Need Research Question Related to Multiverse (High School Level)

shaz.662

I am new to this, but in desperate need of help. I'm doing the IB and in our final two years of school we are required to write an essay (extended essay) on one of our chosen subjects. I chose to write an essay on physics and my topic is parallel universes. However, I am really stuck as the physics is beyond my level of understanding. I need some ideas that I could write a 4000 word essay about. (The essay would be mainly research based) Thank you

Vorde

You could talk about the various kinds of multiverse theories (like parallel universes vs multiverse) and their various observational evidences. But I'm not sure how long you could stretch that.

Chalnoth

Tegmark's got a good website on this stuff:
http://space.mit.edu/home/tegmark/crazy.html

He organizes in a reasonable fashion the different multiverse ideas, and adds a new one that he has proposed himself. It might be a good idea for an essay at this level to not go for the mathematical universe hypothesis, but his overview of the other multiverse ideas is quite good.

shaz.662

The website has a lot of information about the multiverse. I am also familiar with the various levels of universes. However, the problem presists that I cannot formulate a research question in this field. e.g. How does the density of liquid affect the waves created. I need a question realted to multiverse in that sense. It cannot be a descriptive essay, to some extent it needs to answer a question.

Chalnoth

Well, there is basically no way to tie most of the multiverse ideas to any sort of experiment at the current time. The quantum multiverse is (sort of) an exception, as quantum decoherence, the essential component of the quantum multiverse, has been experimentally demonstrated:
http://www.atomwave.org/rmparticle/a...refs/BHD96.pdf

So you could focus on that point. Or, alternatively, you could argue given what we know in other areas why a particular multiverse idea is likely or unlikely to describe reality.

Mark M

The multiverse of eternal inflation does offer testable predictions relating to variations in the cosmic microwave background. This paper details how the CMB can provide evidence of an eternal inflationary multiverse.

Chalnoth

Well, sort of. It leads to the possibility of particular kinds of random features that may, even if this particular kind of multiverse is true, not even be there at all. So it's a potential experimental result, but a very weak one.

Ken G

Come to your senses and choose a different topic! It is highly questionable if the multiverse idea is even science at all, and you are looking to answer a question about it? Bad idea, find something you are interested in but is much more clear-cut the kinds of scientific questions it connects with.

Chalnoth

Many multiverse ideas are most definitely science. They're just rather difficult science.

Ken G

I'd be curious to hear even one good example, indeed an example of any type of distribution anywhere that we can learn something about and do science on when we are limited to experiments on one single member of that "distribution."

Chalnoth

See the paper posted by Mark M earlier in this thread for one example. Or the one I posted which (obliquely) tests the many worlds multiverse.

Ken G

Those don't qualify, as the first is a "fringe" paper, not in the sense of being "crackpot" but in the sense that it has no clear connection to mainstream astronomy and would tend to be ignored by mainstream astronomers who are mostly not "multiverse enthusiasts", and the one you cited is about decoherence (a standard quantum phenomenon with no obvious connection whatsoever to any multiverse). There are always lots of highly speculative things getting published all the time, with very little chance of making any kind of mark on mainstream science. The problem is, it's not enough to simply be able to say that I have some theory that makes predictions to count as mainstream science, though it isn't pseudoscience either, it's just questionable that it isn't some detour from the scientific process. The predictions have to be falsifiable, not just shots in the dark. There is never going to be any way to falsify a multiverse, if the observations go against one multiverse prediction, they can always just modify the multiverse to accomodate the observations, and if the predictions happen to work, well, there's always coincidence.

A classic example of this is Weinberg's celebrated "prediction" that the cosmological constant would come out to about 70% of the needed energy to flatten the universe. The fact that we exist certainly does constrain that parameter, but how is that a "prediction"-- we already knew we existed, we already knew the expansion is constrained by that, so I'm predicting that the expansion has to be constrained by my existence? How is that science? It was more like a test on GR than anything else-- had it not been correct, we would still know we are here, so if the expansion was incorrectly constrained by our presence, then our theory would have had to have been wrong. But the wrong theory would have been GR with a cosmological constant, not a multiverse. There is never any way to falsify a multiverse, simply because no one can ever do any observations on it, so it is completely unconstrained and can be moved and modified any way that is needed to fit the observations, consistent with the obvious things we already know (like that we are here).

So bringing it back to the OP, I'm saying that multiverse "science" is a terrible topic for an actual investigation, it would only be suitable for a descriptive paper along the lines of "this is what is currently being thought about on the fringes of science where it is not clear that mainstream astronomy or physics will ever embrace these notions." It is highly unsuited for a paper along the lines of "here is my investigation into X and here is what I learned about our universe by doing so," which the OPer seems to be saying is what is required for this project. You can certainly not agree with me that multiverse thinking is highly questionable science, all that matters is we are agreed that it makes a lousy investigative project that attempts to do anything more than just report on what the oracles are saying. I think it's a fascinating topic, but one more along the lines of scientific sociology than investigative learning.

Chalnoth

Well, sure, if you throw out everything that demonstrates you're wrong, you'll never be convinced of anything. Making up nonsensical restrictions on what is or is not science is just an excuse to throw out ideas you have an emotional aversion to.

marcus

That sure seems like good sound advice based on what I've seen of it.

Ideally, such advice might be offered along with some help finding an alternative research topic. Do you have any ideas? I'll try to think. Maybe Shaz can tell us some other areas or questions that stimulate excitement/curiosity.

Ken G

Actually, I thought I was quite clear on the objections I raised. Now let's look at what you are doing-- you are claiming that a perfectly mainstream investigation into quantum decoherence in a measurement is actually an investigation into the multiverse! That's a little worse than just "oblique."

Chalnoth

The existence of quantum decoherence demonstrates that wave function collapse is observationally unnecessary. This leads inexorably to the many worlds interpretation (or at least something that is essentially the same in its primary implications).

But no, you were clear. You were clearly wrong. What you said about the limits of science in your post has pretty much nothing to do with how a great deal of main-stream science is actually practiced in the real world.

Ken G

I agree it would be nice to offer a constructive suggestion, but it is exactly the problem with multiverse thinking that it is hard to come up with a physical principle that is "kind of like the multiverse" but closer to a mainstream project that a high school student could actually do. But perhaps we could take the fundamental idea behind multiverse thinking, which is that you can get seemingly very unlikely outcomes if you have a stringent enough selection criterion that you apply to a large enough sample.

The classic example of this would be if you were a newsperson who was interviewing people who had won a lottery. You might start to think that winning lotteries was fairly commonplace after interviewing 10 winners, and forgetting that they were selected from a huge sample of non-winners. Accounting for the non-winners would help return you to an understanding of how rare winning a lottery really is. But note the key difference here-- we could actually interview the non-winners too! That's exactly what you cannot do with a project on the multiverse.

But maybe Shaz could do an investigation of unlikely events, and show that they can actually happen if you select from a large enough sample. If he/she wants to aim the conclusions at insights into multiverse thinking, that's up to him/her, but the actual project could be much more mainstream science. Or another interesting take could be to flip a coin 10 times, record the sequence of outcomes, and calculate the probability of exactly that set of outcomes. It will be 1/2¹⁰ of course, which is a number like 1/1,000, so that might qualify as an "extremely unlikely event." But we can all see that it had to come out an extremely unlikely event, so what does this tell us about the meaning of unlikely events? It says that to be counted as unlikely (or "finely tuned"), you need to be considering a particular outcome before you know what happened, not after you know. That is also trying to tell us something about the validity of multiverse thinking. So maybe there's some kind of "investigation into unlikely events" here, that can be connected in some way with the multiverse idea, if Shaz really wants the investigation to be about that somewhat indirectly.