Free Physics E-book

Space and straightness pose subtle challenges. Some strange people maintain that all humans live on the inside of a sphere; they (usually) call this the hollow Earth theory. They claim that the Moon, the Sun and the stars are all near the centre of the hollow sphere.

I've heard of a hollow earth theory, but not this one. He references two webpages. One of them is in a foreign language. The second one is in English and seems to reference the hollow earth I've heard of:

"Turning the Universe Inside-Out"

I don't see anything about the earth, moon, sun, and stars being inside a hollow sphere.

You have two hourglasses: one needs 4 minutes and one needs 3 minutes. How can you
use them to determine when 5 minutes are over?

I can't figure this out!!

And it's supposed to be easy. There are no clues.

reply to post by Mary Rose

You have two hourglasses: one needs 4 minutes and one needs 3 minutes. How can you
use them to determine when 5 minutes are over?

I think I have this...

Turn over both hourglasses. (this is not the start of timing, so don't put anything in the oven yet, etc.)
When the 3 minute one is out, flip over both hourglasses again.
The 4 minute one now has one minute of sand. Flip the 4 minute one over and now start timing the 5 minutes (put your food in the oven, or whatever else you are timing. When the minute has elapsed, flip both timers over (we're now at one minute). When the 3 minute one is done (4 total minutes have elapsed), turn over the 4 minute one. It now has one minute of sand left, giving you 5 total minutes of elapsed time.

Man, that was nasty....

Just saw more on the first page.

Not every movement is a good standard for time. In the year 2000 an Earth rotation did not take 86 400 seconds any more, as it did in the year 1900, but 86 400.002 seconds. Can you deduce in which year your birthday will have shifted by a whole day from the time predicted with 86 400 seconds?

Bah, edited it out, as I thought I read it as 1990, not 1900.

So, is 0.00002 seconds slower each year.
Takes 3 million years to be off a full second.
3 million x 60 to get off a full minute
3 million x 60 x 60 to be off a full hour
and 3 million x 60 x 60 x 24 to be off a full day.

I seriously doubt I'll live to see even the second, hehe (nor would I want to).

reply to post by Gazrok



Thanks!!!!

Do you know I had to draw a bunch of hourglasses following your instructions to understand?

I feel much better now. (But embarrassed that this guy calls the challenge "easy.")

Originally posted by Mary Rose
"Turning the Universe Inside-Out"

I don't see anything about the earth, moon, sun, and stars being inside a hollow sphere.

Maybe you didn't scroll down far enough? The last 2/3 or so of that link is about Teed's universe and Teed and Morrow's measurements proving the hollow Earth theory:

Teed's universe occupies a "Hollow cell" in solid rock, 8000 miles in diameter. We live and walk on the spherical inner surface of this cell, our heads pointing toward its center. The entire universe that we "see in the sky" lies within this cell, cradled "in the hands of God." Inside this Earth-shell there are three atmosphere shells: air, hydrogen, and aboron.

At the center is the sun, an invisible electro-magnetic battery in the form of a helix, rotating on a 24 hour cycle....

Due to turbulence and aberrations in the atmospheres the focalizations of light are sometimes imperfect or blurred. These appear as nebulae. Comets are reflections of the sun's rays through lenticular reflections and refractions from belts of tiny crystals around the central solar sphere.

At least with Teed's model we didn't have to choose between heliocentric or geocentric, it was both at the same time!

I like the author's charactizerizations of the pseudoscientists like Teed:

Some of these folks seem to be motivated by religious beliefs, attempting to make the model consistent with their interpretations of their sacred literature. Some are motived by a distrust and dislike of science. Many feel that science has become just too difficult for people to grasp, so there must be a simpler way to understand it. A few have even majored in a science at the university for a while, but dropped out because they found it distasteful. All are sustained by a monumental confidence in the "rightness" of their world-view. They comfortably accept the notion that scientists are part of a vast conspiracy to suppresss the truth, in order to maintain their own positions of power and prestige.

Like pseudoscientists of all varieties, they carefully select those aspects of experience they wish to incorporate into their model, ignoring the vast amount of other scientific phenomena that conventional science has already successfully dealt with. They cite old, discredited, or poorly documented, observations, experiments and theories as supportive of their views. Often they wage a guerrila war against "conventional science", and characterize scientists as imperceptive or even stupid for not acknowledging their cleverness and the truth of their alternative models. They take pride in being a member of a select few, the elite, who can see things clearly.

What's really sad is that Eratothsenes correctly calculated the diameter of the Earth in 240 BC (within about 1% accuracy) and his measurement showed the Earth's surface was convex, not concave, yet in 1896, Teed was still trying to prove the curvature of the Earth is opposite what Eratothsenes measured it to be in 240 BC!

I think that story about Teed's experiment is a good study in expectation bias, he know what the measurements needed to be to support his theory, and somehow the measurements he came up with weren't too far off of his expectations. And if the author of that webpage is right, neither Teed nor his critics correctly identified the source of experimental error (sagging of the equipment that was thought to be rigid).

The story is also a good argument for Occam's razor, as Teed's explanations were quite convoluted to explain his hollow Earth, and just using the much simpler explanations of competing theories has proven to be more accurate.

reply to post by Arbitrageur


But it seems to me that normally when a theory of a hollow earth is discussed, it's more like the passage about Halley:

Halley postulated that the Earth we walk on is a hollow shell about 500 miles thick, with two inner concentric shells and an innermost core, about the diameters of the planets Venus, Mars, and Mercury. These sheels [sic] are separated by atmospheres, and each has its own magnetic poles. The spheres rotate at different speeds, thus accounting for long-term magnetic field variations. Halley did wonder whether clay and chalk beds of the outer crust are sufficient to prevent the oceans from leaking inside, but he was sure that "the Wisdom of the Creator has provided" some way to prevent this.

Halley even suggested that each sphere "might support life," because the spheres were bathed in perpetual light from a luminous gaseous atmosphere that filled all of the inner spaces. He even entertained the possibility of "more ample creation" within the Earth, which might include suns.

Isn't a hollow earth theory something like Halley's still very much alive today?

Originally posted by Arbitrageur
"whom did you go to the party with?"

But then you're ending the sentence with a preposition - a no-no.

I guess if you were doing formal writing, you would want to say "With whom did you go to the party?"

But I like "Who did you go to the party with?" for informal speech, cause it sounds natural and unaffected. And I agree with you that it's common usage.

Originally posted by Arbitrageur
To bring it back on topic, the grammar in the textbook seems pretty good for a physicist . . .

Yeah, and it sounds from his bio that English is not his first language.

Originally posted by Mary Rose
Isn't a hollow earth theory something like Halley's still very much alive today?

That's a loaded question. Let's first take one I know a little more about, and ask if a geocentric model is still alive today, rather than a heliocentric model.

A few years ago I would have told you incorrectly that almost everyone who is educated knows the heliocentric model is correct and the only people who believe in the geocentric model would be aboriginal tribes with no modern education. But that was based on my opinion and not any research, so I was totally shocked when I saw the research that one in five Americans and one in four Brits believes the sun revolves around the Earth.

Scientific Savvy? In U.S., Not Much

only 20 to 25 percent of Americans are "scientifically savvy and alert," he said in an interview. Most of the rest "don't have a clue."

So he's saying 75 to 80% of Americans are scientifically clueless based on his research, a number I don't want to believe but I can't dispute his research, he is considered an expert on this subject.

Dr. Miller's data reveal some yawning gaps in basic knowledge.... One adult American in five thinks the Sun revolves around the Earth, an idea science had abandoned by the 17th century.

I don't know if his survey asked about the hollow Earth theory or not, but it would be interesting to see how many people believe it if the question was asked.

Then the question is, what criteria should we use to determine if a theory is "still alive today" as you put it?

If the criteria is "does anyone believe it?", then I'd have to say just about any crackpot theory no matter how ridiculously incorrect is probably alive today including the hollow Earth theory.

If the criteria is "Do well educated people believe it?", the answer is different. According to Wikipedia: "The Hollow Earth hypothesis says that the planet Earth is either wholly hollow or otherwise contains a substantial interior space. The hypothesis has long been contradicted by overwhelming observational evidence, as well as by the modern understanding of planet formation. The scientific community has dismissed the notion since at least the late 18th century."

I don't think Dr. Miller's data shows that many well-educated people believe that the sun revolves around the Earth, or believe that evolution is false, so I think there is an educational problem with people not knowing the overwhelming observational evidence, or not knowing how to interpret it:

"Our best university graduates are world-class by any definition," he said. "But the second half of our high school population - it's an embarrassment. We have left behind a lot of people."...

Lately, people who advocate the teaching of evolution have been citing Dr. Miller's ideas on what factors are correlated with adherence to creationism and rejection of Darwinian theories. In general, he says, these fundamentalist views are most common among people who are not well educated and who "work in jobs that are evaporating fast with competition around the world."

But not everyone is happy when he says things like that.

So according to Dr. Miller, a good education matters, which is why it's nice to see threads like this one referencing real scientific literature that may help people educate themselves about which ideas have merit, which ideas don't, and why. The e-book author's focus on collecting and interpreting observational evidence to support a point of view is commendable and may help dispel some peoples' beliefs in some crackpot theories long dismissed by science, if he can get more people to read his free books.

reply to post by Arbitrageur


Yeah, I know the general populace tests poorly for basic knowledge about a lot of things, including things like not being able to name the 3 branches of the government.

But you think Haramein is a crackpot so we disagree on what constitutes a crackpot. Of course, you're a scientist and I am not. I'm just curious about things.

I think there are credible people who advocate a hollow earth theory - not Leed's theory - but a hollow earth theory - and since you brought it up, that the theory of evolution is wrong as well - not that creationism is right, but that the theory of evolution is wrong.

Being "well educated" doesn't mean a thing to me. There are plenty of things that are taught that need a second look.

reply to post by Mary Rose
I agree with you to a point, that just because someone is well educated is no guarantee they're right, so that's not a good enough reason to accept what they say.

But where the education seems to come in handy, is understanding and interpreting observational evidence, and that's where the pseudoscience falls apart. There's a thread on ATS about a geocentric universe theory, where the thread author admits to not being any kind of math expert. Some of the claims in that thread are that scientists are wrong about the estimated masses and densities of the sun and the Earth, etc.

So do I believe the NASA scientists over the geocentric model guy because they have PhDs? Not exactly. But I read papers by the PhDs about how they are puzzled by a 0.05% deviation in the performance of the spacecraft versus their calculated expectations, and I can see in detail how their calculations are derived and the possible sources they've looked at for the anomaly. I also know enough about the models the NASA scientists are using to know that if the geocentric model in that thread was right, the NASA engineers wouldn't have a 0.05% discrepancy, it would be more like 50%. But without adequate advanced education, some people are completely blind to this overwhelming observational evidence which contradicts their crackpot theory. And they don't seem to understand how and why NASA would know immediately if their geocentric model was right and NASA's model was wrong.

Now if someone gets enough education to understand why NASA thinks what they do, and can then explain why NASA's model is wrong and how the alternate model works better, then that becomes a whole lot more interesting discussion. I can think of one ATS member at least who fits that description, and their education probably isn't a PhD, but they can at least understand the math and the issues in the debate about which theory is right, the mainstream theory or the alternate theory.

What I'm trying to say is the education isn't an end. It's a means to an end, which is understanding. Now can someone predict spacecraft trajectories against their model without an education? They don't have to get a PhD but they do need to be able to do a lot of math, so perhaps knowledge would be a better description of what's needed, than education. They could be uneducated and self-taught and if they can do the math that's good enough, but that's exceedingly rare.