Category: Space

Tegmark’s Level I Multiverse: infinite space

I've just finished reading Max Tegmark's latest book, 'Our Mathematical Universe', about his views on multiverses and the ultimate nature of reality.  This is the first in a series of posts that I plan to do on it.  Tegmark postulates four levels of multiverse.  This post is about the first, and simplest version, the Level I … Continue reading Tegmark’s Level I Multiverse: infinite space →

Minimum crew size for an interstellar generation ship

John Hawks takes a look at a fascinating article in Popular Mechanics that looks at what the minimum crew size would need to be for an interstellar generation ship, and relates it to what is known about genetics in anthropology. Popular Mechanics asks, "How Many People Does It Take to Colonize Another Star System?". The basic problem … Continue reading Minimum crew size for an interstellar generation ship →

The hard working but unloved multi-stage rocket

If you've ever read about rocket technology, particularly the issues involved in how much fuel is needed to get somewhere, you quickly run into a stark reality.  The payload, the part of the rocket that you want to get somewhere, is inevitably a tiny portion of the size and weight of the rocket. The rest … Continue reading The hard working but unloved multi-stage rocket →

The space age is in full swing, for robots

Yesterday I made the observation that it was much cheaper to transmit information than to travel to an interstellar destination, observing that sending a microscopic robot able to use raw materials in the destination system to bootstrap manufacture what it needs. The Leather Library pointed out that this applies as well to destinations in our solar … Continue reading The space age is in full swing, for robots →

For interstellar travel, transmission is much cheaper

It will always be a lot cheaper to send a radio signal to an interstellar destination than any kind of physical presence.  Our discussion the other day on the difficulties of interstellar travel left me pondering this, something that is well known to astronomers and other thinkers in this area. Given sufficiently advanced technology, the … Continue reading For interstellar travel, transmission is much cheaper →

How far away is the closest extraterrestrial civilization?

First, let me be clear on what I'm talking about: intelligent aliens with an advanced civilization.  This is a different question than extraterrestrial life in general.  For life in general, particularly simple life, I'd be surprised if we'd have to look more than a hundred light years from Earth.  (We may know the answer to … Continue reading How far away is the closest extraterrestrial civilization? →

Beasts or gods; why a War Of The Worlds is very unlikely

One of the scenarios that is often played out in science fiction is what would happen if we encountered an alien civilization.  Often, we are portrayed as defending Earth from an alien invasion or fighting battles with the aliens in a war.  Another scenario, commonly found in more culturally introspective fiction, focuses on what our … Continue reading Beasts or gods; why a War Of The Worlds is very unlikely →

Comet ISON and our lack of fear

Lots of people are excited about comet ISON and the spectacular show it will hopefully provide.  However, unlike most people throughout history, most of us do not regard it as an evil omen, an attack from an angry god, or fear it for any other reason.  There's a reason this.  Science! Aristotle thought that comets … Continue reading Comet ISON and our lack of fear →