# August-September hits on Smolin latest

• ### 130+

• Total voters
5
Gold Member
Dearly Missed
http://arxiv.org/abs/hep-th/0507235
you say
http://uk.arxiv.org/abs/hep-th/0507235
then you get the abstract for Smolin latest, "The case for background independence"
http://uk.arxiv.org/pdf/hep-th/0507235.pdf
(or something like that, I'm not quite sure if that's the correct form)
and download the full text, then it gets counted---the yookays bump the counter. But if you download from any of the umpteen other mirror sites like Cornell or LosAlamos then it does not bump the counter.

HERE'S THE RECORD OF A SAMPLING OF PAST SMOLIN PAPERS UK downloads.

"How far are we from the quantum theory of gravity?"

"Scientific alternatives to the Anthropic Principle"

"An invitation to Loop Quantum Gravity"

"Falsifiable predictions from semiclassical quantum gravity"

"A quantization of topological M theory"

"The case for background independence"

HOW MANY UK downloads first two months DO YOU THINK THERE WILL BE? Since it is late in the month let's count August-Sept 2005 as well as the tail-end of July

Under 50
50-69
70-89
90-109
110-129
130+

Last edited by a moderator:

Gold Member
Dearly Missed
I'm guessing 70-89
We will know by the end of September.
It is a major issue paper like "Scientific alternatives to the Anthropic Principle", which got 98 downloads from UK site the first couple of months it was out. But background independence (even tho very important concept) does not have the name recognition that Anthropic Principle does and the subrosa connection to hot issues like theology, intel. des.

ohwilleke
Gold Member
Under 50. You have to be very much an insider to see what issues he's raising from the title alone.

Gold Member
Dearly Missed
ohwilleke said:
Under 50. You have to be very much an insider to see what issues he's raising from the title alone.

Great! now we have a real difference of opinion. I am actually guessing 80s like 85, if I had to pick a number. And you say under 50.
Your reasoning is good, other things being equal---background independence is unknown compared to the Anthropic Principle. But I noticed today that Lubos Motl has given a lot of space to Smolin's paper. Predictably he says it's an abomination. Defensive reaction from stringies could get the paper a wider reading than you'd otherwise effect, or so I'm guessing anyway.

Gold Member
Dearly Missed
Ohwilleke, I was curious so I went over to Lubos site and printed out
his blog condemning and scolding Smolin's paper and it came to 12 pages!
Plus people's comments. With that kind of reaction, I still hope that my guess of 85 is not too far off.

BTW I have no idea what downloads would be worldwide compared with from the UK site, on average. I suppose an order of magnitude more, something like that.

Last edited:
wolram
Gold Member
Dearly Missed
Some thing big has to happen to revitalise these topics, other wise it will be
like reading war and peace over and over.

As I am in the UK, I have always downloaded from this site(have all of the above!)..but just recently I noticed (thanks to your detailing 7:00pm watershed!)..that I can access papers sooner rather than later by going outside UK.

From now on I am reverting to the UK!

Gold Member
Dearly Missed
selfAdjoint and Chronos have contributed to the forecasts.

I will list our guesses.
This is about Smolin's new article "The case for background independence": HOW MANY UK downloads first two months (thru September) DO YOU THINK THERE WILL BE?

Spin Network: 110-129
Chronos, me: 70-89
Ohwilleke: Under 50

We should also probably discuss the article on its merits.

Last edited:
Gold Member
Dearly Missed
This is the article.

http://arxiv.org/abs/hep-th/0507235

Here is how I see it, in broad outline.

I think it is an important article. I note that it derives from a talk given last year to a UK association of Philosophy of Science. This explains why it mentions Aristotle and Leibniz etc etc. and has some history of the absolute/relational space debate.

But that is not how I see the main thrust. I think the paper is NOT critical of string theory! I think it recognizes that string has great promise and it says that it is STUCK now (because of the Landscape essentially) and it argues that it is time for theorists to TRY SOMETHING to get out of being stuck and he urges they try the strategy of REFORMULATING STRING IN A LESS BACKGROUND DEPENDENT WAY.

He also summarizes various more background independent approaches (causal set, Loop, Triangles) but what I hear is not a salespitch for them but that he is surveying them to show it is possible and to show that B-independence is gradual, by degrees, always partial, never total. And he is laying B-independence out as a STRATEGY that you can use to solve various problems and predicaments that string is having.

And he talks about his own CNS idea and he EXPLICITLY INCLUDES STRING in it as a possible mechanism for the properties of particles of Std Model to change slightly in a black hole branchpoint.

He explicitly depicts that role for string theory (in a more background independent version) which I thought was interesting.

Well other people can have a different take on it. Maybe I will read it again and see what else stands out. But what stood out for me is that it is not argumentative and it is not saying my-theory-is-better-than-your-theory. The message is different. I hear Smolin PEACEABLY COAXING string researchers saying

"try this, I tried it with my background independent M-theory paper this year, it is not all that hard! Other approaches use it. It actually helps get past certain difficulties. Look, you are stuck (or so it seems) and this is one clear thing you can try. You have been saying for years that EVENTUALLY you would make string be background independent. So why not try it NOW?"

the important part of the message, that I hear, is for string researchers to get busy and try background independence now instead of waiting any longer.

did anyone else hear this message to string theorists in the paper?

BTW I appreciate that the paper must have made Lubos Motl uncomfortable and was like being told to take bad-tasting medicine, so he devoted 12 pages of blog to dismissing it contemptuously as rubbish, essentially not worth the paper to print it or the time to read it.

Last edited:
Chronos
Gold Member
I agree, marcus. I see this as another effort by Smolin to reach out to the different camps and bring all the best ideas to the same table. In that sense, this most recent paper is very reminiscent of 'Scientific alternatives to the Anthropic Principle'. I was disappointed by Lubos' sharp and divisive commentary. It appeared he was defending the fairy princess [ST] from a ghost. After all, why submit her to the indignity of a beauty contest when you already know she is going to win? He did, however, make a case that non-string theorists are almost as clueless about the implications of string theory as string theorists are about the implications of background independence.

Gold Member
Dearly Missed
To reinforce what both of us were saying I will quote a couple of things from Smolin's paper
He has these two italicized passages at the beginning and then at the end (with reference to the previous) which say explicitly what he is trying to do in this paper and why he wrote it.

--quote from Smolin introduction--

Now here is my thesis, which it is the task of this essay to support:

The reason that we do not have a fundamental formulation of string theory, from which it might be possible to resolve the challenge posed by the landscape, is that it has been so far developed as a background dependent theory. This is despite there being compelling arguments that a fundamental theory must be background independent. Whether string theory turns out to describe nature or not, there are NOW few alternatives but to approach the problems of unification and quantum gravity from a background independent perspective.

This essay is written with the hope that perhaps some who have avoided thinking about background independent theories might consider doing so NOW.

--end quote--

The italics here are Smolin's. I put the word "now" in caps to call attention to what I think is a vital part of the message.

--quote Smolin conclusions--

...The former are more constrained, hence harder to construct. More of what is observed is subject to law, as there is no background to be freely chosen. Hence, it appears that relational, background independent theories are more testable, and more explanatory.

This is the reason for my provocative hypothesis. If it is true then the reason that string theory finds itself in the situation described in the introduction is that no background dependent theory could successfully solve the five key problems mentioned there. If this is true, then the only thing to do is to go back and work on the less studied road of relational theories.

At the same time, I have tried here to explain the key problems still faced by the relational road...

--end quote--

Last edited:
Chronos
Gold Member
That's about as clear as you can put it, marcus. Is there a problem defining 'background independence'? I am not aware of? I concede it may be philosophically difficult, but not mathematically. That is where I take issue with Lubos'. I do not claim any particular expertise, but, I like to think I can spot hand-waving. I had issues with the 16th century logic analogy.

marcus said:
Great! now we have a real difference of opinion. I am actually guessing 80s like 85, if I had to pick a number. And you say under 50.
Your reasoning is good, other things being equal---background independence is unknown compared to the Anthropic Principle. But I noticed today that Lubos Motl has given a lot of space to Smolin's paper. Predictably he says it's an abomination. Defensive reaction from stringies could get the paper a wider reading than you'd otherwise effect, or so I'm guessing anyway.

Heh, I find Motl's comments a bit too 'arrogant', he's too 'orthodox'...Whilst I do not deny his competences, he has still to prove that there is a single path toward a true theory of everything, that we can prove soundly that science 'progresses' toward truth or that nature/observations impose on us this [single] path (the 'coherence' criterion alone is not necesarily a sign of truth, the coherentist criterions of justification have still important problems, we still lack a theory of good observations so we can at most interpret the experiments we do not deduce 'truths' from them, even at the level of observables, the logical positivist program is dead long ago etc).

Those having a minimum understanding of modern philosophy of science will easily understand why I criticize him :-). No it is not 'futile' to try to develop alternative programmes based on 'aether'...it's wrong to claim epistemological privilege without sufficient 'pro' arguments, a totally different thing. Here I disagree with Feyerabend, I'd argue that we can still define an unified scientific methodology, nonwithstanding that a minimal one (something like Maxwell's-the philosopher of science-'metaphysical' falsificationism/realism; no clear cut difference between science and metaphysics, only a gradual one). I'd argue that we can still define currently a clear 'ladder of preferences' (variable in time of course, fallibilism in a not trivial way is retained) when more programmes seem to be equally supported by experience, taking in account also reliabilism, 'frequentism', bayesianism or probabilistic causation (where applicable of course, especially in 'higher order' sciences where underdetermination and theory ladenness are not so important). This 'ladder' indicate, orientatively, on what reserach programmes we should focus, basically based on previous 'success', but it is in no way strongly prescriptive, acceptable alternative programmes situated at 'lower levels' are not considered 'dead ends', they deserve to be pursued further, actually some of them could prove theoretically and empirically progressive in the future (although they look stagnant at a certain moment in time), even the 'first choice' program, the 'normal science' of tomorrow.

Anyway from the fact that a research scientific program look degenerative at a certain time we cannot draw the much stronger conclusion that it will ever be so, this is one of the lessons of the history of science...So, possible, Smolin's paper ("The case for background independence") has errors but I do not think that the broad program he propose is a 'dead end' such a conclusion is too strong, I'd argue that a revised version could prove to be sometime the accepted science of tomorrow...it fully deserves to pursue it further. Clearly Motl has not read yet at least some ideas of Feyerabend...I bet that if he could somehow travel into the future, let's say few hundred years from now, he would be astonished by the strong change in paradigm, in physicis at least...Finally dogmatism is never the most rational path, we should better always remain open to strong nontrivial paradigm changes...

Last edited:
Gold Member
Dearly Missed
metacristi said:
Heh, I find Motl's comments a bit too 'arrogant', he's too 'orthodox'...Whilst I do not deny his competences, he has still to prove that there is a single path toward...

The main thing wrong with Motl comments I've found (despite his frequent charm and wit) is unreliability: part of the time he doesn't know what he's talking about. But this does not hinder him from making pronouncements. Here is an example from the recent 12-page post re:Smolin's paper.

This comes at the conclusion of the section "Background Independence of GR". If you are scrolling down looking for it, it is right before the section "Background independence in string/M theory":

---quote Motl---
On the other hand, there are no successes whatsoever of the approaches that Lee wants to call "non-perturbative approaches". The main problem is that they don't care about physics, experiments, and the new principles that are revealed by them; they prefer philosophical dogmas from the 16th century. It is a waste of time to discuss these "non-perturbative" speculations in detail. In all cases (causal set theory, loop quantum gravity, triangulation models), the speculations are based on the naive picture of space as being composed of infinitely sharp points - like in the classical theory - which are moreover exactly discrete. All these approaches make incredibly strong assumptions about the physics at the Planck scale whose probability to be incorrect safely exceeds 99.9999999999%; all of them belong to the discredited category of "gravitational aether theories" and no 16th century philosophical principle is strong enough to transform this intellectual waste into a topic for a meaningful physical debate in the 21st century.
---end quote---

I can't find any true statement here. I don't know much about Causal Sets and something he says might apply to that. But he is making blanket statements including the triangulations approach CDT that Lee was talking about, indeed has a section on.

The developers of CDT explicitly say they have found no evidence of spacetime discreteness or a minimal distance scale. So Motl is attributing to them what they neither postulate nor find as a result.

Here is a May 2005 CDT paper hep-th/0505113. This from the introductory section, page 2 (the first page of text.)

"The alternative we will advance here is based on new results from an analysis of the properties of quantum universes generated in the nonperturbative and background-independent CDT (causal dynamical triangulations) approach to quantum gravity. As shown in [5, 6], they have a number of appealing macroscopic properties: firstly, their scaling behaviour as function of the spacetime volume is that of genuine isotropic and homogeneous four-dimensional worlds. Secondly, after integrating out all dynamical variables but the scale factor a($\tau$ ) in the full quantum theory, the correlation function between scale factors at different (proper) times $\tau$ is described by the simplest minisuperspace model used in quantum cosmology. We have recently begun an analysis of the microscopic properties of these quantum spacetimes. As in previous work, their geometry can be probed in a rather direct manner through Monte Carlo simulations and measurements. At small scales, it exhibits neither fundamental discreteness nor indication of a minimal length scale."

There is nothing I can see in CDT about spacetime being composed of infinitely sharp points, or according to 16th Century dogma, or an "aether theory". As far as I can see that is just Motl foaming at the mouth. The CDT spacetime is a 4D topological continuum which for analytical purposes is triangulated and then the scale of the triangulation is allowed to shrink to zero. It certainly is not made of triangles, it just happens not to have a prior designated metric which makes it different from the arena in which strings operate.

And the CDT approach is not rigidly linked to one particular version of the action. They can freely modify the microscopic dynamical principle that is used to generate random spacetimes and indeed HAVE explored different microscopic actions in Monte Carlo simulations.

This contradicts what Motl suggests here:
"All these approaches make incredibly strong assumptions about the physics at the Planck scale whose probability to be incorrect safely exceeds 99.9999999999%"
What he says here is either exaggerated handwaving or is intended to give some definite impression---such as that he knows, somehow, that all these approaches depend rigidly on some fixed choice of the Einstein-Hilbert action to which they cannot add additional terms. And that is simply not true.

I have to conclude from this and other Motl critiques of QG that he actually does not know very much about the approaches to nonperturbative quantum gravity that Smolin was discussing in his paper.

====ON THE OTHER HAND I definitely LIKE THIS=====
I have to acknowledge that a lot of what Lubos says is charming and appealing in its own right. Like this passage really speaks to me. It just is not effective as blanket criticism of nonperturbative QG.

---quote of nice passage from Motl---

Coordinates: synthetic vs. analytical geometry

Also, as a kid, I was very impressed by coordinates and the possibility to analyze geometrical questions analytically, by looking at the equations involving coordinates. I don't know whether some of you have had the same feelings, but the mathematical tasks to solve a geometrical problem by "synthetic geometry" without the coordinates always looked like a useless childish exercise to me (which does not mean that one can't get good at it); it was recreational mathematics for children. If you can find the truth by using the coordinates, why shouldn't you use them? Coordinates are great and they are, to some extent, real. They are real modulo translations, rotations, and the Galilean (or Lorentzian) boosts. But there are only 10 parameters for this Poincare group in the whole Universe while the coordinates of the objects you want to study may be counted in thousands. No doubt, most of them are physical. We can't live without them or something more or less equivalent. The Cartesian coordinates, for example, look more fundamental than the angle between a bucket, Mercury, and a Mercedes, so why shouldn't we use them?

The relationist approach seemed to be an attempt to fight against the concept of coordinates; an attempt to pretend that they don't exist or they are unphysical; an attempt that must fail unless the coordinates are replaced by some assumptions that are equally powerful and essentially equivalent (but perhaps more awkward than the coordinates) because the space simply exists, to some extent, and you can't hide it. Also, the relationist approach did not look like a mathematical constraint on the possible form of physical laws. Instead, it was a way to make the questions quantitatively ill-defined. The relationist principles never looked like well-defined symmetries of a physical system; they were a method to show that no choice of the degrees of freedom is good enough for a sufficiently dogmatic person. We may summarize the situation: there was nothing that I would naturally like about the relationist approach.

Don't get me wrong: self-contained "bootstrap" systems that look non-quantitative and uncalculable at the beginning may be fine and very deep in physics but only if they're temporarily uncalculable. Relationism seemed to be a direction that wanted to make things permanently uncalculable.

---end quote---

The trouble with this charming passage is that the nonpert. QG I watch definitely does NOT go in a direction that "wanted to make things permanently uncalculable"! Very much to the contrary.
There is a lot of calculation already. Areas, volumes, angles, bending of lightrays. spreading of congruences of lightrays. diffusion processes. dimensionality. I will get some examples.

Lubos seems to be wavering here and allowing that there could be "good" nonperturbative and "bad" nonperturbative. It is bad if it makes things permanently uncalculable. But then this is a straw man argument.

Calculation is a big part of the nonpert. QG program. The idea is that it may be harder to get started (without a prior fixed choice of background) but once you get started you just might calculate BETTER: with fewer infinities blowing up and more uniqueness in the results.

Last edited:
ohwilleke
Gold Member
Damn publicity. If I knew someone was making a fuss over it, I would have guessed higher.

Gold Member
Dearly Missed
ohwilleke said:
Damn publicity. If I knew someone was making a fuss over it, I would have guessed higher.

heh heh. well you may have guessed right anyway. I dont know how many people are affected by Lubos blog, and there doesnt seem to have been a LOT of fuss in the past few days.

http://citebase.eprints.org/cgi-bin/citations?id=oai:arXiv.org:hep-th/0507235 [Broken]
and it showed zero downloads. there have probably been some but they just didnt update yet

BTW has anyone besides me watched this video of May 2005 colloquium
at harvard by Smolin?
http://cfa-www.harvard.edu/colloquia/spring05/smolin.html

Last edited by a moderator:
Gold Member
Dearly Missed
the smolin paper has one reported citation so far

http://arxiv.org/abs/cond-mat/0507454

the author is a condensed-matter Russian. he says on page 8:

"...These emergent phenomena are background independent,... Background independence is the main criterion for the correct quantum theory of gravity. [9]"

and reference [9] is to Smolin "the case for background independence"

the UK arxiv site has not yet reported the "hits" or full-text downloads of this paper, it is too new for them to do that yet. maybe by the end of August.

=============

remember that what Smolin calls the thesis of this paper is that the troubles of String can be traced to it not being B-indep. His message to String people is that they have been saying for many years that they must eventually make the theory B-indep. Why put it off? He advises them to build a B-indep formulation right away---as a way to get out of the Landscape quagmire and get predictiveness.

Well Smolin was at the Toronto String 05 conference and he was in the audience when they had the Tuesday evening Panel hopefully called "the next string revolution". And Smolin spoke up from the audience and said
he did not know what was the next revolution String people would make, but he guessed the LAST revolution they would need would be getting a B-indep version (because that would finally complete it to a predictive theory able to explain stuff and be tested).

This drew from Lubos Motl his first even remotely complimentary remark about Smolin.

Here is the quote:

---from Motl blog---

Some people in the audience, notably Lee Smolin, have even questioned whether the string theorists will be celebrated as heroes and he insisted that the background independence was more paramount. That's like screaming that God is dead in the church during the mass, and Lee gets points for his courage. ;-)

---end quote--

http://motls.blogspot.com/2005/08/anthropic-principle-lacks-confidence.html

so we know where we stand, about background independence and the string rank-and-file

Gold Member
Dearly Missed
Now it is getting to be time when we could do a midcourse check and see what the downloads situation is

http://citebase.eprints.org/cgi-bin/citations?id=oai:arXiv.org:hep-th/0507235 [Broken]
and it showed zero downloads. there have probably been some but they just didnt update yet

BTW has anyone besides me watched this video of May 2005 colloquium
at harvard by Smolin?
http://cfa-www.harvard.edu/colloquia/spring05/smolin.html

Now (or soon) they should have updated and be showing August hits.

BTW I now think that my guess was ridiculously optimistic and that Ohwilleke had by far the best guess. I have heard fairly little about this paper and it is, as Ohwilleke says, about something technical. not many people know about background independence. My enthusiasm misled me, I suspect.

But we will see. Maybe in September it will get more attention. We are guessing about August + September hits.

Last edited by a moderator:
Gold Member
Dearly Missed
WHOAH! DONT GIVE UP YET!

I just checked this
http://citebase.eprints.org/cgi-bin/citations?id=oai:arXiv.org:hep-th/0507235 [Broken]

something like 52 download, assuming I am reading it correctly. that is quite a surprise, if true.

UPDATE: Today, Wednesday, I checked here
and it gave a breakdown of where the 52 so-far downloads came from.

what I meant by August-September hits includes the tailend of July (the paper came out near the end of July)
as it happens, of the 52 hits, 40 of them were in tailend July
and only 12 were properly in August.
so simply following the trend leads one to expect that there will be fewer than 12 in September and one recalls that

so it is a very good bet that he is right

since we already have 52 and we can expect just a few more.
for a while I felt sure Ohwilleke would have made the correct guess, under 50, but that is now ruled out.

Last edited by a moderator:
Gold Member
Dearly Missed
Arxiv now lists four papers that cite Smolin "The Case for Background Independence"

one is in particle physics---discussing the Higgs mechanism.

It is interesting that this Smolin B.I. paper could turn out as a litmus or as a search tool for finding papers that get into B.I. in OTHER FIELDS OF RESEARCH BESIDES GRAVITY.

this is kind of exciting. i would not have notices this paper about Standard Model physics and the Higgs except that I saw it on a list of papers that cite the Smolin B.I. paper. And I was fascinated.

they are talking about a "MACH PRINCIPLE" for MASS. wow.

========quote=======
A NOTE ON MACH’S PRINCIPLE

Finally, it is interesting to note the distinctly Machian nature of this result: the mass of a particle is due, at least in part, to its interactions with all other particles. This reflects a greater degree of background independence of the Standard Model [31] than is usually considered, since not only the background Higgs field but in fact all the local masses are to some extent dynamically determined. The fact that masses are reduced due to interactions with a scalar (and thus attractive) field produced by surrounding particles would seem, however, to offer little hope for a Machian picture of a scalar interaction being responsible for the inertial mass of an object which would be thought of as intertialess in an empty universe. A similar conclusion might seem to follow for the attractive spin2 force associated with gravitation, however this line of reasoning lies firmly within linearised general relativity and requires more careful consideration.

CONCLUSIONS

The Standard Model predicts that particles not only obtain their masses from coupling to a background Higgs field, but that they themselves are the sources of a Higgs field which can modify the masses of nearby particles. While a full calculation contains many subtleties, its sign is unambiguous, and reasonable estimates of the effect in the production of pairs of heavy particles are that the effect can be very large, especially near threshold. An additional feature of the effect which is quite appealing in terms of whether the Higgs...

=======end quote=========
their reference [31] is to the Smolin paper
here is the paper I'm talking about

http://arxiv.org/abs/hep-ph/0509151
Probing the Higgs Field Using Massive Particles as Sources and Detectors
S. Reucroft, Y.N. Srivastava, J. Swain, A. Widom
6 pages

"In the Standard Model, all massive elementary particles acquire their masses by coupling to a background Higgs field with a non-zero vacuum expectation value. What is often overlooked is that each massive particle is also a source of the Higgs field. A given particle can in principle shift the mass of a neighboring particle. The mass shift effect goes beyond the usual perturbative Feynman diagram calculations which implicitly assume that the mass of each particle is rigidly fixed. Local mass shifts offer a unique handle on Higgs physics since they do not require the production of on-shell Higgs bosons. We provide theoretical estimates showing that the mass shift effect can be large and measurable, especially near pair threshold, at both the Tevatron and the LHC."

Gold Member
Dearly Missed
this source shows 4 citations and 54 UK downloads to date (15 Sept)
http://citebase.eprints.org/cgi-bin/citations?id=oai:arXiv.org:hep-th/0507235 [Broken]

this source shows 4 citations, including the Higgs paper by Swain et al.
http://arxiv.org/cits/hep-th/0507235

the original paper we are talking about is
http://arxiv.org/hep-th/0507235 [Broken]
The Case for Background Independence.

I am excited by the Higgs paper, has anyone looked at it?

Last edited by a moderator:
Staff Emeritus
Gold Member
Dearly Missed
From the paper:
Finally, it is interesting to note the distinctly Machian
nature of this result: the mass of a particle is due, at least
in part, to its interactions with all other particles. This
reflects a greater degree of background independence of
the Standard Model [31] than is usually considered, since
not only the background Higgs field but in fact all the lo-
cal masses are to some extent dynamically determined.
The fact that masses are reduced due to interactions with
a scalar (and thus attractive) field produced by surround-
ing particles would seem, however, to offer little hope for
a Machian picture of a scalar interaction being respon-
sible for the inertial mass of an object which would be
thought of as intertialess in an empty universe. A similar
conclusion might seem to follow for the attractive spin-
2 force associated with gravitation, however this line of
reasoning lies firmly within linearised general relativity
and requires more careful consideration.

Reference 31 of course, is the Smolin paper.

What is exciting for me about these proposals is they could extend the lifetime of Tevatron by providing a rich field of significant physics within its energy reach. At the present time, Tevatron may not have any funding after the LEP comes up.