Slashdot Mirror
Largest-Known Planet Befuddles Scientists
langelgjm writes to mention that scientists are quite puzzled over the discovery of the largest planet yet. According to study-leader Georgi Mandushev it should theoretically not even be able to exist. 'Dubbed TrES-4, the planet is about 1.7 times the size of Jupiter and belongs to a small subclass of "puffy" planets that have extremely low densities. The finding will be detailed in an upcoming issue of Astrophysical Journal. [...] "TrES-4 is way bigger than it's supposed to be," Mandushev told Space.com. "For its mass, it should be much smaller. It basically should be about the size of Jupiter and instead it's almost twice as big." "TrES-4 appears to be something of a theoretical problem," said study team member Edward Dunham, also of the Lowell Observatory. "Problems are good, though, since we learn new things by solving them."'"
Uh no.
Go back to school. The hierarchy in science, in order of increasing evidence, is speculation, conjecture, hypothesis, theory.
The word "theory" in common parlance is an unsubstantiated guess. In science, the word "theory" means hypothesis supported by a large body of evidence, where the truth value of the theory is considered very high. Evolution is a theory that has so much evidence in its favor that the IDers are essentially nutcases who can't read or reason properly. It is the IDers that try to equivocate the position by using the common parlance flavor of the word "theory" when discussing science.
Ok, it isn't the mass that is surprising, it is the volume. Larger (in mass) exoplanets have been found, sometimes they fall in to the category of Brown Dwarfs. But TrES-4 is hardly massive. According to the article, the density is .2 g/mL and the volume is 1.7 times that of Jupiter. That gives a mass of
1.7*(1.43128*10^15 km^3) * .2 g/mL = 4.866352 * 10^26 kg.
Jupiters mass is 1.8986*10^27 kg. That means TrES-4's mass is only about one quarter the mass of Jupiter ((4.866352 * 10^26 kg)/ (1.8986*10^27 kg)= 0.256312651)
No self-respecting advanced technological civilization would bury significant amounts of useful matter at the center of a planet. They would instead construct objects filled with fiber optic cables to carry large amounts of data between all of the computational nodes. The compute nodes have to be on the surface because they have to radiate away the heat they generate but the central part of the Jupiter Brain (aka Borg sphere) should have a density low enough that gravitational compression doesn't distort the one-to-many point-to-point transmission over the fibers.
The difference between a Jupiter Brain and a Matrioshka Brain is that the center of a Jupiter Brain is not running off of a gravitationally bound and driven fusion reactor (aka "star"). Most of the energy used by the Jupiter Brain comes from the external solar energy it absorbs (though in theory it could house a number of "small" fusion reactors fueled by hydrogen or helium siphoned from the nearby star).
Side note to the Dyson "Sphere" advocates -- classical "spheres" are impossible (you've been watching too much Star Trek) -- Dyson never used the word "sphere" and made a point of clarifying this in his response to the letters following his original paper. A better term to avoid confusion is a "Dyson shell".
Because their theories better fit the data. When they find a place where their theories and those of their predecessors don't work (this planet may be such a case), they work on formulating more general theories based on what they already know. And when they do this, they don't start from scratch each time, but build instead on previous discovery.
That's what science does. It progresses. It works. Would you rather we abandon the scientific method and just make up random stuff without testing it against reality? Even dark matter and dark energy aren't arbitrary: they're provisional descriptions of stuff we're actually seeing happen.
I'm getting really sick of this "oh, we can't really ever know anything because no theory is perfect, so let's just give up on this science thing" attitude.
DNA just wants to be free...
Dark energy is a mathematical placeholder name. There is an observed force which we can measure, but which we have no tested model to explain. We call this force dark energy.
When you say, "maybe dark energy," you demonstrate that you don't know what that phrase means. That's like saying, "maybe the solution to the problem is x!" X is just a variable name, not an answer to a question. Even maybe we have to revise theories in astrophysics because we were wrong on something... Which happens all the time as our ability to measure and test the universe around us expands. This is an expected consequence of having more information. Someday, we'll marvel at how little we knew "back then" (e.g. today). For now, we have some very good ideas of how the universe in our local vicinity works, but no one expects to not be surprised by something new. sigh, why do scientists think they are right now when their forbears were wrong? Why do you think that scientists are some alien species that don't understand basic logic? Of course astrophysics know that they have some things wrong today, but this is how we learn. We build solid ground upon which to base further ideas, and we constantly assail these ideas and their underpinnings in order to determine which parts are reliable enough to continue to bear the weight of many other theories. Speaking of Astrophysics, if we can look into the sky and only see x millions of years back based off of light years, That's kind of broken statement. Let's try again, shall we? We can measure distance (in ways that range from simple triangulation to measuring red-shift). We know that light travels a certain distance in a certain amount of time. We therefore know how long light from an object would have traveled in order to get to us.
Now that's not quite "seeing x millions of years back," but it's close enough that I understand (I think) where you're going. how do we know that we are not seeing the opposite side of the big bang curve? What is the "big bang curve?" Do you mean, "how do we know that we're not seeing light that started out at a time before the big bang?"
Well there are several easy reasons for that: 1) The big bang started as a singularity. You can't measure or view anything through a singularity. It's a cosmic wall through which no information can pass 2) If that were true, then the expansion of the universe would change as we looked out into deep space, and those distant objects would be moving toward us. This is not the case.
Of course, your question (at least, as I understand it) assumes that the big bang was "preceded" by a big crunch (the universe collapsing into a singularity). That may or may not be true, and we have no way to prove that it is or isn't, since we can't extract information about what happened before the singularity.
Here we are -> ( *Bang* )
More dumb observations later.