Article by ‘t Hooft (January 2008)

Counter - A theory of everything should only deal with certainties by Prof. G. 't Hooft


Published in the Dutch language science magazine "Natuur Wetenschap & Techniek", issue January 2008 as part of a collection of articles from leading scientists describing a common idea in their field they disagree with. Translation below is by Korneel van den Broek with permission from Prof. G. 't Hooft and Natuur Wetenschap & Techniek.


An issue where I disagree with almost all of my colleagues, deals with the question what one may expect of a complete theory of all natural phenomena, the "Theory of Everything".


Issues we mostly agree upon (apart for some details):

1) It is very unlikely that mankind will ever be able to formulate the exact universal laws of nature, although this just might nonetheless be possible. We believe this because combining the laws of quantum mechanics and gravity suggests that there is a 'smallest distance'. At even smaller scales, the concepts 'space' and 'distance' loose their meaning. This is similar to zooming in on a digital image: once one is able to distinguish the individual pixels, zooming in becomes useless and it doesn't make sense to attribute individual properties to one half or one quarter pixel. At that level there could exist a fundamental, universal equation of motion which determines with infinite precision what happens. From there, everything follows using induction and mathematics.

2) We cannot expect that one can describe with infinite precision all macroscopic phenomena with such a theory, let alone predict. We will still be forced to use approximation techniques with very limited precision. In practice, such a fundamental theory would therefore only have a limited impact.

Now the disagreement:

3) Will an equation of motion completely determine all events in the universe or, just as we are used to from quantum mechanics, will it only provide probabilities of what could possibly happen? This is what current theories do. For every experimental setup studying small particles such as atoms, quantum mechanics can only provide probability distributions.

According to current understanding, it is fundamentally unpredictable when a radioactive atom will decay. The theory only provides the probability per unit of time that it will decay (as such the theory is very precise once one deals with a macroscopic amount of material). For all practical purposes, this works so well that nobody complains anymore. If one would have a deterministic theory for atoms and molecules, it would not provide better predictions since for experiments dealing with millions of atoms one cannot know the initial state, so one would have to rely on statistical techniques anyway.

I am one of a few who claim that a complete theory should only deal with certainties. While I expect that nature contains so many moving cogwheels that it will remain impossible to capture them with infinite precision, the issue deals with the principles on which such theory should be based. If one knows for all the dynamical variables the exact initial state, the final state should be completely determined and not a probability distribution.

Most of my colleagues tell me, with varying amounts of tactfulness, that my ideas are outdated since the beginning of the last century, and that it is naive to try turn back time. Quantum mechanics is too beautiful to reject. They believe that nature, including the most fundamental laws to which any phenomena can be reduced, are fundamentally quantum mechanical. My suspicion is that not nature, but our understanding of nature is quantum mechanical. The laws we know only provide probabilities since we don't know the actual laws (yet?).

My colleagues confront me with theorems by John Bell and others, which purportedly show that my point of view is untenable. What those theorems do show instead is that their interpretation of my ideas is untenable. The 'reality' I talk about does not consist of atoms, electrons or other particles that have energy levels and rotate around their axes, but instead little cogwheels which are billions and billions of times smaller. Their collective behavior implies that one can use the quantum mechanical language for atoms and electrons. However, the behavior of atoms or electrons can never be considered completely independent from what happens at that much smaller scale. This could be an explanation for the odd phenomena we call 'quantum mechanics'.

The major difficulty of my point of view, which I indeed realize, is that I am unable to demonstrate the mathematical laws which would underlie this special situation.

Gerard 't Hooft
Professor Theoretical Physics


Note: VScape is no longer being maintained.


Vscape (a.k.a. a Metastable Program for Metastable Vacua)

Vscape is an interactive tool for studying the one-loop effective potential of an ungauged supersymmetric model of chiral multiplets. The program allows the user to define a supersymmetric model by specifying the superpotential. The F-terms and the scalar and fermionic mass matrices are calculated symbolically. The program then allows you to search numerically for (meta)stable minima of the one-loop effective potential. Additional commands enable you to further study specific minima, by e.g. computing the mass spectrum for those vacua. Vscape combines the flexibility of symbolic software with the speed of a numerical package.

The program can generate data files that can easily be plotted with a mathematical package (Mathematica, Maple,...). Vscape also produces output files formatted according the Model Input File standard described in the Les Houches Accord 1.0. The output of Vscape can thus subsequently be fed into a susy spectrum generator (e.g. SOFTSUSY).



To install the program you will need a C++ compiler. Besides the standard C++ libraries, you will also need the (developers) version 1.10 or higher of the GNU Scientific Library (GSL) for numerical outines, version 1.4.1 or newer of GiNaC and version 1.2.0 or higher of Class Library for Numbers (CLN) for symbolic routines. Although not essential, it is useful to have a version of the GNU Readline Library installed for handy tab completion. CLN has to be installed before you install GiNac, since GiNaC is based on CLN. Note that CLN only compiles without hassle on the GNU g++ compiler version 2.95 or newer. To install Vscape the pkg-config utility is required.

Once the libraries are installed, download the file:


For a default installation, execute the following commands on a terminal in the directory containing the downloaded file:

tar -xvf vscape-1.1.3.tar.gz
make install               
Additional installation options are detailed in the INSTALL file included in .tar.gz file. You run the program by typing:


A compiled version for Windows (XP) can easily be installed by downloading

Unzip the file in an empty directory, then run the program Vscape.exe. To remove the program again, delete the directory with its content. This compiled version might not work on all Windows versions. To study more complex, computationally intensive models we suggest to use the Linux version, since this Windows version is at least 4 times slower, since it relies on the emulator dlls from cygwin.


Check the manual, for more information on how to use the program. To ask questions, report bugs or make suggestions please contact the author.


Korneel van den Broek <>

Physics Graduate Student
Rutgers University
136 Frelinghuysen Road
Piscataway NJ, 08854


Copyright © 2007 Korneel van den Broek - Rutgers University, New Brunswick NJ, USA.

If you use Vscape to write a paper, please cite

Korneel van den Broek, "Vscape V1.1.0 - An Interactive Tool for Metastable Vacua", arXiv:0705.2019v1 [hep-ph].

which is the Vscape manual. The version on the arXiv will be updated along with new releases of the program.

This program is free software. You can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY, without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.