# How to explain the benefits of string theory to my grandmother

1. May 15, 2007

### chrisina

My grandmother asked me "what has string theory achieved so far ?"
(poor her, she seems to think I could answer that question, so I tried my best not to deceive her...)

I gave here the analogy of a crime scene investigation (CSI):

- suppose you´re a detective (string theorist) and you are presented with a very mysterious crime scene (our universe) with aprroximately 50 indices (the fundamental constants of nature). You are asked to find the culprit (the laws of nature).
- so you think, the best approach (the scientific one) is to build a CSI model, with all the most advanced mathematics (and you even develop new ones).

In the process, you become very enthusiastic, because your model also provides better explanations on other crime related issues : for example, how a cat gets destroyed in a washing machine (black hole entropy).

- then you say : well, our conclusion, is that probably we´ll never be able to solve the crime, because our model shows that there are at least 10^300 possible culprits. But rest assured, the crime really happened, because we were there to observe it... we are pretty confident that our model is the best to explain how crimes are performed (including the one with the cat).

So my grandmother says : " so they don´t solve the crime ? Christian, you probably got it wrong"

I surely did, so now suppose I am your grandmother...

PS : despite the cynical and somewhat irreverentious tone, this is a GENUINE question.

2. May 15, 2007

### neutrino

Don't worry gran'ma, even the string theorists haven't answered that yet.

3. May 15, 2007

### ccdantas

4. May 16, 2007

### Demystifier

Chrisina, in order to successfully explain the benefits of string theory to your grandmother, you have to choose a different strategy. The analogy with CSI is simply bad. I would start from the assumption that your grandmother is religious (most grandmothers are) and compare the benefits of string theory with the benefits of her religion. Even if she is not religious in a traditional sense, she certainly believes in something, in some ideals for which a proof does not exist, which can always be taken for a basis of the analogy.

5. May 16, 2007

### Demystifier

An additional, more serious comment: In the modern landscape view of string theory, asking string theory to explain the Standard Model is like asking quantum electrodynamics to explain life on the planet Earth.

6. May 17, 2007

### chrisina

come on ST fans, isn´t it possible to find at least one single, easy to explain achievement for a theory which has cost more than 10000 man year of cumulated effort... ?

7. May 18, 2007

### Demystifier

Let me compare it with religion. Has religion (that costs much more) made any achievement? One may say that it gave us a hope. Well, so did ST.

8. Jun 7, 2007

### CyberRBT

chrisina:
What has ST achieved thus far (in our verse)? Well ... it has managed to voraciously devour 10K man-years from some of the best theoretical minds on our planet. :)

Perhaps a less conCERNed model of comparison is in order. This is what i would tell my grandmother.

"What has a one-month old baby achieved? What has a two-month old baby achieved? Granny, string theory is that eager infant squirming in its crib. Right now she mostly sleeps, but she is starting to interact with us and sometimes you can catch her smiling. She's developing from head to foot. Lots of good folks are attentively working with baby Esstee teaching her to talk and to walk. They feed her; clean her; clothe her; and, they enjoy playing with her. Soon, she will talk ... soon, she will walk. And, granny, when she learns to run you won't need to ask 'what has she achieved'. Instead, you'll be installing child safety gates, double-locking the cabinets, and wondering where she gets all that energy."

Demystifier: (deify timers?)
Religion is religion, and ST is ST; never the twain shall meet? Or, shall they?

Last edited: Jun 7, 2007
9. Jun 7, 2007

### Leopold Infeld

I thought there were 10^500 culprits give or take?

Eric Cartman would have made the best investigator :P

10. Jun 7, 2007

### Demystifier

The best answer so far. Now I will tell to my grandmather the same.

11. Jun 7, 2007

### Fra

As long as we have faith in the method I'd buy this. But the method is exactly my personal problem with string theory, thus I would have no faith in the result if there is no other proof than self consistency. Self consistency alone, devised by means of a line of reasoning that isn't very attractive.

Since our attempts is considered to be an investment, the minimum requirement I would like is to justify the method, not hope that maybe or maybe not the result can be justified.

/Fredrik

12. Jun 7, 2007

### neutrino

Granny better not have watched those Discovery Channel shows where they talk about the growth of a baby, and what they achieve (as human beings) as they become a year or two old.

13. Jun 7, 2007

### CyberRBT

neutrino:

14. Jun 8, 2007

### Demystifier

Unfortunately, as we cannot do experiments at energies as large as the Planck scale, self-consistency is the only guide. There are only two possibilities: We can either not even try to say anything about phenomena on these energies, or try to do the best using only what we have - self-consistency. One should not forget that general relativity (GR) was also constructed from almost nothing but self-consistency. As GR latter turned out to be correct, it does not seem so unreasonable to hope that string theory could be right as well.

15. Jun 8, 2007

### Fra

Yes, but consistency has meaning only within a given foundation. At best it seems string theory is trying to answer how the universe will look like, if the minimum block is a string, and everything else is explained in terms of string dynamics.

But IMO that is the answer to the wrong question. String theorists seem to pose both the question and and answer to make them consistent.

I can not wrap my head around the idea that these string ideas can qualify as some kind of first principles. It's at special case, or IMO weird approach at best. I can buy that. So even if it ends up useful, it is still not possibly the final answer. So I see no reason at all that I should waste my time on earth, trying to the the answer to a question that I find wrongly posed to start with. In a certain sense posing the right questions is part of the problem, and often part of the solution involves reformulating the question. But still. In my thinking the whole string philosophy is too off target to get my attention. Wether that's due to string theory, or my incompetence, does in fact not matter from my subjective point of view, because any incompetence is intrinsic and not something I can choose away in fractions of a second.

However, perhaps you're right that there hasn't been much options around. I'm too young and ignorant about the exact history to have an opinion on that, but I will speak for myself today and currently I see some very exciting approaches that IMO, outperforms string theory in its ambitions. However these approaches are too young to be able to compete on total progress level, but to me the string route is not radical and fundamental enough. Mathematically fancy maybe. But that's not what physics is about for me at least. I want a clean, logically and philosophicall consistenct line of reasoning behind all this.

/Fredrik

16. Jun 8, 2007

### Fra

> So my grandmother says : " so they don´t solve the crime ? Christian, you
> probably got it wrong"

Perhaps we may have understimated old grandmothers wisdom ;)

/Fredrik

17. Jun 8, 2007

### Anonym

Christian, suppose that there is no crime, do not exist. How do you explain that?

Grandfather.

18. Jun 8, 2007

### CyberRBT

re: Planck, i believe it was he who said

"A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather its opponents eventually die, and a new generation grows up that is familiar with it."

Fra:
If we reflexively reject an established though nascent scientific/mathematical pursuit predicated on its inability to fit snugly within our own conceptual framework, how else can we establish the foundation upon which to attain your next 'radical' superset of theories? Perhaps some independent, punctuated theory will abruptly emerge. But, until we have repeatable experimental validation there is, IMO, no substantive differential between the "fancy math" of ST and "mathematical genius".

Last edited: Jun 8, 2007
19. Jun 18, 2007

### Demystifier

Possible in principle, but not very likely. Every society we know has crime.

20. Jun 18, 2007

### mjsd

Was she really asking a question or being cynical? Now if she was just asking a genuine question on the status/development of string theory, you could go on for hours/days to tell her all the exciting (and frustrating) development. If she was being cynical, ie. she was really asking "WTF is the use for String Theory?" then there are two approaches (at least) in my opinion to answer the question
First choice is to (pretend you don't understand what she is getting at) ask back "what do you mean by what has ST has achieved? ST has achieved more things than we can ever comprehend, it is like God itself who has done so much for mankind and yet we constantly take things for granted and when things don't work to our satisfaction, we start condemning..."

Second choice is to (become like her) and reply "not a lot really, just enough to stir up some interest/fundings for those who really love knowledge and doing it as a hobby. It is quite fun sometimes too, doing integrals with weird symbols, it is like playing scrabble!"

cheers

21. Jun 18, 2007

### Anonym

You are right, but 10^300 or 10^500 culprits is much more even than entire Moslem world. Do not look reasonable.

Regards, Dany.

22. Jun 18, 2007

### Anonym

I have impression that even God itself can’t ever comprehend ST achievements.

Regards, Dany.

23. Jun 18, 2007

### Fra

Naturally each individual has the benefit to place his own bets and the proof is in the success. "My" bets implies "my potential loss" or "my potential gain", ultimately my responsibility.

In general I'm in favour for multiple attempts. I think that those who have
their heart in string theory should go for it, no doubt.

In general I'm in favour for multiple attempts. But part of the complicating factor with "public research" is the public funding of scientific research for benefit of the public. I guess this is partly a political question, which I've chosen to stay out of. But, I am not pleased to see my share of tax money going into string research.

I see differences in *risk*. The whole idea with risk analysis is that you don't know, thus you have to guess. But you can further just "estimate the risk". But it's true that different people may make different judgments. I can buy that. If that's as far as we can agree, that's fair enough. I make my bets and you place yours. I guss time will show what grows faster. But for a fair game I think the financial support should be in proportion to the estimated benefit. It's true though that splitting a small amount of money in too many bins, will not be efficient either. But I am still doubtful.

You might think similary, that since nonone can predict the stock market, you might place your bets arbitrary - it's just a potluck game anyway. But that is un unsatisfactory idea to me. If it's truly random - don't play! (ie take minimal risks). Humanity has plenty of other research areas to feed as well. Many that is extremely interesting. If it is not potluck, there should be discriminating evidence to what is the better place to bet (assuming you have to make a single bet), ideally if the splitting isn't too degrading for performance, a risk spreading seems wise.

To me string theory is a true high risk project. That might make large progress if successful, but also a large loss if wrong. To say that we have no other options and thus need to spend even more on this, sounds like those people addicted to gaming. They've already so large "investments made" that would be totally lost if they give up, so they need to keep investing and hope to "get lucky".

Getting lucky isn't what I associate with scientific methods. I picture that a good bet is one that can be fully defended even in the event is is proven wrong. How would the string community defend this in the event it's wrong? Was it the only choice we had? really? Was it the best bet?

I am not to judge anything or anyone but "in my world", I don't understand how string theory is up to standard in what I picture as a scientific method. It's is too speculative. Nothing wrong with that as such, the problem I have is that there seems to be no ranking of the degree of speculation and that just bugs me to the bones. Of course I'm just an amateur, and no professional. But I make my own judgements like everyone else should.

I guess am a happy fool :shy:

/Fredrik

24. Jun 19, 2007

### Demystifier

I do not find unreasonable to have such large numbers. In fact, it is more surprising to me that this number is finite, rather than infinite. This is just the number of stable solutions. Loosely speaking, one can compare it to some simple classical equation of motion in which the number of stable solutions may very well be infinite, which usually nobody finds problematic.

I also like to put it this way:
Asking string theory to explain the Standard Model of particles is like asking quantum electrodynamics to explain life on Earth.

Last edited: Jun 19, 2007
25. Jun 19, 2007

### Anonym

Yes, loosely speaking, you ignore Chrisina’s definitions. The universe is not a crime scene and the laws of nature are unique, moreover, extremely exceptional.

Indeed, it is matter of attitude.

Consider, for example, P.A.M. Dirac, Proceedings of the Royal Society, A133 , 60 (1931). It ignites my curiosity: if so, why it is not there? The alternative is what would happen if it would be there? Amusingly, usually that attitude is presented by the people that claim that the moon is there only when they look at it and denies the existence of photon. Chrisina consider that kind of activity “sexy”, I agree that this is kind of sexual activity but use a different name.