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Guest post: Louise Riofrio, “Fundamental Values” October 14, 2007

Posted by dorigo in astronomy, Blogroll, internet, physics, science.
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Louise Riofrio is a researcher in Cosmology. She questions the validity of the standard cosmological model, and she owns a site,  http://riofriospacetime.blogspot.com, where she discusses cutting-edge news on the matter, as well as on astrophysics and astronautics. So let us hear it from her.

FUNDAMENTAL VALUES

As scientists we spend much of our time seeking values. These could be the height of plants or the masses of subatomic particles. We have built measuring devices from rulers to giant telescopes and accelerators. Experimental results are then catalogued to end up in books or databases. A large portion of our scientific knowledge is based on fundamental values like the speed of light or the gravitational constant. By measuring the Universe, scientists hope to find what is constant in nature.

Every basic astronomy textbook will list the distance to the Moon. Thanks to laser reflectors left by astronauts, we know that value to the meter. Numbers in the back of the book will be accurate for many centuries, but are not constant. Geologists have known for decades that the Moon is slowly drifting away. Those reflectors on the Moon say that it is receding even faster than geology predicts. If an astronaut returned after a million years she would find the Moon many kilometers more distant from Earth. Though the Moon’s distance is fixed in the astronomy book, it is not constant.

Some values have been nicknamed “constants” even when they are not. The Solar Constant is the amount of sunlight falling per square meter of Earth’s surface when the Sun is directly overhead. This value varies slightly as Earth travels in its elliptical orbit, and to an unknown degree because of variations in the solar interior. These variations are important for study of Earth’s climate, because nothing affects global warming more than the Sun. Though the Solar Constant has allowed life to evolve on Earth’s surface for billions of years, standard models say that when Earth was forming the Sun was only about 75% as bright. Whether the Sun’s luminosity is constant has been an open question.

For much of human history Earth’s location was considered constant. The Sun, planets and stars were seen as circling Earth in epicycles. This can be a reasonable stipulation–for navigating on the planet or even observing stars it is convenient to treat Earth as fixed. Galileo’s discovery of Jupiter’s moons was evidence of objects circling another body. Galileo suffered in part because he lacked a mechanism for holding the planets in place. Defying the complicated mathematics of epicycles, Galileo showed that Earth was not fixed.

Isaac Newton’s gravity provided a mechanism for orbits and a constant. Newton concluded that gravitational force between two objects is dependent upon the product of their masses divided by the square of their distance. To give an answer with the dimensions of force, Newton introduced his gravitational constant G. Though many theories have been proposed about G, at present most measurements say that Newton is truly constant.

The nature of light has long been a subject of wonder. Scientists from Aristotle to Kepler believed that light traveled instantaneously. Galileo tried to time the light of lanterns from distant hilltops, but lacked a good clock. A finite speed of light was finally found using Galileo’s satellites. By timing when the moons appeared to pass in and out of Jupiter’s shadow, Ole Roemer made the first measurements of c. As measurements have become more accurate, many scientists have wondered whether c is constant. While Newton’s Constant and even the “Solar Constant” are part of our vocabulary, a “speed of light constant” is not.

To explain atomic energy levels, a conservative physicist named Max Planck was forced to introduce his own constant. The product hc was key to Planck’s solving the ultraviolet catastrophe of blackbody radiation. Planck called his introduction of h an “act of desperation.” The product hc also appears in Chandrasekhar’s Limit and the fine-structure constant ?. Nature’s subtleties include energies which are constant but whose component values are not. Albert Einstein is quoted as saying, “God is subtle but he is not malicious.”

Though his Relativity incorporated the speed of light, Einstein himself would not state that it was fixed in time. He wrote that fixed c was “neither a supposition nor a hypothesis about the physical nature of light but a stipulation which I can make at my own free discretion.” Though he was careful to include c in his calculations, after Einstein had passed on a branch of Relativity arose that removed the value c.

Einstein introduced his own constant, which he later called his greatest blunder. He realised that enough mass would curve the Universe into a sphere of four dimensions. Such a spherical space would collapse unless it were expanding or supported by a repulsive “cosmological constant.” Edwin Hubble’s observations convinced Einstein to withdraw this hypothetical constant.

Hubble found that recession velocity of a galaxy divided by its distance is constant, indicating an expanding Universe. From the beginning astronomers knew that “Hubble’s Constant” was not constant. It would change over time depending upon whether the Universe’s expansion slowed. Finding the value of this constant was a principle scientific goal of the Hubble Space Telescope.

Though the power source of Type Ia supernovae is not completely understood, astronomers consider their luminosity to be constant. Distant supernovae appear dimmer than expected, making the Hubble expansion appear to accelerate. At first this was seen as return of the cosmological constant. Soon it was realised that a repulsive force would not be constant, but would evolve as a form of “dark energy.” Speculation about this hypothetical energy has expanded to include modified gravity and other additions to Relativity.

Inferences of cosmic acceleration depend on many other values being constant, including luminosity of supernovae. Many values have changed in the billions of years since distant stars exploded. The metal content of ancient stars is known to have been much less than today. Since we cannot time-travel into the past, it is difficult to determine if fundamental values are constant.

In our brief history of measuring the Universe, many values that appeared to be constant have been found to change. We may find that the only constant is change. There is a constant in science, which is the continuing quest for knowledge. New ideas and observations have been introduced, considered, tested and if worthy added to our books. In science, the true fundamental value is a search for truth.

Comments

1. Alejandro Rivero - October 14, 2007

It is fascinating that the particle data group keeps two consecutive tables, “Physical constants” ans “Astrophysical constants”, the second one even with an extra remark “… and parameters”.

2. Matteo Martini - October 15, 2007

I guess posting the photo of Louise with naked legs, is another shoot by Tommaso at the bigots that attacked him few weeks ago..

3. dorigo - October 15, 2007

Hi Matteo,

it is, but the one who took the shot at the sitting ducks of CV and Asymptotia is Louise herself (she did defend me back then). Louise provided the picture, so I can only say I approved it😉

Cheers,
T.

4. dorigo - October 15, 2007

That is a very good point Alejandro. I wonder whether one day there will be one further table, with “cosmological constants” to be used for different parts of the multiverse🙂

Cheers,
T.

5. jeff - October 15, 2007

Am I missing something? Are these comments triggered by the contribution by Riofrio?

6. dorigo - October 15, 2007

? Jeff, I guess you are talking about the comments to my post on Lisa Randall, which resulted in accuses of sexism from the mentioned parties. From then on, now and then I take the liberty to pull a leg on the matter, by posting comments on the look of male speakers or pictures of sexy babes in a totally appropriate context, such as the one above of Louise.

Cheers,
T.

7. Ohio - October 15, 2007

I’m surprised she got through such a long post without quoting her Formula.

8. Ohio - October 15, 2007

I’m also surprised she doesn’t mention that we currently treat the speed of light as an absolute constant, thus setting the standard of length when combined with our atomic time standard. It’s a rather important point.

9. dorigo - October 15, 2007

Dear Ohio,

Louise’s model was not the topic she chose to deal with here. She decided freely what to discuss, as anybody else who produces guest posts. Her text did not require any editing on my part.

About the second comment, I think the fact that we use c to derive other quantities is good point, but it does not necessarily belong to the post. I think you came to read it with too much expectation about hearing steep claims… So I gather you agree with what is written here, don’t you ?

Cheers,
T.

10. Quasar9 - October 16, 2007

Hi Louise,
I guess redshift need should not be viewed as absolute ‘proof’ of an expanding or accelerating universe – nor necessarily the presence of dark energy.
After all a distant object several billion light years away in an eliptical orbit may appear to be accelerating away from us, but several billion years later could well appear to be accelerating towards us, would it not. Pity a human lifetime doesn’t stretch that long, to wait & see.

All the best.

11. jeff - October 16, 2007

To be honest I don’t get the point of the starting post. So vague and “obvious” that I just don’t get any hint of the meat.

12. Kea - October 16, 2007

Very enjoyable post, thank you. When my grandmother was a young woman, the Milky Way was thought to be the entire universe. Although we can now see so much further back in time, we need to remember how little we really know.

13. Alex - October 16, 2007

Mr .Dorigo

Not long time ago you complaint about a headache caused by hearing a lecture of L.Riofrio on alternative cosmology.
I hope you feeling well first of all,and wonder what would cause you to change your mind and to wellcome Loiuse on your site?

Perhaps it is an absence of any formula ?

14. island - October 17, 2007

Oh Louise, you make me think about Dirac, large numbers, and the reinterpretation of his hole theory as it applies to t’ Hoofts’ recent comments about the negative energy states.

15. Pioneer1 - October 17, 2007

Isaac Newton’s gravity provided a mechanism for orbits and a constant.

No. Newton’s gravity never provided a mechanism for orbits. Newton’s proposed mechanism is the occult. Occult does not exist.

Newton concluded that gravitational force between two objects is dependent upon the product of their masses divided by the square of their distance.

Newton did not conclude. Newton defined. Newton broke Kepler’s Rule into two and equated each part to a placeholder he called force.

To give an answer with the dimensions of force, Newton introduced his gravitational constant G.

No. Newton did not know about G. Newton did not work with equations and constants. He worked with proportionalities. G was invented in the 19th century by C.V. Boys in order to colonize astronomy in the name of the Empire. G is simply k (now known as Gauss’ constant) written in British units.

Though many theories have been proposed about G, at present most measurements say that Newton is truly constant.

Measurements of Newton’s constant are not measurements. Physicists build a given oscillator with dimensions to give G. A pendulum can oscillate only with its natural period. If you build a pendulum to give G then the pendulum will give G. Such a pendulum is redundant. G is not a measurable quantity.

16. dorigo - October 17, 2007

Hi Jeff,

my idea is that the nice post by Louise above, which is uncontroversial and simple, could be thought as a “negotiation basis”: by agreeing on some basics with her, you are then more likely to consider what she has to say about cosmology in her blog with a unbiased eye.

Yes, Kea, we do know very little! We have two theories, the two standard models, and they appear to be confirmed by experiment, but they will never cease to require our tutoring unless we frame them within larger theories of which they constitute only a part. One example is of course the fact that we know the particle SM can’t stand on its own feet – it’s inconsistent and incomplete – but still we have nothing better in our hands…

Dear Alex, where exactly did I talk of headaches with respect to a talk by Louise (which I never attended to) ? I only said here I would have loved to hear it from her, but she did not make it to the conference I was at. That was last March. About the absence of formulas, as you know it is a good way to avoid losing readers. It is a perfectly reasonable editorial choice on her part, with which I have nothing to do.

Pioneer, you are missing the point a bit. This is not about arguing on the details of the history of physics. It is about providing a picture of our investigation of the immutability of laws of nature.

Cheers all,
T.

17. jeff - October 17, 2007

Tommaso I was just being kind!

I belong to an older generation and think that all physics is “effective”: “laws”, even the most fundamental (=comprehensive), are effective. “Laws” of physics are reality based, as physics is an empirical and experimental enterprise (as are all serious sciences), and although assuming them to be platonic truths has proved many times to be a damn good working hypothesis, it doesn’t follow that they are, as was many other instances have shown! Having said this little I think I have explained why I was not disappointed in reading Riofrio’s post. I am still trying to be kind.

jeff

p.s. I don’t agree with Pioneer but I do feel he was not simply “arguing” about details.

18. dorigo - October 17, 2007

Hi Jeff,

please continue being kind then😉

As for Pioneer, well, maybe he/she may explain whether the comment was directed to anything in particular or just the kind of flak old rifles are used to aim at an easy target in a seminar.

Cheers,
T.

19. Alejandro Rivero - October 17, 2007

I hope Pionner was inviting everybody to read the Principia🙂, most probably you can find some free scanned version in books.google.com, taking care of selecting “full view” in the advanced search options. To my regret, Kepler’s “Solid Geometry of Wine Barrels” is not there. Galileo is, and “two new sciences” always do good reading ever if it is more mechanics than astronomy.
About laws being effective, well they could be, but in order to research it is better to believe the contrary. For instance, a strong believer in effective quantum field theory had never worried about renormalizability, then never finding that gauge theories have this property.

20. jeff - October 17, 2007

Alejandro. I agree but with some qualifiers. Indeed I thought I was being clear when I said that to assume a law platonically true, rather than recognize it to be a very effective way of encapusulating what we know and an aid, a tool, for learning more, is a damn good working hypothesis. And indeed I do feel that it may very well be the only way to do research. But to insist in psuedo-philosophical discussions that it is LAW, forgetting that laws (no capital letters) are reliable tools for exploring incharted waters, and that they are credible (reliable) because they summarise empirically gathered information, is to betray science.

“The great tragedy of science – the slating of beautiful hypothesis bu an ugly fact.” (Thomas Henry Huxley, the bulldog of Darwin)

“It doesn’t matter how beautiful your theory is, it doesn’t matter how smart you are. If it doesn’t agree with experiment, it’s wrong.” (Feynman)

21. jeff - October 17, 2007

Mis print in quotation of Huxley.
“The great tragedy of science – the slatyng of beautiful hypothesis by an ugly fact.” (Thomas Henry Huxley, the bulldog of Darwin)

22. jeff - October 17, 2007

Miss prints abound. SORRY.
“The great tragedy of science – the slaying of beautiful hypothesis by an ugly fact.” (Thomas Henry Huxley, the bulldog of Darwin)

23. Alejandro Rivero - October 17, 2007

Indeed Jeff, it is a big paradox of research: one must believe his own hypothesis, to feel them inside the bones, but one must be always ready to dispose of them.

24. jeff - October 17, 2007

YESSSS

25. Pioneer1 - October 21, 2007

I reread the post. Very nice. I agree with most everything in it.

My question is: Is it possible that the historical development of G can tell us if G is a constant or not?

I think the answer to this question would be helpful if the original article is about our “investigation of the immutability of laws of nature.” Although I think rather than laws of nature Riofrio was discussing constancy of constants.

So if we look at the history of G, would this ever help us understand if G is a constant or not?

I answer this question Yes.

What about measurement of G versus history of G? If we find by studying the history of G that it is not a measurable quantity, would we have to question the measurements of G? Yes.

To Alejandro: I wouldn’t advise anyone to read Principia. Anyone interested in Principia instead should read Dana Dansmore’s Newton’s Principia: The Central Argument (Green Lion Press). The beauty of this book is that she totally excludes anachronistic interpretations of the content of Principia. I think it is a great revelation to look at Principia without modern physics. Prof. Densmore does not use equations or modern notation. The book is like a tutorial and she explains everything step by step with beautiful drawings. What I learned from this book was that in Principia Newton used Kepler’s Rule to make astronomical calculations but he wrote a parallel narrative using his dynamical concepts that he never used in calculations. This is the only basis of his assertion that he computed astronomical quantities from his occult doctrines.

So this is not just history. This tells us something about Newton’s force. If Newton’s force is a placeholder invented by Newton and it does not exist then G, its supposed unit, cannot exist and G is not a constant.

I strongly believe that history has a lot to teach about the quantitative investigation of constants.

Thanks.

26. dorigo - October 21, 2007

Hi Pioneer1,

if you go to pdg.lbl.gov, you will find some interesting plots about historical series of measurements of fundamental quantities. Look for instance at the neutron lifetime, or gv/ga for beta decay, or the lambda mass. These show just how much experimentalists are influenced by current beliefs.

http://pdg.lbl.gov/2007/reviews/historyrpp.pdf

Cheers,
T.

27. Reuben Parker - April 20, 2008

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