From the Director

Rex

 

 

 

by Rex Parker, Director

May 9 meeting – election of officers. We’ve come around in our orbit to the point when we elect officers again for the next season of AAAP. Or re-elect, because each of your officers has agreed to stand for another term. All members are urged to attend the May 9 meeting at Peyton Hall to give us your vote of confidence, and we do need a quorum.

This is an appropriate time to acknowledge those who have made this year an interesting and enjoyable one for AAAP. I’d like to thank Ira Polans (Program Chair), Michael Mitrano (Treasurer and chief carpenter), Larry Kane (Asst. Director), and Jim Poinsett (Secretary) for their key contributions and dedication as officers and trustees — and I’m very happy they have agreed to serve again. Others in the club made important impacts this year. I’d especially like to thank Prasad Ganti who worked with Ira and got several of the excellent program speakers this season. Further thanks go to Surabhi Agarwal for website improvements and to Surabhi and Tony Coventry for co-editing Sidereal Times; to Bill Murry for making the Planetarium a bigger part of our club; and to observatory co-chairs Dave & Jenn Skitt for driving the observatory improvements and keyholder training. Outreach is becoming an even bigger part of our mission as a club, and Gene Allen has recently agreed to join with Dave Letcher on the outreach committee. Finally, thanks go to all of the observatory keyholders (33 at last count) for representing AAAP to the community and making observatory public nights successful and fun.

AAAP Activities Coming Up

  • Celestial Refresher at the State Planetarium (May 13 at 10AM). We’re holding an astronomy night sky refresher session inside the dome so that members can improve deep sky skills away from the public and occasional pressure of finding and showing others. The Planetarium’s technical capabilities will be on display as AAAP member and Planetarium staffer Bill Murray runs the system. Location: NJ State Museum, 205 W State St in Trenton, park at the lower level near the Planetarium entry doors.
  • Members’ Nights at the Observatory (2 Saturdays, May 27 & June 24, dusk till midnight). These nights are reserved for AAAP members (you’re welcome to invite friends and family) at our Observatory at Washington Crossing State Park, NJ. This is a terrific opportunity to learn more about observing and telescope equipment, and get to know others in the club. Even if you know little or nothing about telescopes (especially so) we want to see you out there! Check out the new equipment and software which have improved the observing experience. Experienced members are asked to bring their telescopes to show others. See the website for directions.
  • Solar eclipse plans (Aug 21, 2017). If you want to join in on the Eclipse trip to Oregon, it’s essential that you make plans as soon as possible — please contact assistant director Larry Kane (assist.director@princetonastronomy.org). The chosen locale near the town of Monmouth OR, where one of our members has a family connection, is in the path of totality across the U.S. from Oregon to South Carolina. Of course, a clear sky is key, and August weather considerations are favorable at this site. NJ and surrounding states will see only a partial eclipse, far less impressive than totality.

What fraction of the sky do we actually see in a telescope? At last month’s meeting we considered the size perspective of observing through the eyepiece of a telescope. To revisit that idea, here’s the slide (below) I showed giving the geometry and math. We concluded that the field of view using the equipment described is only a tiny fraction of the entire sky, about 1/31000 or ~0.0032% of the entire sky (considering the sky over a year). Yet the full moon seems so large! Of course, what this really means is that we have a lot of observing to do in the months ahead…

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From the Program Chair

By Ira Polans

The May AAAP meeting is on the 9th at 7:30PM in Peyton Hall on the Princeton University campus. The talk is on “Dense Gas in Distant Dusty Galaxies” by Dr. Andrew Baker of Rutgers University.

To understand how galaxies evolve across cosmic time, we must understand not only their dark matter and their stars, but also the properties of their interstellar gas, from which new stars form and into which old stars release the products of nucleosynthesis. Cold, “dense” gas, in which hydrogen is largely molecular, constitutes one of the most important yet elusive components of galaxies’ interstellar media. Dr. Baker will describe how radio astronomers use molecular emission lines to detect and characterize dense gas in galaxies. He will then explain how observations of distant galaxies allow us to determine their dense gas masses and their exact distances. Such observations are especially critical for understanding recently discovered populations of galaxies that are so heavily obscured by interstellar dust that they cannot be effectively studied at optical wavelengths.

Prior to the meeting there will be a meet-the-speaker dinner at 6PM at Winberie’s in Palmer Square in Princeton. If you’re interested in attending the dinner please contact program@princetonastronomy.org by noon on May 9.

If you have suggestions for speakers please send them to program@princetonastronomy.org. Please provide the speaker’s name, topic, and affiliation. Thanks!

We look forward to seeing you at the May meeting and the dinner!

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Minutes of the April 11, 2017 meeting of the AAAP

by James Poinsett, Secretary

• The director, Rex Parker, called the meeting to order.

• There will be a night sky refresher at the planetarium of the NJ State Museum on Saturday, May 13th at 10:00 AM, all members are welcome to attend.

• There are members nights scheduled at the WC Observatory on Saturday May 27th and Saturday June 24th. All members are welcome, refreshments will be available.

• Mercer County Park Association is planning a campout on the summit of Baldpate Mountain on the night of August 11th for a Perseids viewing party. They have asked our assistance as night sky guides.

• Some club members are meeting near Monmouth, Oregon for the August 21st total solar eclipse. If you want more information contact Larry Kane or John Church.

• It is election time and the current Board of Directors has agreed to run for another term. If anyone else is interested please notify Gene Allen to have your name added to the slate. The current board is director:

     o Director – Rex Parker
     o Asst. Director – Larry Kane
     o Treasurer – Michael Mitrano
     o Program Chair – Ira Polans
     o Secretary – Jim Poinsett

• Rex sadly informed us that former director Dick Perry has passed away.

• There is a proposal to add Outreach and Observatory Chair positions to the board of directors. The procedure for doing this will be discussed at the next board meeting.

• There is a proposal to add a committee to help the Outreach Chairperson, the board will discuss this at the next meeting.

• Participation in outreach events has fallen off, please make every attempt to help the club reach potential new members by participating in outreach events.

• There was some discussion on how much of the night sky are we seeing through the C14 telescope at the observatory. It was concluded that using the Nagler31 eyepiece we are seeing about 1/31000th of the night sky.

• Communiversity was held on April 30th, AAAP had a table at the event.

• The Stokes Star Party was held on April 21st and 22nd.

• Larry has the logo and will be ordering shirts, details to follow at the next meeting.

• The meeting was adjourned.

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quantum entanglement.

by Theodore R Frimet

pass the uranium, please.

It was 10 marbles for 99 cents, plus shipping, and I couldn’t resist. Imagine, uranium embedded into glass. Not a new thing, of course! Uranium glass has been around before there was electric light. Imagine having a uranium glass vase, seated by the window, catching glancing photons from the setting sun. And glowing…green. Aside from radioactive glass being, well, very cool, and out-right geeky, I was becoming transfixed on some purposeful use of uranium marbles.

It started with an attempt to find a science book, on line, in MP3 format from our local library. And I was not disappointed. I found, Entanglement, by Amir D. Aczel and installed and downloaded Overdrive onto my iPhone as quickly as I could. Azcel thoroughly presents the topic and makes it a point, to repeat key concepts and re-weave them into the storyline. Although more of a history of science, there were many tidbits that got my juices going. And my mind seemed to wander off to new horizons.

The new horizon seemed to become entangled. I found old thoughts, become washed anew. Last year, during one of our AAAP Friday night observation, I shared a thought with an astronomer that the nebula that we were viewing, was gas a-glow from ultraviolet light emanations from the white dwarf, contained within. Reradiating light, it seems, was perfectly rational. Photons, being well, photons, would excite electrons in the nebula to higher energy states, only to settle down into a lower energy state, and re-emit a photon in the process. Hence the glowing. What I was unaware of, was that there is also a process called down-conversion. And now, being titillated with a new concept, I was apt to apply it..somehow..somewhere..

I gleefully put together an email to a scientist that knows how light propagates thru a medium, and started my suggestions on green glass, and somehow ended up asking if gravitational lensing, causing Einstein rings, entangles light. Re-reading the email, I must have bit my lip, because, at the least, I never suggested having two or more telescopes aiming at the phenomena to capture entangled photons. And of course, he may have been a physicist, however, he was no astronomer. So the thought may have been lost on him in its entirety. No matter, as the light coming forth from such distant objects inherently are highly incoherent. Having had their presumed entangled photons come into contact (measurement) with other cosmological hooligans, they became less fuzzy. They collapsed their wave functions long ago.

I learned, from the auditory text, that science has been able to entangle photons, and more complex items, such as 2,000 atoms of Rubidium. Hardly stellar stuff…not just yet. So I set myself up and got insightful when the author spoke of spontaneous parametric down-conversion (SPDC). As evidenced thru the application of laser experiments and non-linear crystals; two crystals were specified, one was lithium iodate, the other barium borate. And both exhibited a faint halo – with rainbow color. That meant that not all the laser light was emitted as expected. When measured, it became apparent that for every one photon in, we get two out, and more specifically, the frequency of the two output photons was one half the frequency of the input. Later analysis proved the light was a good source of quantum entanglement. The phenomenon, according to the author of my latest fling, was discovered in 1970 by DC Burnham & DL Weinberg. The Wikipedia listing gives credit to additional authors. The implementation of SPDC as a source of entangled photons, for experiments related to coherence, was done by the likes of Leonard Mandel (May 9, 1927 – February 9, 2001) and others (another Wiki reference).

So, I found my jumping off point. It was Astronomy Day at Jenny Jump, UACNJ, and we had 20 minutes or so to kill, while a member went about finding an adapter for the present speaker’s laptop. Two other club members, helped kill time on entanglement. And my idea of entanglement of photons from Einstein Rings, and White Dwarfs, got shot down really fast. So I played my Ace card, and suggested that the UV input into a uranium crystal, yields a frequency one half of that input. UV being about 778 Ghz, green light 545 (thanks Google), Perhaps we have two photons out, for every one, in? Nope, not exactly. The math simply does not work, here. However, this is my delusion, so we march on to say we have a new source of entanglement. Nothing new under the sun, I’m told, and because I am dealing with a macro system, and coherence isn’t likely. But I persist. I want to focus the green fuzzy uranium light thru a beam splitter. With one source hitting a cut-out triangle target, and the second source becoming the ghost. Expecting much from my marbles, I want to see quantum entanglement in action.

And then the brighter of the four of us, asks me a question. What exactly is entanglement? I started to tell him how a photon becomes entangled, but he interrupts me, and says, “no, what is the cause of entanglement”. I say, give me a few seconds to think on that. And then I remember seeing an article with a picture that shows some concentric circles. And I seem to recall that there were several points of circular intersection that were referred to as “entanglement”. I also recall, at this time, learning that many different wave forms, say multiple sin and cosine waves can contribute and add to one wave form. And that one wave can represent, something, say like an electron. So the “particle” aka electron, is as spread over many probabilities as is the many waves that can represent it. And I put together the two thoughts (either of which may have been highly inaccurate) and tell my friend: “When one wave function intersects with another, the point of intersection is the entanglement.”

So when my marbles arrive, I’ll count them out, and have some fun. I am assured as long as I don’t grind the glass down for ingestion, uranium glass is presumed safe. I did order a low cost UV light source, and some eye protection, as the UV is probably more damning than the uranium will ever be. I may not ever get a chance to focus really huge telescopes onto Einstein Rings, however, in a few days, I will be able to find my marbles.

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The Search for Extra-Terrestrial Life in the Universe

A book by Bangladeshi author Obaidur Rahman

Cover of Obaidur Rahman, a Bangladeshi author's new book "The Search for Extra-Terrestrial Life in the Universe".

Cover of Obaidur Rahman, a Bangladeshi author’s new book “The Search for Extra-Terrestrial Life in the Universe”.

Click here for the PDF version of the book.

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Recycling rockets.

by Prasad Ganti

Space X recently launched its flagship rocket Falcon 9 to send cargo to the International Space Station. It was almost a routine launch, barely indistinguishable from the others except for one feature. The first stage of the rocket was flying for the second time. In essence it was being reused. This reuse planted a significant milestone in the history of space launches.

Space is a vastly complex business and very expensive too. Mainly due to the single use of the rocket which launches a spacecraft. In a multi stage rocket used to launch any significant payload, the first stage drops back to the Earth after giving a big initial boost to the payload. Typically, that dropping was into an Ocean or a Sea where it became debris. Space X in an effort to reuse the first stage, tried to take baby steps towards recovering and refurbishing the first stage.

After all, nobody uses a bus or a train or a plane or a horse for one trip only. But getting to the multi-use was not easy. The rockets which powered the spacecraft to the Moon in the 1960s and 1970s were all single use. An attempt was made to build a reusable space vehicle. The result was the Space Shuttle. It took off strapped to a rocket, and came back and landed like an airplane. It needed extensive refurbishment before launching again. Each of the hundreds of heat protecting tiles underneath the Shuttle had to be carefully inspected and replaced. Eventually, the economics did not work in its favor. Much like the supersonic Concorde airplane which does not run anymore. The Space Shuttle also got relegated to the museums like the Concorde.

Space X designed its first stage to come back and touch down gently either on a floating barge or on land. Success followed after initial stumbles. One of those recovered first stages was refurbished and used for the latest launch. That completed the cycle of recovering, refurbishing, and relaunching. This cycle is expected to be repeated over and over again to reduce the cost of future space launches.

The way Space X recovers the first stage is by leaving some fuel unburnt. After separation from the main rocket, the leftover fuel in the first stage is used to reignite the engines on the rocket in a series of burns, to help the vehicle reenter the Earth’s atmosphere and then slow down for landing. This technique is known as supersonic retro propulsion.

Now that the concept of recycling the first stage has been proven, SpaceX’s new goal is to begin reusing rockets within 24 hours of landing, with just an inspection and refueling like for many of the passenger and cargo jets.

Space X is not the only game in the town. Blue Origin, owned by Amazon Chief Jeff Bezos. Although Blue Origin rockets have not gone into space yet, but it did get to the edge of the space. And reused its New Shepard suborbital rocket five times last year. In the bargain, Blue Origin won the prestigious Collier Trophy. Collier Trophy is given for the greatest achievement in aeronautics or astronautics in America, with respect to improving the performance, efficiency, and safety of air or space vehicles. It is a healthy competition between the private space companies – Space X, Blue Origin, Orbital Sciences etc.

What happened to aviation a few decades back is now happening for space launches. Boeing 707 ushered in the jet age. Then Boeing 747 made cheap intercontinental travel possible. In the coming years, space is going to get its A380 and Boeing 787 Dreamliner. It is exciting times to be living in.

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