Thanks Mosfet. It's an interesting article (even if the website is plastered with ads), though little of it is 'news' to me . The story and investigation of Loeb's work has been on a low simmer since fall last year.

Thanks Mosfet. It's an interesting article (even if the website is plastered with ads), though little of it is 'news' to me . The story and investigation of Loeb's work has been on a low simmer since fall last year.

There isn't much to this is there?  It's just a weird shaped rock kicked out from another solar system?

Shame A-L-E-X! The discovery of 'Oumuamua is one of the greatest astronomical discoveries of the decade! Although thousands of interstellar asteroids and other space rock probably whizz through our solar-system every year, with many becoming trapped as the Trojan and Centaur asteroid clusters around the Lagrange points of the gas-giants, particularly Jupiter - it IS the first confirmed interstellar traveler that humanity has witnessed. If anything, it's prolific media presence should be indicative (if for the wrong reasons) .

As far as any extraterrestrial origin connotations go, that remains to be seen. I'll assume you have some basic knowledge of the 'Traveler From Afar' and how it was discovered before I address your question. If not, I'd highly recommend Avi Loeb's scientific paper on his investigation of the possible artificial nature of 'Oumuamua and his theory that it could be a defunct lightsail probe, evidence of which may be present it its mysterious speed boost as it left our solar-system.

It has been stated numerous times, both by Avi Loeb (the principle investigator of 'Oumuamua's possible origins) and others in his field that an alien explanation for the object's strangeness is not unscientific or unreasonable. It could satisfactorily explain 'Oumuamua's characteristics as well or better then it's most popular natural origin theories. Loeb and his colleagues are not UFOlogists or tabloid 'reporters' grasping for an "Aliens of the Gap" logical fallacy to garner public interest.  They are simply trying to be thorough with an investigation and the alien hypothesis seems to be persistent. Loeb does acknowledge of course that he may be biased to humor the alien explanation due to his involvement in the Breakthrough Starshot program, for reasons that are obvious in light of his current theory on 'Oumuamua.   

The caveat to the alien explanation is the Copernican Principle, a rule in astronomy that no place in the universe is universally special and that each point in space/time is as special as the next. Thus, despite the fact that Earth harbors life and to the best of our current knowledge is alone in this respect, it is no more unique or noteworthy then the planet orbiting the next star over. It is an important rule that has it's roots in the startling scientific revelation that the Earth was not the center of the universe, and in fact was rather mundane. *Certain* experiments in quantum mechanics and *certain* scientists (cough Kaku cough) seem keen on challenging this reality check, but it's purpose serves us still. So despite the logic of aliens sending an probe (whether it breaks down en-route), to a planet that has had life polluting its atmosphere with oxygen for over a billion years, it breaks down if compared to Copernican theory.

PBS Space-Time had a good run-down on this idea of 'Oumuamua being an alien solar sail (and why it probably isn't.)

[youtube]wICOlaQOpM0[/youtube]

Shame A-L-E-X! The discovery of 'Oumuamua is one of the greatest astronomical discoveries of the decade! Although thousands of interstellar asteroids and other space rock probably whizz through our solar-system every year, with many becoming trapped as the Trojan and Centaur asteroid clusters around the Lagrange points of the gas-giants, particularly Jupiter - it IS the first confirmed interstellar traveler that humanity has witnessed. If anything, it's prolific media presence should be indicative (if for the wrong reasons) .

As far as any extraterrestrial origin connotations go, that remains to be seen. I'll assume you have some basic knowledge of the 'Traveler From Afar' and how it was discovered before I address your question. If not, I'd highly recommend Avi Loeb's scientific paper on his investigation of the possible artificial nature of 'Oumuamua and his theory that it could be a defunct lightsail probe, evidence of which may be present it its mysterious speed boost as it left our solar-system.

It has been stated numerous times, both by Avi Loeb (the principle investigator of 'Oumuamua's possible origins) and others in his field that an alien explanation for the object's strangeness is not unscientific or unreasonable. It could satisfactorily explain 'Oumuamua's characteristics as well or better then it's most popular natural origin theories. Loeb and his colleagues are not UFOlogists or tabloid 'reporters' grasping for an "Aliens of the Gap" logical fallacy to garner public interest.  They are simply trying to be thorough with an investigation and the alien hypothesis seems to be persistent. Loeb does acknowledge of course that he may be biased to humor the alien explanation due to his involvement in the Breakthrough Starshot program, for reasons that are obvious in light of his current theory on 'Oumuamua.   

The caveat to the alien explanation is the Copernican Principle, a rule in astronomy that no place in the universe is universally special and that each point in space/time is as special as the next. Thus, despite the fact that Earth harbors life and to the best of our current knowledge is alone in this respect, it is no more unique or noteworthy then the planet orbiting the next star over. It is an important rule that has it's roots in the startling scientific revelation that the Earth was not the center of the universe, and in fact was rather mundane. *Certain* experiments in quantum mechanics and *certain* scientists (cough Kaku cough) seem keen on challenging this reality check, but it's purpose serves us still. So despite the logic of aliens sending an probe (whether it breaks down en-route), to a planet that has had life polluting its atmosphere with oxygen for over a billion years, it breaks down if compared to Copernican theory.

The Breakthrough Starshot program is a pretty laudable effort on the part of scientists to create new technologies that will allow us to pursue interstellar travel one day, I've been intrigued by it.  We have so many sunlike stars within a 50 light year radius surrounding our solar system that I'd be VERY surprised if there wasn't one form of life or another within that radius, though it's doubtful whether it would be of the technological variety yet.  I think SETI has done a pretty thorough investigation of any sunlike stars within 100 light years so it would probably have to be some form of life below the technological threshold (could still be multicellular and complex though.)

I wasn't aware of that objects speed boost as it exits- I wonder what's going on there?  Also, I also believe in the Copernican Principle and I wasn't aware that either quantum mechanics or Michio Kaku was trying to disprove it?  I thought he supported it also.

The Breakthrough Starshot program is a pretty laudable effort on the part of scientists to create new technologies that will allow us to pursue interstellar travel one day, I've been intrigued by it.  We have so many sunlike stars within a 50 light year radius surrounding our solar system that I'd be VERY surprised if there wasn't one form of life or another within that radius, though it's doubtful whether it would be of the technological variety yet. I think SETI has done a pretty thorough investigation of any sunlike stars within 100 light years so it would probably have to be some form of life below the technological threshold (could still be multicellular and complex though.)

Same here .

Also, I also believe in the Copernican Principle and I wasn't aware that either quantum mechanics or Michio Kaku was trying to disprove it?  I thought he supported it also.

Neither Michio Kaku or any quantum experiment aimed to *disprove* Copernican theory. The experiment I'm referring to was the famous Pilot Wave experiment, wherein observation and measurement collapsed waves of potential particles into an assortment of definite destinations for the particle(s). Scientific philosophers have been quick to suggest that this rattles Copernican thought a bit because it seems like the observer has special importance to how the universe is observed, and by doing so, how the universe operates within our reality. This would mean that there IS special places of importance within the universe unique from others, namely that region of matter that can independently measure itself - i.e. life. This is of course the basis for the Anthropic Principle (something of a parallel of the Copernican Principle, rather then an opposition like many think it is) - and it comes in two flavors:

1: strong anthropic principle asserts that man makes the universe by observing it, thus the universe is the creation of sentience and man (the only form of self-observing sentience that we know of) is the center of the universe yet again because the universe strove to fine-tune itself to observe itself. This thought-process could harker back to that grand old time when we thought we were the center of the universe due to religious beliefs and ignorance.

and 2: the anthropic weak principle basically restates the strong anthropic principle above, but instead explains it by way that certain natural processes in nature statistically will result in self-observation - the development of some kind of life.

There is also a Principle of Mediocrity (that can co-exist with many of the assertions made by the other Principles) wherein it is stated that any one random sample from any set of categories is most likely a sample from the most numerous categories rather then the less numerous ones. So what can seem miraculous or rare is statistically most common and our bias is due to our limited sample. This has some interesting implications for the Fermi question, as do any of the above principles, as you could imagine.

As for Kaku, he is fully in support of the Copernican Principle and in fact is one of my favorite physicists and science communicators. (BTW, have you read his latest book: The Future of Humanity?) The problem lies in our old friends in the popular media - they have often misrepresented Kaku's work to further memetic or political causes. An example that sticks to mind was the 2014 documentary The Principle, a heavily-anti Copernican documentary that used and misrepresented interviews with Michio Kakau, Lawrence Krauss and other esteemed scientists to push their radical anthropocentric worldview (a reimagining of old Christian cosmology wherein the Earth was the literally the center of creation - this should NOT be confused with the Anthropic Strong Principle) based on the recent finding christened the 'Axis of Evil anomaly' on the CMB maps. I didn't wish to imply that Kaku did this on purpose, just that greater care must be taken by the academia to not be dragged into 'false balance' or downright misinforming infoblurbs and educational documentaries.

PBS Space-Time had a good run-down on this idea of 'Oumuamua being an alien solar sail (and why it probably isn't.)

[youtube]wICOlaQOpM0[/youtube]

A good video Wats, but a little outdated.

[youtube]rDZyI83Bj2w[/youtube]

A good video Wats, but a little outdated.

What is rendering it out of date?

From what I can tell, the new information is a calculation for the shape (either cigar or a pancake) based on its light curve.  But this relies on a number of assumptions about its reflective properties, much like how the original idea of it being shaped like a solar sail arises by assuming the acceleration is due to radiation pressure rather than outgassing.  In short, its shape is not measured.

If it does have such a thin geometry (with the implications that follow), then the same problems still arise.  if it is a solar sail, then space must be filled with a stupendous number of them.  Assuming it was a targeted probe solves that problem, but then contradicts its observed velocity.

What information is new and published since their paper (available here)

Yes. Available HERE at the Harvard site. The paper takes another look at the objects supposed geometry. Another paper gives a more general look at 'Oumuamua and it's relation to the sun and that of other potential natural interstellar asteroids.

r otherwise not discussed in the PBS Space-time video?

I'm glad you asked. There were a few omissions left out perhaps in part due to some journalistic integrity or just to keep the video clean of conflicting theories. So here they are:

No mention was made of the other possible shape for the object, namely that of a thin pancake or elliptical plane. The 'evidence' presented in the first PBS video on 'Oumuamua lightly skimmed over how the shape of the object was found. The evidence of an elongated cigar is based solely off of early interpretations of the lightcurve data that were made by using a conservative estimation of the object's rotation and non-constant reflectivity or albedo. A full exploration of this is presented in the recent Harvard paper.

Details regarding the exact reflectivity of 'Oumuamua were not explored. These would be vital to determine it's exact nature as a comet, asteroid, or 'other'. The Nov. 2017 findings (or non-findings) of NASA's Spitzer Space telescope were not shared. Spitzer looked at where 'Oumuamua was, and yet saw nothing - meaning no infrared was visible. Since we roughly know it's overall size, we can calculate how much light it could have absorbed to generate those results. This data would have clarified the strangeness of 'Oumuamua even more, as they put absolute size limitations on the object due to the heat it could absorb. It's subsequent smaller size would mean that the object was much brighter then previously thought in relation to size and a further ten times brighter then any other comet thus far seen. Typical for interstellar asteroids/comets? We don't as 'Oumuamua is the first we've seen.  Interestingly, if an absolute size can be teased from the data of the object, this would mean that if the object has a total size of about 20 meters, it would be a perfect mirror, whereas if it was about 100 meters in size, then it would only reflect 20% of all light on it, rather like the most reflective asteroids and comets we know of today. The full findings of Spitzer were published here.

Furthermore, the oddities of 'Oumuamua's apparent motion through space was not explored in relation to the local standard of rest (i.e. the collective motion of galactic material around the galaxy, including stars, around the sun). 'Oumuamua matched the local standard almost perfectly  before it encountered our solar-system, something almost impossible from an object that has been conceivably ejected from the outer reaches of a solar-system. It could be slightly less improbable if it was spat out of an inner portion of a solar-system, but only if it was forced in the exact opposite direction to which it's sun was moving.

It's not quite that these details are present to keep the mystery alive about 'Oumuamua, but instead they encourage us to consider all the available data instead of casting inconvenient arguments it aside in a cavalier manner for the sake of public opinion. I really got the feeling that Spacetime made the video to get people to stop nagging about it and it's disheartening that such a well-researched show do that.

Bear in mind though - I said the video was only a little out of date!

The Breakthrough Starshot program is a pretty laudable effort on the part of scientists to create new technologies that will allow us to pursue interstellar travel one day, I've been intrigued by it.  We have so many sunlike stars within a 50 light year radius surrounding our solar system that I'd be VERY surprised if there wasn't one form of life or another within that radius, though it's doubtful whether it would be of the technological variety yet. I think SETI has done a pretty thorough investigation of any sunlike stars within 100 light years so it would probably have to be some form of life below the technological threshold (could still be multicellular and complex though.)

Same here .

Also, I also believe in the Copernican Principle and I wasn't aware that either quantum mechanics or Michio Kaku was trying to disprove it?  I thought he supported it also.

Neither Michio Kaku or any quantum experiment aimed to *disprove* Copernican theory. The experiment I'm referring to was the famous Pilot Wave experiment, wherein observation and measurement collapsed waves of potential particles into an assortment of definite destinations for the particle(s). Scientific philosophers have been quick to suggest that this rattles Copernican thought a bit because it seems like the observer has special importance to how the universe is observed, and by doing so, how the universe operates within our reality. This would mean that there IS special places of importance within the universe unique from others, namely that region of matter that can independently measure itself - i.e. life. This is of course the basis for the Anthropic Principle (something of a parallel of the Copernican Principle, rather then an opposition like many think it is) - and it comes in two flavors:

1: strong anthropic principle asserts that man makes the universe by observing it, thus the universe is the creation of sentience and man (the only form of self-observing sentience that we know of) is the center of the universe yet again because the universe strove to fine-tune itself to observe itself. This thought-process could harker back to that grand old time when we thought we were the center of the universe due to religious beliefs and ignorance.

and 2: the anthropic weak principle basically restates the strong anthropic principle above, but instead explains it by way that certain natural processes in nature statistically will result in self-observation - the development of some kind of life.

There is also a Principle of Mediocrity (that can co-exist with many of the assertions made by the other Principles) wherein it is stated that any one random sample from any set of categories is most likely a sample from the most numerous categories rather then the less numerous ones. So what can seem miraculous or rare is statistically most common and our bias is due to our limited sample. This has some interesting implications for the Fermi question, as do any of the above principles, as you could imagine.

As for Kaku, he is fully in support of the Copernican Principle and in fact is one of my favorite physicists and science communicators. (BTW, have you read his latest book: The Future of Humanity?) The problem lies in our old friends in the popular media - they have often misrepresented Kaku's work to further memetic or political causes. An example that sticks to mind was the 2014 documentary The Principle, a heavily-anti Copernican documentary that used and misrepresented interviews with Michio Kakau, Lawrence Krauss and other esteemed scientists to push their radical anthropocentric worldview (a reimagining of old Christian cosmology wherein the Earth was the literally the center of creation - this should NOT be confused with the Anthropic Strong Principle) based on the recent finding christened the 'Axis of Evil anomaly' on the CMB maps. I didn't wish to imply that Kaku did this on purpose, just that greater care must be taken by the academia to not be dragged into 'false balance' or downright misinforming infoblurbs and educational documentaries.

Yes I love Kaku and BPP, but never read any of his books, just his online articles on his site Is his book very good? It would be a must-read for me!
I like the weak anthropic principle, because I dont believe we are the only self-observing sentient beings, even on our own planet!  Certain other animals clearly do it too.  I also like the Principle of Mediocrity, even though our sample size is only one, I dont believe we are that "special."

How much did that object accelerate as it exited the solar system?  Can it be accounted for in any way?

Is his book very good? It would be a must-read for me!

Yes of course his books are good. A tad optimistic of course, but well worth the read. I'd personally suggest Physics of the Impossible, Beyond Einstein, Einstein's Universe and Hyperspace.

From what I can tell, the new information is a calculation for the shape (either cigar or a pancake) based on its light curve.  But this relies on a number of assumptions about its reflective properties, much like how the original idea of it being shaped like a solar sail arises by assuming the acceleration is due to radiation pressure rather than outgassing. In short, its shape is not measured.

Outgassing was never directly measured either.

Assuming it was a targeted probe solves that problem, but then contradicts its observed velocity.

It could be that the probe is a defunct one, hence it's erratic spinning, low overall speed in relation to the other stars and lack of detectable energy-signals. 

But I suppose the lesson here is that we can spend all night finding explanations for the observed phenomena, potentially endlessly without any firmer evidence  . 

Is his book very good? It would be a must-read for me!

Yes of course his books are good. A tad optimistic of course, but well worth the read. I'd personally suggest Physics of the Impossible, Beyond Einstein, Einstein's Universe and Hyperspace.

Yes I read his papers on those three and loved them so now I want to read the books too lol.  He is like Brian Greene in his optimism, I like that.
Can the acceleration of that object as it exits the solar system be explained in any natural way that we know of?

Oops, I edited a little too late.   Anyway yes, I did see the more recent paper, but this is just a different method of calculation with more assumptions (we don't know the usual albedos or reflective properties of interstellar comets) which also does not distinguish between a pancake or cigar shape.  Some might say it corroborates the idea that the object has an extreme geometry indicative of a solar sail, but I think this is pretty dubious.

Outgassing was never directly measured either. 

We do not easily observe outgassing -- what is more easily observed is light reflected from dust, if dust is present along with the gas.

It could be that the probe is a defunct one, hence it's erratic spinning, low overall speed in relation to the other stars and lack of detectable energy-signals.  

So space is filled with failed probes that were launched with uselessly low velocities?

I really got the feeling that Spacetime made the video to get people to stop nagging about it and it's disheartening that such a well-researched show do that.

I don't think so.  To me the thrust of their video was that the object is even more interesting than initially expected and deserves tons of study -- just that it probably is not interesting for the reasons the media thinks it is.  It also raises some hard questions on how science is presented to the public.