Gravity Experiment

[Dills0n]

I have an acquaintance who is really pushing hard for a gravity experiment to get real evidence of the interior solution for gravity. I don't fully understand everything about the work though it's laid out plain enough in his papers. My intent is to create a mod that can simulate the experiment in KSP. 

I haven't modded KSP or any other game for that matter. How difficult would this be to learn and any good pointers on what utilities or software? I'm imagining right now a Kopernicus mod that added a planet with a hole in it and then drop... a ship through? Does anyone who can interpret physics tell me how gravity is calculated in KSP? Compared to what we may (or may not!) know about reality?

Your insight is appreciated ... 

Edited July 4, 2016 by Dills0n

[p1t1o]

Without being too judgmental, the website has quite a few hallmarks of pseudoscience, and I will eat my hat if it turns out that a cannonball dropped through a hole (omitting air resistance, which at the bottom of a 6000km hole, would be very significant) right through the Earth slows down and stops at the centre without crossing the midpoint.

Not sure what the point of recreating the experiment in KSP would be, other than aesthetic, the only result you will get will be the one dictated by the model used by the software, and I doubt that it allows for this kind of experiment (the software would have to be calculating the gravity induced by all parts of a mass, and not just simulating it with a point-mass.)

There *have* been some deviations from the original theories of gravitation found in modern times, though they involve incredibly small discrepancies in accelerations in extremely low gravity fields. The idea that there might be some gross deviations from current models, with large masses moving unpredictably is quite unlikely, we would be seeing strange things happening all over the place - for example we would see strange things happen to bodies in space, as a system of orbiting masses (like the Earth-moon system, or the solar system itself) can be seen as a model of a "hollow" mass. You'd get masses falling in from above or below the plane of the ecliptic and settling there without any outside force, which would look, for all intents and purposes, quite a lot like an alien spacecraft arriving.

Edited July 4, 2016 by p1t1o

[Dills0n]

I guess there's another point that physicists are quick to presume that what happens outside of gravity is conclusive evidence of it's inner mechanics. There actually isn't any empirical evidence proving that our current interior solution for gravity is correct, that's the larger issue at hand. Some experts might compare it to "stars moving through a star cluster" however that isn't the inside of a gravitating mass. Other experts will refer to some preconceived notion, that it is what everyone says it has been and painting it green-black polka dots won't change what it is even though today no one can tell you how gravity truly works.

Yeah, I mostly want to do this for aesthetics as I realize the results will be as you say, based on the software. I'm still curious to find the answer to Galileo's 300 year old question. The space generation model actually matches up quite will with the forces in the GR model. So my excitement with it is -- Do the safe, slow moving, unobtrusive (potentially inexpensive), experiment and if the thing oscillates it does and great my acquaintance can move on with his life finally and so on ... however if it doesn't, it might just change the way we see gravity.

An accelerometer indicates zero acceleration when free falling on earth. If you set it down it indicates positive acceleration.

I can't really relate or argue fully because anything I know about "physics" I've basically learned from a K-12 education and this acquaintance who I run into a few times a week. It's all his work and he's been at it for some time.

[Stratoroc]

Sooo when the Apollo mission flew from the earth to the moon, and at some point reached a gravity minimum, presumably the capsule came to a stop while approaching said minimum and never actually flew past.

Oh and as for the mod, in how KSP works, all you need is a simple model and a simple animation module that you program to give whatever answer you want.

Edited July 4, 2016 by Stratoroc

[Guest]

10 hours ago, p1t1o said:

There *have* been some deviations from the original theories of gravitation found in modern times, though they involve incredibly small discrepancies in accelerations in extremely low gravity fields. The idea that there might be some gross deviations from current models, with large masses moving unpredictably is quite unlikely, we would be seeing strange things happening all over the place - for example we would see strange things happen to bodies in space, as a system of orbiting masses (like the Earth-moon system, or the solar system itself) can be seen as a model of a "hollow" mass. You'd get masses falling in from above or below the plane of the ecliptic and settling there without any outside force, which would look, for all intents and purposes, quite a lot like an alien spacecraft arriving.

But we do see gross deviations all over the place. This is why we have "dark matter" theories. I think I understand what you are saying. Sure, when it comes to predicting motion of bodies in our solar system, we do a very good job. But when it comes to explaining the motion of stars within a galaxy or the motion of the galaxies themselves, we are somewhat clueless. We have only unlocked the tip of the iceberg, so to speak. There is way, way more unknown than there is known. Even Neil DeGrasse Tyson has to eat a big slice of humble pie sometimes.

[p1t1o]

9 hours ago, Otis said:

But we do see gross deviations all over the place. This is why we have "dark matter" theories. I think I understand what you are saying. Sure, when it comes to predicting motion of bodies in our solar system, we do a very good job. But when it comes to explaining the motion of stars within a galaxy or the motion of the galaxies themselves, we are somewhat clueless. We have only unlocked the tip of the iceberg, so to speak. There is way, way more unknown than there is known. Even Neil DeGrasse Tyson has to eat a big slice of humble pie sometimes.

Of course, but did you have a look at the claims?

[RichardBenish]

As the author of the work referred to by Dills0n, I am grateful for the opportunity to provide some clarification to this discussion.

First, if the Kerbal software accommodates only one point source-mass, the desired simulation would not work. But if three source masses are allowed (and one test mass) then the principle could be tested. Simply arrange the three sources in an equilateral triangle that rotates in its plane just enough to maintain stability. Then “drop” the test mass from any height over (or under) the triangle’s plane, perpendicular to its center. If gravity is modeled as an inverse-square force of attraction, the test object will oscillate through the center of the triangle.

P1t1o, who has offered to eat his hat if my non-standard prediction were to be confirmed, may be interested to know that, in response to my work, Italian physicist Carlo Rovelli offered 100 to 1 odds for the same bet. When I replied, “OK, let’s do it,” he reneged.

Though testing my non-standard prediction is an important motivation, I regard this as my “Plan B” argument. Plan A is simply that the idea of doing the experiment has been on the books at least since Galileo proposed it in 1632. It is routinely discussed in hundreds or thousands of modern articles, books, and physics classrooms, as though the result were “well-known.” Yet no empirical back-up is ever given.

Human beings have never observed gravity-induced radial motion through the centers of massive bodies. The empirical ideals of science have, in this case, been sacrificed.

Observations of trajectories in the Solar System do not suffice as a substitute because the directions of the force vectors are completely different. Inside a solid sphere with a hole through its diameter, Newton says the force toward the center gets stronger as one moves away from the center to the surface. In the case pointed out by Stratoroc, for example, moving outward from the point of force cancelation between the Earth and Moon, the force gets stronger toward the Earth and Moon. The circumstances are therefore not at all analogous.

In response to Otis, p1t1o defended his standard stance by asking whether Otis has “looked at the claims,” i.e., things written on or linked to my website. I would ask, do you (p1t1o) have an issue with any particular claim? I am prepared to defend every claim I’ve made. If the hypothesis underlying my Plan B strikes you as too far-fetched, I would recommend “Rethinking Einstein’s Rotation Analogy,” which frames the hypothesis as being the most natural one for an imaginary civilization that evolved on a distant rotating world.

Most importantly, I claim that we don’t know the result of the Small Low-Energy Non-Collider experiment proposed by Galileo nearly 400 years ago. I stand to be corrected. I yearn to be corrected—not by vaguely connected allusions to other predictions of Newton and Einstein, but by direct empirical evidence involving gravity-induced radial motion through the centers of massive bodies.

[p1t1o]

 

11 hours ago, RichardBenish said:

In response to Otis, p1t1o defended his standard stance by asking whether Otis has “looked at the claims,” i.e., things written on or linked to my website. I would ask, do you (p1t1o) have an issue with any particular claim? I am prepared to defend every claim I’ve made. If the hypothesis underlying my Plan B strikes you as too far-fetched, I would recommend “Rethinking Einstein’s Rotation Analogy,” which frames the hypothesis as being the most natural one for an imaginary civilization that evolved on a distant rotating world.

Hi Richard, welcome. First things first, I will speak very plainly and as literally as possible, to avoid as much contention as possible.

Of course, being an outsider, I do not have the advantage of knowing the literature intimately, nor do I have the time or inclination to become familiar with the particular body of maths involved. This is only a statement of practical necessity, it would literally take me a long time to do this, and if I spent that time on every internet discussion, I would not have time for anything else!

So I can't mathematically attack your claims, nor give in-depth analyses with reference to the minutae of current theory. This is just an internet forum after all.

But I am a professional scientist with some experience, and my objection to your hypothesis is based merely on a "gut feeling" - that the experiment of dropping a mass through another hollow mass would not result in anything other than what the classical theory currently predicts. I see no reason to assume otherwise, even in the absence of empirical data. That is the main focus of my scepticism.

To put it another way, I challenge the claim that the results of the "Small Low-Energy Non-Collider experiment" cannot be predicted by current Newtonian/Einsteinian theory.

Honestly, the fact that nobody has offered to run the experiment for you (I assume the only thing preventing you from running it yourself is the extreme sensitivity required from the instrumentation which would be hard to attain without the necessary infrastructure) is telling in-and-of itself. And please don't give me some excuse about "mainstream science".

 

11 hours ago, RichardBenish said:

P1t1o, who has offered to eat his hat if my non-standard prediction were to be confirmed, may be interested to know that, in response to my work, Italian physicist Carlo Rovelli offered 100 to 1 odds for the same bet. When I replied, “OK, let’s do it,” he reneged.

Haha! Perhaps he thought that if he turned out to be wrong it might harm his career, and I dont think anyone would risk their career even for a 100-to-1 bet! 

Myself, I would prefer to make a bet that would be less harmful to my health were I to be proved wrong, but other than that am not invested in the outcome either way, so am free to maintain my wager. I cannot guarantee the size of the hat.

 

 

In conclusion then, as you are personally invested in this body of work that you have, I do not want to attack something that is possibly close to your heart, or livlihood, as I would only really be able to use opinion and personal judgement to challenge something which is possibly quite important to you, and honestly about which you are probably privy to much more detail. I would consider it highly inappropriate to risk such harm/offence to another when I myself am risking nothing [this is not meant to be an assumption that I am right], especially when my instruments would be so rudimentary and without solid evidentiary treatment. I merely register my scepticism, and hope that I have explained it sufficiently. 

Edited July 13, 2016 by p1t1o

[RichardBenish]

What follows addresses p1t1p’s gracious response to my earlier comment.

Evidently responding to my request to challenge a particular claim, p1t1o wrote: “I challenge the claim that the results of the ‘Small Low-Energy Non-Collider experiment’ cannot be predicted by current Newtonian/Einsteinian theory.”

Current theory does of course make a definite prediction. So I guess what you mean is just that you think the standard prediction is correct and mine is wrong.

The basis for your confidence (a “gut feeling”) is pretty much the same as what I’ve encountered from physicists. A few of these correspondents have agreed that it would be worthwhile to do the experiment. Yet no concrete steps have been taken. This, I agree, is “telling in itself.”

What is actually told by this? I am reminded of a blog post by Caltech cosmologist Sean Carroll. It concerns Carroll’s chastisement of two social scientists who had recently published an article in which they propose to replace empirical evidence with “thinking deeply.” Carroll asserts:

Quote

Sorry but “thinking deeply” doesn’t cut it. People are not especially logical creatures, and we’re just not smart enough to gain true knowledge about the world by the power of reason alone. That’s why empiricism was invented in the first place.

I commented that, until Newton’s “deeply thought” prediction for Galileo’s experiment is tested, Carroll effectively commits the same error.

Though Carroll has not replied to me, I should mention that some of my work has elicited responses (some of it quite favorable) from prestigious physicists (e.g., from Berkeley, Harvard, Oxford, Sydney, a Nobel Laureate, et al). Why none of this communication has led to someone doing the experiment is an excellent question. In my essay, Gravity: The Inside Story, I’ve argued that the main reason is probably embarrassment.

Of the sociology of physics, physicist Daniel Kennefick has written:

Quote

There is a preference not to remember or not to overstress the significance of something which may be seen as vaguely disreputable to the field. It is a characteristic aspect of physics that to pose a problem or a question may, in itself, be taken as a sign of bad character.

This remark was not about outsiders, but about members of the established physics community. Say something to embarrass the group and you pay.

The undone experiment, proposed by the veritable Father of Modern Science, has been on the books for 384 years. I don’t think physicists fear the embarrassment of being proved wrong. I think they fear the embarrassment of having left this stone unturned for so long and of having it be pointed out by an amateur. Physicists may sometimes be kind enough to salute me, and to respond momentarily to my valid observations. But when my probing implies negligence on their part, they withdraw; they think they can afford to ignore me.

Sociological issues may appear to you as “excuses.” Yet they certainly bear on this curious circumstance, because “people are not especially logical creatures.”

Finally, don’t they make colorful little jelly-candy hats?

 

[CobaltWolf]

Why do all conspiratards talk in the same tone of voice? It's creepy.

[Andem]

1 hour ago, CobaltWolf said:

Why do all conspiratards talk in the same tone of voice? It's creepy.

Try talking to creatards in youtube comments. Same arguments, every time.

[p1t1o]

10 hours ago, RichardBenish said:

 

Finally, don’t they make colorful little jelly-candy hats?

 

Scientific issues, sociological, physical or otherwise, aside - I figured in the event the wager was lost, I could make a paper hat and then blend it into a fruit smoothie without too much problem. My "gut" says that that would be survivable [heuheuheuheuhe]. A Lannister always makes bets they can pay. Or something.

[Dills0n]

On 7/13/2016 at 3:02 PM, CobaltWolf said:

Why do all conspiratards talk in the same tone of voice? It's creepy.

So the conspiritarnoids can hear the calls, of course.

[Dills0n]

I think after all, we could safely say, the issue is best left at hand for the specialists and experts. Although they can look very closely (or look closely from afar!) at the issues at hand it's up to them to determine and interpret information for the rest of us. It's very important that scientists maintain a high level of scrutiny and empirical evidence for their work. They must also be incorruptible to the guesses and suggestions of others. Here's the gig. 400 years, no one's dropped a thing through another thing to get the proof. I'll go on seeking reasonable explanations for reality. Nothing will sate my hunger for knowledge except the truth and with evidence the truth is revealed! 

I did make a new post for this because I heard the national science foundation is looking for  help to measure G.

 

[HebaruSan]

@RichardBenish, would it be fair to summarize your position as being that the shell theorem is or may be wrong? That was my initial impression, and I read enough of your web site to confirm it to my satisfaction, but I was surprised that you never summed it up in those simple terms.

[RichardBenish]

HebaruSan: Excellent question. And thank you for spending some time on my website.

The shell theorem is fine because it is a consequence of the inverse-square law. Anything that spreads itself out from a point-like origin (electricity, light, spray paint) will obey this law. The gravity that would be caused by any concentric shell of matter interior to the shell is exactly canceled everywhere inside the shell because the amount of matter involved varies as the square of the distance. (Do a search for Gauss' Law and look at the images found there to get the idea.) A beautiful thing, really. The question is, what exactly does the inverse-square law refer to. According to Newton's theory (and also Einstein's, although expressed in different terms) it refers to a force of attraction. According to the model discussed on my website, it refers to the generation of space.

For more detailed discussions about how I support this idea, please read the "Maximum Force" paper on the website. You may also want to trace the argument further back to the work of Tangherlini (cited therein) or to the work of Tom Martin, who relates Tangherlini's work to his own hypothesis on "spatial flows": http://www.gravityresearch.org/pdf/GRI-010515.pdf

It is pertinent to mention that the same kind of symmetry argument should seemingly also apply to the prediction for the rates of clocks inside such a shell, or inside a more physically realistic ball of dense matter. General relativity predicts that inside the shell, the rates of clocks are uniformly slowed, corresponding to the prediction for the ball of dense matter that the rates of clocks reach a minimum at the center. Curiously, general relativity does not explain how matter produces this effect. One might reasonably surmise that the same "shell theorem"-like symmetry argument should apply, resulting in a maximum (not minimum) rate for the central (or inner shell) clock.

These issues are discussed in some detail in my most recent paper, which was motivated by Feldman et al's recent proposal to send a Small Low-Energy Non-Collider to deep space to measure Newton's constant G. They call the device a "gravitational clock" because they expect it to tick; the oscillation period is the observable from which they would calculate G. But according to my model the device will not function as a clock. So I've urged the authors to consider building a simpler Earth-based version prior to investing in a fancy version that would be sent to "deep space." A summary article describing Feldman et al's proposal is found here: https://cqgplus.com/2016/05/25/taking-newton-into-space/ . My response paper may be found on my website or at http://vixra.org/abs/1612.0341 .

[paul23]

Define "inside".

 

Gravity works on mass: as soon as you have an object with mass you have gravity. And as long as you can split up an object into multiple masses you can go "inside" and gravity doesn't care. earth consists of atoms, if we would be small enough to "enter" those we would experience gravity (overshadowed by all other fundamental forces) between the electrons and nuclei.

Similarly from a giant who eats star systems we are "inside" the solar system, we experience gravity from each separate body, but the giant would experience the (for him) small solar system as one whole.

 

 

PS: I realize the similarity stops after this, since quantum gravity makes the way you experience gravity on a quantum scale differ from the classical scale. 

PPS: please don't "urge" people to do something based on what you think. Modern science isn't dictated by what people think, modern science is based on what is being observed. If you observe something that doesn't stroke with the current accepted theories by all means publish it. But don't use mind-games to prove something in the science world; We're not a religion.

 

[RichardBenish]

Paul23: For the purpose of the present discussion, it suffices (and maintains maximum simplicity) by defining inside the same way general relativity's Schwarzschild solutions distinguish as between inside and outside. Inside is at radii less than the surface radius R. And outside is at R or greater distances. Of course we are inside the solar system. But for the purpose of basic gravitational phenomena the effects of the Moon and outer planets are extremely small. They do not affect the argument at hand. It would make sense to worry about such things only after the simpler questions before us are answered. How are the rates of clocks affected by mass inside matter? What happens to an object that falls into a hole through the center of a larger body?

If I were a child with limited resources who saw a house on fire I would THINK that somebody (with greater access to resources) ought to "do something" about it. I would not hesitate, in fact, I would yell and scream with all the power I could muster to "urge" somebody to do something about it. I "observe" that physicists seem to be oblivious of the sorry state (fire) of their enterprise; they sometimes admit to being especially confused about gravity. I observe that, though they routinely pay lip service to empirical ideals, they do not hesitate to invent the most unrealistic, untestably fantastic "theories." In the present case I observe that they kick their ideals to the curb, satisfied that they "know" the result of an experiment they have not yet performed.

Every form of communication, every grunt, cry, attempt to sell scriptures or snake oil, every Hollywood movie or PhD dissertation is a "mind game." Marvelous, isn't it?

Observing other humans helps us to navigate the quagmires and celebrations of human existence. Observing Nature is the only reliable way to unfurl and understand the magnificence of physical reality. Which is the more "religious" response: to urge others to do an experiment, or to pretend to know the result before doing it? Which is the more scientific response?

 

[HebaruSan]

15 hours ago, RichardBenish said:

The shell theorem is fine because it is a consequence of the inverse-square law. Anything that spreads itself out from a point-like origin (electricity, light, spray paint) will obey this law. The gravity that would be caused by any concentric shell of matter interior to the shell is exactly canceled everywhere inside the shell because the amount of matter involved varies as the square of the distance. (Do a search for Gauss' Law and look at the images found there to get the idea.) A beautiful thing, really.

This is where you lost me. (I'm going to stick to Newtonian language and approximations for this because we're talking about everyday human scales and low speeds/energies here, and what sounds like GR and QM can sometimes be misused to dazzle and exclude people who otherwise ought to be able to follow what's going on.) The shell theorem tells us that as the ball falls through the Earth-spanning tunnel, at each point it feels a gravitational pull proportional to all the mass at a lower "altitude" than itself, as if from a point source located at the center of mass. This means that at the exact core, where there is no such mass at a lower altitude, the net force is zero, so if the object has any momentum at that point, it simply coasts through without interruption. The force increases with altitude, always toward the center, until back up at the surface, it's proportional to the entire mass of the Earth. This gives exactly the conventional sine-wave outcome that your web site pooh-poohs.

15 hours ago, RichardBenish said:

The question is, what exactly does the inverse-square law refer to. According to Newton's theory (and also Einstein's, although expressed in different terms) it refers to a force of attraction. According to the model discussed on my website, it refers to the generation of space.

This is where I regrettably have to agree with earlier commenters that your rhetoric start to sound like pseudoscience. Whether we're talking about "a force of attraction" or "generation of space," if they both follow an inverse square law, then the shell theorem still applies equally in either case, and we should expect sine wave oscillations as a direct consequence. So if you accept the shell theorem, then where does the extra upward force come from that would be needed to stop the ball at the center? (I realize that you offered many links to papers, but at this point they don't rise above my minimum threshold level of apparent credibility to spend the time to read them. Maybe that will change if you can explain what you're talking about a bit more clearly.)

2 hours ago, RichardBenish said:

I "observe" that physicists seem to be oblivious of the sorry state (fire) of their enterprise; they sometimes admit to being especially confused about gravity. I observe that, though they routinely pay lip service to empirical ideals, they do not hesitate to invent the most unrealistic, untestably fantastic "theories." In the present case I observe that they kick their ideals to the curb, satisfied that they "know" the result of an experiment they have not yet performed.

Paging @K^2... are physicists negligent because they haven't drilled a giant tunnel through the core of the Earth, despite having nearly 400 years in which to accomplish this task? 

[RichardBenish]

HebaruSan: Beginning with your final quip concerning the idea of drilling a tunnel through Earth, it seems to reveal the intent to misunderstand, because I have never suggested doing this.

In 1632 Galileo suggested it as a thought experiment. In the late 1960s and early 1970s various physicists proposed doing a small-scale version, to be launched into Earth orbit to measure G. https://ntrs.nasa.gov/search.jsp?R=19750014902  Their reasons to not go ahead and build any of these devices were not about feasibility, but about the poor cost/benefit ratio. Technology available at the time would have resulted in little or any improvement in measurements of G over those that had already been conducted in Earth-based laboratories.

More recently, George Herold of Teachspin (Buffalo, NY) has conceived of building an Earth-based laboratory version using a modified Cavendish balance. Apparently he is currently either underfunded, under-motivated or both. So we may have to wait (a few years?) till Feldman et al get their device launched and on the way to deep space before we discover whether their apparatus functions as a clock or not.

My website does not “pooh-pooh” the standard oscillation prediction. It simply presents another possibility.

From the Newtonian perspective, your description is accurate. But I question what it means to “feel a gravitational pull.” Do we or anything else ever feel a gravitational pull? The answer is yes only in such cases as being suspended from above, as an apple being pulled upward by the branch of a tree. While seemingly “at rest” on Earth, we actually feel gravity pushing us upward. All of these circumstances correspond to clear-cut accelerometer readings. All accelerometers attached to Earth give readings indicating that they are accelerating upward. Accelerometers that fall (as in a tunnel) all give zero readings. They feel no pull.

In the Newtonian framework one learns to disbelieve accelerometer readings by, for example, invoking a “normal” upward force that supposedly neutralizes the unfelt downward pull, leaving an accelerometer attached to Earth in a state of “rest.”

Without any intent to “dazzle” anybody, it should be pointed out that one of the founding principles of Einstein’s theory of gravity, the Equivalence Principle, recognizes in the above facts that our experience of gravity is exactly “as though” the ground were accelerating upward. One thus finds in the standard literature remarks like the one by Lewis C. Epstein: “Einstein’s view of gravity is that things don’t fall; the floor comes up!”

The idea that this fact of our gravitational experience ought to be interpreted more literally than it typically is, has arisen several times in the last 120 years or so. Superficially, the idea seems like preposterous pseudo-science. In its most naïve sense of suggesting the “accelerated expansion of matter,” many objections may be adduced to refute it.

Having about reached the end of an acceptably-lengthed blog comment, I cannot here defend against these objections or ones that I expect may be forthcoming. The defense exists in the form of papers cited earlier and one more: Rethinking Einstein’s Rotation Analogy ( http://fqxi.org/data/essay-contest-files/Benish_Rethinking_Rotation.pdf ). The latter paper adopts the perspective of an alien civilization (Rotonians) who evolved in a distant rotating cylindrical world where matter-produced gravity is unknown and everyone learns to believe accelerometer readings as meaning what they say.

When they disembark from a long voyage and encounter a gravitating planet for the first time, they too adopt the initial idea that “the floor comes up” (because they instinctively believe their accelerometers). Being conscientious scientists, they then plan to discover empirically whether or not this idea is true by conducting Galileo’s experiment. If accelerometers always tell the truth, then an object falling into the center of a massive body will not pass the center because nothing ever pulled it downward. Whereas accelerometers attached to the tunnel walls all indicate upward acceleration, as though the material body were an inexhaustible source of space, and an inexhaustible source of perpetual propulsion. Rotonians suspect this is what gravity is. But they refrain from concluding before hearing Nature’s testimony on the matter.