Is the multiverse fake physics?

[TeethWhitener]

Right but I mean if that's the criteria you use, then stars and galaxies beyond the cosmic horizon are also unscientific as well.

Aren't they? We can't say anything meaningful about them. Our assumption that they exist is based on the Copernican principle, but that's no proof in itself.

At the end of the day there is more to science than simply testability.

There may be more to science than testability, but there's certainly not less. In other words, testability may not be sufficient (that itself is debatable) for science, but it's certainly necessary.

 

[JorisL]

Judging by a combination of empirical success and empirical predictiveness, I'd say holographic QCD is the best thing to come out of string theory,

If I'm not mistaken the empirical success has become less significant when reaching higher energies e.g. for the case of a quark-gluon plasma.

 

[astrobassist]

To call string theory and the multiverse "fake" physics degrades the meaning of the term fake. People like to claim that the idea of the multiverse is inherently untestable, but that just represents a lack of imagination, a lack of understanding of the current state of the field, and a lack of a sense of how fields change over time, sometimes yielding tests down the line.

The multiverse may well have observational, even falsifiable implications. For instance, Garriga, Vilenkin, and Zhang have recently derived a distribution of black hole masses that would confirm/disconfirm the existence of some common multiverse models based on astronomical observations.

People thought Einstein's attempts to unify forces to be "fake" physics at the time, but now unification has yielded new "real" physics with confirmed predictions etc.

Real physics is a balance of theory and experiment. This balance is dynamic over time, and hard to assess at any particular time.

 

[Chronos]

I consider logical paradoxes a red flag in any theory. Since paradoxes are not known to occur in nature, theories that predict them deserve serious prejudice. This has nothing to do with mathematical 'elegance' or 'beauty'. Fortunately, nature has no evident interest in conforming to such anthropic concepts. In ancient times, science was fixated on symmetry. Everything under the heavens consisted of four irreducible elements in various combinations - earth, fire, wind and water. We've come a long way since then, even though we still have not entirely shaken the symmetry malaise. My predilection is to lump things like multiverse and MWI into that primordial symmetry bin - an extension of our innate desire for a higher 'purpose' in the natural order of things that suits our personal preferences. In that universe truth is unbounded, it's just a question of selecting the proper stage to set your play. We are better served by understanding how things really work than any ideas, however lovely, of how we think they should work.

 

[David Neves]

Without the multiverse, how would you explain the following?

In the second and third generation of fermions, the quark with 2/3 charge is heavier than the quark with -1/3 charge. If that were also true in the first generation, which you would logically expect to be the case since that's the pattern, the up quark would be heavier than the down quark, so the proton (uud) would be heavier than the neutron (udd), so then the proton could decay into a neutron, and the proton would be unstable outside the nucleus, so in the early Universe, all protons would quickly decay, and there would be no atoms at all. The most likely explanation is that that indeed is what happens in the vast majority of universes that have a particle spectrum resembling the Standard Model, but those universes have no physicists. We are in a rare exceptional universe in which the pattern is broken, enabling us to be here.

How could else could you possibly explain this without the multiverse?

 

[nikkkom]

How could else could you possibly explain this without the multiverse?

Take eternal inflation model. It may be so that there may be no "multi"verses: every newly created bubble of real vacuum (a "new Universe") has the same physical laws - ones we observe. IOW: the true vacuum state may be unique. All "Universes" are similar.

 

[mfb]

How could else could you possibly explain this without the multiverse?

It could be random.
There could be some deeper reason for the particle masses that we don't know yet.

If all up-type quarks would be lighter than their corresponding down-type quarks, we would get a universe similar to our own as well. So why don't we reverse the question: Why is m(charm)>m(strange) and m(top)>m(bottom)? How can you possibly explain this?

Aren't they? We can't say anything meaningful about them. Our assumption that they exist is based on the Copernican principle, but that's no proof in itself.

Consider galaxies that are currently 20 billion light years away from us. We can observe how they formed billions of years ago. Do they still exist? We cannot see them as they are today and we will never be able to do so at any point in the future. But it would be ridiculous to assume that they don't exist. We know the initial state, we know the laws that lead to galaxy formation. Even though we cannot have direct evidence of their existence today, we conclude that they exist (probably).

 

[TeethWhitener]

@mfb My point was that (other than via the Copernican principle) there is no way for us to assert the existence of stars and galaxies beyond the cosmic horizon. But I had a couple of other questions about your post.

Consider galaxies that are currently 20 billion light years away from us. We can observe how they formed billions of years ago. Do they still exist?

You'll have to bear with me, since this is not my area of expertise. It's unclear what you mean by "still exist" since this implies some sort of simultaneity, and events happening "now" at your far away galaxy are spacelike separated from us.

we will never be able to do so at any point in the future.

If we can observe the galaxy as it was in the past, aren't we inside its future lightcone? Why would we be outside of it at some point in the future?

But it would be ridiculous to assume that they don't exist.

I don't know if it's that ridiculous. What if all the Population III stars have gone supernova by now? (I use "now" to mean that observers at our position in 20 billion years would not observe your far away galaxy).

 

[mfb]

If we can observe the galaxy as it was in the past, aren't we inside its future lightcone? Why would we be outside of it at some point in the future?

We are not in the future lightcone of the galaxy now. Where "now" means the galaxy 13.8 billion years after the big bang, measured in the frame of this galaxy.
We are in the future lightcone of the galaxy when it was younger.

Why: Accelerated expansion of the universe. The amount of matter still in causal contact to us (with the same definition of "now" as above) is decreasing. In other words, matter constantly leaves the volume of the universe we can observe in the future. The rate is something like a galaxy per day, give or take 2 orders of magnitude.
I don't think anyone expects those galaxies to suddenly disappear just because their distance to Earth gets larger than some value. But they (or, more precisely, recent events there) become unobservable.

 

[David Neves]

It could be random.
There could be some deeper reason for the particle masses that we don't know yet.

What? You just happened coincidentally to have the value they needed to have for us to be here?

There are also many other free parameters where if their value had been even slightly different then life would not be possible in the universe. If the fine structure constant had a different value, we wouldn't be here. If gravity had been stronger, life would not be possible. If gravity had been weaker, late scale structure would not have formed, and again, life would not be possible. Are you are claiming that all of that is just a huge stupendous coincidence, and we are all just stupendously lucky?

If all up-type quarks would be lighter than their corresponding down-type quarks, we would get a universe similar to our own as well. So why don't we reverse the question: Why is m(charm)>m(strange) and m(top)>m(bottom)? How can you possibly explain this?

Well I would conclude from the pattern of the second and third generation that the progressing masses are the "natural state" of the universe, which holds true in the vast majority of universes, and some random statistical fluctuation put our universe in a rare aberrant state that broke the pattern, enabling biological life to be possible.

Consider galaxies that are currently 20 billion light years away from us. We can observe how they formed billions of years ago. Do they still exist? We cannot see them as they are today and we will never be able to do so at any point in the future. But it would be ridiculous to assume that they don't exist. We know the initial state, we know the laws that lead to galaxy formation. Even though we cannot have direct evidence of their existence today, we conclude that they exist (probably).

Are you trying to argue in favor of the multiverse? If that's your point, then I agree. Just because we can't see the other universes, does not mean they don't exist. We can infer the existence of other universes, even if we can't directly see them, the same as we can infer the existence of other galaxies, even if we can't directly see them.

 

[mfb]

There are also many other free parameters where if their value had been even slightly different then life would not be possible in the universe.

Or life would look differently.
Is the desert fine-tuned for the cactus?

As an example, it has been argued that we could get a universe similar to our own with much simpler rules - you can have a universe completely without the weak interaction and with just 4 fermions (up, down, strange, electron) (reference).

We don't know how large and how frequent regions that allow life are in the parameter space.

Well I would conclude from the pattern of the second and third generation that the progressing masses are the "natural state" of the universe, which holds true in the vast majority of universes, and some random statistical fluctuation put our universe in a rare aberrant state that broke the pattern, enabling biological life to be possible.

We have 1 generation where up-quarks are lighter and 2 generations where up-quarks are heavier. Based on that, you claim that heavier up-quarks are the "natural state" and our first generation is the big outlier?
If I throw a coin 3 times and get 1 "heads" and 2 "tails", should I conclude that the coin usually gives "tails" and "heads" was a big outlier?

We can infer the existence of other universes

In some theories. I'm arguing that we should consider the existence of other universe if (a) we have a theory that performs well within our universe and (b) this theory necessarily generates other universes.

 

[PAllen]

But this is the other way around! You can do away with the aether in LET and just be left with SR because there is no need to assume the aether of LET. In the same way, there is no need to assume an eternal inflation to explain what is going on in the observable universe.

Of course you can try to extrapolate a theory, but doing so you must be aware of that this is what you are doing - just as we know that we are extrapolating GR to a domain that by definition of the theory itself is untestable when we try to describe the interior of a black hole. If the theory is true in that regime - then you can never know that it is.

On the latter point, sure you can. You just can't tell anyone about it. (There are even stable orbits inside the outer horizon of a Kerr BH, so your life need not be short) The multiverse is fundamentally less accessible than this.

 

[Orodruin]

On the latter point, sure you can. You just can't tell anyone about it. (There are even stable orbits inside the outer horizon of a Kerr BH, so your life need not be short) The multiverse is fundamentally less accessible than this.

Agreed, I made the implicit assumption that the experimenter was not suicidal...

 

[Victor Ray Rutledge]

I find all of this to be a tempest in a teacup. http://www.math.columbia.edu/~woit/wordpress/?p=5907 is a discussion of current articles, and fails to point in any defined direction. Look at this piece of rampant speculation, to see what I'm discussing. http://www.livescience.com/17796-science-fiction-imaginary-worlds-countdown.html If we can't agree on what is even possible, then how can we expect to research what is probable?

 

[Urs Schreiber]

Even without inflation, there is no specific reason to assume that the observable universe is but a tiny speck in something much larger.

If people had been careful to always say "observable universe" instead of just "universe", then "universe" would simply refer to all that exists, and there'd be no particular reason to assume that what meets our eyes (via telescopes) is but a tiny speck of all that exists. But somehow people had been careless and started to say "universe" (or worse "bubble universe") instead of just "observable universe" and so then a new word was needed for everything that might be beyond, and that word is now causing unnecessary confusion.

The assumption that "all that exists" is enormously more and larger than what meets the eye is at least as plausible as the opposite assumption, if not more so. This is not fake anything, that's just the obvious state of the matter, as was clear to people like Giordano Bruno way back. The ignorants burned him for saying the obvious.

Similarly, that one needs to beware not to search for patterns where there is randomness. Poor Kepler would have saved himself some trouble with trying to fit the orbits in the solar system to the Platonic solids had he had some sense of how non-unique our solar system is.

The assumption that some facets of nature are random has always been at least as plausible as the opposite assumption. In fact the opposite assumption is rather weird, if you think about it. Even Hegel left room for randomness in his attempted deduction of the ...verse from first principles.

It is absolutely possible that some aspects of fundamental physics are random, subject to some constraints, and this has always been so.

The real question is whether it's particularly fruitful to fill research articles with this obvious possibility. The problem is not that it's fake, but that it's mostly premature: besides stating the possibility, there is just not much to be deduced at the moment.

 

[mitchell porter]

Judging by a combination of empirical success and empirical predictiveness, I'd say holographic QCD is the best thing to come out of string theory,

If I'm not mistaken the empirical success has become less significant when reaching higher energies e.g. for the case of a quark-gluon plasma.

I meant the part of holographic QCD that models hadron masses and couplings, e.g. this recent paper claims success in modeling rho and omega meson decays, and makes glueball predictions. The work on QGP seems to me less grounded and more qualitative, more about learning to model holographically the complicated phase diagrams of QCD-like theories. btw there was a new twist on QGP holography released today.

In the second and third generation of fermions, the quark with 2/3 charge is heavier than the quark with -1/3 charge. If that were also true in the first generation, which you would logically expect to be the case since that's the pattern,

In some models, it's not what you expect. For example, suppose that the quark-Higgs yukawa interactions (that generate the quark masses once the Higgs field develops a nonzero energy density) are all the same size in some basis - this is called "democratic" and it has been a common hypothesis, inspired among other things by how the BCS model for superconductivity works. A democratic matrix has one very large eigenvalue and two very small eigenvalues, so this implies one heavy quark and two light quarks. Then you need to suppose that there is an extra, "radiative" contribution to the light quark masses, from heavy particles in virtual loops. According to this 1992 study (see the very end), in some models this is enough to explain why down is heavier than up - because of how the radiative corrections work out.

In evolution they talk about proximate and ultimate causes. The proximate cause of a plant growing towards the light might be enzymes (auxins and expansins). The ultimate cause if that if it doesn't, it will die. So natural selection produced an organism with a mechanism capable of implementing that imperative. The relation between a model like the democratic radiative theory of quark mass, and anthropic reasoning, might be the same.

 

[bob012345]

woit over at his blog not even wrong considers string theory based multiverse to be fake physics. he cites sean carroll as others on his blog as examples of fake physics.

is string theory based multiverse fake physics?

Can you state your definition of what constitutes fake physics vs. merely disputed or wrong physics?

 

[Dr. Courtney]

As you have guessed, I strongly disagree with this. If there are no testable differences, I see no scientific point in debating the issue. Just pick whichever interpretation you fancy (if you must) and nobody can disagree with you. To me this violates the very core of empirical science.

The absence of testable predictions renders any theory meaningless and unscientific. It becomes a kind of speculation that may be interesting to some scientists, but it is not science.

At the end of the day there is more to science than simply testability.

Testability may not be sufficient, but it is absolutely necessary.

Anyway, there are many very good physicists who take this material (in its multiple incarnations) seriously, so its surely not junk science.

How many times in the past would have addressing the demarcation problem regarding what is and is not junk science by an opinion poll of physicists led to an unreliable result?

If enough good physicists support creation science, does that make it OK?

 

[AlexCaledin]

Probably the only way to think clearly about physics is to think like an engineer :

1. Real things have their physical interface and interact according to the universal physical protocol;

2. The physical science is the search for the mathematics constituting that protocol;

3 Multiverse (as well as electron, molecule etc) is no more than a mathematical object found in that search.

 

[stevendaryl]

Here's what annoys me---people moralizing about what physics other people should be doing.

 

[stevendaryl]

Here's what annoys me---people moralizing about what physics other people should be doing.

I also think that arguing about what is and is not physics is itself not physics. It's philosophy. That isn't to say that it isn't worth doing (unless you're one of those who say that philosophy is a waste of time, since it isn't physics...)

 

[Dr. Courtney]

Here's what annoys me---people moralizing about what physics other people should be doing.

You are absolutely right. We should not be concerned at all unless we are helping pay for it - like through tax supported grants or other public funding mechanisms.

If the scientific community does not monitor and police when other members of the community are wasting public money, then who will?

 

[stevendaryl]

You are absolutely right. We should not be concerned at all unless we are helping pay for it - like through tax supported grants or other public funding mechanisms.

If the scientific community does not monitor and police when other members of the community are wasting public money, then who will?

Well, what counts as a "waste"? From some people's point of view, funding science is a waste unless practical applications result from it. The relationship between cutting-edge physics and engineering that applied that physics stayed tight for a long period of time, but in my opinion, at some point, possibly in the 60s, experimental and theoretical physics began probing extremes of physical conditions that were unlikely to ever occur in practical applications. I suppose it happened even earlier with General Relativity: weak-field approximations have practical applications (accurate GPS, for instance), but extremes such as the early universe and black holes and cosmology have pretty close to zero practical value. That isn't to say that there is no point in funding it, but it's not a matter of getting return on research investment dollars (I guess there is the beneficial side-effects, which is that studying fundamental physics can spur progress in the engineering, computing and mathematics).

Anyway, I don't think that practical applications should be the criterion for whether research funding is "wasted", but if not that, what? Personally, I think that research is valuable if it connects to other research, and is a dead-end if it has no impact outside itself.

 

[stevendaryl]

Anyway, I don't think that practical applications should be the criterion for whether research funding is "wasted", but if not that, what? Personally, I think that research is valuable if it connects to other research, and is a dead-end if it has no impact outside itself.

Just speaking personally, I have no idea how much taxpayer dollars Sean Carroll receives, but I consider every penny to be worth it. He's the only physicist that I read on an almost daily basis (because he writes so much and does videos and so forth). So this taxpayer is happy with what he does. I think that young people are a lot more likely to enter physics because they are inspired by Sean Carroll.

 

[Dr. Courtney]

Well, what counts as a "waste"?

If a scientist is spending taxpayers' money, then what counts as waste is a public policy issue that gets decided by the taxpayers based on open discourse (remember the first amendment?)

Here's what annoys me---people moralizing about what physics other people should be doing.

Are you really saying those who pay for the physics should not have a say in which programs are worthy or unworthy of funding? It's a free country. Do whatever physics you want, as long as you don't want me to help pay for it.

But if you are asking for public funding, you need to be prepared for an open and honest discussion where people like me share our opinions that untestable aspects of string theory and speculations about "multiverses" are not real physics and certainly not worth the amount of public funding they have enjoyed.

When colleagues and I have science we want to do but are not willing to jump through all the hoops waiting for funding, we fund it out of our own pockets, subsidizing it with funds earned from more profitable science ventures. We don't stomp our feet, accuse detractors or moralizing, and whine about the disasters if the taxpayer isn't willing to pay for it.

See:
https://www.physicsforums.com/insights/science-love-money/

 

[stevendaryl]

If a scientist is spending taxpayers' money, then what counts as waste is a public policy issue that gets decided by the taxpayers based on open discourse

Well, I put in my two cents. I think that Sean Carroll's work is worth every penny that is spent on it.

I think that if you go down the road of blasting stuff as "fake science", you're treading very dangerous territory. Climate science is the first to go, as we have seen.

It seemed to me that the tone of this thread was about whether it is legitimate science. It seems like a completely different thread to talk about how taxpayer research dollars should best be spent. For one thing, if you're worried about the money spent, that you have to take into account how much it costs. Theorizing about infinitely many universes is not more expensive than theorizing about just one.

 

[anorlunda]

The term fake science is too emotional and an obvious intent to associate it with contemporary caustic politics.

The absence of testable predictions renders any theory meaningless and unscientific. It becomes a kind of speculation that may be interesting to some scientists, but it is not science.

You are correct, but I think overly harsh. If we applied that strictly, then discussion of MWI or string theory or QM interpretations and this very thread would not be allowed on PF because they aren't mainstream science.

I suggest that a more sensible term would be "provisional physics" That implies speculative research that is on probation. It can be investigated for a finite time with finite resources in the hope that testable predictions will result. Speculative research is allowed provided that reasonable hope exists that it will produce real science in the near future. @astrobassist gives us an example of such hope. If we required a testable prediction as a precondition to spending the first $1, then we could shut down progress. Einstein worked on GR from 1907 to 1915 before producing testable predictions.

The multiverse may well have observational, even falsifiable implications. For instance, Garriga, Vilenkin, and Zhang have recently derived a distribution of black hole masses that would confirm/disconfirm the existence of some common multiverse models based on astronomical observations.

But I also believe that we should be fully transparent and more systematic in public funding of provisional physics which is what @Dr. Courtney said.

But if you are asking for public funding, you need to be prepared for an open and honest discussion where people like me share our opinions that untestable aspects of string theory and speculations about "multiverses" are not real physics and certainly not worth the amount of public funding they have enjoyed.

It would be quite proper for the President to order NSF to publish reports revealing provisional science expenditures, and to publish their process and criteria for cutting off funds when they determine that hope is no longer reasonable. If Congress wanted to put a cap on provisional science (such as 5% of NSF funds) that would be proper. It is also necessary to allow the public into debates about such policy about public spending.

Finally, @stevendaryl makes a good point. We should permit such arguments on appeal of funds cutoff.

Personally, I think that research is valuable if it connects to other research, and is a dead-end if it has no impact outside itself.

 

[Dr. Courtney]

I think that if you go down the road of blasting stuff as "fake science", you're treading very dangerous territory. Climate science is the first to go, as we have seen.

It is foolish to argue that a standard to determine what is real science and what is fake science should never be applied.

There will always be a need to blast stuff as "fake science." Or should we be silent on AIDS denialism, vaccine pseudoscience, and all the lastest snake oil and miracle cures?

It seemed to me that the tone of this thread was about whether it is legitimate science. It seems like a completely different thread to talk about how taxpayer research dollars should best be spent.

If you look in the Acknowledgement sections most of the papers, you'll see that the greater majority of this work is funded with taxpayer dollars. Curbing the enthusiasm for pseudoscience almost always requires curbing the funding.

Both the Woit blog and a lot of Sean Carroll's blog posts speak loud and clear to the funding issues. When the bulk of support comes from taxes, the scientific merit of the work cannot really be separated from whether funding is warranted.

For one thing, if you're worried about the money spent, that you have to take into account how much it costs. Theorizing about infinitely many universes is not more expensive than theorizing about just one.

Of course, the same physicists could always be more productively employed teaching or researching theories that are actually testable.

Otherwise, we may as well spend taxpayer funds on art and music.

 

[haushofer]

I think we just entered the demarcation problem.

 

[David Neves]

The average person, without a scientific background, is not able to judge whether something is science or pseudoscience. They have no way of telling the difference. They have to rely on experts to make that determination for them.

This means the public can not be directly involved in deciding what science should be funded, based on its merits. This is not true for other subjects. An educated member of the public can form a reasoned opinion on the best use of tax payers regarding non-science spending, even if they are not an expert on those other subjects, such as whether we should fund a specific military jet, an oil pipeline, government health care, agricultural subsidies, a program to teach children to read, or any number of subjects. However, the same person would be incapable of forming any opinion whatsoever on whether we should spend money on the search for axions. When the debate about government spending on a fundamental physics project becomes a public political debate, it degenerates into a farcical charade. Think of the political debate about funding the Superconducting Super Collider. The public and the politicians did not have slightest clue what this machine was supposed to do, or look for, so the best argument that the proponents could come up with was that it would bring jobs to Texas, which played into the hands of critics, who claimed that it was just pork barrel spending. I remember watching the McLaughlin group on PBS, and Jack Germond was arguing in favor of the project by claiming that it would lead to technology that would improve our daily lives, which I knew was ludicrous. What this means is that the debate about government spending on physics can not, and should not be politicized. Instead, funding should be determined by experts similar to a referee or peer review process.

 

[bob012345]

The average person, without a scientific background, is not able to judge whether something is science or pseudoscience. They have no way of telling the difference. They have to rely on experts to make that determination for them.

This means the public can not be directly involved in deciding what science should be funded, based on its merits. This is not true for other subjects. An educated member of the public can form a reasoned opinion on the best use of tax payers regarding non-science spending, even if they are not an expert on those other subjects, such as whether we should fund a specific military jet, an oil pipeline, government health care, agricultural subsidies, a program to teach children to read, or any number of subjects. However, the same person would be incapable of forming any opinion whatsoever on whether we should spend money on the search for axions. When the debate about government spending on a fundamental physics project becomes a public political debate, it degenerates into a farcical charade. Think of the political debate about funding the Superconducting Super Collider. The public and the politicians did not have slightest clue what this machine was supposed to do, or look for, so the best argument that the proponents could come up with was that it would bring jobs to Texas, which played into the hands of critics, who claimed that it was just pork barrel spending. I remember watching the McLaughlin group on PBS, and Jack Germond was arguing in favor of the project by claiming that it would lead to technology that would improve our daily lives, which I knew was ludicrous. What this means is that the debate about government spending on physics can not, and should not be politicized. Instead, funding should be determined by experts similar to a referee or peer review process.

Sixty years of fusion 'breakthroughs' promising unlimited energy 'just around the corner' make a good counter argument. When scientists benefit from public resources, they must also allow public scrutiny.

 

[anorlunda]

This means the public can not be directly involved in deciding what science should be funded, based on its merits.

whether we should spend money on the search for axions.

I agree that a layman can't have a specific opinion on something like axions. But as I suggested in #62, NSF should have written policies and procedures for determining what should be funded, and the public can and should have a voice in those policies and procedures.

Among other things, we taxpayers must protect ourselves from "You scratch my back, I'll scratch yours. collusion between scientists." I would want to see participants in the decisions who have no skin in the science game or the research industry, and are thus free from real or apparent conflicts.

I learned to be skeptical by witnessing many cases of misspent research grants given by organizations whose performance was measured by how much money they spent, rather than by the benefits produced to the public. Some taxpayers may be satisfied that GAO says that they audited NSF. I am not one of them.

 

[PAllen]

Sixty years of fusion 'breakthroughs' promising unlimited energy 'just around the corner' make a good counter argument. When scientists benefit from public resources, they must also allow public scrutiny.

But fusion is clearly not fake physics. Consider the time from first serious experiments with human gliding to commercially viable flight. That was centuries. The always wrong predictions were a problem, but what if no predictions were ever made? Since, at each point, the next major hurdle was unknown, there really was no basis for predictions.

 

[Dr. Courtney]

But fusion is clearly not fake physics.

Cold fusion may not have been fake, but it was wrong. Fake suggests intent to deceive. But wrong is wrong, and the funding sources should have an honest assessment on the potential for valid and promising results on the timelines of interest.

But the issue with aspects of string theory and multiverses is that it is not even wrong. Testable hypotheses like cold fusion can be wrong.

http://www.math.columbia.edu/~woit/wordpress/?cat=2

 

[maroubrabeach]

Most scientific theories were at one time just hypothetical speculations.
Controlled nuclear fusion power experiments is expensive and have been ongoing for a long time, but the benefits that it could produce is exceptional...
Many many other issues also, alternative propulsion methods to take us further, validation of QGT's like string and its derivitives, would give us knowledge and where that knowledge could lead to is extraordinary.
Is there anything really that science should not try to explain?
Without science, without reasonable speculation, and hypotheticals, and subsequently scientific theories, we would still be swinging in the trees.
Think how much money would be available if all nations ceased their militaristic endeavours..Yeah OK, perhaps I have watched to much Star Trek, and perhaps that maybe wishful thinking, still wouldn't it be great?