The generally accepted age of the universe is slightly less than 14 billion years. Given that the speed of light is a barrier for how fast things can travel through spacetime, one would think that the size of the universe would then be about 28 billion light-years in diameter. Not so! Because even though matter travelling through spacetime cannot reach the speed of light, spacetime itself can expand much faster than lightspeed. Recent research puts the estimated size of the universe at more than 250 times that of the visible universe.
Archive for the 'Space' Category
Everyone’s heard the phrase, “once in a blue moon.” Turns out it has nothing to do with the color of the moon at all, but instead refers to either two full moons within one calendar month or four full moons within a single season. The linked article attempts to explain it all, but concludes that the no single, precise definition exists. On a side note, I suggest you check out the memorable short story, “Blued Moon,” by Connie Willis, where incredible coincidences occur in Chugwater, Wyoming after chemical plant emissions turn the moon blue.
Thanks to Ciro for this link.
Somehow I’ve never considered that diamonds could have a melting point, much less that there may be oceans of liquid diamond on Uranus and Neptune. Turns out that solid diamond floats on liquid diamond, much like ice floats on water. Melting a diamond, however, is more complicated than just raising the temperature. The linked article explains all.
As I grow older, I’m amazed to see the creation of technologies that I once read about in science fiction books. The Japanese government is spending $22 billion on a project to put a large solar panel array in orbit that will generate energy and beam it down to the Earth.
Interorbital Systems is selling satellite kits for the low, low price of $8000—this includes launching the satellite into a low-Earth orbit that will be maintained for a few weeks. The kit has quite a bit of pre-configured hardware and software, but you can send pretty much whatever you want as long as it meets the size and weight requirements. I’m thinking this would be a great way to make a marriage proposal.
It started out in the mid-1700s with the discovery of the five Lagrange points, relatively stable areas in a rotational system with two bodies (e.g., Earth/Moon or Earth/Sun). But the solar system, with its multitude of planets and moons, is much more complex. The forces exerted by gravity are changing all the time, sometimes stronger or weaker, sometimes in one direction then in another.
These dynamic forces can be modeled, and it’s possible to generate a low-energy flight path for a spacecraft, where it could (theoretically) use no fuel but instead be propelled through the solar system by these changing gravitational forces. In the real world, of course, some fuel is necessary, but it’s a minimal amount.
This type of spaceflight would not be suitable for human beings, as the path meanders significantly, taking much, much longer to reach a destination than a direct flight. But the interplanetary superhighway is ideal for certain types of unmanned probes. And kudos to the people who first came up with the idea—this is definitely thinking outside the box.
Thanks to Josh for the Lagrange point link.
Update: Here is some more recent information on this topic.
July 20th is the 40-year anniversary of humankind’s first walk on the Moon. To help celebrate, here are Ten Things You Didn’t Know About the Apollo 11 Moon Landing. My favorite is #7: “When Buzz Aldrin joined Armstrong on the surface, he had to make sure not to lock the Eagle’s door because there was no outer handle.”
Construction has started for Spaceport America. I believe we need to encourage commercial space travel as much as possible, or it will forever be the ultra high-priced monopoly of governments. It’s my hope that space travel will someday be as common as air travel is today.
The video in the linked article is from the International Space Station, and shows the stabilizing effect of gyroscopes. The demonstration is done in zero-gravity, and the “gyroscopes” are portable CD players.
This article is one of the more readable explanations that I’ve seen of how universes are created. It’s short and concise, yet manages to cover topics from quantum multiverses to what may exist outside of our universe.
The linked video is a bit long, but definitely worth watching. Astrophysicist Neil DeGrasse Tyson discusses the mechanics of being sucked into a black hole (spaghettification), as well as the possibility of the asteroid 99942 Apophis hitting Earth (and killing a lot of things in the process). Tyson also appeared on The Daily Show, where he covered some of the same topics.