Ask the Dreadlocked Science Geek
 

So a couple of people have expressed a wish for an "Ask Aj" thread where they could post their scientific questions. Now, I may not always have an answer for you off the top of my head but I will always try to get you the *best* available answer even if that means having to do a little bit of research.

So if you have a question about some subject that has to do with science OR if someone has said something to you that seems like it just doesn't quite add up and you suspect there may be a glaring logical fallacy OR if you have a question about skepticism ask away!

Cheers
Aj

ok yes..yes I do.

So, about ghosts.

What do you make of EVP's?

Objects moving on thier own? (I have seen this myself in my own house so I know it's not a prank)

Aparitions?

What do you think about the "scientific" meters used to show "proof"?

So, Electronic Voice Phenomena. I have yet to see an example of EVP that cannot be more economically explained by our brains seeking patterns. Remember that your brain is a pattern-seeking machine. I think that EVP is an example of one of two common brain phenomena:

A) Apophenia--which is seeing meaningful patterns in what is actually random noise

B) Pareidolia--which is really just a special case of apophenia but largely visual.

A good and common example of paraeidolia is seeing shapes in clouds. Is the cloud *actually* shaped like, say, an elephant? No, but our brains perceive it to be.

So why would our brains work that way? Well, our brains evolved to discern meaningful patterns out of a random world. However, the world isn't *completely* random and our brains are nowhere near perfect at what they do. Our brains are prone to two common errors:

1) False positive (seeing a pattern when there is none)
2) False negative (not seeing a pattern when there is one)

Of the two, false positives are the less harmful. To understand why, imagine you are one of our Pleistocene ancestors on the African savannah. You are in the tall grass and you hear a rustling. Is that sound a lion or is it the wind? Well, if it's the wind but you respond as if it is a lion and, say, run for the nearest tree you're out some calories but you'll live long enough to eat and thus gain those back. If, on the other hand, you think it's just the wind and it's actually a lion by the time you realize your error, you're well on your way to being lunch. Needless to say, being eaten drops your reproductive fitness to zero. So our brains have evolved in such a way that they are prone to both Type 1 and Type 2 errors. Since type 1 errors generally don't cost the person making them their life, our brains have not evolved beyond them. Type 2 errors can be more deadly but not necessarily so often as to actually have selective pressure on them.

EVP is a type 1 error--seeing a pattern or subscribing meaning to random noise. Most EVP aren't actually voices it's *literally* noise in the sense that the signal carries no information but we *think* it does.

Objects moving on their own I would have to know the specifics of the event. I can think of any number of reasons one might perceive an object to be moving on its own and without specifics, I just don't have enough information.

Apparitions are interesting. There's a frequency of infrasound that appears to have a very interesting effect on the human brain. While we can't *hear* it, the vibrations cause a physiological reactions that the brain interprets as fear. Our brains then backfill something in to explain why we are afraid. This might explain 'haunted' houses. Old houses as they creak and settle with the change of temperatures from day to night produce infrasound vibrations which are too low for us to hear but would produce a fear reaction.

As far as the scientific meters, again I'd want to know what it is they are supposed to be measuring. Here's the thing, most times people will mention a 'field' of energy and that's what these meters are supposed to measure. The problem with this is that the meters either fluctuate in a random manner or the strength of the meter appears to bear no relationship to the distance from the source. This is a problem.

EVERY field we have encountered so far is subject to what is called the inverse square law. The simplest formulation of it is this:

The strength of a field diminishes as an inverse of the square of the distance. What that means is that the farther away from the source of a field you go, the weaker the field gets. This happens VERY quickly. So if you start at the source of the field and move away from it then when you are, say, 2 feet from the source the field is *four times* as weak. When you are four feet from the source the field is *16 times* as weak. As far as we know (and we know quite a bit about fields) this holds for all forms of fields--this means that all four forces (electromagnetism, gravity, strong and weak nuclear forces) plus sound all obey this rule. This is a big problem for these measuring instruments. The signal should fall off as a square of the distance but no matter where the Ghost Hunters are in the house the signal is always random. That simply can't be.

I have to leave the office, I'll return to this question when I get home.

Cheers
Aj

Ok, Science Geek, answer this one from a oft-flying traveler:

Why does it feel, at times, like the plane "stops" or "slows" down in mid-air? It's the weirdest feeling but I've been on flights and about half-way there I get this sensation like we're slowing down (like a car in rush hour) and then we continue on our merry way.

Go to System Preferences --> Mouse. Adjust there. Alternatively, if this is a third party mouse, try to re-install the driver.

Okay, this is a really interesting one with two different answers. The reason for the feeling of slowing down is most likely that the pilot deployed the flaps but the feeling of stopping is something else altogether.

Without anything to use as contrast, you cannot tell the difference between constant velocity motion and being at rest. The key here is *constant* velocity. If you change direction then your velocity isn't constant and it doesn't matter what direction that change of direction happens in (up or down, forward or backward, left or right or any combination). This is why, if you are in a car you almost always feel like you are moving because the road surface causes the car to have an up or down motion.

If you're at 30,000 and its at night or over fairly uniform clouds and if the plane is in an area where the atmosphere is being pretty calm you wouldn't have many cues that you are moving for just a moment. Then you hit an air pocket and the plane bounces a few feet--that's all it would take--and suddenly you're aware that you're in motion.

Don't believe me? Right now, you are moving at 17,500 m/h (28,163 k/h) as is everything else on the surface of the Earth. We don't feel like it because the Earth's rotational speed is constant and there is nothing to create drag or turbulence to disturb the smoothness of the ride. The only way we would ever feel it is if the planet suddenly came to a stop. Then everything on the planet not anchored into deep rock would suddenly be moving VERY fast as all of that angular momentum was transferred to us.

*Perfectly* constant velocity motion is not achievable in-atmosphere because of friction but in a vacuum you could certainly achieve it. So why do you have these moments in an airplane? It's because the stall speed of an airliner at cruising altitude is in a very narrow band. How narrow? The difference between level flight and a stall can be as narrow as 20 mph either way at cruising altitude. So at cruising altitude, the pilots try maintain a very stable speed. The motion you detect is from the air current buffeting the plane. If the upper atmosphere were perfectly still and the aircraft maintained an absolutely constant speed, you would not be able to tell that you were in motion at all.


Cheers
Aj

Because the Earth isn't *accelerating*. Remember that the Earth's rotation is constant velocity motion so we don't feel it and are perfectly justified in claiming that, at this moment, we are at rest. When you jump into the air while your vertical velocity, relative to the center of the Earth. temporarily exceeds 10 m/square second (temporarily overcoming the force of gravity) your horizontal velocity is 0. Since neither you nor the Earth are accelerating relative to each other, you land in exactly the same place as you started from. From your reference plane (the surface of the Earth) there is no force moving you horizontally and since a body at rest wil stay at rest until acted upon by another force, you jump up (which has a force acting on you vertically) and land in the same place (since no force is pushing you horizontally).


The situation would change if you were accelerating. To see this, let's do a little thought experiment.

You are on a plane, the plane is accelerating. You toss a ball up in the air, the ball will, in fact, land a bit behind you because the aircraft is moving relative to the motion of the ball. If, however, the aircraft is moving at a constant velocity then the ball will land at your feet.

Essentially, this is Einstein's General Theory of Relativity in a nutshell. If you are at constant velocity (what in technical jargon is known as the inertial frame) then you are justified in saying that you are at rest, no matter HOW fast you may be traveling. As long as whatever it is that you are traveling on maintains the same speed and direction, you can treat your environment as being at rest. It is only if you are accelerating that you will be aware of movement. One interesting side-effect of this is that gravity and acceleration turn out to be the same thing. Right now there is 1g of gravity pulling you toward the center of the Earth. We would be completely justified in describing us as falling toward the center of the Earth at 10 meters per square second. The reason we aren't all in the core of the Earth is that the electromagnetic force is MUCH more powerful than the gravitational force and the repulsion of effect of all the electrons in your body trying to keep away from all the electrons in your chair and in the floor is what keeps us from falling through the Earth. But right now, from a physical point of view, you are accelerating toward the center of the Earth. There's just something that prevents you from continuing the fall. If you were in a completely sealed box and were accelerating at 10 meters per sq sec. there is no experiment you could perform that would NOT lead you to conclude that you were not on Earth at 1 g.

Cheers
Aj

So, firstly, let's take that number down by an order of magnitude. 50 billion is a more reasonable figure than 50 trillion. However, fifty billion people is still a LOT of people to have passed through this veil of tears. One would think that if ghosts did exist (and I see no reason to accept the proposition that they do) you would barely be able to walk down the street without running into one.

I think that this fear of ghosts is the confluence of a couple of evolutionary hangovers (as I like to term them) meeting and recombining. The first is our fear of the dark. Compared with a lot of things that were evolving alongside our Primate ancestors we have really poor night vision. Certainly compared to the big cats that were also resident in Africa a few million years ago, we were at a very big disadvantage at night. Imagine two individuals, one of whom is afraid to venture outside of the relative safety of the cave at night and another who isn't. The fearless one is more likely to become a pleasant little late-night meal for some big cat that likes it chimpanzee meat on-the-hoof, as it were. If you are eaten before you can breed, you lose the evolutionary game. So there would be *some* selective pressure to fear the night and, until very recently, lots of good reason to do so. The other thing is our overactive agency detectors.

This is going to take a bit of explaining. By agency I mean ascribing intention to others actions. Let's say that you, I and another person are sitting on your couch. I get up and go to the kitchen and open your fridge. You hear me rummaging around and pulling out a bottle. The other person asks "hey, what is she doing" you are going to use your intuitive psychology to say "Aj is probably thirsty and is getting a beer". You assume (most of the time correctly) that when someone takes an action there is some goal or consequence that they are pursuing. We do this intuitively. In fact our brains can't *help* but do this. The flip-side of this is that we ascribe agency even when agency isn't present.

"Why does it rain."

There have been lots of explanations for the rains, thunder and lightning. Most of them have been *spectacularly* wrong because people ascribed some agent to be behind the scenes causing the rain. So rain was the tears of the gods or was a blessing or curse from the gods. Thunder and lightning were caused by the actions of the sky gods. And our dreams? Why do we see our dearly departed loved ones in our dreams? Because they are spirits who have come back from 'the other side' to impart something to us.

That's all you need for a belief in ghosts to be booted up--a brain that detects agency and patterns enthusiastically, a brain that is capable of dreaming, and one that seeks causal explanations for events that happen in the world.

We have a fear of dark and foreboding places because, until fairly recently, dark and foreboding places either meant caves (someplace that wolves, lions or other apex predators might be hiding), forest primeval or jungle where danger in the form of aforementioned predators could be lurking anywhere. It was absolutely adaptive to have a sense of trepidation about those kinds of places.

One thing we have to keep in mind is that our brains did not evolve to deal with the modern technological world. There's nothing in our brains that *prevent us from dealing with it but this is not a natural environment for our brains. No matter how much education you have, no matter where you are from, what you believe, you are carrying around on your shoulders a brain that is, for all practical purposes, unchanged since about 50K years ago. We're stuck with these formerly adaptive features because the vast majority of them simply do not have the power to reduce reproductive fitness in a modern context.

Cheers
Aj

I'm not sure if answered your question or not, June. If I didn't let me know.

To tag to June's question I was just reading this: http://www.huffingtonpost.com/robert..._b_810936.html

Since humans are known to contain "energy" (about 20 watts) and since energy cannot be destroyed or created but altered, then when we die where does that 20 watts go?




I highlighted the relevant part in red.

Actually Lanza gets the First Law of Thermodynamics almost *precisely* wrong. Yes, the common simplification of the law is that energy cannot be created or destroyed but that's not *precisely* what is meant and you cannot derive Lanza's conclusion from the actual, formal definition of the law.

So what does the law state? In any system where work is performed the total amount of energy of the system (work performed plus loss from inefficiencies) is conserved. What this means is that you cannot get more energy OUT of a system than you put IN to a system. The problem with Lanza's explanation is that he doesn't say that, for instance, physicists are talking about a closed (isolated) system. The total energy amount of the Universe, for example, is actually fixed. Whatever that quantity is, the Universe is a closed system (no energy can be introduced from outside), but the Earth, for example, is not a closed system. Energy is being introduced to the system all the time by way of sunlight.

The second problem is that the 20 watts he mentions can be accounted for WITHOUT it having to go to some mysterious place. The 20 watts or so that your brain uses stops (becomes potential energy) when all of your metabolic processes cease. So then various microbes and worms come along and decompose (eat) your mortal remains. They transfer all of the energy stored in your cells to *their* cells (that is what eating does, it is simply a way of taking the energy from one living thing and making it useful to another living thing). This actually satisfies the requirement that energy is conserved. The energy does not exit the Universe (because it can't be destroyed*) but neither does this energy continue to persist in some kind of coherent state. The 20 watts of energy that Dr. Lanza is invoking is a product of your neuronal activity. Once the substrate that generates that activity no longer functions, the total energy of the system that is described by your body starts to go to its most natural (i.e. disordered) state with a consequent loss of energy.

Dr. Lanza pulls one of these tricks that is always like nails on chalkboard. In the service of his ideology, he invokes some commonly recognized but not well understood (by laypeople, I mean) principle in physics and then offers what seems like a plausible explanation but is actually glossing over the issue. He then claims that this or that physics principle proves that his particular idea/ideology/belief is backed up by science.

Cheers
Aj

From one Atheist to another (unless I'm remembering wrong and you're not one, in which case I apologise but still want you to answer cuz I think this is wicked fun):

How does one explain "manifestations of the Holy Spirit" (ie - "slain in the spirit" "speaking in tongues" etc) without the existence of God?

I was raised in a charismatic evangelical church (Pentecostal) so that stuff was an every day occurrence around me (well, Wednesdays and Sundays since those were the days that I went to church) and I don't for a minute believe that anybody was consciously faking anything. We're talking about people who on the basic level were sincere and well-meaning and convinced.

So how does it happen? Is it like a group-think thing (which I guess is more about psychology than about science, although I guess psychology is a kind of science, and now I'm confusing myself) or a "mind over matter" thing (like if you believe something hard enough the brain can do all sorts of neat things) or a really emotionally exited neurons firing around thing, or kinda like hypnotism?

Dear Hot Dr Sciences,

What exactly is the deal with quantum foam and do you think it is real?

Bonus question NASA scientists reciently discovered that lightening storms create small bits of antimatter, why doesn't this cause anhilation as I thought that if matter and antimatter got together it would be a cataclysm because of the enormous energy produced.
http://newsfeed.time.com/2011/01/12/...ng-antimatter/

Would it therefore be true that if I am accused of sitting on my ass doing nothing, it appropriate to counter that I am actually moving, and that the movement is not obvious to the observer only because said movement is at a constant velocity?

You remembered correctly, I'm also a non-theist. Although I wasn't raised in a Pentecostal church, I was raised in both the AME (African Methodist Episcopalian) and Southern Baptist traditions. In the early 1980s until I came out in the early 90s I was a Pentecostal. The issue of speaking in tongues is interesting. And perhaps in describing what I think was going on for me, it will shed some light on why I am so committed to the idea that there is *some* kind of reality and that this reality is naturalistic. It's not because I don't *want* to believe that there's something else, it's because I do.

I do not think I was consciously fooling myself. I don't think that people are consciously fooling themselves. In 1980, when I had my first experience of speaking in tongues, I truly felt born-again. I was part of God's family and my having the gift of tongues was a sign of that. No matter how bad my home life was, no matter how mercilessly my fellow students picked on me, it didn't matter because my reward was in heaven and I was filled with the Holy Spirit. I believed it with every fiber of my being and if there was any doubt in me, I knew that was just the Enemy trying to turn me away from the Light. At the time, I knew that for a fact. I was more certain of that than I was that the Sun would come up tomorrow. God could decide, at any point, that the Sun wouldn't come up tomorrow but God was constant and could be relied on.

I'm sure the language sounds familiar. There are times that I miss believing so hard that I knew and I knew *why* I knew. I knew because it was self-evidently true. I couldn't make these things up, could I? I wasn't making them up. I really did believe these things to be true.

It was in the process of deprogramming myself and walking myself back from a world where there really were demons (yes, I believed in demons) that I had to find something to hold on to, some way to orient myself. I decided that this would be the physical world. The physical world is what every one of us inhabits. You can believe what you wish, you can believe that this is all the Matrix but at the end of the day, if you walk up to the top of a tall building and step off of it, everyone here knows what is going to happen and using a pretty simple equation, we can describe the arc of the last few very exciting moments of your life. You can, in fact, actually count on that and no ideology or religious belief changes that. The most dedicated devotee of The Secret or the most fervent follower of Jesus is notgoing to step off of a building. This is what I call the point of least common agreement. You and I may be atheists, someone else reading this may be a Christian or a Jew or Tibetan Buddhist or Dianic Wiccan but we *all* agree on what happens when you step off a building. We may not even agree on *why* it happens, but we all agree that it happens. At base, that is reliable enough for us to treat it as reality. That became my life raft and with it I came back to the shores of the real world.

It was because I was able, so easily, to make myself believe that my being queer as a three-dollar bill was a result of a demon that I had to start small. It took me a good ten years, into my early thirties, before I felt like I had some kind of grip on the real world. I no longer look over my shoulder or wake up in the middle of the night worried "what if you're wrong and the Rapture is going to happen this next minute".

In the process, I came across the idea of the mind as a belief engine. I read that and it seemed elegant--in the sense that it was a relatively simple idea with deep explanatory power. What follows is based upon that simple and powerful idea.

I think what is happening is, in part, social phenomena. We want to belong. No matter how individualistic we like to think of ourselves, in the end we really want to belong to a group. In the church I attended one of the rites of passage, if you will, was being possessed by the Holy Spirit. I think that we *convince* ourselves something is happening when it isn't. One cannot help but notice that speaking-in-tongues never actually yields an actual human language. The sounds are what people might *think* as ancient (read Biblical) languages but they're all wrong. It's largely just random sounds more akin to the babble of a baby than even a rudimentary pidgin or creole language.

The human brain is an extraordinarily powerful organ and, for better or worse, it is stuck within itself. By this I mean that we can only use our minds to understand our minds.

Cheers
Aj

I'll take these separately. I'll talk about quantum foam first because, ironically, it's actually the easier of the two subjects.

Prior to the first third of the 20th century, both space and time were thought to be separate entities and to be smooth, inert and constant. Starting with relativity theory and continuing with quantum theory, the picture changed dramatically. Firstly, Einstein demonstrated that space and time were neither smooth, inert or constant. Matter, for instance, curves space-time. In fact the best operational definition of gravity, so far, is the warping of space-time by the presence of matter. Quantum theory demonstrated that ALL our intuitions about the way the Universe 'really is' break down at the sub-atomic level. Cause and effect, for instance, are not quite so straightforward at the subatomic level. Particles--actually virtual particles--pop into existence and then just as quickly pop out of existence. These virtual particles are highly energetic.

The idea behind quantum foam is this. At the finest possible resolution (known as the Planck length which is ~1.612*10^-35) the structure of space-time is not smooth and continuous but is actually like foam with virtual particles popping into existence and then being annihilated. I wouldn't go so far as to say that quantum foam exists---in the sense that it has an independent existence but it is more of a concept to explain the energetic turbulance of space-time at the smallest scale.

There is one big problem, however. The issue is that mass (or energy) warps space-time (which, you'll recall, is what gravity is) and at present there is not a working theory of quantum gravity. All the other forces are carried by a particle (called a messenger particle) and there is a hypothesized particle called the graviton which would be the messenger particle for gravity. Except, we haven't observed it. The issue is that gravity is weak, REALLY weak. I know it doesn't seem like that every time you fall but consider this...when you walk, with each step, you are overcoming the force of gravity to lift your foot. Every time you pick something up, you are overcoming the force of gravity. You can even overcome the force of gravity to pick up a piece of paper using only a comb and static electricity. So the search for the graviton is the search for the most weakly interacting particle of them all! Until the graviton is found, there's no way to account for the warping of space-time that would be the 'froth', if you will, of the quantum foam.

As far as the anti-matter is concerned, it's not that ANY anti-matter would cause massive annihilation it's that sufficient quantities of it would. A small number of anti-protons encountering protons would annihilate one another and release a lot of gamma radiation. A large number of anti-protons would create a far larger release of energy with more destructive power. Fortunately, antimatter is very rare at this stage of the universe.

This was not always the case, in the very early Universe (before things had cooled down enough for atoms to form) there were almost, but not quite, equal amounts of matter and antimatter. LOTS of collisions took place in a massively energetic holocaust of explosions. The matter we see in the Universe now is the result of there being a slight bias in favor of matter so when all was said and done there was still some matter while all of the antimatter had been destroyed. This was actually good for the Universe because had this not happened the Universe would have had much more density than it does and so the formation of stars would have been much less likely.

Cheers
Aj

Is it *possible* that the Sun could break up? Yes, but it would take a truly extraordinary set of circumstances for that to happen. Anything that would cause that (and I can think of only two off the top of my head--a black hole or another very massive star wandering into the neighborhood) would also make life on Earth very interesting and intense--for a very short period of time.

So how do we know that the Sun has a few billion (5 or 6) years left? Largely because of the mass of the Sun. To understand how this relates, we have to digress and talk about stars generally.

A star is simply a ball of plasma (matter in a very energized state) held together by gravity. The energy is provided by the fusing of hydrogen into helium. At the heart of a star, there is a wrestling match--gravity wants to collapse all of the mass of the star into the smallest possible space while heat wants to expand the star. Stars on what astronomers call the 'main sequence' are happily fusing hydrogen into helium. However, in ANY process there is is loss due to inefficiency. So as the star burns it begins to lose mass. Remember that mass is what is creating the gravity so as the star loses mass, pressure begins to win.

Because our Sun is a very ordinary star (it is a G-type dwarf star, the second or third most common type star in the universe) we have a lot of observational data from different stars like ours at different stages of life. Given a particular burn rate (and we know the burn rate of the star by the spectral lines--the light we see from the Sun is only part of the EMF spectrum being put out by it) we can determine at what rate the Sun is losing mass.

The end-game for a star is determined by its mass. For an ordinary dwarf star like ours, the end-game looks like this:

Around 5 or 6 billion years the Sun will have lost enough mass that pressure will, temporarily, have the upper hand. The outer shell of the Sun will then expand out to 1 AU (Astronomical unit which is 93 million miles). This is inconveniently the orbit that Earth occupies. It will then be a red giant star. Over the course of another billion years or so, it will burn off the rest of the helium and slowly collapse back into a white dwarf. This will basically be only the core of the Sun and will be about the size of Earth (although MUCH more massive than Earth is). Over the next few billion years, it will cool down through a brown-dwarf phase until it is a black-dwarf.

Within a reasonable margin of error (say 1% either way) we're pretty certain when the Sun will begin its end-game because of its present mass and heat.

Just because it is SO cool, I'll take you through the end-game of a much more massive star than ours.

REALLY massive stars (like Betelgeuse) have a much more interesting life cycle. They still stay on the main sequence H --> He but once they reach the Helium stage (where that's the only fuel that is left) it will begin fusing Helium into Carbon. This transformation keeps happening until the core becomes Iron. At that point, there's no place else to go. No natural force and fuse Iron into a heavier element and gravity gets the upper hand. The core collapses into itself and the resulting energy release is called a supernova. The star *literally* blows itself apart. If the star has sufficient mass, after the cataclysm of the supernova a black hole or a neutron star will result. A black hole results if the remaining core has sufficient mass to continue collapsing. Otherwise all that is left is a superdense core of neutrons known as a neutron star. These completely exotic objects are some of the strangest things in a very strange universe. They are so dense that a single teaspoon of the stuff would weigh as much as the Earth!

Cheers
Aj

Well, it depends upon what you mean. You, me, everyone in fact most *interesting* features of the Universe are made from the remains of supernova. As a very massive star goes through its end-game it makes all of the heavier elements on the periodic table (everything heavier than Helium). So all of the carbon in your body was once in a supermassive star that exploded. All of the oxygen you are breathing came from the same kind of source. So in a very limited and technical sense yes, all of the matter that we are made of and that sustains us is our creator. We are its creation. Billions of years ago some star burned its fuel, fell into the run-away iron-cycle end-game and then exploded. In the fullness of time that material became the Earth and the other planets.

To the degree I am at all deistic, it is that the Universe is the creator. Now, I don't think that the Universe notices we are here other than in the limited sense that living organisms interact with one another. In as much as you are part of the Universe and I am part of the Universe and we are aware that the other exists, the Universe is aware of our existence. In as much as I love my wife and my wife loves me, the Universe cares about my continued existence. But outside of those interpersonal interactions, I don't think the Universe is intelligent or aware of our existence. Supernovae happen not so that there can be life, it's simply a by-product. Earth isn't here so that there *can* be life, life exists because Earth happens to have a range of environments and is stable enough for life to have a chance to get going.

Cheers
Aj

Speaking of Life on Earth, is there life out there? Do you think it would be as aggressive as Hawking stated:

Found on wikipedia:

In planetary astronomy and astrobiology, the Rare Earth hypothesis argues that the emergence of complex multicellular life (metazoa) on Earth required an improbable combination of astrophysical and geological events and circumstances. The term "Rare Earth" comes from Rare Earth: Why Complex Life Is Uncommon in the Universe (2000), a book by Peter Ward, a geologist and paleontologist, and Donald E. Brownlee, an astronomer and astrobiologist. Their book is the source for much of this article.

The rare earth hypothesis is the contrary of the principle of mediocrity (also called the Copernican principle), advocated by Carl Sagan and Frank Drake, among others.[1] The principle of mediocrity concludes that the Earth is a typical rocky planet in a typical planetary system, located in an unexceptional region of a common barred-spiral galaxy. Hence it is probable that the universe teems with complex life. Ward and Brownlee argue to the contrary: planets, planetary systems, and galactic regions that are as friendly to complex life as are the Earth, the solar system, and our region of the Milky Way are very rare.

http://en.wikipedia.org/wiki/Rare_Earth_hypothesis

I have to say that I would be absolutely stunned if there were no life anywhere else in the universe. The sheer range of environments that life can cling to here on Earth actually suggests that life would have quite a bit of opportunity to get booted up. Consider:

Living things survive in environments as diverse as the bottom of the ocean, next to volcanic vents where superheated water containing high levels of sulfure provide a habitat for tube worms and bacteria to the inside of reactor cores (there is a species of bacteria, Deinococcus radiodurans) that thrive in high radiation environments. There are salt-loving bacteria, sulfur-loving bacteria (some of which are in symbiosis with the aforementioned tube worms). So I think that life probably exists elsewhere in the universe.

I'm even willing to venture so far as to say that intelligent life probably exists somewhere else. Our primary adaptation, the reason why we are such a spectacularly successful species (so far) is our adaptability. That adaptability we call intelligence. Intelligence is SUCH a neat trick that it would quite remarkable if some other species, living in who knows what kind of environment, hadn't hit upon intelligence in the course of their evolutionary history. So would another intelligent species be as aggressive as Hawking suggests? That depends.

There's a couple of schools of thought on what to look for in another intelligent species. For one, taking a naturalistic view any extraterrestrial species we might meet would *also* be a product of evolutionary forces. Evolution doesn't necessarily favor nice guys. It doesn't necessary reward complete bastards either. In most game-theory based models what seems most stable is tit-for-tat. If you cooperate with me, I'll cooperate with you. If you stab me in the back, I'm either going to get retribution OR I'm going to let others know you're not to be trusted. Grant, for the moment, that other species would probably hit on some kind of similar solution.

One school of thought says that intelligent species pass through stages of civilization. The stages were originally proposed by a Russian named Nikolai Kardaschev and the scale is called the Kardaschev scale. It measures total energy output used by a civilization. The scale is four stages (originally three) which are:

Type 0 civilization--this is where we are right now. We are actually at about .72. More on this in a bit.

Type 1--This civilization can use all of the energy available on their planet. This could be achieved through the use of fusion power, power generated from naturally collected anti-matter or space-based solar arrays which would allow us to use much higher proportions of the Sun's energy than we do now.

Type 2--This civilization can use all of the energy available in their solar system. The most common example of this is the Dyson sphere. The idea behind a Dyson sphere is that a civilization breaks down all the other planets in the solar system and uses those to construct a sphere around its primary star. That way ALL of the star's energy is trapped in the sphere and can be put to use. The civilization lives on the inside of the sphere.

Type 3--This civilization can use all of the energy available in their local galaxy.

Another proposed scale is from Robert Zubrin. It is still a three-stage scale but instead of looking at the energy consumption, looks at how far the civilization has spread.

Type 1--Has spread across its entire planet.

Type 2--Has spread across its entire solar system.

Type 3--Has spread across its galaxy.

So, using the two scales applied to science fiction civilizations (since they are familiar enough to most people)

Human civilization is type 0 according to Kardaschev scale and Type 1 according to the Zubrin scale.

The Federation of Star Trek is a type 2 civilization using the K-scale and type 3 using the Z-scale.

Both the Galactic Republic and the Galactic Empire of Star Wars are type 3 civilizations using either scale.

The Ancients in Stargate are most likely type 3.

Here's the challenge--getting from type 0 (where we are) to type 1 (or type 1 to type 2) depending upon the scale you prefer. IF we manage to neither blow ourselves to kingdom come or create our own little Venus here then in another hundred years we'll become a Type 1 civilization according to the K-scale. I think that any civilization that manages to get that far will probably persist indefinitely. So the optimistic view would be that if we were ever to encounter a type 2 or type 3 civilization, they would simply be too mellow and evolved to conquer us.

The less optimistic view, though, is that any type 2 or type 3 civilizations we might encounter here are going to be here for a reason. I can't imagine why any civilization would go to the trouble and expense to travel possibly hundreds of light-years JUST to see the sights. If an alien civilization comes to Earth it would likely be because Earth has something that they want/need and cannot synthesize themselves. If that is the case, the best we could hope for is that they would relocate us someplace and then take the planet for themselves.

Also keep in mind that a type 2 or type 3 civilization would have technology so far advanced from ours that we would all have full and complete appreciation of Clarke's Third Law, "Any sufficiently advanced technology is indistinguishable from magic". I think that if we were to encounter a type 3 civilization we might be very likely to fall upon our knees and worship them as gods as they would be able to do things to and with matter that we can hardly fathom. If we gave them any guff, however, sweeping us aside would be no more trouble than, say, any modern military would have sweeping aside the armies of Caesar or Hannibal. Imagine the modern US military transported back a few thousand years to the time of Caesar. They would appear as gods to them.

Hawking makes a really good point. As much as we may romanticize why the Europeans, Chinese, Persians and Ottomans set out on their voyages of exploration they were looking for resources, fortune and glory. They weren't just seeing the sights, that was an interesting by-product. Whenever or wherever those three groups found people who were inconveniently in the way they either destroyed them or conquered them. I suspect that any intelligent species that went to the trouble of traveling here would probably do the same.

One other option--and this was a point that Hawking made and other scientists also made after a couple of instances where NASA or some other group of scientists sent messages into deep space saying "here we are"--is that a civilization might detect us and decide that BEFORE we become a problem in the galaxy, they might want to just save themselves the trouble and wipe us out now while we are still not much more than monkeys with nuclear weapons, some satellites and digital-fiber optic technology. It would certainly be tempting particularly if the species were aggressive. Using the Star Trek universe as a guide, I could see the Vulcans wiping us out because it would be easier to do so now than AFTER we developed FTL travel. I could see the Romulans doing so for much the same reason. I could see the Klingons doing so because we would look like the competition and it would be a nice exercise for young Klingon warriors. :)

Cheers
Aj

[QUOTE=The_Lady_Snow;269886]Dear dreadgeek,


Could you explain the phenomena of [B]Déjà vu????


The déjà vu illusion occurs when a person has an inappropriate feeling of familiarity in a situation that is objectively unfamiliar or new. The amorphous nature of this experience has made identifying its etiology challenging, but recent advances in neurology and understanding of implicit memory and attention are helping to clarify this cognitive illusion. More specifically, déjà vu may result from (a) a brief change in normal neural transmission speed causing a slightly longer separation between identical messages received from two separate pathways, (b) a brief split in a continuous perceptual experience that is caused by distractions (external or internal) and gives the impression of two separate perceptual events, and (c) the activation of implicit familiarity for some portion (or all) of the present experience without an accompanying conscious recollection of the prior encounter. Procedures that involve degraded or occluded stimulus presentation, divided attention, subliminal mere exposure, and hypnosis may prove especially useful in elucidating this enigmatic cognitive illusion. [ABSTRACT FROM AUTHOR]

Brown, A.S (2004). The Déjà Vu illusion. American Psychological Society, 16: 256-259.

Thanks AJ for your excellent replies. That quantum foam thing has tripped me up and you helped very much to clarify!

As to the antimatter, clearly I watch too much Star Trek.

Thanks again!

PS this thread is SO giving me a brain wood

I've always been curious....

Does "Electroweak Breaking" Affect the Macroscopic World?

I love to cook and so I'm always interested in the science of food.

I've always wondered two things:

1. What is the science behind churning butter? How does the churning turn cream into butter? What are some of the molecular changes going on?

2. Who figured this out? How do you accidentally churn and churn cream until it becomes butter?

Rufus

Daywalker - I think you would love the poetry of Whitman and William Blake. They both have the idea that the creator and the creation are the same thing. They argue for Poets replacing priests and institutionalized religion and people learning to value and be in awe of the natural world of which we are a part (hence Whitman's odes to the body, sex, and life) and Blake's awe of art (as creation), and the natural world.

Rather than worrying about an afterlife and keeping an unknowable god figure happy they tell us to revel in life itself and that "god" is in us and in everything we see and to worship that and not some arbitrary angry figure that demands we do X but not Y in order to have an afterlife.

Blake (late 18th century) was an anti rationalist because he said they reduced life to nothing but atoms and molecules and diagrams and theories. In one of his paintings, Blake has Newton looking down at the ground creating a diagram. In this picture, Newton has lost his creative imagination and has lost his capacity to be in awe of and in wonder of the natural world and in doing so has lost his humanity. For Blake, true humanity was located in the creative arts and in the human imagination.

Melissa

As I was kindly reminded, I am sorry if I had the nerves to answer some questions... I will not participate in this thread... the only thing I have to say though, it would be nice to have seen some sources or articles related....

Buhbye

[quote=Softhearted;269911]

Rufus has a theory that deja vu is related to DNA. Since all our likes and dislikes and preferences are related to genetics then deja vu is a genetic memory. We think we have seen or done something before but we are just flashing to gentically passed likes and dislikes, almost like a genetic memory. Just theory of course but I like the idea. What do you think?

Melissa

I refuse to say "Science Wood" because it makes me uncomfortable. Putting it in quotation marks does not count as saying it.

Dear Person Who Likes Science:

Since we know that Sundowning (the tendency toward increased abnormal behaviours from a person with Dementia in the late afternoon or night time) exists and is real, and since we think that the Lunar Effect (the tendency toward increased abnormal behaviours from a person with Dementia or mental health issues related to the full moon) MIGHT be a little bit real - Is it fair to say that there is a little bit of science behind astrology?

I mean, surely if moon phases and time of day can effect people...it's not completely unreasonable to say that the position of the planets and/at time of birth can lead to some predisposition of personality types?

Sorry folks
 

I have to catch up. I don't spend as much time online during the weekend as I do during the work-week so it may take me a bit to get up to speed. :)

Cheers
Aj

June:

Actually, this is not quite correct. The Earth forms and then over a period of time, gets bombarded by comets (which is where the most likely came from). Now, as far as mass being added by the living things actually that's not the case. All of the mass in your body and in the bodies of other living things was already present on the planet. Here is where the conservation of energy comes in. Right now, chances are, one of the oxygen atoms you've just inhaled was breathed by a Caesar, or some Roman slave from the time of Caesar. All of the activity you've spoken of--comets and asteroid collisions notwithstanding--redistribute the mass of the planet without actually adding or reducing the total mass.


Strictly speaking, we should talk about the *mass* of the Earth and not its weight. The weight of an object is a function of the gravitational field the object is in. So if you are, say, 180 lbs on Earth on the Moon you would weight just 30 lbs. So in order to talk about the weight of the Earth we would have to know what gravitational field we're talking about. The mass of the Earth, however, is more or less a constant. We gain trivial amounts of mass from dust blown at us by the solar winds and we gain slightly more (but still trivial) amounts of mass from asteroid impacts (large ones actually cause us to lose mass).

Actually, the Earth IS slowing down but not because of its mass. Remember that any body in motion will continue in motion unless acted upon by another force. The Earth's rotation is slowing down but not because of OUR mass but because of the mass of the Moon. Some of the energy of Earth's rotation is transferred to the Moon. There is also friction from space dust.

It will take a few billion more years before a day on the planet gets appreciably longer though. :)

Cheers
Aj

Ok. I need to know. Is there a true scientific reason for the level of stupidity on Fox News?

http://www.huffingtonpost.com/2011/0..._n_817723.html