Wavepacket Blog

Wavepacket Blog
only displaying 'science' posts

Sun Jul 25 22:24:41 2010
Little Green Men
SETI's poor strategy may save humankind...

SETI's first contact
Image courtesy of Wildroot (wiki)

Lately, Stephen Hawking made news with his comments that attempting to find or contact advanced civilizations are dangerous because we might tempt "nomads, looking to conquer and colonize". That is, we might attract predators (maybe even like these).

Proponents of SETI aren't worried, and continue to look for radio signals from extraterrestrials. Even our own local billionaire, Paul Allen, has jumped on to the SETI bandwagon with his own set of radio telescopes.

Some of the arguments against Hawking are valid. This article has some great points, for instance. Even a predatory advanced civilization could get whatever materials it needed without bothering with Earth.

However, I think Hawking is worth listening to. There is a chance we could meet someone friendly, but every known example of advanced contact has turned out very, very badly for the contacted civilizations. To quote Wikipedia:

The historical record indicates that when one culture is significantly more technologically advanced than the other, this side will be favored by the disruptive nature of conflict, often with dire consequences for the other society.

So on balance, why take the risk of attracting the attention of a dangerous advanced civilization?

However, there is another reason I think SETI is a waste of money and resources. As it turns out, an advanced civilization wouldn't send us electromagnetic signals anyway. Looking for radio signals is almost certainly a waste of time.

In 2004, two researchers submitted a letter to Nature. In it, they calculated the energy it would take to continuously broadcast radio (or other) signals throughout the galaxy, or even neighborhoods of the galaxy, vs. just sending physical objects to candidate systems. As they note in their abstract:

The results suggest that our initial contact with extraterrestrial civilizations may be more likely to occur through physical artefacts--essentially messages in a bottle--than via electromagnetic communication.

Their calculations were pretty back-of-the-envelope, and pretty compelling. Sending physical objects would be millions of times more efficent than beaming radio waves. Any advanced civilization would be foolish to broadcast messages.

Saturn: holding a message from aliens?
Image courtesy of TonyBallioni (wiki)

I remember when the Letter to Nature came out. Commentary noted something to the effect that we'd be better off sending probes to the Lagrange points of our gas giants than listening for radio signals. It's kind of a trippy idea: there may be ancient alien probes dormant in our solar system, waiting for us to find them!

However, even though the math is simple and the conclusion obvious (no one would try to contact us by radio waves) SETI is still looking for radio signals.

Given that Stephen Hawking thinks advanced civilizations may be dangerous, perhaps it is a good thing that SETI is barking up the wrong tree!

Comments

Related:
  > science <

Unrelated:
  books
  economics
  energy
  environment
  geopolitics
  lists
  mathematics
  predictions

Fri May 21 23:30:08 2010
Space Plan
Now I have even more respect for the new NASA direction.

The Constellation program: beautiful! But not smart.
Image courtesy of Cassini83 (wiki)

A friend of mine is the Astronomy columnist for the Seattle Examiner. If you are interested in Astronomy in the Seattle area, you should definitely read his articles!

He recently posted an article about former NASA administrator Michael Griffin's talk at the Boeing Museum of Flight, in which Griffin wasn't entirely supportive of the new NASA direction. In particular,

Michael Griffin takes strong exception to most of President Obama's proposed space exploration policy, disagreeing with the major points and calling much of it "drivel."

Harsh! Griffin called the new direction "Obama's proposals", although most of them came from the so-called Augustine Report, the outcome of the Review of US Human Spaceflight Plans Committee.

You can find the Augustine Report here, which is very readable! If you are at all interested in the US space program I recommend flipping through it. It is over 150 pages (ack) but I read through the Introduction (Chapter 1), the coverage of current programs (Chapter 4), and their evaluation of critical technologies (Chapter 7).

It is a pretty interesting report! Popular Mechanics has an online article about 5 Surprising Passages from the Full Augustine Report.

[If you flip through the report, on page 12 you'll find an awesome diagram showing the International Space Station, color-coded by which country supplied the components. It is clear that the ISS is almost exclusively a US and Russian venture, although Japan kicked ass (far above the European contributions). Although, before I deride Europe too much, I should given them the benefit of the doubt--they may have recognized early on that the ISS was a colossal waste of money.]

Orion docked at the ISS -- that's a lot of cash!
Image courtesy of GDK (wiki)

Michael Griffin also didn't like the Augustine Report "which he feels got some things right but blew many others."

Many astronauts also don't like the new direction. Neil Armstrong and Eugene Cernan, the first and last astronauts on the moon, testified to the Senate that

...this budget proposal presents no challenges, has no focus, and in fact is a blueprint for a mission to nowhere.

Ouch! However, not all astronauts agree with them. For instance, Russell Schweickart recently wrote that the new direction was a much-needed change. Schweickart noted

Our current situation is akin to being on a dead end road... [the Obama plan] recognizes and eliminates the waste of precious resources in the current program and heads us in a productive direction toward our desired destination. In other words, when you recognize you are on a dead end road, stop, turn around, and head in a direction more useful to your goal.

And of course, my own blog posts ( No Moon and Moon Shot ) significantly elevated the national debate.

Recently The Space Review ran a series on the new direction (see part 1 and part 2 ). The review is somewhat politically-heavy (for instance, worrying that a more efficient NASA will mean less pork to keep congress happy) but basically calls out the main differences of Obama's plan:

We aren't building a big new crew module, but will rely on private industry for many launches.
We aren't landing on the moon again. Instead we'll land on an asteroid.
We are still heading for Mars as an end goal.

Orion in orbit around the moon -- why?
Image courtesy of GDK (wiki)

Obama's plan is good about separating the many phases of launching people and material into orbit. For instance, both the Shuttle and the Constellation programs have the same problem: they use the same vehicles for people and cargo. This is very expensive, since any manned vehicle has huge overhead for safety! Separating the two (launching people and cargo using different vehicles) is much cheaper and may be more reliable--and safer.

Also, Obama's plan puts more funding into private space companies for launches into low earth orbit. This wasn't a viable option ten or twenty years ago, but it is now. And it means that we'll build out our private launch industries, let them spread the risk and try out new technologies, and let NASA focus on other issues such as deep-space propulsion and life support. Much better!

So I understand why many people aren't happy about he change in direction. And certainly Michael Griffin is worried about his legacy. But the new NASA direction looks better and better the more I look at it.

Comments

Related:
  economics
  > science <

Unrelated:
  books
  energy
  environment
  geopolitics
  lists
  mathematics
  predictions

Fri May 7 22:44:43 2010
Tree-Hugger Me
I'm a die-hard environmentalist in spite of my SUV.

This environmentally-conscious SUV also has a snorkel.
Image courtesy of Dazzuko (wiki)

Today I celebrated 6 weeks of commuting to and from work without driving!

This is all because I recently moved (see The Dream Tour), and I can bus to work and walk to almost everywhere I need to shop. I've been mostly commuting by public transit since December, but in March my parking pass ran out so I've been commuting 100% car-free since then. My gasoline consumption has dropped by around 50% or more compared to 2009, even though I often drive into the mountains on the weekends.

However, I still drive a large black SUV that gets really crappy gas mileage. So I can't really call myself an environmentalist, can I?

Well, actually I can and I do.

I was inspired by this story, which pointed out that most people think about environmentally-friendly driving entirely wrong. Most people think that we can help the environment by buying cars with better gas mileage. But as the article noted:

Science shows that cutting miles traveled by personal automobile is far more effective at reducing carbon than improving gas mileage.

So by moving and driving far less, I've actually reduced my carbon footprint much more than had I stayed where I was and bought a Prius.

Don't get me wrong, eventually I'll get a greener car. But it won't be a Prius. It will be an SUV that has cleaner emissions. I need a truck with clearance, room for cargo and gear, and four wheel drive.

That's another thing many people (including proclaimed environmentalists) get wrong, by the way. When it comes to the environment, gas mileage isn't important: emissions are important. The two are related, but they don't have to be. Car and truck manufacturers could be held to much stricter emissions than they are now. Paradoxically, better catalytic converters could slightly reduce gas mileage, but that would be overall worth it.

So what is the responsible, green future for the planet? It won't be suburbia with hybrids. It will be people living much closer to where they work and shop, driving far less, in cars that have about the same gas mileage as now, but with lower emissions. That's going to be a big demographic shift, but it will be better for the atmosphere, and will also be forced by rising gasoline prices.

Comments

Related:
  economics
  > science <
  environment
  predictions

Unrelated:
  books
  energy
  geopolitics
  lists
  mathematics

Links: