Congratulations to the whole James Webb team. Against all the odds they have built us a cathedral in Space as awesome as Santa Sofia, and a window through which we can potentially look almost all the way back to the beginning of Time. What might we see? What should we be looking for?
I’m waiting as eagerly as anyone because I have been involved in this stuff going right back to 1977 as a key member of three Hubble Space Telescope teams, including the one that built the camera still going strong up there now. And in this post I want to pass on some words of both encouragement and warning. Be ready for surprises!
Before they design a single lens or circuit Space-camera teams must look deeply into the kinds of science they might be doing 20 years ahead and my team asked me to look into high redshift galaxies. Knowing nothing of that subject at the time (1977) I naturally went round to ask the real experts. They were unanimous: “Don’t bother with them because you’ll never be able to see them owing to the Tolman effect.”
I looked it all up and found that Richard Chase Tolman was a brilliant American astrophysicist who probably knew more about Relativity than Einstein. The idea that the whole universe was expanding had just been mooted in the 1930’s and Tolman tried to find a test that would prove it. And he did. Extended objects like galaxies would be dramatically dimmed by redshift in an expanding universe, so dimmed in practice as to become invisible in any decent Space camera. Imagine my shock then in 1993 when we got our first really deep Hubble image. It was plastered all over with very distant but quite distinct galaxies not dimmed in the least. That meant the universe couldn’t be expanding – not according to Tolman.
But when I tried to point this out the new self-appointed experts said; “No ; it just means that young galaxies in the distant past were intrinsically much brighter than the galaxies today – after all they were younger in the past and generating more brilliant young stars.”
That sounded vaguely plausible – but not really convincing. Why not? Because all the galaxies: irrespective of their distance had exactly the same surface-brightnesses as each other, and as the galaxies around us here today. For that to be true there just had to be far too many fortuitous coincidences. But by the time I’d measured this and worked it all out a whole
industry consisting of hundreds of newly minted ‘High redshift galaxy astronomers’ had become wedded to their fortuitous hypothesis. The idea that the universe wasn’t expanding was to them completely unthinkable. To my shame I mostly shut up and kept my council. Tolman had presumably screwed up somewhere back in the 1930s.
But later (2009) we sent an even more sensitive camera (WFC- 3) up to Hubble specifically to look at the higher redshift universe – and guess what – it was plastered with high surface brightness galaxies going out all way to redshift 7 – to a time when the universe was less than 1 billion years old (it’s 13 billion today).
Still the ‘experts’ weren’t shocked – and I realised they could explain everything – and in doing so – nothing. They were too wedded to their trendy hypothesis to ever question it.
But by 2010 I had officially retired which meant I could do something those experts could not. I could spend literally thousands of hours thinking about the problem of high redshifts galaxies and my colleague Huw Lang and
I eventually produced a refereed paper entitled “The Galaxy Ancestor Problem” in a prestigious astrophysical journal (see Note). We argued that the trendy picture simply couldn’t be right, and that something probably far more interesting was afoot.
Nobody read it, apart from the referee. And you can’t blame them. It contains 70 numbered equations and is hideously complex. It was much easier to ignore it than try to understand it. That’s part of a long tradition in astronomy going back 600 years: if you don’t like something, stick with the crowd and ignore it. 15th century astronomers didn’t want to believe the Earth was orbiting the Sun, and invented ridiculous ‘epicycles’ to disguise the truth from themselves – and everybody else. Only when Galileo saw with his first spyglass (1609) that Venus was crescent-shaped did they finally ‘Hesitate’. What they did though was imprison Galileo for life (1632) – because that was much easier than changing their minds.
There is a more general point here though. Explorers rarely comprehend what they have discovered at the time. Columbus never admitted that he’d run into a new continent – so far as he was concerned he’d been to Cipangue (Japan) – because that is where he’d set out to go. It took his successors, notably Amerigo Vespucci, to acknowledge that the previously unknown continent of America actually existed.
I’m not claiming that Huw and I are right, and that everybody else is wrong, I’m merely pointing out that the true interpretation of the high redshift universe, the universe Webb will soon see in unprecedented detail, may be very surprising, very surprising indeed.
Without going into any detail let’s enumerate three key puzzles:
(I) Tolman couldn’t be wrong: his physics is as sound of a bell. So, if the universe really is expanding, which seems likely, why do all the galaxies, irrespective of their redshift, appear to have the same identical surface- brightness? High redshift galaxies are no less than 4000 times brighter than they ought to be. There’s no escaping from that. 4000 times!
(II) That we can see so far means that the cosmos out there is transparent. That’s obvious. But how did it become so? Where did all the energy come from to split all the electrons in extra-Galactic space apart from their natural proton partners ? That is called ‘The Re-ionisation Problem’. There are vastly too few galaxies out back there to produce the ionising starlight needed to bust all those atoms apart and make Space transparent.
(III) Very high redshift objects, notably Quasars, have dozens, sometimes hundreds of dark lines in their spectra(see our Post ‘The Cosmic Rosetta Stone’). Those lines could only be produced by the atoms in galaxies along the lines of sight to such quasars. But there are vastly too few such visible galaxies out there to produce them.
Many people will be surprised that such egregious problems are not shouted from the roof tops; there is almost a conspiracy to cover them up. The only comment I will make upon that is that ‘experts’ are generally reluctant to admit “We really don’t know”. Take the situation of Continental Drift. For 50 years the experts at all the ‘big’ universities pooh-poohed Alfred Wegener’s radical idea. They were only forced to eat their hats when otherwise inexplicable geomagnetic patterns turned up on the ocean floor. Perhaps the James Webb will force a similarly dramatic rethink.
During its recent briefing about Webb NASA was anxious to emphasise that “The telescope belongs to all of us”. That will only be true if we all dare to think about the new high red shift observations – when they come in. If we don’t, the ‘experts’ might cover up the truth – yet again.
NOTES: The Disney/Lang paper is at Disney M J., and Lang R.H, The galaxy ancestor problem, Mon. Not. R Astron. Soc., 326, 1733-1749 (2012). Other relevant Posts on this site are: ‘The Cosmic Rosetta Stone’; ‘How Dark is the Night?’; ‘Hidden Galaxies, Hidden Universe’. They’re under the ‘Astronomy’ Category.
Tags: cosmology, galaxies, hidden galaxies
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