Showing posts with label Pulsars. Show all posts
Showing posts with label Pulsars. Show all posts

Thursday, November 14, 2013

SETI Strategy

The traditional, even the untraditional Search for ExtraTerrestrial Intelligence (SETI) has been going on now for over five decades; six decades if you include UFOs, and a century’s worth if you include listening for Martian radio signals. Of course, as we are all well aware, nothing has, to date, come from these extensive searches. Either there’s nothing out there worth searching for, or perhaps one is shooting at a moving target. A better search strategy might be to shoot at a stationary target(s). My suggestion is for an optimal static SETI target – the Moon.    

Traditional SETI, the Search for ExtraTerrestrial Intelligence, uses a search strategy of looking for extraterrestrial radio signals broadcast by technologically advanced, well, extraterrestrials.  Alas, you don’t know in advance where in space the alien radio station is; what strength it’s broadcasting at; what radio frequency it’s using; how often it’s broadcasting or for what duration per broadcast. Further, the station is probably on a rotating planet, and we on the receiving end are rotating too and so the meshing of the two such that we face each other is dicey at best. It’s a search with all the odds stacked against it. That’s what I call SETI in motion. Static SETI has better odds in its favour, IMHO. What SETI needs is to eliminate the motion associated with possible ETI from the search. In other words, search for ETI via those artefacts of ETI that 1) pretty much stand still and 2) remain standing still for very lengthy time frames.  

TRADITIONAL SETI IN MOTION: The Electromagnetic Spectrum

Optical and radio wave SETI relies on some alien technological civilization pointing a radio or optical transmitter in the outward bound direction and letting briefly fly the photons in just the absolute right direction such that a terrestrial radio or optical receiver just happens to be pointed in that exact same direction at the exact relevant time frame later on down the track. The odds are not good that all these variables of motion will mesh together. I mean, what if you had one spinning terrestrial globe (globe A) with some random rate of spin and orientation (axis tilt), and another spinning globe (globe B) with another random rate of spin and orientation, both positioned at some random distance apart, what odds that say, one specific latitude and longitude on globe A would exactly match up in a straight line, allowing for the speed of light representing that straight line, with the exact same latitude and longitude on globe B?

UNTRADITIONAL SETI IN MOTION: Space Probes

We have sent out messages to ET in the form of plaques (Pioneer 10 and 11) and audio-visual recordings (Voyager 1 and 2), which have odds of success that even the most optimistic of optimists wouldn’t bet a nickel, far less the family farm, on achieving reality. That’s because space probes are very, very small and space is really, Really, REALLY, very, Very, VERY, big, as “The Hitchhiker’s Guide to the Galaxy” as so adequately pointed out and made that concept clear to us. Finding alien space probes: it’s the needle-in-a-haystack or perhaps the message-in-the-bottle carried to extremes.

UNTRADITIONAL QUASI-SETI IN MOTION: UFO SETI

The problem with trying to search for and pin down UFOs as an example of ETI is that UFOs will not stand still. They come and they go like short-duration will-of-the-wisps in a totally random way that cannot be forecast in advance. But the skies can be monitored 24/7, and they are monitored 24/7, and guess what, UFOs are spotted 24/7. Of course a UFO doesn’t automatically translate into an alien spaceship, and in any event, while the skies stand still in a manner of speaking, those pesky UFOs don’t.

TRADITIONAL STATIC SETI: Galactic Searches

External galaxies, like stars in our galaxy, sit still in the night sky. Unlike targeting individual stars in our galaxy, or rather the inhabited planets whizzing around them (orbiting and rotating) which is traditional SETI in motion, targeting entire galaxies at one go, assuming a reasonable number of ET civilizations are in that galaxy, suggests that something that’s of an EM nature (on a myriad of frequencies) emitted at random time intervals by someone(s) or something(s) is intersecting our local geography upon which sits our radio telescope 24/7. The fly in that ointment is that, as the introduction to “Star Wars” pointed out, external galaxies are far, far away. That means that while we’re getting some signal(s) from an external galaxy 24/7 just on sheer probability, it’s like trying to hear someone, say your ex, shouting at you from L.A. when you’re, alas, in N.Y.C.

STATIC SETI: Omnidirectional Signals

Omnidirectional electromagnetic signals would appear as a ‘light bulb’ that was always on, but the drawback is that it is a very energy intensive way of advertising yourself and saying “hi there” to the cosmos.

STATIC SETI: Dyson Spheres

We’re all for solar energy, and a really advanced extraterrestrial civilization could take the concept to an extreme. Only a tiny, tiny, tiny fraction of the Sun’s output hits Earth, so even if all of that were captured and put to good use, it would still be just a tiny fraction of what’s theoretically available. But, if one could build a quasi-flexible sphere (of say colony space stations) around a parent star, then a large fraction of the star’s solar energy could be intercepted and put to a useful purpose. The light energy would ultimately be converted to heat energy, or infrared (IR) wavelengths. So, if we SETI by looking for anomalous infrared stellar sources, we just might detect or capture evidence of a vast extraterrestrial astro-engineering projects, known in the trade as Dyson Spheres. The trick will be to distinguish a natural IR source from an artificial one. Further complicating matters is that the search pretty much has to be conducted from above Earth’s atmosphere which is pretty opaque to IR wavelengths.

STATIC SETI: Pulsars

When pulsars were first discovered, they were immediately thought to be the SETI smoking gun, and were named LGM 1, LGM 2, etc. where LGM stood for “Little Green Man”. Alas, it quickly became apparent that in terms of SETI, pulsars were too much of a good thing, now numbering in the thousands, and a natural alternative explanation quickly came to the fore – rapidly rotating neutron stars. However, if author Paul LaViolette* is to be believed, pulsars are not naturally rapid rotating neutron stars but artificially constructed interstellar navigation and communication beacons – the product or creation of ETI. Fortunately pulsars stay put and thus LaViolette’s ideas can be tested.

STATIC SETI: Planetary Disequilibrium

Another possible example of static SETI is the search for planetary atmospheres in chemical disequilibrium – the search in all probability for bio-signatures. Earth’s atmosphere is in a state of disequilibrium; so apparently is Titan’s atmosphere. The ‘intelligence’ part comes in regarding the detection of unnatural pollutants, again in disequilibrium. A variation on that theme is to look for anomalies in a star’s spectrum, say for uranium, plutonium, radium, thorium, or technetium. Finding such would be suspicious – hey, what’s going on here? The answer being that a technological civilization used their parent star as a nuclear waste dump (quite a sensible idea); or to advertise their existence.

STATIC SETI: The Sun

As per above, there are some who have suggested that extraterrestrial intelligences with advanced technologies might deliberately ‘pollute’ their parent star with unnatural or anomalous elements, perhaps an exercise in radioactive waste disposal. The upshot being that the stellar spectra of such ‘polluted’ stars would give the game away that there was intelligence afoot since no natural process could account for such anomalous spectra. Now if such a strategy were used as a calling card by said extraterrestrials, perhaps they have artificially altered the natural solar spectra of our Sun. Alas, I assume by now our Sun’s spectra has been analysed and re-analysed and re-re-analysed with nothing anomalous discovered.

STATIC SETI: The Moon

If you want to leave a message or a calling card akin to “Kilroy was here” for someone unknown or unknowable in the future (whether near future or distant future is also unknown) what would you do, especially if you had some space-faring capability? Translate that scenario now and assume that there must have been some sort of visit to Planet Earth by ET(s) over the past several billion years (and Earth was inhabited even if only by microbes at that time) and maybe they left behind their equivalent of “Kilroy was here”. Well you wouldn’t leave your calling card on Planet Earth since Planet Earth is both geologically and meteorologically active and the ocean bottom isn’t much better. You wouldn’t leave it in high Earth orbit or at the Langranian Points since that makes your message a moving target and/or subject to dislodgment from gravitational forces say from a passing near Earth asteroid or a close encounter with a passing comet. Solar flares, etc. over the long haul could also disrupt any stable orbit. Positioning the message elsewhere in the Solar System is probably placing it too distantly away requiring too much power to sustain itself over the long haul – assuming ET supplied it with batteries – or placement would result in just too much real estate to have to cover for future recipients. What about the Moon as a repository for an alien artefact or two? Did Arthur C. Clarke get it right in “2001: A Space Odyssey”?

The Moon has and hasn’t for all practical purposes any dynamic geology or meteorology and certainly no ocean bottoms. The Moon is not, for all practical purposes a moving target as we tend to think of moving targets. Has the Moon ever been targeted by SETI? Not formally to the best of my knowledge.

If there was an EM beacon on the Moon broadcasting on our radio/TV frequencies we’d know about it. I imagine there must have been times when the Moon was in view or in the line of sight with radio telescopes doing traditional interstellar electromagnetic (radio) SETI analysis. If so, no dice resulted. I imagine the Moon (from space) has been looked at in the ultraviolet, infrared, and other parts of the EM spectrum not readily accessible from ground level. Still, I think a formal SETI attack on the Moon might not be a bad thing – if only to dot I’s and cross all the T’s.

QUASI-STATIC SETI: Transient Lunar Phenomena

For more years than you can shake a stick at - and that’s a lot of years - anomalous lights, glows, or luminescences have been seen and recorded on the Moon by astronomers, both amateur and professional. These enigmatic lights have been tagged with the general phrase Transient Lunar Phenomena (TLP). They come and go with total unpredictability. The usual theory is some sort of volcanic activity, maybe a meteor impact, but to date they remain just one of those mysteries Mother Nature chucks our way. TLP’s require far more investigation, just in case they have a ‘Kilroy’ aspect to them.

STATIC SETI: Alien Artefacts

The ‘Face on Mars’ is probably the best known example of an ‘alien artefact’, and when first photographed by a Viking orbiting space probe it indeed looked like a human ‘face’. However, later photographs under differing lighting conditions just revealed a big rock that had to be lit just so in order to show a pseudo-‘face’. Though the ‘Face on Mars’ proved not to be a real ‘face’, the key point with respect to SETI is that the ‘face’ stood still to be photographed and studied another day under differing conditions. It stood still!

STATIC SETI: Ancient Astronauts

Many myths and legends, from ancient cultures around the world, especially surrounding religious figures of all-powerful deities, can often be reinterpreted in terms of flesh-and-blood aliens as opposed to supernatural gods and goddesses. Alas, while provocative, its marginal evidence at best for ancient astronauts. Engineering feats seemingly impossible for ancient societies are equally provocative, are bona-fide archaeological mysteries, but are again just marginal evidence for high-tech aliens, not smoking guns. However, if there were artefacts, images or equivalent, indisputably produced by ancient man yet which clearly exhibited a degree of knowledge they could not have possessed, that’s a different horse of quite another colour. As a hypothetical example, if there was an image or carving clearly showing the planet Saturn and satellites, all in correct proportionality, in say an ancient Egyptian tomb that would be more than just something provocative. Ditto the image of a kangaroo or a map showing Tasmania or Long Island (N.Y.). Even better would be a really real alien artefact with a “made in Krypton” stamped on it somewhere! Regardless, I suggest a detailed examination of ancient artefacts/images as viewed from the eyes and perspective of a physical, even biological scientist or geographer as opposed to a traditional archaeologist might be in order. Even    

STATIC SETI: Crop Circles

Crop circles stand-sit-lie still (as it were until farmers mow them down) but I’m not convinced they have anything to do with ETI, even if they are high strangeness. But if they do, have anything to do with ETI that is, they would a tempting SETI target.

STATIC SETI: Junk DNA

Some out-of-the-box thinkers have suggested that aliens might have left an internal message within us (as in terrestrial life) that ‘Kilroy was here’ the message being in the form of a coding within those parts of an organism’s DNA that isn’t particularly used for anything – junk DNA. The only problem I see with that is that even junk DNA can and will mutate and thus change the message, just like changing one letter in a word can render that word meaningless. 

CONCLUSION

Our Moon offers the best bet for uncovering evidence that aliens have been (and maybe still are) in our neck of the stellar woods. Since the Moon is close by, and can be observed 24/7 (we know where it is at all times) and is a logical place for aliens to have left evidence of any visitation, it should be the focus of SETI. Such evidence, by implication, would prove that ET exists, or at least one ET existed once upon a time.


*LaViolette, Paul; The Talk of the Galaxy: An ET Message for Us?; Starlane Publications, Alexandria, VA; 2000.


Tuesday, April 9, 2013

A Trip Inside A Black Hole: Part Two

Suicide missions are hardly unknown happenings, so presumably it wouldn’t be too hard to find a volunteer to take a long walk off a short pier and dive into the heart of a Black Hole. Well, let’s trade in the walk and the pier for a spaceship, with our suicidal pilot crewmember willing to boldly go. What might she expect? For that matter what might a chickenhearted outside observer expect to see?

Continued from yesterday’s blog…

Now for the speculation: Let us suppose that our suicidal voyager survives her voyage (curses, foiled again) and gets to play tourist. What will she see or will she see anything at all? Well, yes, she will – see that is. The event horizon is like a one-way mirror. Light can pass through the event horizon into the interior of the Black Hole, but light cannot pass from the interior of the Black Hole through the event horizon to be witnessed by an outside observer. Okay, let there be light, and there was light. Light is energy, so there’s energy inside a Black Hole. It’s also been shown that a Black Hole has entropy, or in other words a temperature. That too is energy. 

There’s matter (mass) inside a Black Hole – obviously, since there’s gravity. Now the big unknown is what kind of matter is that matter? We don’t know. Outside of a Black Hole matter exists in four states – solid, liquid, gas and plasma. The transition from one state of matter to another is called a phase change, as in ice to water to steam. One speculation is that the matter inside a Black Hole undergoes a phase change to something even more solid and denser than, well a dense solid.

We sort of observe this in a Neutron Star, a star extremely massive with extreme gravity, but just short of enough gravity to form an event horizon and turn into a Black Hole. Why is it called a Neutron Star? Well, the gravity is so great that the bits and pieces of the atom, electrons, neutrons and protons are squashed together into one big glob. The positive protons fuse with the negative electrons – these electric charges thus cancelling out – to make neutrons, hence join with the already neutral neutrons, so everything forms into just one huge glob of neutron soup, or a Neutron Star. Rapidly spinning Neutron Stars are also known as Pulsars.

Now if atoms lose all sense of identity, there is no atomic structure, no isotopes, no molecules, no elements, no compounds, no electrons and no protons, then I’d have to define that as a phase transition, but one we don’t witness on Earth. Given the even more extreme gravity inside a Black Hole, would that same phase transition to a neutron soup hold sway, or might there be another beyond that found in Neutron Stars? 

Neutrons are not fundamental particles. A glob of neutron soup is ultimately a glob of quark soup, as quark trios comprise the identity we call a neutron. Neutrons are actually composite particles. However, as quarks are fundamental particles, it’s unlikely they can be crushed or fused together. Electrons too are fundamental, but it is well known – to particle physicists at least – that an isolated neutron will in fairly quick-smart order decay to a proton, an electron and an antineutrino. Reactions are reversible so it is straightforward to create a neutron if the ingredients are brought together with sufficient energy.

Since a Neutron Star is just one coin short of a Black Hole dollar, the inside of a Black Hole could well be akin to a Neutron Star, only slightly more massive. One thing is certain IMHO, the interior will not be matter crushed down to the infinitely small (i.e. – zero volume); the interior will not be infinitely dense.

What lies at the heart of a Black Hole? The traditional answer is a ‘singularity’ – a point of (near) infinite density and (close to) zero volume, matter crushed down to the final, ultimate limit – or maybe not.

Start with a hunk of matter. Keep on keeping on adding more and more and more matter (mass) to it. Your original hunk grows larger, ever denser; its gravity swells in proportion. Finally it’s just a fraction away from achieving Black Hole status – meaning its gravity is so strong not even light can escape from its grasp. It’s that Neutron Star entity.

So you are a thimbleful of salt away from crossing the not-quite-yet a Black Hole to an actual Black Hole boundary. You can (barely) still see your now super-sized hunk of Neutron Star stuff. Now toss in that final thimbleful of stuff onto the hunk. No light now reaches you – you’ve crossed the threshold or boundary and have got a Black Hole. But do you doubt that lurking on the other side of the not-quite-yet a Black Hole to an actual Black Hole boundary, though unseen, you still have that super-sized hunk of stuff, not a singularity, but a really real solid 3-D hunk of stuff? Or, in other words, if the escape velocity of your hunk is 185,999 miles per second, no Black Hole and no singularity, but if it climbs to 186,001 miles per second you have a Black Hole and your hunk morphs into a singularity? A two mile a second difference makes that much difference? I don’t think so.

The other issue though is this really going to be a one-way trip for our boldly going voyager, dead or alive? One of the 64,000 $64,000 questions: Can you pour stuff down a Black Hole indefinitely, or does the Black Hole have a finite capacity and ultimately or eventually will have to spew stuff out the ‘other side’ (i.e. – producing a White Hole) as you keep pouring in more and more and more? I’d wager the conservation relationships and principles of physics and chemistry hold sway here. What goes in ultimately comes out. That doesn’t mean there’s not a temporary holding vessel. Or, in more human terms, you fill what’s empty; you empty what’s full, but in-between those two there’s storage in the stomach and the intestines; the lungs and the bladder.

Let’s adopt that point of view that what goes in, ultimately has to come out.

And so, our intrepid voyager might well exit elsewhere, maybe even elsewhen. The exit could be deemed the opposite of a Black Hole, or a White Hole; the passageway from Black Hole entrance to White Hole exit is that staple of sci-fi, albeit based in the realm of theoretical physics, the Wormhole. That the exit could be elsewhen is based on the theoretical ‘fact’ that a wormhole could be manipulated in such a manner as to allow for time travel. If that’s too far out for you, then a Wormhole elsewhere shouldn’t be. The apt analogy is with an apple. Mr. Worm can crawl around the outside of the apple to get from one side to the other, or Mr. Worm could take a shortcut and worm his way through the apple to get to the other side, or elsewhere.

Now the question arises, is there any observational evidence that White Holes and associated exits exist? Astronomers and cosmologists would argue in the negative, but I’m not convinced. What would be the signature of a White Hole? Well, it would be roughly stellar-sized, not planetary or galactic. It would be vomiting out one heck of a lot of stuff including lots of energy. Does the cosmos contain such beasties? Obvious candidates are quasars – quasi-stellar objects. Quasars are roughly stellar in size, but violently emitting the froth and bubble of nearly an entire galaxy worth of stuff and energy. The other high-energy astrophysical anomaly is gamma ray bursts. They occur way out back of beyond, in the outer fringes of the cosmos, which is all to the good for if a gamma ray burst happened in our stellar neck of the woods, the results would be akin to Kentucky Fried Humans! Still, we don’t know enough squat about them to be able to predict exactly where and when one will happen. So, astronomers who are into studying these cosmic critters are akin to sleeping fireman who never knows when they will be rudely awakened to respond to that rare five-alarm event.

So, in short, we have Black Holes that are your ultimate in garbage disposals; Quasars and gamma ray bursts that are your ultimate in, IMHO, recycling that garbage back into useful cosmic stuff – matter and energy. In other words, they are the exit to the Black Hole’s entrance. 

No matter. Either our boldly going voyager has snuffed it going into a Black Hole; is forever trapped in a Black Hole; or has been turned into a Kentucky Fried Human and vomited back out again via a White Hole quasar or gamma ray burst to become as one with the cosmos. We all started out as starstuff – and so shall we (or what’s left of our remains) all ultimately return to become starstuff again a millennia of millennia from now.