The Future of Physics

Yesterday, David Gross, one of the winners of the 2004 Physics Nobel Prize, gave an interesting colloquium here at CERN, presenting his list of the 25 most important questions in physics. He formulated each question in quite some detail, dividing many of them into several sub-questions. See http://agenda.cern.ch/fullAgenda.php?ida=a05302#2005-01-26 for a video recording. Here I just provide some brief paraphrases to stimulate thought and discussion. It would be interesting to know what people think of his list, whether some could be dropped and replaced by others.

1 - The origin of the Universe:

Was there a Big Bang, was it preceded by a Big Crunch, ....

2 - The nature of Dark Matter:

Is it composed of some unknown elementary particle, if so, what ....

3 - The nature of Dark Energy:

What is its microphysical origin, is it constant or varying ....

4 - The formation of structures in the Universe:

Testing the standard Cold Dark Matter paradigm, formation of stars ..

5 - The validity of General Relativity:

Does it work at all scales, in strong fields, ....

6 - The validity of Quantum Mechanics:

Is it modified at short distances, for large systems, in the Universe ...

7 - The problems not solved by the Standard Model of particles:

Particle types, masses and mixing, unification of forces ....

8 - The existence of supersymmetry:

Does this framework for new physics appear at accessible energies ....

9 - The solution of QCD:

Can it be solved analytically, e.g., via a string model ....

10 - The nature of string theory:

What is it ....

11 - The nature of space and time:

Are they fundamental or emergent phenomena ....

12 - Whether the laws of physics are unique:

Perhaps they are statistical accidents ....

13 - Can kinematics, dynamics and initial conditions be separated:

Perhaps they cannot be disentangled ....

14 - Are there new states of condensed matter:

Not just the usual Fermi liquids ....

15 - The understanding of complexity in computing:

Is there something beyond the artefacts of approximations ....

16 - The construction of a quantum computer:

One with 10,000 qbits would be useful ....

17 - The existence of a room-temperature superconductor:

It would make a technological revolution ....

18 - The existence of a theory of biology:

Does it have an underlying conceptual structure, like physics ....

19 - Deducing physical form from genomics:

Can one deduce the shape of an organism from its DNA sequence ....

20 - The physical basis of consciousness:

New physics, emergent phenomenon, or ....

21 - Could a computer become a creative physicist:

Would we train it starting from Newton and Einstein ....

22 - How to avoid the balkanization of physics:

People from different fields should understand each other ....

23 - The scope of reductionism:

Is it universal, or do new laws emerge in complex systems ....

24 - The role of theory:

Does it lead or follow experiment ....

25 - How to avoid depending on unrealizable big physics projects:

They cannot continue for ever growing in size, cost and time-scale ....

Following this list, David Gross posed a supplementary question - Does physics have a future - to which he replied affirmatively!

Continuing the sociological spirit of this and questions 22 and 25, I have my own supplementary question: What can physics do for Society - in particular to avert or mitigate catastrophes. We used to be supported, at least in part, because of the new technologies we made available. Now, at least one distinguished astrophysicist, Martin Rees, is pessimistic about our surviving the century, in part because of potential catastrophes of our own making, in part because of natural dangers. Perhaps only physics and astrophysics could provide the tools to avert an asteroid strike or mitigate the effects of a nearby supernova explosion or a gamma-ray burst. Perhaps physics could provide better tools for warning or reducing the impacts of earthquakes and tsunamis.

Comments

[Paolo Palazzi]

About to write up a summary of the colloquium by David Gross for the benefit of a colleague who could not attend, through physcomments.org I found this blog entry with the full list of the 25 questions and I decided to post my remarks here;

I found the talk stimulating and the speaker very pleasant, and I particularly enjoyed his terse humor; before the talk I noticed that he was running the same beautiful MacOSX astronomy screen saver as I do, at the end I was convinced that we are running a very different crystalball software, as I had already guessed;

-- important questions that were not in the list:

a- geophysics:
the center of the earth, origin of magnetic field and internal heat; is the earth expanding?;

b- nuclear physics:
the current situation with several incompatible models of limited applicability is not satisfactory; a convincing bridge from nuclear forces to particle models is lacking;

-- questions in the list that I consider important:

1- Big Bang or not Big Bang:
if the answer is no, points 2 and 3 can be dropped from the list; the recent multipole analysis of the WMAP data finds surprising evidence that the largest-scale features of the microwave sky seem to be correlated with both the motion and the orientation of the solar system; are we really looking at the edge of the universe? this looks like yet another problem for the BB;

http://www.cerncourier.com/main/article/44/10/4/1

4- formation of stars, planets, comets: so many open questions;

7- particle masses, quark-lepton relationship, baryons, proton stability:
the strong sector of the SM is neither complete nor satisfactory; depending on how this goes, questions 8, 9 and 10 could be relevant or not;

12- are laws and/or constants of physics accidental/historical?

20- the physical basis for memory and consciousness;
about these problems I am less pessimistic than the speaker was, and my favorite hypotheses are:

memory: http://www.cesaremarchetti.org/abstract.php?id=3

consciousness: http://www.klab.caltech.edu/~koch/crick-koch-cc-97.html

22- is physics balkanized or about to be?
24- the role of theory

David Gross answered NO to question 22; I believe that questions 22 and 24 are related, and that particle physics and to some extent cosmology are not really balkanizing, rather at the onset of a religious involution, with the emergence of a clergy officiating ceremonies, enforcing dogmas and belief systems, and occasionally acting as a "behavior police", but this would be a long story;

-- Q&A session

two questions from the audience were asked at the end of the talk, here is a summary:

Q1: why not the Higgs among the 25 points? (G. Altarelli);
A1: I only had 25 points, I chose supersymmetry instead of the Higgs;

Q2: (in reference to point 24) OK with elegance, if possible, but we still do not know how to calculate the spectrum of the particles, is this satisfactory? (W. Blum);
A2: we compute the masses of low-lying hadrons within 1% on the lattice;
--: this is not good enough;
--: you are spoiled by electro-weak interactions, 1% is very good for a controlled estimate based on first principles; two problems though: (a) being this approach based on evaluating integrals on the computing it is opaque, and (b) limited to masses energy and form factors, no scattering; back to question 24, it is an important one, and a source of tension .. [omissis];

Q2 was a tough question to a QCD Nobel laureate, the answer was, to me, not convincing; watch the video and make up your mind;

Paolo Palazzi
particlez.org

[Sean]

Hi John-- Thanks for transcribing the list. I've commented a little at my blog:

http://preposterousuniverse.blogspot.com/2005_01_01_preposterousuniverse_archive.html#110703702965929900

[Carl-G. Källman]

A short comment on issue 14 "are there new states of condensed matter?" . Although not being an expert, it is hard not to see the growing evidence for some kind of "low energy nuclear thing", sometimes called LENR, some of them almost weird, like the Iwamura transmutations in Ba etc. I don't know, but it seems that this is a "challenge" for nuclear physics. Maybe not on the top 25 list, but still not far from?

Thanks for a fine page

Regards

Carl-G. Källman

[Paolo Palazzi]

(in reply to Carl-G. Källman)

interesting; nuclear physics should definitely be on the list; I had a look at the papers by Iwamura and also at some other relevant material at this address:

http://www.lenr-canr.org/News.htm

with a new name cold fusion might become politically correct again; see the links about Brian Josephson at the URL above; he was blacklisted by arXiv when attempting to post a review paper on the subject; funny story:

http://www.tcm.phy.cam.ac.uk/~bdj10/archivefreedom/main.html

Paolo Palazzi

[Quantoken]

The Big Bang is undoubtly WRONG, because one of its fundation, the CMB radiation, has a totally different, more natural, and more accurate explanation. CMS is none other than star radiations!!!

See this web page to see how a completely accurate CMB temperature, 2.7243K, is obtained from the star radiation calculation:

http://quantoken.blogspot.com/2005/02/predictions-of-guitar-theory.html

Please note, it is not a postulation, but a scientific fact that stars radiate energy, and that energy accounts exactly for the CMB energy. Any one who wants to explain CMB as any thing else MUST explain where does the star radiation energy go! Because out in the sky CMB constitutes 99.9% of the total radiation energy.

I have also calculated the exact neutron mass, ased on measured neutron mean lifetime, up to 10 decimal places accuracy.

[Harish Alagappa]

In my miniscule and worthless opinion, Question 1 is the most relevant. The Big Bang theory sounds too unreal for some reason(probably because I dont know its mathematical proof) but I think that it was not a single "BANG" but rather a 'progressive bang', a chain reaction of heavy elements being produced, breaking up being annihilated and a larger amount of lighter elements being created later on. I dont know, this is just a 16yr old's view. Whatever, Nevermind!

[Random]

A glipse of the future

1+m_mu/m_Z+m_e/m_W+ 1/2 (m_mu/m_W)^2=
1.00116590899

To be compared with experimental
1.0011659208(6)

[Bibhas De]

On 2004 Nobels for Physics:

http://www.geocities.com/bibhasde/priory.html

[Suresh Sharma]

commenting on Q-4, I would say the space and time(travel) is still a reality which we have not yet discovered not even excepted.
Can anything exist without having a duration. OK it has Length, breadth, height....and IT has DURATION. If duration = 0 , the object cant exist. So, now we can travel in three dimensions.. and we may in the FOURTH-- THE TIME. Travelling in time creates a World which is parallel to the existing world and that creats.....

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