Showing posts with label SolidWorks. Show all posts
Showing posts with label SolidWorks. Show all posts

Wednesday, December 21, 2016

Habitable Worlds Around Binary Star Systems might not match Sci-fi

It's hard to talk about planets in binary (dual) star systems without mentioning Star Wars: A New Hope.  The famous scene of Luke Skywalker standing and looking off into the distance while two suns appear near the horizon is iconic.  However, there's a problem with that iconic scene.  The problem is a not full-fledged error, just an unlikelihood: both suns appear as the same size in the sky in very close proximity to each other.  The reason this is unlikely is due to the two types of planetary orbits in binary star systems: s-type and p-type.  A planet in either type of binary system would rarely see both suns as the same size in the sky and that close to each other, even if the suns are the same size.

S-type is the name for the orbit of a planet that revolves around just one of the two stars within a binary system. P-type is the name for the orbit of a planet that revolves around both stars within a binary system, having a common barycenter (or center of mass) with the suns as the suns orbit around each other.[001]

S-type orbits are interesting, but for this article, I'll cover P-type because this is more interesting to me when talking about Habitable Zones, particularly where the suns have similar masses.  Of course, even with p-type orbits, there exist many possible varieties for how the suns can orbit each other.

The ability of a planet to maintain liquid water depends on the interaction between stellar radiation and the top of its atmosphere.  Also, that interaction is complicated in a binary system.  There can be substantial difference in energy received by the dual suns.  Sometimes both suns appear side by side in the sky, providing maximum energy.   However, when one sun is eclipsed by the other, the amount of energy is lessened due to the closer sun blocking the stellar radiation from its partner.[001]

In either case, this variation in stellar radiation can limit how small a planet's orbit can be around the dual suns and still be capable of harboring life.   As stated in Calculating the Habitable Zone of Binary Start Systems II: P-Type Binaries:
This interaction strongly depends on the stellar spectral energy distributions implying that stars with different energy distributions will contribute differently to the absolute incident flux at the top of the planet’s atmosphere.[001]
Even with all of these factors, planet formation within the Habitable Zone of a binary system would be similar to that of a singular star system.[001]

Common binary system and P-type orbit
Two suns of similar mass with elliptical orbits around a common barycenter
Another common binary system and P-type orbit
   Two suns of similar mass in the same orbit around a common barycenter

Where two suns are of the same size, their location to the planet can vary greatly depending on the size of their orbit around their common barycenter.  If there is a wide orbit, it is safe to assume that one sun will provide more energy than the other sun which is farther away.  In this case, the further sun would appear smaller in size within the sky, even though both suns are of the same mass.  The graphics above suggest why the iconic Star Wars scene isn't likely accurate.  The scene is possible maybe one or two times per year if the suns are in similar orbits which are tight and circular; or in rare instances where the suns have elliptical orbits and the planet just happens to be in the right place at the right time.


Close up of Alpha Centauri A and B, NASA photo
Here's a close up of Alpha Centauri A and B. Their distance from each other can be as much as 11 AU's, which would make a type-p planetary orbit so large, that habitable planets would be unlikely.  Planets have been discovered in type-s orbits around Alpha Centauri B and their sibling Proxima Centauri.

HZ reference:
N. Haghighipour, L. Kaltenegger, The Astrophysical Journal, 777 (Nov., 2013) 166, arXiv:1306.2890 [astro-ph.EP], Calculating the Habitable Zone of Binary Star Systems II: P-Type Binaries 

Hacker News

Friday, September 09, 2016

Limited lifespan of Habitable Zones around other stars [and a loosely held secret finally revealed about me]

Habitable zone around a red dwarf, image © Matthew Lorono, 2016
Habitable Zone around a Red Dwarf star
I've been fascinated by the idea of planets around other stars since I was young.  In fact, I developed several fictional solar systems, one of which became the basis for an online gaming and science fiction club.  That solar system is called Greeop System,[001]  which inspired the development of many more solar systems and formed the basis of many gaming and fictional story plots.[002]

At some point, I stumbled across the book Rare Earth: Why Complex Life Is Uncommon In The Universe (2000), which is one of the earliest sources that discusses the idea of Habitable Zones around stars.  

What's a Habitable Zone?  If a terrestrial planet orbits its sun at just the right distance, that sun provides the right amount of light and other energy to make life more likely, given several other factors.  If a planet is too close to its sun, it is likely too hot.  If a planet is too far from its sun, it is likely too cold.  This is why Habitable Zones are sometimes called Goldilocks Zones, in reference to the fairy tale Goldilocks and the Three Bears and finding options that are "just right" between two extremes.

In the past decade, the concept of Habitable Zone has been refined.  From the study Habitable Zone Lifetimes of Exoplanets around Main Sequence Stars, it is now often defined similar to,
...the circumstellar distance at which surface temperatures allow liquid water to be present on the planet’s surface, assuming variable H2O/CO2/CH4 greenhouse forcings.  The Habitable Zone has a minimum and maximum extent, forming inner (closer to the star) and outer boundaries that are set in part by biogeochemical climate feedback mechanisms and stellar luminosity.[003]
Yeah, Goldilocks metaphor seems to get the point across easier.  The question is, what's "just right" for life?  Star size and age appear to play the substantial roles in setting the limits of a Habitable Zone.  Not only is the Habitable Zone different between large and small stars, it can move over the life-cycle of a star. For example, main sequence stars gradually output more energy over billions of years.  A planet that initially forms within the Habitable Zone of a young star might not remain in the Habitable Zone later in the star's life-span. It is predicted that our Sun will be so hot in 1.75B years, surface water will no longer be possible on Earth, presumably making life on Earth no longer sustainable.[003]

If a planet has the right conditions and resides within the Habitable Zone, life still has to appear and evolve in some sort of sequence.  Taking Earth as the only example we have,
... this stepwise progression began with the origin of life, continued through the transition from replicating molecules to RNA and then DNA [1B years after Earth formation], from prokaryotes to eukaryotes [1.5 to 2.5B yrs after Earth formation] and cell differentiation [3.5 to 4B yrs after Earth formation], and concluded with the final step from primate to human societies [4.54B years after Earth formation].[003]
However, if just one of these steps takes a lot longer, there is a drastically lessen chance of having enough time to develop intelligent life similar to humans; assuming the march toward more intelligent creatures is inherent to the process of evolution on different planets.  Different stars may also extend or reduce the time-frame within which life may appear and develop.  Larger stars will have short Habitable Zone lifespans.  Smaller stars, such as Red Dwarfs may have very long and stable Habitable Zone lifespans.

Of course, a lot of this is based on assumptions that life on other planets will resemble life that formed on Earth.  Maybe life of different kinds exist in the Universe.[004]  The rules may be different for different kinds of life.  Maybe Earth is extremely unusual. Worse, maybe we will not be able to immediately recognize other forms of life simply because it is so different from our experience.  As more information is gathered, these issues will hopefully be addressed.

Pirmary reference:
Andrew J. Rushby, Mark W. Claire, Hugh Osborn, and Andrew J. Watson. Astrobiology. September 2013, 13(9): 833-849. doi:10.1089/ast.2012.0938, Habitable Zone Lifetimes of Exoplanets around Main Sequence Stars.


Sunday, October 28, 2012

Recent trip to Lancaster, PA

Well, of all the things not on my bucket list that I got to experience anyway, I woulda never have guessed that I'd passing an Amish horse-and-buggy on state and city roads.  Yet, there I was in Lancaster, PA, the heart of Amish Country. 

At Hersey Restaurant and Inn (no where near Hersey, PA)

I was in Lancaster, PA for a SolidWorks 2013 rollout event to show off the newest version of SolidWorks to our customers.  I don't normally talk about SolidWorks on this blog too much because it's a bit specific to my career, but this story would be incomplete without mentioning it.

SolidWorks 2013 rollout event

On some roads in Amish Country, there are special lanes where trails of horse "exhaust" mark the way, showing clearly which lanes are for cars, and which are for carriages.  There was a lively conversation on a my Facebook posting about driving through Intercourse, PA.

Amish horse and buggy

A funny thing about the Lancaster area are the references to Dutch culture.  This is a bit odd since Dutch influence on Pennsylvania is a bit light.  There is a substantial German population in the Lancaster region who are sometimes referred to as Pennsylvania Dutch, but this is a misnomer that comes from the archaic term that refers to people from Germany.  They aren't Dutch we know from the Netherlands.  Even still, images of old fashion windmills are invoked.  Maybe I'm missing something here.

Another thing that impressed me about this region as its beauty.  I took no pictures to demonstrate this beauty, unfortunately.  Rolling hills of farms and trees and rustic buildings meld together like a series of landscape paintings I've only seen in books.  Words (and even simple photographs) could not due it justice.

Would I go back to this region?  Prolly not going out of my way to visit it again.  I am glad I got a chance to see it, though.

Friday, February 05, 2010

Avatar now highest grossing movie ever? No.

I got a chance to meet James Cameron this week. I told him I liked Dark Angel, while I was having my photo taken with him. There, you can see me saying out of the corner of my mouth.

I do love Avatar. I've seen it once in AMC's fake IMAX theater in 3D. I want to see it again soon. This week, it has become the highest grossing film of all time in terms of actual dollars. However, it is not even close to being the highest inflation adjusted grossing film of all time. Right now, Avatar is #21 and Titanic is #6. Adjusted for inflation, the highest grossing film of all time is actually Gone with the Wind currently at over $1.5 billion, followed by Star Wars at $1.3 billion in today's money. These numbers are well over double Avatar's earnings of $603 million.

Though it doesn't benefit me at all, I am rooting for Avatar to approach those numbers. If Cameron can keep the magic of this new franchise alive, the rumors are that this movie is the first of a trilogy. My hope for any sequels is to not allow familiarity with the characters to interfere with making two more great films. Star Wars balanced this fairly well with its first sequel, Empire Strikes Back, but lost much of its magic since. Here's to the hope of continued high quality entertainment from James Cameron!

Tuesday, November 10, 2009

Tuesday Two: SolidWorks World edition

Tuesday 2 header

There's been many inventions and innovations that have been profiled at the various SolidWorks World conferences. This week's Tuesday Two covers to wind power winners that are getting notice.

Tuesday Two

Mageen airborne Wind PowerMagenn has an innovative balloon wind power generator which goes by the name Mageen Air Rotor System (MARS). It floats far above the ground to take advantage of wind that is more reliable than ground based turbines. Here's an ancillary article in Design World on material used to make MARS.

Microwind TechnologiesJeff Ray gives us an update on MicroWind Technologies which makes relatively small rooftop wind turbines called MicroWind Residential Turbine which will be able to produce 3 kW. They also have the MicroWind 300W which can be lamp post mounted.


The Smart car that just isn't all that smart. It is not much bigger than a go cart, while only netting 41 MPG highway (which is worse than many real cars already on the market). Too much is sacrificed in both functionality and safety for no real gain; and don't get me started about the price for the "well equipped" version! For that, it recently ranked as the worse car of the 2000's by, not to mention it wins this week's Epoch-Fail award!

Thursday, February 14, 2008

Nothing like San Diego

There's nothing like going to San Diego and then not being able to just relax and do nothing. I was there recently, and missed the great weather and the rainy weather too. Why? I was in doors all day at a convention for the engineering software I use called SolidWorks. I learned a lot, and was able to make a lot of contacts with others in my field. However, the only time I got to really get out and enjoy San Diego was after the sun was down. The block party that shut off several blocks of the Gaslamp Quarter that the convention organizers put on one evening was a lot of fun. Nothing beats the flow of free beer.

Monday, January 21, 2008

Evening in San Diego

I'm in the Gaslight district in San Diego,
by chance the San Diego Chargers played
there play-off game against the New
England Patriots. Now that the game is
over,and the chargers have had there ugly
loss, the mood here is very subdued. Blue
and yellow balloons hang low along the
street outside of bars and rest'rants as
their helium deflates almost was quickly
as the Chargers. Fans are along walking
slowly in that sort of walk the commutes
'I don't really care...(but it's obvious I
really do.)'

Goodnight Chargers. BTW, what is a charger anyway?
___Sent with

Saturday, April 21, 2007

Super Geek

I recently went to a users group meeting for SolidWorks. SolidWorks is a 3D modelling program that engineers use to create components on the computer to have them made in real life. The fact that I feel I have to explain this may suggest that perhaps this is a geek topic. Well, in the wrong context, this can be a bit of an embarrassment to some. ::Queue wrong context:: (-:

At this meeting, for some reason they had these car large magnets that said something like "I design with SolidWorks". Not exactly the coolest statement around. Most everyone at the meeting was like scratching their head as to why SolidWorks would make these things. But, of course, I immediately realized their value. I picked one up.

I waited for the ideal opportunity to put this magnet squarely on the passenger side door of my coworker's 1989 Nissan Z. This opportunity came on Tuesday (a couple weeks ago). So on that Friday morning, Elvis comes in to work and precedes to tell me how he has been rolling all around town the day before, only to discover to his horror this magnet on the side of his car. He even explained to me why he didn't notice it right away (cuz he doesn't see the passenger side of his car very often). The only reason he found it is because he happened to need to get something from the right side of his car that night (Thursday). He was telling me this first because he knew the thoughtful gift was from me.

Of course, being the good friend I am, I made sure he knew just how long it had been on his car, since that Tuesday lunch time. He was all, "Oh man! You mean I went all over town with this super geeky thing on my car? I went [to the local college] for an evening class, rolling around pimpin' in the parking lot, laid back with my arm up on the wheel [straight armed]." Elvis takes classes at the local college in order to meet girls. So, all the while he was rolling around with confidence, he had this super geeky magnet on the side of his car, proudly displaying his inner geek for all to see.

My only regret is that I didn't pick up more of these magnets to plaster all over the passenger side of the car to amp up the humiliation, NASCAR style.

Wednesday, January 24, 2007

SolidWorks Yahoo! Group revival

The story of the SolidWorks Yahoo! Group revival begins way back in Feb 2006. I was looking for new macros that I would use to improve work flow on SolidWorks at my company. I looked everywhere online. One of the places I found was the SolidWorks Yahoo! Group. It was fairly active, with professional participation in discussions about SolidWorks. There was a problem, however.

I tried to contact the group owner, but never got a reply. Eventually, I started looking into why the group was unmoderated. The owner had disappeared; bouncy, bouncy. No one else was assigned to run the group, so the group was left to the elements, those dreaded spammers. Well, the rule with Yahoo! Groups is ownership cannot be transferred except by the owner. Since the owner was bouncy, there was no hope. I forget about the group for awhile. Then, in November, I checked it on a whim. It appeared that SolidWorks users where still actively using the group to post questions and answers.

It got me thinking that maybe, just maybe I could take ownership of this group to revive it. So, I contacted Yahoo! Groups with the following feedback comment:

Are you a... Member

Subject: Other

Type your feedback here: The moderator of SolidWorks yahoo group is not maintaining it, and has a bouncy email address. How does one claim control over a group that is experiencing this kind of neglect by still has large potential value to its members?

I waited for a few days before receiving this boiler plate response:

In a message dated 11/28/2006 11:49:36 P.M.
Pacific Standard Time,


Thank you for writing to Yahoo! Groups.

I have received your email and you are asking on how does one claim control over a group. I appreciate you contacting us and I'll be glad to assist you on this matter. I have checked the Yahoo! Group "solidworks", and it shows that the owner's account was bouncing. However, in as much as I would like to accommodate your request, I cannot appoint a new owner or moderator to the group as specified in the terms of our Privacy Policy. What I usually suggest is for you to contact the Group owner regarding this issue of handing over group's ownership. You may send an email to: In the event that the owner can no longer be contacted, one alternative is for you to create your own group and send out invitations to those people who you would like to join your new group. I appreciate your utmost patience and understanding with regard to this matter. If you have any other concerns, do not hesitate to get in touch with us. Thank you again for contacting Yahoo! Customer Care.


Shelley, Yahoo! Customer Care

Well, the bureaucratic wheels are churning. There was even double-speak that was self-referencial. At this point, I know I have one chance at getting what I want. My reply will have to be forceful and direct, with points with which cannot be argued. Here's my Hail Mary:


Thank you for your reply.

I do realize that there is a Yahoo policy against the transfer of ownership
for yahoo groups. However, in light of this situation with SolidWorks yahoo group, I (as a Yahoo customer) feel that such a rigid and absolute rule on the matter is counter productive to members of Yahoo Groups in general (not just in regards to SolidWorks yahoo group). Though I don't speak for the SolidWorks Corporation, the name "SolidWorks" is a trademarked name whose customers would benefit from having the only Yahoo Group that bares that exact name being made active again. Customers are users that are working, educated professions that seek convenient interaction with other customers of SolidWorks. A new group creates confusion and increases the lack of interest in using Yahoo Groups at all for this purpose.

Also, if the current state of SolidWorks yahoo group is an indicator, with so many groups without reachable owners or moderators, Yahoo Groups appears to be cluttered which makes the over all Yahoo Groups less valuable as a service, in general. As a matter of customer service, I request that you reconsider your policy in regards to the transfer of ownership for groups whose owners are bouncy for more than six months. Moderators should be able to claim a group at that time. If no moderators exist, members should be able to petition for ownership directly to Yahoo. To avoid spammers from taking charge of groups for professional purposes, set criteria for the approval of those petitions.

Matthew Lorono
Santa Clara, CA

The reply I think got surprized me. Yahoo! Groups staff stepped up the plate.

Hello Matthew,

Thank you for
writing to Yahoo! Groups.

We appreciate your comments on this matter and can understand your concerns.

Because your group is not currently moderated, we may be able to appoint a new moderator for the group. If you would like a new moderator for the group, please start a poll using the group's polls feature and list the member names of a few members, who would like to be a moderator, as choices for the poll. Please announce the poll to your group and ask the members to vote on who they would like to be moderator. Once the poll has closed, please email me back and I will appoint the "elected" moderator. I do apologize for any inconvenience.

Thank you again for contacting Yahoo! Customer Care.

Gidget, Yahoo! Customer Care

The squeaky wheel gets the grease! This is how we do it! And I even got a reply from some girl with an overly cute name.

So, I left a message on the group asking for volunteers. Two people piped up. Of those two, only one had a history of contributing to the site. So, I put that person up, and myself as the two options in the poll. A month later, I closed the poll and notified Yahoo! Groups staff. I wondered if I would hear from this "Gidget" again?

Gidget (Customer Care),

Per your requirements (see Customer Care email below), I have run a poll for the SolidWorks Yahoo Group to determine a new "elected" group moderator, because the group is not currently being moderated. Two individuals with a history of contributing to the site were self-nominated for this poll. The person with yahoo id maccormackc (Chris MacCormack, who is cc:'d on this email) won the poll results. Please appoint maccormackc as the new group moderator for the Yahoo! Group SolidWorks as soon as possible.

Thank you for your prompt action in advance.

Matthew Lorono

Well, Gidget did not respond back. However, Derek did respond back with the happy news.

Hello Matthew,

Thank you for contacting Yahoo! Customer Care.

The situation you describe has been completed.

We apologize for any inconvenience this issue may have caused you. Please be ssured that we'll do our best to prevent such problems in the future. If you continue to experience the problem, or if we can be of assistance in another matter, please let us know by replying to this email. If you can describe in as much detail as possible the problem you are having, any steps you take leading up to it, how frequently it ccurs, and the exact text of any error messages you receive, it will help us to provide a solution more quickly.

Thank you again for contacting Yahoo! Customer Care.


Derek, Yahoo! Customer Care

Derek was no Gidget, and his response didn't make much sense, but he gave me what I wanted, and that's all that mattered! ;) After a couple of days, Chris and I began to revive the group, adding content, removing spam, banning spammers, approving new members, etc. And
it now appears to be getting the attention it deserves! The main guy at the SolidWorks corporation that manages user groups has just joined and may contribute to the site as well! Kudos!