedia.org/wiki/Redshift
I see < 300 Million Years after the Big Bang.
Last edited:
Well included!
What was not made quite clear from my contribution is that the spectrum obtained confirmed the redshift (z = 14.32) within narrow limits (+0.08 / -0.20) and hence accurately determined the distance to Galaxy JADES-GS-z14-0.
I was intrigued by the furthest thing we can see. The Cosmic Microwave Background. This has an enormous redshift,
https://en.wikipedia.org/wiki/Redshift
Due to the expansion of the Universe, this is apparently now 46 Bn. Ly away. AFAIK, expansion just increases the redshift further. But doesn't make any part of the Universe invisible. Just inaccessible.
All this Lyman alpha Hydrogen stuff is all very interesting, but really needs a proper Quantum Mechanical treatment, IMO. Lyman alpha is a doublet AFAIK, due to having two spin states possible in the ground or 1s state. The 21 cm microwave line and all that.
I am getting on well with Sean Carroll's new book on this subject. Bit of a revision thing really, but interesting.
The classical Kinetic Energy (13.6 eV) is half the (negative) potential energy (27.2 eV) for the electron.
The sum of energies is the Hamiltonian H = K.E. - P.E. = -13.6 eV
This leads to some interesting puzzles in Quantum Mechanics and Schrodinger's Equation:
We saw that 3/2 factor in Black Hole photon orbits too, earlier. I wonder what it all means? 🙂
https://en.wikipedia.org/wiki/Redshift
Due to the expansion of the Universe, this is apparently now 46 Bn. Ly away. AFAIK, expansion just increases the redshift further. But doesn't make any part of the Universe invisible. Just inaccessible.
All this Lyman alpha Hydrogen stuff is all very interesting, but really needs a proper Quantum Mechanical treatment, IMO. Lyman alpha is a doublet AFAIK, due to having two spin states possible in the ground or 1s state. The 21 cm microwave line and all that.
I am getting on well with Sean Carroll's new book on this subject. Bit of a revision thing really, but interesting.
The classical Kinetic Energy (13.6 eV) is half the (negative) potential energy (27.2 eV) for the electron.
The sum of energies is the Hamiltonian H = K.E. - P.E. = -13.6 eV
This leads to some interesting puzzles in Quantum Mechanics and Schrodinger's Equation:
We saw that 3/2 factor in Black Hole photon orbits too, earlier. I wonder what it all means? 🙂
Me too!
Allow me to put some flesh on the bones: The Hamiltonian is associated with orbits in central force fields such as those performed by electrons in the classical model of the atom.
The Hamiltonian (H) is the sum of the kinetic (T) and potential (V) energies of an object, i.e., it represents the total energy.
H is a conserved quantity, e.g., during the trajectory of a ball through the air, the Hamiltonian will stay constant (ignoring air resistance).
Steve has calculated the Hamiltonian of an electron in the ground state of the hydrogen atom: H = T + V = 13.6 + (-27.2) = 13.6 - 27.2 = -13.6 eV.
Those puzzles will no doubt go over my head. However I read that Hamiltonian mechanics is important for describing how a system changes or evolves with time. This makes it pretty important for quantum mechanics.
Last edited:
But exactly what is it that is now 46 billion light years away? Wiki answers my question:
"The cosmic microwave background radiation that we see right now was emitted ... about 380,000 years after the Big Bang, which occurred around 13.8 billion years ago. This radiation was emitted by matter that has, in the intervening time, mostly condensed into galaxies, and those galaxies are now calculated to be about 46 billion light-years from Earth."
It can be tricky getting one's head round cosmic expansion.
Take the example of a galaxy at redshift z = 13. This means we are seeing it as it existed 13.4 billion years ago, 300 million years after the Big Bang.
However, in the time that has passed since the image we see of it, cosmic expansion has carried the galaxy farther away from us and today it is over 32 billion light-years away.
And in that time the galaxy will have grown substantially through mergers with other galaxies.
One for Steve: https://www.quantamagazine.org/mathematicians-attempt-to-glimpse-past-the-big-bang-20240531/
I call bull. But I suck at math so I might be wrong 😉 - now, my "calling" is not math based but rather based on the insight that a big bang is such a tremendous reset that I simply dont think it is possible to find out what happens before it - well these is one case and that is if the big crunch-bang-crunch could be proven... the we will know.
"The simplest example of a mathematical singularity is what happens to the function 1/x as x approaches zero. The function takes a number x as an input, and outputs another number. As x gets smaller and smaller, 1/x gets larger and larger, approaching infinity. If x is zero, the function is no longer well defined: It can’t be relied upon as a description of reality."
Is no longer well defined .
//
I call bull. But I suck at math so I might be wrong 😉 - now, my "calling" is not math based but rather based on the insight that a big bang is such a tremendous reset that I simply dont think it is possible to find out what happens before it - well these is one case and that is if the big crunch-bang-crunch could be proven... the we will know.
"The simplest example of a mathematical singularity is what happens to the function 1/x as x approaches zero. The function takes a number x as an input, and outputs another number. As x gets smaller and smaller, 1/x gets larger and larger, approaching infinity. If x is zero, the function is no longer well defined: It can’t be relied upon as a description of reality."
Is no longer well defined .
//
- Captain, we are approaching a singularity.... Change the coordinate system now!!
- Sir, the Coordinate System Coordinator, CSC, has jammed.... Okay, then our only hope is that it is a "mild" singularity ;-)
"The researchers showed that if the amount of matter is negligible compared to the amount of dark energy, then the singularity can be eliminated. “Light rays can actually go through the boundary,” Quintin said. “And in that sense, you can see beyond the boundary; it’s not like a brick wall.” The universe’s history would extend beyond the Big Bang."
What the heck has "Light ray can actually go through the (what?) boundary" to do with a mathematical analysis? Nonsense...
and ending with...
"In order to make sense of the universe at the highest energy levels, he said, “we first need to understand classical physics as well as we can.”
As good as can... wh000t... as good as it takes of course.... "as can".. phffft..
//
- Sir, the Coordinate System Coordinator, CSC, has jammed.... Okay, then our only hope is that it is a "mild" singularity ;-)
"The researchers showed that if the amount of matter is negligible compared to the amount of dark energy, then the singularity can be eliminated. “Light rays can actually go through the boundary,” Quintin said. “And in that sense, you can see beyond the boundary; it’s not like a brick wall.” The universe’s history would extend beyond the Big Bang."
What the heck has "Light ray can actually go through the (what?) boundary" to do with a mathematical analysis? Nonsense...
and ending with...
"In order to make sense of the universe at the highest energy levels, he said, “we first need to understand classical physics as well as we can.”
As good as can... wh000t... as good as it takes of course.... "as can".. phffft..
//
Last edited:
C'mon, you don't need to be a world class mathematician like Steve to realise that as x tends to zero, 1/x tends to infinity!
I have my bullsh*t detector at the ready!
The researchers build upon the Borde–Guth–Vilenkin (BGV) theorum that leads to the assumption that not only must inflation have had a beginning, but that the universe itself must have originated from a definite beginning.
If I have understood the article correctly, the mathematicians may have found a way to see beyond this "definite beginning", i.e., found a way to pull back the curtain to see past the singularity and into times before the Big Bang.
Read more in the actual research paper if you wish: https://link.springer.com/article/10.1007/JHEP10(2023)182