Gravity doesn't make sense? ... hold that thought!

At New Scientist, Michael Brooks tells us "Seven Things That Don't Make Sense About Gravity," including

- If gravity were a tiny bit stronger, the universe as we know it would not exist

- From plants to quail, life of all stripes seems to need gravity to work properly

Uh ... so then gravity doesn't make sense because ... why, exactly? Because there wasn't supposed to be a solution to those problems? Why not?

It reminds me a bit of this earlier kvetching about gravity.

Fine tuning is a big problem for these people.

Cosmology: Crisis of the month - Gravitation

Cleaning out the In box, I noticed "Study Plunges Standard Theory of Cosmology Into Crisis" (ScienceDaily (May 5, 2009), in which we learn:

“The only solution would be to reject Newtońs classical theory of gravitation,” says Pavel Kroupa. “We probably live in a non-Newton universe. If this is true, then our observations could be explained without dark matter.” Such approaches are finding support amongst other research teams in Europe, too.

It would not be the first time that Newton’s theory of gravitation had to be modified over the past hundred years. This became necessary in three special cases: when high velocities are involved (through the Special Theory of Relativity), in the proximity of large masses (through the theory of General Relativity), and on sub-atomic scales (through quantum mechanics). The deviations detected in the satellite galaxy data support the hypothesis that in space where extremely weak accelerations predominate, a “modified Newton dynamic” must be adopted. This conclusion has far-reaching consequences for fundamental physics in general, and also for cosmological theories.

Astrophysicist Bob Sanders from the University of Groningen declares: "The authors of this paper make a strong argument. Their result is entirely consistent with the expectations of modified Newtonian dynamics (MOND), but completely opposite to the predictions of the dark matter hypothesis. Rarely is an observational test so definite."

Well, this is a nice change from speculation.

See also: "Time for a New Theory of Gravitation? Satellite Galaxies Challenge Newtonian Model" (ScienceDaily, Apr. 23, 2009) where some of the same cast of characters note the this problem:

The team of scientists looked at the distribution of these satellite dwarf galaxies and discovered they were not where they should be. “There is something odd about their distribution”, explains Professor Kroupa. “They should be uniformly arranged around the Milky Way, but this is not what we found.” The astronomers discovered that the eleven brightest of the dwarf galaxies lie more or less in the same plane - in a kind of disk shape - and that they revolve in the same direction around the Milky Way (in the same way as planets in the Solar System revolve around the Sun).

Professor Kroupa and the other physicists believe that this can only be explained if today’s satellite galaxies were created by ancient collisions between young galaxies. Team member and former colleague Dr Manuel Metz, now at the Deutsches Zentrum fuer Luft- and Raumfahrt, also worked on the study. “Fragments from early collisions can form the revolving dwarf galaxies we see today” comments Dr Metz. But he adds that this introduces a paradox. “Calculations suggest that the dwarf satellites cannot contain any dark matter if they were created in this way. But this directly contradicts other evidence. Unless the dark matter is present, the stars in the galaxies are moving around much faster than predicted by Newton’s standard theory of gravitation.”

Most interesting, but I'm not clear on what the "crisis" is.

Oh never mind. By fall, a different crisis.

It's sure as the law of gravity, you say? Well, check the refund policy ...

In "Newton, Einstein Lost in Space?" Robert Lee Hotz has some fun with the idea that Newton and Einstein might have been wrong about gravity. Russian-born astrophysicist Slava Turyshev, working at Jet Propulsion laboratory, noted the "Pioneer anomaly",

Beyond the edge of the solar system, something has gradually dragged two of America's oldest space probes -- Pioneer 10 and Pioneer 11 -- a quarter-million miles off course. Astrophysicists have struggled 15 years in vain to identify the infinitesimal force at play.

It's just a tiny anomaly, but radio wave physicist John Anderson, also of JPL, who does not overlook small deviations,

monitored the trajectories six years before calling attention to the matter. "I'm a little like an accountant," Dr. Anderson said. "We have Newton's theory and Einstein's theory, and when you apply them to something like this -- and it doesn't add up -- it bothers me."

Does it mean anything? We don't know yet. But Turyshev hints,

"We would expect the two spacecraft to follow Newton's law of gravity," Dr. Turyshev said, "but they in fact fail to confirm Newton's law. If Newton is wrong, Einstein is wrong too."

For now, I will put my cash on the dead white males being right about gravity and similar stuff (it's what they do best). Still, I can't help quoting from The Spiritual Brain, re anomalies:

In science, small, persistent effects cannot be ignored. Sometimes they force a revision of major paradigms. For example, Lord Kelvin remarked in 1900 that there were just “two little dark clouds” on the horizon of Newtonian classical physics of the day, namely, Michelson and Morley’s measurements of the velocity of light and the phenomenon of blackbody radiation. Kelvin was certain that these troubling little clouds would be blown away shortly.149 Yet all of modern physics—relativity and quantum mechanics—derives from these two little dark clouds. (P. 173)

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