Great Spangled Fritillary

I caught this butterfly on a dianthus bloom. Click to enlarge.

No Phone Home—Part 2

Some SETI researchers have asked an intriguing question: If there are civilizations out there, why haven't we received a message by now? In other words, where are they? Well, a mismatch in technology could well be one reason. How do we get in touch with a civilization that may be thousands of years behind or ahead of us? What chance would intelligent creatures on Mars 2500 years ago have had of talking to the ancient Greeks by EM signals from that planet?

I believe that the lack of contact may be explained in a different way, however: simply due to the vast distances involved. I have written a couple of times on this blog about the enormous distances of stellar space. (As a reminder, one of my analogies was to collapse our solar system into something the size of a basketball. On this scale, the nearest star would be five miles away and the nearest galaxy—Andromeda-- would be 360,000 miles away!) It is a huge challenge for us to fathom the actual interstellar distances. 

For example, Andromeda is 1.5 million light years away. To send and receive an EM signal from any creatures in that closest galaxy would require three million years round trip! That's just too long a time span to “phone home” and wait for an answer.

Thus, there may indeed by “life out there”, but it could likely be just too far away for us ever to discover—let alone communicate with. We indeed may not be alone in the universe, but we may never find that out. The universe is simply too big. Would an ant in my back yard have any chance of finding out about similar critters in the rain forests of Brazil?

Let's face it: Earth and its life forms are but the tiniest blip in the universe—in both time and space. We do not amount to much in the grand scheme of things. We are not the center of the cosmos. We are a flash in the pan that will most likely soon be gone.

I think the more relevant question is: Does it matter whether or not there's life out there? We would love to know, but we may well remain ignorant. It matters to some people, because if we were to discover some kind of civilization beyond Earth, it would surely rattle some cages—especially those which contain anthropocentric people, or people tightly attached to religious beliefs that would have us at the center of it all. It's a fascinating question to ponder, but don't hold your breath for an answer any time soon. Maybe in three million years.

No Phone Home—Part 1

One of humankind's enduring questions is whether or not Earth is alone in the universe in harboring life. Are we the only—and therefore exceedingly special—example of animation in the vast cosmos, or might there be others out there? This very question has evolved as our understanding of the universe has grown. The ancients may have wondered about life existing on the other shore of the sea, and people a couple of hundred years ago speculated on beings living on the Moon and Mars.

Today, however, we know much more about the vastness of the universe (even though we may not be able to wrap our heads around how truly vast it is), so now our imaginations extend way beyond our solar system, even our own galaxy, to the billions of galaxies out there. Yet the same question still poses itself, but the potential territory has gotten immensely greater, and thus the possible answers far more manifold.

We also now know much more about how life may have arisen on Earth and the extreme forms that it can assume here. We know that the presence of humans, along with all the other planet's creatures is the result of a long and torturous path that could have taken countless other directions. Some of those other alternatives could easily have resulted in the final termination of life on Earth (it could have come to a dead end and may still), or brought about life forms quite alien to what we know today.

So back to that perennial question: Is there life out there? What chance is there that it bears any resemblance to Earth's critters? Would we even recognize it as life, if we were to encounter it? More to the point, are the distances so vast that we'd ever encounter it? Movies like “ET” offer us fascinating and bizarre creatures who come to visit, and then “phone home,” to return to their world. But any kind of life out there may be simply too far away for us ever to come in contact with, or simply be unable to phone home, because of the tremendous distances.

And the distances are what matters. Humanity has for a few decades been engaged in space communication efforts, in which various researchers have scanned deep space, looking for electromagnetic (EM) signals that distant civilizations may have broadcast to the universe—signals that announce their existence. These projects are labeled Search for Extraterrestrial Intelligence (SETI). The premise is that distant technological civilizations (if they exist) would likely emit EM transmissions, in an attempt to notify other civilizations of their presence. 
 
But is this assumption justified? The SETI project surmises that distant technological species would choose to send out some kind of “I am here” signal, but is this true? Stephen Hawking wrote that this can be a risky process for Earthlings, if we engage in this game, because some life forms that may be far superior to us could thereby discover we are here and subsequently launch space ships to come and dominate Earth.

Another point to consider is that our SETI projects have evolved dramatically, in the last few decades. As our technology has advanced, we come up with progressively better methods of searching. But the civilizations we hope to contact may be centuries or millennia ahead or behind us. They may have developed communication schemes that we either once rejected or have yet to discover. We may be way out of temporal sync with these creatures and miss connecting, simply because our technologies do not match. It could be analogous to Europeans in the 19^th century looking for radio wave emissions from Tierra del Fuego, when the inhabitants there preferred smoke signals.

More on extraterrestrial life next time...

Lions Mane Mushroom

This is an edible mushroom. If it were golden color, it would appear much like a lion's mane. Click to enlarge.

Ultimately Untestable?

Contemporary physics is facing a problem—some physicists would even describe it as a crisis. And as is true for most crises, controversy erupts. Factions appear and engage in debate. Emotions bubble up. Yes, even staid physicists can become emotional, and a few of them even become impassioned.

The cause of this particular crisis is the shortcomings of what has come to be known as the “standard model” of physics. It describes the fundamental behavior of matter—which is essentially the core of physics. But the standard model, although it has been very successful in describing most of the behavior of aggregate matter, does not explain the behavior of elementary particles. The model does very well at the macro level, but is quite useless at the micro level.

Beginning about 100 years ago, a few physicists developed a new micro-matter theory that's come to be called quantum mechanics. It does a very nice job of describing the behavior of subatomic particles—such as electrons, protons, and neutrons. The problem—the crisis—lies in physicists being unable to reconcile the two theories.

What's worse, while the standard model has been verified by countless experiments, that's not true for several aspects of quantum theory. While many predictions of quantum mechanics have been verified by tests, there are some aspects of the theory that seem to be beyond experimental investigation. And that really bothers some physicists. The time-tested scientific principle is that scientific theories must be proven by experiment. So what do you do, when you can't put your theory to the test?

A rough parallel is the theory that was put forth by the Ptolemaic model for the universe—the nearly 2,000-year-old idea that placed the Earth at the center of the universe. Ptolemy's model was very cumbersome and complex, but it explained various phenomena for centuries. It was finally replaced by the far simpler Copernican (sun-centered) model in the 17^th century by Kepler, but his model's proof had to wait until science had the tools to do the experiment and irrefutably demonstrate that the new model was correct. The crucial tool that did the job: the telescope.

Quantum physics today is in a rather similar place. It could be that we may someday have the tools to run the experiments and confirm the correct theory (or correct theories). Yet some physicists are convinced we may never be able to do the experiments. If so, do we abandon the venerable rule that all theories must be testable, or just abandon those theories that can't be tested? The debate continues. Emotions are roiling.