Chronicling the follies of religion and superstition, the virtues of skepticism, and the wonders of the real (natural) universe as revealed by science. Plus other interesting and educational stuff.
"Tell people there’s an invisible man in the sky who created the universe, and the vast majority believe you. Tell them the paint is wet, and they have to touch it to be sure."
“If people are good only because they fear punishment, and hope for reward, then we are a sorry lot indeed”.
“Skeptical scrutiny is the means, in both science and religion, by which deep thoughts can be winnowed from deep nonsense.”
Because space is weird, there is a lot of confusion today, as always, about where exactly Voyager 1 is now. Many headlines have claimed that it has “left the solar system.”
But according to NASA, Voyager 1 is still in the solar system and will continue to be in the solar system for the next 30,000 years or so. Get ready for some NASAsplaining:
So, would the team say Voyager 1 has left the solar system? Not exactly - and that’s part of the confusion. Since the 1960s, most scientists have defined our solar system as going out to the Oort Cloud, where the comets that swing by our sun on long timescales originate. That area is where the gravity of other stars begins to dominate that of the sun. It will take about 300 years for Voyager 1 to reach the inner edge of the Oort Cloud and possibly about 30,000 years to fly beyond it. Informally, of course, “solar system” typically means the planetary neighborhood around our sun. Because of this ambiguity, the Voyager team has lately favored talking about interstellar space, which is specifically the space between each star’s realm of plasma influence.
In other words, this is a semantic debate. The important part is that Voyager 1 is really far away from Earth right now, collecting data in a place where we’ve never done that before. It’s a pretty big achievement for a species that can barely agree on what sports to play in the Olympics.
(Source: New York Magazine)
Scientists at MIT have discovered a “hidden flux” of material deep in the Earth’s mantle that would make the planet’s overall composition more similar to that of meteorites, supporting the theory that Earth arose from the collision of asteroids.
It’s widely thought that the Earth arose from violent origins: Some 4.5 billion years ago, a maelstrom of gas and dust circled in a massive disc around the sun, gathering in rocky clumps to form asteroids. These asteroids, gaining momentum, whirled around a fledgling solar system, repeatedly smashing into each other to create larger bodies of rubble — the largest of which eventually cooled to form the planets.
Countless theories, simulations and geologic observations support such a scenario. But there remains one lingering mystery: If the Earth arose from the collision of asteroids, its composition should resemble that of meteoroids, the small particles that break off from asteroids.
But to date, scientists have found that, quite literally, something doesn’t add up: Namely, the Earth’s mantle — the layer between the planet’s crust and core — is missing an amount of lead found in meteorites whose composition has been analyzed following impact with the Earth.
Much of the Earth is composed of rocks with a high ratio of uranium to lead (uranium naturally decays to lead over time). However, according to standard theories of planetary evolution, the Earth should harbor a reservoir of mantle somewhere in its interior that has a low ratio of uranium to lead, to match the composition of meteorites. But such a reservoir has yet to be discovered — a detail that leaves Earth’s origins hazy.
Now researchers in MIT’s Department of Earth, Atmospheric and Planetary Sciences have identified a “hidden flux” of material in the Earth’s mantle that would make the planet’s overall composition much more similar to that of meteorites. This reservoir likely takes the form of extremely dense, lead-laden rocks that crystallize beneath island arcs, strings of volcanoes that rise up at the boundary of tectonic plates….