We live on a rocky ball about 12,750 kilometers through and 40,050 kilometers around its widest diameter. It has a mass of about six quadrillion megatonnes, which is so ridiculously large compared to things we’re used to that it doesn’t really mean anything to us. Our size compared to Earth’s size is roughly equivalent to the size of viruses compared to us.
And it doesn’t imply that humans are merely an unimportant example of a repeating theme. After all, why is our size one of the levels? We could just as easily be included with all of life to fall between the very small and the very large. As in – subatomic particles – living things – planets and stars. But that’s another analogy that shouldn’t be pushed too hard.
We choose humans as a level because we’re human. We tend to look at things relative to what we’re used to, so we don’t think twice about our size being one of the steps on the ladder. Besides, it was necessary to use something familiar as a point of reference in such a wide array of dimensions.
The dimensions of the physical universe are measured by such huge numbers, both hugely big and hugely small, that they don’t convey much meaning on their own. The very large is measured in billions of light years. Light years are trillions of kilometers each. Even a single kilometer is big compared to us. The small is measured in fractions of meters, changing the numbers from positive to negative right about our size. The very smallest things are such small decimals of a meter that we don’t write them out in full, using special mathematical shorthand instead.
In all that vastness, all that range of realities and possibilities, what is most amazing is that part of it is conscious. A narrow band in the middle has produced something that can look out and try to understand the whole thing.
I think we can justify being a little self-centered.
I’m linking to this story about high altitude balloons because it has a small reference to the balloon-based rocket launch system that I wrote about in the Green Comet Trilogy. It’s nice to know that my idea wasn’t impractical.
[Zhou Fei, head of KC Space’s R&D team] says that Traveller could also be a ‘secondary launch’ platform. This would mean lifting a rocket above most of the Earth’s atmosphere, from where it could fire a small rocket into orbit far more easily than from sea level. This would be useful for the growing market for tiny CubeSats.
“One of the holy grails around the world is whether you can lower the cost of launching a small CubeSat into orbit,” says Jeffrey Manber, whose company Nanoracks is working with KC on the Traveller programme.
Credit Stefan Xp – CC-BY-SA – Self-made UFO over Meersburg
It was a good year for aliens. Whether it was the fluctuations in the brightness of Tabby’s star, the oddly shaped interstellar visitor that passed through the Solar System, or a spate of sightings of UFOs, aliens received a lot of nominations. As always with the advocates of alien visitations, they want us to prove that it isn’t aliens. They say, “How do you know it isn’t? Can you prove it isn’t?” They always get that backwards, don’t they?
From the Scientific American article:
What do a strangely fading faraway star, an oddly shaped interstellar interloper in the solar system and a curious spate of UFO sightings by members of the U.S. military all have in common?
Far from being close-minded killjoys, most scientists in the “never aliens” camp desperately want to be convinced otherwise. Their default skeptical stance is a prophylactic against the wiles of wishful thinking …
Finding aliens—or coming up empty in our searches—has profound implications for our own ultimate cosmic fate.
UFO detections have remained marginal for decades; they’ve just gone from being blurry shapes on film cameras to blurry shapes on the digital infrared sensors of fighter jet gun cameras. This, in spite of the fact that the world’s total imaging capacity has expanded by several orders of magnitude in the past 20 years.
Hypothetical aliens with advanced technology could do that, of course. But then you have to ask why they would choose to remain marginally undetectable rather than just being undetectable.
It was a good year for alien hunters, but not good enough. They still haven’t come up with solid proof that their beliefs are true. I guess that’s why they keep asking us to prove that they aren’t, even though that’s the wrong way ’round.
NASA has compiled a two minute video showing the interactions between the major hurricanes of 2017 with the aerosols dust, smoke and sea salt. The dust (brown) can be seen coming from the Sahara and heading out over the Atlantic Ocean. Most of the smoke (grey) is from wildfires in western North America, with some coming from Portugal. The sea salt (blue) comes from the ocean, of course. The video shows how the hurricanes directly affect the aerosols, and how the larger atmospheric currents affect everything.
You might be aware of the website dedicated to the Astronomy Picture of the Day (APOD.) You can visit the site and see another great picture every day. Some people even set things up so their computer’s desktop image is the APOD changing daily. It’s a NASA website and just one of the ways that organization shares its discoveries with the public. Today I’m going to direct you to another one called the NASA Image and Video Library. They have brought together about sixty of their media archives into one source. Here’s an article on Space.com about the library.
Here are some samples of the images available. They link to the much larger originals. These images are Public Domain.