Tag Archives: Big Wide World

Watching a Planet’s Death Spiral?

Fifteen years ago, Geneva Observatory researchers Michel Mayor and Didier Queloz discovered a planet more massive than Jupiter circling a mere 5 million miles (8 million km) from the Sunlike star 51 Pegasi.

Some “hot Jupiters,” like the exoplanet designated OGLE-TR-56b depicted here, orbit their stars so closely that tidal forces are gradually dragging them to their doom.
David A. Aguilar / Center for Astrophysics

Dynamicists have struggled to understand how this and the many other “hot Jupiters” found since then managed to orbit so tightly without being gobbled up. Some were perhaps flung into their star-skirting orbits after losing tugs-of-war with other massive planets in their systems, and some were probably dragged inward along with the natal disks of matter around their young Suns. After the disks dissipated, these massive worlds were deposited in precarious but seemingly stable orbits

There they might remain, roasting for eons, were it not for the tides these close-in planets incite in their stars. For some, long-term survival is not in the cards.

Why so? Consider how the Moon raises tides in Earth’s oceans. Because our satellite takes a month to complete one orbit, whereas Earth spins in just 24 hours, the exchange of tidal energy is a net gain for the Moon, which is edging ever farther from Earth.

But a hot Jupiter completes its orbit in a few days — sometimes in less than 24 hours — creating stellar tides that have the opposite effect. Slowly, inexorably, the planet is dragged to its doom.

Why Earth's Rotation Slows Down

Earth tugs on the Moon and the Moon tugs back, causing tides in our oceans. Because of tides, an energy transfer takes place: Earth’s rotation slows (days get longer), while the Moon gains orbital energy, causing it to slowly migrate farther away. Some hot Jupiters, however, orbit faster than their suns spin, so the tidal exchange gradually draws them inward instead.
Night Sky: Gregg Dinderman

That’s the fate of OGLE-TR-113b, a hottie with 1.3 times Jupiter’s mass crowding a Sunlike star 1,800 light-yeas away in Carina. Because it transits, or passes directly in front of its star, astronomers can time the planet’s orbital period exactly. (TR in its designation is for transit; OGLE stands for Optical Gravitational Lensing Experiment.)

As Elisabeth Adams told a meeting of planetary scientists on Friday, precise timing of six such transits over the past few years reveals that OGLE-TR-113b’s 34⅓-hour orbital period does seem to be very gradually shrinking. Using the timings she and her observing team made with the 6.5-m Magellan Telescopes in 2007-09, Adams finds that OGLE-TR-113b shaves about 60 milliseconds off its period each year.

It’s possible, she notes, that the system contains a massive but as-yet unseen companion that’s yanking the planet around. Some kind of librating resonance with a second planet isn’t out of the question either, though the perturber couldn’t have more than twice Earth’s mass. Instead, the simplest explanation is that astronomers have, for the first time, captured a hot Jupiter in its death spiral.

So when might we kiss OGLE-TR-113b good-bye? Adams emphasizes that it’ll happen long before the planet actually reaches the star’s surface. Rather, the point of no return occurs when the orbital period shrinks to 10.8 hours. By then the planet will be close enough for tidal forces to rip it apart. Depending on assumptions about how strongly the star and planet are interacting, the end could come only 1½ to 2 million years from now.

Magellan Telescopes

Twin 6.5-m Baade and Clay telescopes were built for the Magellan project in 2000 and 2002 by the Carnegie Institution of Washington. They are sited at Las Campanas Observatory in Chile.
Carnegie Observatories

“This detection is still quite tentative,” writes the team in a paper submitted to the Astrophysical Journal, in part because there’s a less-than-perfect fit to other timings made in 2002 and 2006. Clarity should come early next year, when OGLE-TR-113b again becomes observable and more transits can be clocked.

“Other people have been on this trail,” Adams adds, with the hot Jupiter OGLE-TR-56b also getting special attention. Discovered in 2002 and orbiting just 2.1 million miles (3.4 million km) from its stellar host, it might meet its doom in as little as a million years.

Posted by Kelly Beatty, October 12, 2010
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Germs!!!!! Ewe!!!!

Not that I believe much in the way of conspiracy theories of today, but I do find them incredibly thought-provoking and interesting, and Jesse Ventura’s new investigative show “Conspiracy Theory” is not only maybe shedding a few secrets but also a bit humorous at times and quickly becoming my favorite reality/documentary show to cuddle up with a nice box of cookies and milk.

Most of the former Governor’s theories are a bit unbelievable and out of my scope of belief, but he presents a nice view and conversation piece over dinner the following night, except this week… this week he skeeved me out.  Jesse V investigated Plum Island, the alleged secret germ base where the US scientists are supposed to be experimenting on animals, germs, viruses and bugs.

For a germ lab to be within a few hours of my home and so close that a disaster would leave us just down wind and little time to count our blessings before the latest incarnation of a small pox-polio hybrid plume cloud of  death overcomes Massachusetts.

Is the Germ Lab real?  I have no doubt there is something going on, maybe the Government is making counter strategy antidotes to all the scary shit that Al Qaeda is cooking up overseas and the next threat is brewing in their home science kit.  I highly doubt some beliefs that the US is doing anything sinister to hurt people or our enemies citizens.

Here is the kicker, no matter how good the intentions, no matter how good the security, accidents always happen.  And I don’t like it being so close, not that it should be near anyone if Ventura’s accusation that the lab will be moving to Kansas smack dab in the middle of the US of A.  Six of one, half-dozen of another.  With Plum Island you are threatening the strongest concentration of population in Boston, NYC and DC just a hop skip and jump away, with the Kansas lab you are centrally located to equally distribute a catastrophe in all directions around the US, great planning folks.

Germ warfare manufacturing is a clear violation of the 1972 treaty that was signed into effect to stop a country from creating a mass epidemic that will not only wipe out the intended citizens but also likely spread worldwide.  How many horror movies start with a rouge germ on the loose from a sloppy facility or terrorist plot?  Might not be a movie for long, might be a section in future generations history books.

Feel a cold coming on?


US’s 100-Year Plan to Settle Other Worlds

Starship

The Daily Galaxy sheds light on our own Starship Enterprise project going on as we speak.  Sadly none of us will be around to see it’s completion.

[LINK]

Starship Enterprise might have some competition: NASA Ames Director Simon “Pete” Worden has revealed that NASA Ames has “just started a project with DARPA called the Hundred Year Starship,” with $1 million funding from DARPA and $100K from NASA.

“You heard it here,” said Worden at “Long Conversation,” a Long Now Foundation event in San Francisco according to Kurweil.net. “We also hope to inveigle some billionaires to form a Hundred Year Starship fund,” he added.“The human space program is now really aimed at settling other worlds,” he explained. “Twenty years ago you had to whisper that in dark bars and get fired. NASA needs to build a true starship, probably using electric propulsion, probably also using solar energy and nuclear energy.”One new propulsion concept is electric propulsion, said Worden. “Anybody that watches the [Star Trek] Enterprise, you know you don’t see huge plumes of fire. Within a few years we will see the first true prototype of a spaceship that will take us between worlds.

“We are [also] funding a young scientist to develop microwave thermal propulsion. The idea is if you can beam power to the spaceship, so you don’t have to carry all the fuel; and then you use that energy from a laser or microwave power to heat a propellant; it gets you a pretty big factor of improvement. I think that’s one way of getting off the world.”

Worden also cautioned that in settling on other worlds, we need to be cautious. “How do you live in another world?  I don’t have the slightest idea,” he said. “If you’re a conservative, you worry about it killing us; if you’re a liberal, you worry about us killing it. I think things like synthetic biology have lot of potential for that. I think rather than make an environment on Mars like Earth, why don’t we modify life … including the human genome … so it’s better suited to [Mars]?

Wordon thinks we should go to the moons of Mars first, where we can do extensive telerobotics exploration of the planet. “I think we’ll be on the moons of Mars by 2030 or so.”

Worden also says NASA Ames is exploring another radical new concept: a heavy-lift airship that could carry hundreds of tons. “I think that could revolutionize air transport, because it becomes very cheap and still goes 100 knots. The idea is that you could easily go to Hawaii overnight, for example… with a lot less fuel.

“The long-term answer [to the rapidly accelerating growth of travel in the developing world and the increase in greenhouse gas] is a “Tesla in the air” — using high-density batteries powered off ground-based solar grids, so your airliner stays plugged in overnight, and it’s got an electrical engine rather than a chemical engine. I think within ten years we’ll have small-scale business-level ones, and within 20, they’ll be the airliners. If we don’t, I think aviation’s through.”

Casey Kazan via kurzweilai.net


Could Time Flow Backwards in Another Universe?

Reprinted from The Daily Galaxy:

A new rock star in theoretical physics offers a fresh vision of our universe and beyond, all beginning with a simple question: “Why does time move forward?”

Caltech physicist Sean Carroll  suggests that our perception of time is informed by entropy — the level of disorder in a system. The basic laws of physics work equally well forward or backward in time, yet we perceive time to move in one direction only—toward the future and that the movement from low to high entropy as the universe expands establishes the direction in which time flows. To account for it, we have to delve into the prehistory of the universe, to a time before the big bang.  Our universe may be part of a much larger multiverse, which as a whole is time-symmetric.

Time may run backward in other universes. Some universes, Carroll argues, don’t experience time at all; once a universe cools off and reaches maximum entropy, there is no past or present. 

Here’s how Carroll describes his thesis: “Microscopic laws of physics are essentially time-reversal invariant, but macroscopic thermodynamics exhibits a profound time-asymmetry; entropy typically increases in closed systems. This intriguing feature of the real world has a cosmological origin: the entropy of the early universe was fantastically small. After a century of effort, it has been difficult to explain this arrow of time without assuming time-asymmetric boundary conditions.

“Jennifer Chen and I have suggested a simple scenario in which increasing entropy is natural, based on the idea that the entropy can increase without bound (there is no equilibrium state) and that the way entropy increases is by creating universes like our own. In our picture, any generic state first evolves to an empty de Sitter phase; the small temperature of de Sitter allows for fluctuations into a proto-inflationary configuration, which grows and reheats into a conventional Big-Bang spacetime. The same thing happens in the far past, but with a reversed arrow of time. On ultra-large scales, therefore, entropy is growing without bound in the asymptotic future and past.”

Casey Kazan

http://www.scientificamerican.com/article.cfm?id=the-cosmic-origins-of-times-arrowhttp://preposterousuniverse.com/research/#arrowhttp://www.wired.com/magazine/2009/12/pl_print_carroll/

Obi – This made my head spin, had to share.


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