Category Archives: Science

Fermi Paradox – Why can’t we see aliens?

I’ll try to find my Dragon Con presentation from 2014, but here is the question and short answer, for those interested.

Fermi Paradox: With all the stars in the galaxy, there is a high probability of aliens. Why can’t we see them and why don’t they visit?

The first part is simple. We can’t see much of the galaxy. Most of our view is out of the galaxy. If you want to think of our galaxy as rotating around a Z axis,+/- Z is our long view. It is only a few tens of light years. (Still a lot of stars) If you look toward the other directions, we are limited to around a thousand light years.

quarters_general

How big is 100 light years? Imagine that the galaxy is a queen sized bed. Scale runs around 600 light years per inch.

Try an experiment: Take a bunch of quarters and toss them randomly all over the bed. Each quarter is an active, visible, alien civilization. Nice, big pile near the center, maybe a stack by the headboard. A lot of those quarters are touching, right? Those civilizations can see each other.

YouAreHereGalaxy

Good, now put a quarter one foot toward the center from the lower left corner. Did you throw another quarter there? Well, apparently God didn’t either. The Fermi Paradox. There may be intelligent aliens out there, we just can’t see them.

As to why they don’t visit? Because space travel is hard. Star Wars is awesome, Star Trek is sufficient, but both break basic rules. Frankly, if those rules could be broken, they would have been. I expect that we’re always to be limited by light speed. Which basically means our top velocity is 0.1 C. We might plant a colony at 14 light years, but it is a several hundred year trip. The only aliens we’ll ever see with share our DNA.

AC75-1086f

http://blog.longnow.org/02010/01/04/generation-starships-theyre-not-fast/

Weather and Global Warming – Heavy Clouds but, No Rain

global_warming-758157We all want to be proven right. We want to argue with someone and put the evidence in their face. To paraphrase an argument I had on Facebook the other day, over Global Warming.

AGW: “It is December and Warm! Clearly Global warming!”

Science: “It has been this warm in December many times.”

AGW: “But more heat in a system means more bad weather!”

Science: “Cool Magic system you’ve created there. Non-science.”

Of course, this is ironic. Heavy rain does not mean they get their proof of global warming. Unseasonal heavy rain is just that, unseasonal heavy rain. Unseasonal things happen all the time, seasons are, to mis-quote a famous movie pirate: Weather is more of a guideline, really, than a rule.

Ok, so what if the basic premise is correct. We agree that the temperature is 0.3 to 0.4 degrees C higher than in the 70’s or early 80’s. Is the weather worse?

Well, lets look at hurricane statistics. We’ll look at the late 70’s and Early 80’s:

1974 Sep LA, 3 3 952 —– Carmen
1975 Sep FL, NW3; I-AL1 3 955 —– Eloise
1976 Aug NY, 1 1 980 —– Belle
1977 Sep LA, 1 1 995 —– Babe
1978 None
1979 Jul LA, 1 1 986 —– Bob
1979 Sep FL, SE2, NE2; GA, 2; SC, 2 2 970 —– David
1979 Sep AL, 3; MS, 3 3 946 —– Frederic
1980s
1980 Aug TX, S3 3 945 100 Allen
1981 None
1982 None
1983 Aug TX, N3 3 962 100 Alicia
1984 Sep * NC, 2 2 949 95 Diana

10 Hurricane in 10 years. Compare to current values:

2004 Aug * NC, 1 1 972 70 Alex
2004 Aug FL, SW4, SE1, NE1; SC, 1; NC, 1 4 941 130 Charley
2004 Aug SC, 1 1 985 65 Gaston
2004 Sep FL, SE2, SW1 2 960 90 Frances
2004 Sep AL, 3; FL, NW3 3 946 105 Ivan
2004 Sep FL, SE3, SW1, NW1 3 950 105 Jeanne
2005 Jul LA, 1 1 991 65 Cindy
2005 Jul FL, NW3; I-AL 1 3 946 105 Dennis
2005 Aug FL, SE1, SW1; LA, 3; MS, 3; AL, 1 3 920 110 Katrina
2005 Sep * NC, 1 1 982 65 Ophelia
2005 Sep FL, SW1; LA, 3; TX, N2 3 937 100 Rita
2005 Oct FL, SW3; FL, SE2 3 950 105 Wilma
2006 None
2007 Sep TX, N1; LA, 1 1 985 80 Humberto
2008 Jul TX, S1 1 967 75 Dolly
2008 Sep LA, 2 2 954 90 Gustav
2008 Sep TX, N2; LA, 1 2 950 95 Ike
2009 None
2010s
2010 None
2011 Aug NC, 1 1 952 75 Irene
2012 Aug LA, 1 1 966 70 Isaac
2012 Oct * NY, 1 1 942 65 Sandy
2013 None
2014 Jul NC, 2 2 973 85 Arthur

Wow, 2005 and 2004 were huge. 11 hurricane in 2 years – 20 in 10 years. Hugely more. Of course, had I conveniently started at 2006, there would have been 8 hurricane in 9 years. Slightly less. We had a couple bad years, then things returned to normal.

Weird, so if you change your starting dates to useful numbers, you can completely change your answer? Again, the excitement isn’t that the world has warmed. The argument is that the warming is unusual. We Deniers, believe that the warming is natural, not man-made. Will the warming affect climate? That is an interesting subject, but not a politically useful one.

 

 

NASA views

I guess the good news is that NASA is still funding JPL missions to the outer planets. I’m a bit disappointed in their engine selection, some of their mission choices, but overall, it looks like decent return on investment.

This is a view of Pluto. Nothing too exciting, really. There is a certain uniformity in the ice flows that looks artificial, or at least weirdly large-scale crystal formations. Maybe it is just a feature of liquid flow in a very consistent environment. Maybe if we were closer, could get better resolution, we’d see the same pattern going down, showing natural fractal-ization.

So, any point to all this? yes. Choices matter. We do have information on Pluto because NASA has a budget and some will to use it. Most of the money is trapped in bureaucracy, much of the rest goes to Goddard for Earth exploration, but a little goes to JPL for its regular “big mission.”

sp-100-space-nuclear-reactor-2

Getting a nuclear reactor off the ground is still impossible, due to the Greens. A political choice to demonize nuclear power as a way of reducing the spread of nuclear weapons. Weapons are made in laboratories, not reactors. I keep hoping we’ll get sense in the US, but I don’t see much sign of that happening. Without 1) better launch technology or 2) refueling options. There isn’t much hope of a chemical rocket getting good results in the outer system. Too much Delta V to overcome. I’m still betting on a good nuclear reactor and ion drive for future deep-space missions. I guess I shouldn’t hold my breath.

Musical Science – String Theory

Published on Sep 16, 2013

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Dr. Woosley sent this to me the other day. (A brilliant Physicist who also is a friend of mine.) It is a couple years old, but I missed it the first time around. Lovely. Yes, it makes almost no sense unless you’ve done some String Theory reading, (I recommend String theory for Dummies and The Problem with String Theory as primers.) then the words pop out at you fairly well. Ok, does string theory make sense? Yes, but not in any testable way.

Basically, imagine a buddy of yours went to D.C. had a private meeting with the President and some senators, came home with a completely new understanding of how the government worked. One that didn’t fit into laws and such, but seemed to match observable reality well enough. He says that he doesn’t have the ability to prove anything in a court of law, it just is how it works.

You can say that he’s a wacky conspiracy theorist or that he’s a visionary. But, does it matter? Well, yeah, that’s the big question. We can’t seem to figure out Dark Matter, Dark Energy, how forces work at distance, etc. This is my profession, and a lot of it doesn’t make sense.

The fact is, Physics doesn’t know all that much. I mean, we’ve learned a lot in the last 2,000 years. And a good bit more in the last 200 years. But, the last interesting developments were nearly 80 years ago. Sure, the models are getting better, but having the answers makes models work better…not smarter or more correct. (If I know who wins the Superbowl, my model to predict which football team is superior works every time. If I use it at the beginning of the season, the answer isn’t better than 10% accurate.)  The fact is, we’ve been explaining these results for most of 100 years. I have a paper on my desk, from the 30’s, which explains nuclear reactions with “Magic Numbers.” Her predictions were correct to 3 decimal places. Using Schrödinger’s Equations we can get closer, but what does a decimal place or two mean? We have the results to tweak the fomulas with.

string_theory

picture source – xkcd.com/171/

So,  String Theory isn’t too useful, yet, but might be explanatory. Current theory is not providing much of a look into the future, but has the advantage of being testable. I don’t have a solution, yet, but I have hope that someone will come up with one soon.

 

Space Mining

asteroidsCongress Passes the Space Act

https://www.congress.gov/bill/114th-congress/house-bill/2262/text?dom=pscau&src=syn

http://www.popsci.com.au/space/us-senate-votes-to-legalize-space-mining,411747

Space Mining is now legal.

So, technically, you can go mine your asteroid and bring home the materials for profit. A few small problems:

  1. No spaceship can get to the asteroids right now
  2. No mining ships have even been seriously designed
  3. No fuel depots in space
  4. No customer base for space materials

This is one of those self-squaring circles. Once you have space miners, you’ll need fuel depots, which will need/buy space materials, which it can buy from miners, who it is fueling up to go back ….

Unfortunately, absent A -> B there is not B-> A.

There were some presentations at Dragon Con about this state of affairs and I think they’ll go far. It might take a few years, decades, but I think it will happen. Robotics will lead, robotic miners, water depots. Smelters, metal printers.

The real problem lies in creating a self-sufficient world in orbit. That world can have humans in it, then there will be humans there. We’ll begin to live in space sometime, I hope soon.

 

 

Plasma Gun – Mad Science Stories

gun

There has been a lot of discussion the last few days about some fellow who printed a “plasma gun” and was shooting a bb at 450 ft/s. I’ve got some experience working with Dr. Mohamed Bourham back in 1992 – 1995. Plasma Engineering at NCSU. So I feel like responding to the usual threads.

The usual crap is:

  1. This must be fake.
  2. Regulate this before someone gets hurt.
  3. Really this isn’t very impressive.

 

  1. I don’t know much about 3D printing, ask Chad Ramey if you need to know. He runs (ran last year) Georgia Tech’s 3D lab. I’ve done some laser cutting and some milling, mostly plastic but a little steel. But, you can basically 3D print any shape. Usual limitations involve re-curvature and support of extended structures, same as any model building.
  2. Seriously, regulating 3D printing is as purposeless as regulating sex acts between consenting adults. Completely F*d up. Unless you decide to regulate the transfer of CAD files on the internet. You are outa luck.
  3. First off, 3D printing is cool, but milling is better. You can do a much better product with a 3D milling machine and a block of steel. Lexan makes a great ablative barrel material and a good bullet, but that’s it. This is a cute toy which could be sold next to the CO2 powered (paint ball) markers. No more dangerous (unless you shock yourself playing with wiring.)

So, what is a Plasma Gun?

Technical term – Electro-Thermal Chemical Plasma Device. Why? You use an electrical current to heat plastic so that it chemically changes into gas. The gas, mostly Hydrogen, is further heated to become a plasma. You get some Carbon deposition along the walls, which is good for encouraging all the current to flow through the gas. The Hydrogen gets hot, like 30 – 50,000 degrees Celsius. I normally divide by 11 k and call it electron-Volts, so around 3 eV.

The plasma expands at a much greater speed than speed of sound, so it won’t be limited to 1 km/s. Depending on how much energy you can get stuffed into that plasma. Well, a Dragon Con friend of mine asked for a plasma story, so I figure I can write that up today.

So, Here is the story. I was working in the lab and we had an idea to do an experiment, accelerating a 10 gram mass of Lexan with a plasma pulse. We were trying to determine how much momentum was coming down the barrel as a function of V applied. This mattered to some materials experiments we were working on. (Trying to separate out the thermal shock from the physical shock) So Eric and I decided to give it a try.

So, the ETCP device is set up in a wire Faraday cage about 10 feet on a side, lined with lead bricks. Hey, we worked in a reactor, there were lead bricks spare. We built three cubicles out of them, and lined them all with Faraday cages…we made a lot of EMP.

The device is solid stainless steel, bolted to the table, which is bolted to the floor. Very Immobile. The end was pointed directly at the wall, so if we pulled the rear seal off the experiment, the “bullet” er Lexan Mass would fly out of the back and hit a target in the center of the wall. We hooked up a pair of laser beams to measure the crossing speed of our 5 foot racetrack, and got to business.

I carved a bunch of 10 gram Lexan masses. They were about the size of your pinkie fingertip. (Little things) Eric put some bolts into the wall and suspended a chunk of Aircraft Aluminum, 3/4 inch thick, 4 inches wide, a foot long. We ran up a charge on our mass of capacitors. When we got to a good charge, I’d insert a bullet and we’d duck into our control room, turn on the warning light for 5 minutes, and he’d fire the gun. The Lexan converted to plasma on arrival on target, completely destroyed the bullet.

A few hours, a new charge, a new bullet, a new shot, a new velocity. Science! Each shot made a huge, single, noise. Like smacking a garbage can with a hammer. Scared the neighbors something awful.

So, at around 45,000 V, the shot made a sound like ringing a dinner bell, *ding a ling a ding a ling a ding a ling a ling a* It went on for a few seconds, louder, dimmer, louder, dimmer, louder… done.

We looked at each other, what the heck? Checked out the room, no damage, but the target was behind the control station folded in half. Marks on the walls, all the walls. Oh crap. The 10 gram mass of Lexan had folded the aluminum in half and bounced it off of every wall, probably twice. Dr. Doster decided that we didn’t need to be doing that experiment any more. But hey, we got to 3.54 km/s. Beat that.

Future of Space Flight – Interplanetary Civilization

The final question is “Why are we doing this at all?”

  1. The Exploration Gene?
  2. Use of Resources on Earth is Limited?
  3. Protection of the Human Race?
  4. Growth.

thCAYE28X7

  1. There will always be arguments of “Because it is there,” forever and ever. Humans are like that. But honestly, seeing Earth from orbit would be awesome, but the space between Earth and Mars is full up of NOTHING. Almost as bad as space between Earth and Jupiter, Saturn, Pluto, the next star. 99.99999 % of space is nothing. The other 0.000001% is amazing views…which, since we can’t see them with the naked eye, might as well be seen with a camera.
  2. We can extract resources in space without digging up the Earth. Yeah, not so much. There are good reasons to dig up resources in space, but we can cleanly extract resources from Earth for thousands of years before we NEED anything from an asteroid. Especially considering the cost of delivering it to the Earth.
  3. Sure, I would feel “safer” with mankind an interstellar species…but if we can’t make it on Earth, we won’t survive long in space. Filtering Earth water is EASY compared to water rationing on a colony.

Colony: “What is our acceptable Cyanide level again, honey? I think we have a pressure leak in one of the grey water tubes. Well, don’t drink anything till I check for bubbles in the piss tank.” When THAT sentence is comparable to

Earth: “Gosh, I think we’ll need to start a billion dollar desalination plant again or our almond harvest may fail.”

So, 4. Growth.

Science is easy, but its really easy when no one is checking your answers. I can define a specific spectrum as a “Magnetostar, magnetic-spinning neutron star” and have people nod wisely, but … its just a model. Heck, almost everything in Astronomy is just a model. (Really, really good models, don’t get me wrong, this is science, but we can’t really check the answer, can we?)

Engineering isn’t like that. When we build something, you can kick the tires, or whatever it has, and determine if it is better than the previous model. But if you want something good in the future, start building in the present.

In time, humanity will move into space as a natural progress. We will find ways to survive in the big dark, we will extract resources – sunlight is the easy one – and build habitats. In time, we will have an Interplanetary Civilization. Each build is hard, each round of improvements will take decades. People will die. Habitats may fail. But, this is growth.

The development of one project for the International Space Station improved water reclamation from waste by over an order of magnitude. ECLSS.

625727main_eclss_226

https://www.nasa.gov/sites/default/files/104840main_eclss.pdf

Before, we only reclaimed less than 50% of water, now we reclaim 95%. A person used over a cubic foot of water a day, now that is down to cubic inches. Improvements will continue to be made, but they don’t happen automatically.

And those way-out science models drive some of these concepts. When we see a light curve that indicates something passing in front of a star, we get an idea of size. It blocks 20% of the sun’s light… wow, that’s big. It has weird gaps in it… it is cloud-like? It might be a meteor swarm, or it might be a habitat cloud.

Unfortunately, at over 1000 light years, it is unlikely that we’ll ever get answers of engineering questions from these aliens, if they exist. But, if the engineering is possible, we will do it and I’d prefer sooner to later.

The Future of Space Flight – Ion Propulsion

As I mentioned last time, in The Future of Space Flight – Nuclear Propulsion, the nuclear thermal engine is a necessary step for moving cargo and fuel in near-Earth Space. This isn’t to say that nuclear engines aren’t capable of taking us to the outer planets, but the ISP gains still leave us shipping a huge amount of fuel. In the distant future, we may have a fuel depot in the outer planets. I can envision a robotic ice station in Jovian orbit, however, it isn’t near or necessary.

I’d rather not get into the depths of ISP, there is a Wikipedia if you need it, but lets just say that the push part of a rocket has 2 parts (theoretically) the mass of the engine and the mass of the fuel. The ISP really just talks about the fuel needed. ISP of 500 means that 1 tank of fuel gets you to … lets just say 10 km/s. If your ISP changes to 1000, you’d only need 1/2 a tank of fuel to get you to 10 km/s. If your ISP goes to 10,000 – you only need 5% of the fuel your first space ship needed. This leaves out that the engine might weigh ten times more. Meh, Rocket Science is hard.

What is best for near? Ion drives. The Nuclear Thermal engine has an ISP around 1000 s. Maybe, when they cross an MWatt, they may look at one of the enhanced propulsions, which may lead to 2000 s ISP. BUT, that starts trading on excess electric power, which is excess weight. (Not as excess as all that, since you could assume that the delivery of cargo included delivery of a working nuclear reactor, but, this works with Ion drives as well.)

Ion drive? From Hall Effect to VASIMIR, they involve the same things:

  1. Heat something up a lot. (Argon, Helium, Lead) till it becomes an ionized gas. (Shoot the lead with a laser, works fine.)
  2. Confine and heat the plasma
  3. Let the Plasma Escape, slowly, at great temperature.

The VASIMIR has a low-ish ISP, around a few thousand, but the thrust can be significantly higher than Hall Effect thrusters.

VASIMR_system

VASIMIRs are good for near planets, where the balance of thrust and low fuel use gives you short mission times. You may drop the Mars trip, a distance 1 – 3 AU depending on date, to six months or less. Very reasonable. Jupiter, at a distance of 4 -6 AU, would take about a year. However, at that time, we start getting in fuel to mass ratio issues again.

The Hall Effect Thruster may have an ISP on the order of 40,000.

Hall_thruster

XHT-1

What does that “MEAN?” It means that a ship with a Hall Effect thruster will have a very high final velocity. It may take years to reach that velocity. Hall Thrusters usually run about a ten micro G. A push felt that would leave an adult male weighing in at 220 lbs on the Earth, at about 1 gram on the spacecraft. Literally, you couldn’t feel the thrust.

Now, Alta’s Hall thruster has much lower ISP (factor of 10) and much higher thrust (factor of 10) than theoretical, but that’s one of the trade offs. If you design a mission, the farther away you are going, the lower, constant, thrust you can deal with if your ISP is high enough.

Your final velocity could easily be in the 10’s of km/s. Velocities like that let you get to Pluto with enough fuel left to park, not just fly by into infinity. Had the mission designers agreed to a better power supply for the New Horizon mission, then they could have selected an Ion drive, and be parked around Charon as we speak.

Not that I think Pluto is anything but a big comet, but think about a decade of data, instead of one picture. That’s the future of spaceflight.

Pluto-NorthPoleNEW

 

Global Warming – Modeling and Measurement

Initial Note: The temperature is measured at present at 0.5 degrees above baseline. The temperature increase from baseline may be caused by many factors, including CO2. Experimental data is needed to verify the models.

We can thank Dr. Hansen for his work disproving the effects of CO2 on global temperature. His work appears to disprove the catastrophic anthropogenic global warming theory. I understand, that as he has made millions of dollars promoting global warming, he probably doesn’t see this result as publishable.

hansen warming predictions

Figure 1. Hansen’s models of global warming following a steady increase in our production of CO2 (1.5%), a continued production of CO2 at the current (year 1989) rate, and an abrupt halt of producing CO2.

On Figure 1, you can see that Dr. Hansen predicts a large increase in temperature driven directly by the increase of CO2 in the atmosphere. Temperatures by 2015 are 1.5 degrees above baseline. While the US and Europe have reduced production of CO2 significantly, world production of CO2 remains significantly above year 2000 levels, leading to the top line prediction being the predicted outcome.

hansen warming results

Figure 2. A combination of Figure 1 and current temperature data.

On Figure 2, you can see the current temperature data plotted along with the predictions made in Hansen’s model. It is clear from observation that, with the exception of 1998, the data falls along the lowest line of prediction. 1998 has been explained as a specific Pacific Ocean event, resulting in the hottest year on record.

Conclusions: The model which contained no CO2 forcing more correctly predicted the future than either model which contained CO2 forcing. CO2 forcing does not appear to correctly predict future temperatures.

Further Study: CO2 is known to absorb specific bands of IR light at 2349 cm−1 and at 667 cm−1. Addition of CO2 does increase absorption of heat in the atmosphere at those two wavelengths, however, those wavelengths may be sufficiently filled such that no further addition of CO2 causes added absorption. However, that is just a theory and needs further modeling and experimental data to prove. Alternatively, the current heating may have nothing to do with CO2. The CO2 heating may become significant at some future partial pressure. Again, modeling and testing is needed to quantify this assertion.

The Future of Space Flight

The other day, on Facebook/Twitter, I reposted a snarky comment.

“It’s amusing seeing NASA try to use The Martian to build support for their Journey to Mars. Using hard sci-fi to help sell fantasy…”

Why can’t NASA launch a manned mission to anywhere?

  1. Because it is a bloated bureaucracy
  2. Because “safe” space travel is nearly impossible, and politicians don’t waste their precious vote capital on anything but sure things.
  3. Because it takes 10 years to do a mission. Presidents only last 8. It makes no political sense to make your predecessor a hero. Obama cancelled Bush’s Constellation, whoever comes next would cancel Obama’s mission priorities…if he had any.

JPL runs a tight ship, so I’ve been told. They put instruments on planets. However, deeply unsexy. They tried hard to sell New Horizon, I doubt anyone heard about the Pluto fly-by that didn’t have a space-geek in the family. The last popular mission was Mars, Spirit… landed in 2004. It has been a decade since “normal people” downloaded space images from the internet.

SO, NASA needs a road map that is unsexy and can be followed without glorifying the name of any sitting president, meaning cheap as well.

  1. Get to Low Earth Orbit, LEO

1024px-X43a2_nasa_scramjet

I love space planes. Get them up to MACH 9, hit the outer limits of the atmosphere, release the cargo. The cargo is traveling at escape velocity, a little bit of thrust and it docks with the ISS.

There is a bit of trouble with space planes, they need to be going about MACH 3 before the Scramjets will kick-on.

Launch_ring

SO, we build an accelerator which gets them up to speed on the ground. (I prefer a 10 mile linear, but the ring is an easier picture.)

Do able? yes. Cheaper than rockets? considerably. Further, they fit into the skillset we currently have, not the one we wish we had. We know all about airplanes, we know very little about space travel. We’ve been working with balloons, gliders, and powered air vehicles since the 1700’s, rockets are new-fangled in comparison. We have MILLIONS of hours of air travel, considerably less in space. Work with what we know.

This is only step one, more soon.