musical milliner

January 19, 2012

We Should Become Martians: Part I. ~ Guest Blogger Claude Plymate Returns!

  Claude Plymate is the Telescope Engineer/Chief Observer at  Big Bear Solar Observatory in California, and is the  former chief  wrangler of the McMath-Pierce Solar Telescope at Kitt Peak National Observatory Arizona for many years. He is a regular contributor to Musical Milliner.

It likely won’t come as any surprise to those of you who know me or have read some of my earlier essays that I am a strong advocate of sending humans to Mars. What might surprise you are my reasons which are more about societal needs than about scientific exploration. Our population has now passed the 7 billion mark.

There are indicators all around us that this planet cannot maintain the pressure we’re applying to its resources and resiliency. There is little reason for me to go into the details here; you are all well aware of the risks we are subjecting ourselves to. Global climate change, fresh water depletion, famine, nuclear proliferation, pandemics and war are just a sampling of the dangers we pose to ourselves. On top of our self-imposed hazards, the solar system is in general a menacing place to live.  Asteroid impacts have already wiped out the dominant species on Earth at least once before.  A nearby supernova could disrupt our ozone layer with catastrophic consequences. We are fortunate to have a strong magnetic field and atmosphere that protects us from the harsh radiation coming from solar flares but civilization has left our technology quite vulnerable to such eruptions. It doesn’t appear that a “super flare” will kill us outright but just imagine the disruption to society if the Internet, electric grid, GPS system, radio communications and even telephones suddenly and unexpectedly went ‘dark’– and not just for a few hours but possibly days, weeks or even months!

What I’m trying to point out is that there are many real threats to our civilization and even our existence as a species. Some are self-imposed, some are natural.

This leads us to the question of how to mitigate such threats to humanity.  Consider how you deal daily with risk management of other items you regard as valuable. For example, you wish to protect your documents and photos stored on your computer’s hard drive. What do you do? Of course, you backup your files onto a separate drive stored  in a separate location. (You do back up your files, don’t you?)  Applying this same rationale to society naturally leads to the conclusion that to survive long-term, humanity must expand beyond this one little planet.  Then, even if the unthinkable occurs, all that humanity has achieved won’t completely disappear from history.

The obvious first destination for a human outpost beyond Earth is Mars. Mars is the most Earthlike of the other planets within the solar system. It is close in astronomical terms and has an atmosphere. Mars is a place we can live. Plus, the lower surface gravity of Mars (about 1/4  that of Earth) makes getting on and off its surface much easier than here on the Earth.

Unfortunately, the atmosphere on Mars is very tenuous with a mean surface pressure ~ 600 Pa (0.087 psi), equivalent to an Earth atmospheric altitude of around 90,590 ft (27,612 m). On top of that, it’s a toxic mixture of mostly carbon dioxide. Anyone on the surface would have to wear a pressure suit (space suit). Even this exceedingly thin atmosphere could be used to pressurize suits & shelters. All that would be needed would be a compressor to pressurize the interiors. Simple inflatable structures could even be used for such things as storage, workshops and greenhouses. You still couldn’t breathe in the high CO2 environments but an oxygen mask would be all that’s required for people to work in otherwise shirtsleeve comfort. There are likely many plants that could thrive in these pressurized greenhouses. Obliviously, living quarters would need more oxygen to make a breathable atmosphere which is easily attainable
by liberating O2 from either CO2, water or even iron oxides (rust!) in the soil that gives the planet its red color.

Water means life. We need water to drink, water for crops and water to make oxygen. Recent Mars probes are making it clear that water (at least in the form of ice) is much more common on Mars than previously believed. What is required to harvest the water is energy; energy to drill wells or mine ice, energy to extract the O2. Possible sources for power include solar panels and/or nuclear generators and perhaps even geothermal. I suspect that the atmosphere is simply too thin to support wind power.

There are two primary arguments against going to Mars that people normally state; interplanetary spaceflight is beyond our technical ability and the cost would be far too great. I’d like to address these arguments one at a time.

Stay tuned for We Should Become Martians: Part II next week.

(c)GosGusMusic(ascap)2012

July 12, 2010

Scherzo Tutti: Symmetry Violation

Our resident physicist & occasional guest columnist Claude Plymate offers something for our lazy summer brains to consider.

Symmetry Violation

There is something very strange about the universe we live in and the evidence is quite literally all around us. Go ahead, look around. What do you see? Stuff. Everywhere, stuff. Now that might not seem all that profound at first until you think about the conditions in the very early universe. In the smallest fraction of a second after the Big Bang, the entire Universe was compacted into a tiny volume. All the energy in the Universe was contained it this minuscule space. The temperature was so extreme that matter couldn’t yet even exist! The immense energy density would cause material to spontaneously pop in and out of existence. As the Universe expanded, energy was spread over a greater volume and the temperature dropped. Matter & antimatter began to condense out but would pair up and annihilate almost immediately.

Now we were taught that matter & antimatter are exactly symmetric differing only in the sign of some of their parameters, such as charge and spin. It would seem, therefore, that they should have been produced in equal quantities. But obviously this was not the case. After all the matter & antimatter paired up and converted back to energy, there was a small residual amount of matter left over – all the stuff you see around you! All matter we see today is a result of this minor excess in production of matter over antimatter. Apparently, our Universe has a slight proclivity for stuff versus anti-stuff. The fact that more matter was originally produced is what is known as a symmetry violation. (Specifically CP-violation. “C” for charge conjugate and “P” for parity meaning the particles are mirror images of each other.)

Why there is a preference for stuff over anti-stuff isn’t really understood. As a physicist, it would be more satisfying to have a nice simple symmetric universe but without this complication, the Universe would be a very bland place without any matter to look at, or for that matter, no “you” to look at it. It seems quite profound how perfectly CP-violation is tuned to allow a universe so well suited for things like us to exist. Many might see this as an example of intelligent design by some omnipotent deity. It is all too easy to come to such a conclusion. But, must such remarkable-seeming coincidences require invoking the supernatural? Some might argue “what else could it be?” Not at all if you assume ours is not the only Universe, only one amongst an unimaginably huge and diverse multiverse. It doesn’t matter how unlikely the combination of parameters are, if you try enough examples, you’ll eventually hit upon the ideal magical seeming mix. And of course, we find ourselves in one of the extraordinarily rare universes that is ideally fine-tuned to allow us to exist. If it weren’t, there wouldn’t be any stuff and wouldn’t be any you to look at it.

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Claude Plymate, Engineering Physicist

National Solar Observatory
http://www.noao.edu/noao/staff/plymate
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(c)GoshGusMusic(ascap)2010

May 21, 2010

Strani eventi II: Time Travel Discourse By Our Resident Astrophysicist, Claude Plymate

Wherein Claude discusses his own fuzzy physics and sets things right.

“Okay, how about I take a stab at pointing out just a couple of the problems with the concept of time travel myself? It is almost trivially easy to “prove” time travel cannot exist. Let’s try a simple thought experiment:

Imagine you are a researcher who has come up with a concept for a time machine and after much labor, you’re just about finished with your first test prototype. This prototype is only large enough to send something about the size of a shoe back in time precisely one day. You decide that the first test subject should use some inanimate object like an old shoe. Tomorrow the machine should be ready for its initial test run. To prepare, you go to your closet, find an old shoe and set it next to the machine. Suddenly an identical shoe slides out of the back of the yet unfinished device! Absolute proof that it’s going to work! You excitedly continue work on the final details.

The grand day finally arrived; your time machine is ready to go. You look down at the two identical shoes sitting there and realize that the initial test has to be successful since your shoe already appeared from the machine yesterday. Why, you think to yourself, do I need to send the old shoe through as my first test since I already know that test was successful. So, you decide instead to skip ahead to the second test – sending a live subject through. You take a lab rat from its cage and drop it into the machine.

Hold on, what just happened? Let’s think about this for a moment. You just substituted the rat for the shoe! Where did the shoe that appeared yesterday come from and where did the rat just disappear to? Did you just vaporize the rat? Did the shoe simply appear out of nothing?? Did the rat turn into a shoe??? These are causality paradoxes that obviously can never happen! (So far, this is really just a variation of the infamous “grandfather paradox”.)

Now imagine that you realize these paradoxical questions shortly before dropping the rat into the machine. You hesitate then put the rat back feeling that you MUST put the shoe through to avoid these irrational problems. There is still the problem of a shoe appearing yesterday out of nothingness but you think perhaps the Universe can handle a temporary anomaly such as this so long as it’s paid back in due time, in this case by dropping the shoe into the machine and erasing it from the future timeline. Yes, there seemed to exist two copies of the shoe – but only for one day.

But now you’re not sure which shoe is which! If you drop the wrong shoe into the machine, you’re created yet another paradox. The shoe that appeared yesterday could be the shoe that you put into the machine today. In this case, where and when was that shoe created? It would have popped into existence out of nothing for one day and then simply vanished from the Universe. Another interpretation is that the shoe is stuck in an infinite time loop – appearing out of the machine, being dropped into the machine, going back to appear out of the machine, etc. forever. Just one more paradox without a rational solution! You hesitate again wondering what you should do. You ponder the conundrum until you realize that it too late. It’s now more than a day since the shoe came tumbling out of your time machine. You stand there with a shoe that apparently just came into being out of nothing…

In this scenario the Universe just gained mass in the form of an old shoe. To our understanding, this cannot happen! We know there is a set amount of mass/energy in the Universe that came out of the Big Bang. That’s all we get – no more, no less. (Keep in mind that mass and energy are equated through the handy expression e=mc^2.) A shoe could only appear at the cost of some other mass/energy. Here, the shoe simply appeared. This just can’t happen; there really is no such thing as free lunch in this Universe. (And just in case you missed it, that was a clue.)”

Comment by Claude — May 21, 2010 @ 7:29 pm

(c)GoshGusMusic(ascap)2010

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