Free Republic
Browse · Search
Topics · Post Article

Skip to comments.

Mystery Tug on Spacecraft Is Einstein’s ‘I Told You So’
NY Times ^ | July 23, 2012 | DENNIS OVERBYE

Posted on 07/24/2012 3:42:38 AM PDT by neverdem

It’s been a bad year to bet against Albert Einstein.

In the spring physicists had to withdraw a sensational report that the subatomic particles known as neutrinos were going faster than light, Einstein’s cosmic speed limit; they discovered they had plugged in a cable wrong.

Now scientists from NASA’s Jet Propulsion Laboratory have reported that they have explained one of the great mysteries of the space age, one that loomed for 30 years as a threat to the credibility of Einsteinian gravity.

The story starts with the Pioneer 10 and 11 space probes, which went past Jupiter and Saturn in the late 1970s and now are on their way out of the solar system. In the 1980s it became apparent that a mysterious force was slowing them down a little more than should have been expected from gravity of the Sun and planets..

Was there an unknown planet or asteroid out there tugging on the spacecraft? Was it drag from interplanetary gas or dust? Something weird about the spacecraft? Or was something wrong in our calculation of gravity out there in the dark?

That last explanation would have been big news indeed. Much of what we know about the universe — for example, the existence of dark matter, which seems to swaddle and shape the galaxies, and of dark energy, which seems to be speeding up the expansion of the universe — comes from presuming that Einstein’s General Theory of Relativity, which describes gravity as the warping of space-time geometry — is correct over cosmic distances.

General relativity has passed every test on Earth. Without correcting for it, GPS systems would not work. But some theorists have suggested that if gravity behaved differently over large distances from what Einstein thought, it would relieve astronomers of the embarrassing need to posit...

(Excerpt) Read more at ...

TOPICS: Culture/Society; Extended News; Technical; Testing
KEYWORDS: einstein; physics
Navigation: use the links below to view more comments.
first previous 1-2021-4041-50 last
To: tnlibertarian

Oops!.....forgot the pic!............

41 posted on 07/24/2012 12:36:49 PM PDT by Red Badger (Think logically. Act normally.................)
[ Post Reply | Private Reply | To 38 | View Replies]

To: concentric circles
This source presents the same information without linking to the NY Times, a vile propogandist intent on the destruction of America.

Without the Times' Science Tuesday section, I would not have found the story.

42 posted on 07/24/2012 4:08:34 PM PDT by neverdem (Xin loi minh oi)
[ Post Reply | Private Reply | To 34 | View Replies]

To: shibumi; HiTech RedNeck
They just had an obstruction in the matter/anti-matter conduit between the dilithium crystals and the warp core.

Nope, that's just what was in the official Starfleet reports. The truth is there's a massive destructive force headed for earth and we have to go back in time to save the whales.

43 posted on 07/24/2012 4:17:41 PM PDT by 1010RD (First, Do No Harm)
[ Post Reply | Private Reply | To 5 | View Replies]

To: momincombatboots

Well at least you enjoy using your computer and being on the internet. ;)

44 posted on 07/24/2012 6:59:17 PM PDT by <1/1,000,000th%
[ Post Reply | Private Reply | To 24 | View Replies]

To: HiTech RedNeck; Mr. K
And yet it wasn’t light pressure that achieved this, but differential between how the residual gas in the bulb was warmed and set in motion at the surfaces of the vanes.

Or... the white surface reflected 'light', and the black surface absorbed light. In a sense, repulsion and attraction. The gas near the white surface would tend to expand due to the additional 'reflected heat', adding 'repulsion' to the mix.

Maybe it's a combination of things, instead of one thing.

45 posted on 07/24/2012 7:00:26 PM PDT by UCANSEE2 (Lame and ill-informed post)
[ Post Reply | Private Reply | To 35 | View Replies]

To: HiTech RedNeck; neverdem
Turns out to be the pressure of infrared light emitted from the forward facing heat sinks of the equipment on board.

Sounds just as reasonable as...

Swamp gas from a weather balloon was trapped in a thermal pocket and reflected the light from Venus.

46 posted on 07/24/2012 7:03:47 PM PDT by UCANSEE2 (Lame and ill-informed post)
[ Post Reply | Private Reply | To 3 | View Replies]

To: HiTech RedNeck; neverdem
Oops, I forgot.

Please look right here.

47 posted on 07/24/2012 7:06:03 PM PDT by UCANSEE2 (Lame and ill-informed post)
[ Post Reply | Private Reply | To 46 | View Replies]

To: ArrogantBustard; HiTech RedNeck; Mr. K

A radiometer is a device for measuring the radiant flux (power) of electromagnetic radiation. Generally, the term radiometer denotes an infrared radiation detector, yet it also includes detectors operating on any electromagnetic wavelength.

A common example is the Crookes radiometer, an early-model device wherein a rotor (having vanes which are dark on one side, and light on the other) in a partial vacuum spins when exposed to light. A common myth (one originally held even by Crookes) is that the momentum of the absorbed light on the black faces makes the radiometer operate. If this were true however, the radiometer would spin away from the non-black faces, since the photons bouncing off those faces impart even more momentum than the photons absorbed on the black faces. Follow the link below for an in-depth explanation of the principles behind a Crookes radiometer.

The Nichols radiometer operates on a different principle and is more sensitive than the Crookes type.

A microwave radiometer operates in the microwave wavelengths. The radiometer contains argon gas to enable it to rotate.

The MEMS radiometer, invented by Patrick Jankowiak, can operate on the principles of Nichols or Crooke and can operate over a wide spectrum of wavelength and particle energy levels.

Source: Wikipedia

(I learn something new every day.)

48 posted on 07/24/2012 7:12:10 PM PDT by UCANSEE2 (Lame and ill-informed post)
[ Post Reply | Private Reply | To 39 | View Replies]

To: neverdem
These are links to the signup pages for science newsletters delivered to your inbox via email. I read the L.A. Times but I try to avoid posting from them by doing an online search for other sources for the same story. The mainstream news outlets profit from visits to their web pages and though I may choose to subscribe I don't need to direct others to their pages.

Popular Science Newsletter

ScienceDaily Email Newsletters

Scientific American free Newsletters

Science Oxford Online email newsletter

49 posted on 07/24/2012 7:37:49 PM PDT by concentric circles
[ Post Reply | Private Reply | To 42 | View Replies]


All I can say is the scientists did the math and it made sense once they did. The effect is extremely tiny of course compared with the craft’s rapid velocity. They are talking about a few hundred feet lagged during a period when the craft went millions of miles into space.

50 posted on 07/24/2012 8:18:21 PM PDT by HiTech RedNeck (let me ABOs run loose, lew (or is that lou?))
[ Post Reply | Private Reply | To 46 | View Replies]

Navigation: use the links below to view more comments.
first previous 1-2021-4041-50 last

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.

Free Republic
Browse · Search
Topics · Post Article

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794 is powered by software copyright 2000-2008 John Robinson