Saturday, 31 August 2013

The accelerating universe

In 1998 observations of very ancient and distant supernovae revealed a surprising fact about our universe: it's not just expanding, but it's expanding at an accelerating rate!  Before that it was thought that the universe would necessarily be decelerating because of the gravitational attraction of all the matter and energy.  It debated whether or not the universe would end by a 'Big Crunch', with everything compressed together, or whether it would expand on forever with the expansion getting ever slower.  Acceleration was the last thing that was expected!

The acceleration is though to the the result of a constant force which is somehow built-in to space - each volume of empty space contains something that results in this force.  There are various ideas, mostly to do with some quantum effect, but no-one really has any idea what it is, and so it's given the pretty meaningless name 'dark energy'.  

What will the future be?  Dark energy seems to stay constant in a given volume of space, so it won't ever grow large enough to rip galaxies, planetary systems, stars, or even people, apart.  All these things will be held together by the vastly stronger forces of gravity, electromagnetism, and nuclear forces.  But on larger scales the dark energy force will overcome gravity.  In many billions of years from now distant galaxy clusters will have accelerated away beyond our ability to see them.  The universe will appear much, much smaller.

Friday, 30 August 2013

What would objective goodness and badness be like?

What does it mean for some act to be really, objectively bad?  Or really, objectively good?  This is a question that has puzzled philosophers for thousands of years.  Some think that there can be no such objective nature of morality; others that there can be some sort of shared morality recognised by most mentally healthy humans, a sort of pretty-much-universal form of common experience that is a reasonable substitute for objectivity.  

But what would true objective morality actually be like?  Where could it reside external to the minds of humans and other sentient beings?   There is a problem with this, as moral standards are felt emotionally, they are connected with empathy, with conscience.   Also, a moral standard that wasn't in some way subjective would not need interpreting.  It would not be possible to think of a moral position related to that standard and have a subjective position on that standard, as then we are in the situation of subjectivity - if we are in a position to question whether or not something is really wrong, or really right, then we lose the objective aspect of that moral question.  

The problem, I suggest, is this - the only way an objective moral value can exist is if it's not possible to have a subjective alternative feeling about it.  Objective morality must mean unchallengeable consciences.   

Or does it?

How to make a time machine

As we understand physics today, time machines might be possible.  If they are possible then they have a major limitation, which is that backwards-in-time travel is cannot be before the time machine was first switched on.  The reason is that the only way we know to make time machines is to distort space and time to allow 'Closed Timelike Curves' (CTCs), and these closed curves can't loop back to before the time machine was turned on as that's the earliest that one of these curves can start.  Creating a time machine is like creating a subway tunnel through time - you can enter and exit any time along its length but you can't get off before the start.

There are many ways that a time machine might be made.  There is one idea which requires an infinite spinning massive cylinder, which doesn't seem very practical.  Perhaps the most likely way is to use a wormhole.   A wormhole is a shortcut between two points.  One point might be on Earth, the other around Alpha Centauri, and it might take only seconds to travel between these points through the wormhole.

[Just a quick point - wormholes aren't anything like as shown in science fiction TV series: they don't look like funnels.  The entrances to a wormhole are spherical, not circular.]

To make a time machine, construct a wormhole, say on Earth, with two ends A and B close together.  Now, take end B on a trip to the stars (anywhere will do) travelling close to the speed of light for, say, 100 years, but with B only experiencing 10 years.  Then, bring end B back to Earth.   Time connects differently through the wormhole than outside it.  If you now enter end B, you will exit end A 90 years ago!

This might not be possible.  Some predict that quantum effects would result in destruction of a time machine just before it's possible to use it.  But it's a fun idea.

Thursday, 29 August 2013

Gravity is the creator

Life on Earth doesn't continue just because the Sun provides energy.  What the Sun provides as well is something vital for life on the surface of our world - low entropy.  What this means is that the Sun provides energy in a highly ordered form - it's directional and it's limited to certain wavelengths.  Life uses the order in this energy source to build itself and keep itself going, all the while releasing energy as random heat.  Although life is very ordered - low entropy - life can continue because life is a source of disorder - high entropy as a result of life actually living.

So, having established that the Sun is a vital source of ordered energy, where did this order, this low entropy, come from?  It had to come from somewhere, because the universe shortly after the Big Bang consisted of widely and evenly spread out gas.  The answer is that the order in the Sun came from gravity.  Gravity is a long-range cumulative force, and gravity magnified differences in the gas: where there was slightly more gas even more would be pulled together.  This concentration of matter produced galaxies and stars.

However, gravity doesn't produce order from nothing.  Collapsing gas generates heat, and so the Second Law of Thermodynamics still applies - overall, the entropy of the universe increased - it's just that with gravity very localised spots with much lower entropy could form - stars and planets.

The source of life's complexity, the reason why life can appear and grow and evolve isn't anything strange or mysterious - it's the same force that fires up the nuclear furnaces at the heart of stars.

Wednesday, 28 August 2013

Zara's wager

There is this argument for justifying belief in God which is called 'Pascal's Wager'.  It goes like this:  If you believe in God and you are wrong, all you have lost is a lifetime of belief, but if you don't believe in God and you are wrong, you get an eternity in Hell for being an unbeliever.

This, as you might think, is flawed.  One reason it's flawed is that it's hard or even impossible to choose to believe.  You can't pretend to believe.  Another reason is that there are just so many gods - which do you believe in?

I have a modest proposal, a suggestion which I shall humbly call 'Zara's Wager'.  It goes like this:  If you believe in the wrong god, you are going to Hell.  If you don't believe and there is a god you are going to Hell.  So, it looks like you are going to Hell if there is a god.  Best make the best of it.  How?  Believe in Satan.  You might not be able to convince yourself that Satan exists, but the Devil is the Prince of Lies, and your hypocrisy will surely be appreciated.  You might believe in the wrong Devil, but again, I'm sure Satan will appreciate this, as unlike God, scripture doesn't say he is jealous.   So, do your best to get on good terms with the landlord of where you are going.  You don't have to do evil - a deathbed conversion will do the trick, a winning sign of laziness and inconsistency.

Beat that, Pascal!

Tuesday, 27 August 2013

What is Special Relativity?

Special relativity is an incredibly simple model of physics that leads to very strange (to us) conclusions.
Relativity was nothing new when Einstein published his first paper on Special Relativity.  Centuries before, Galileo had realised that motion made sense only as being relative to something else.  For example, a ball could be thrown and caught easily within a ship even if that ship was sailing at speed.

What Einstein did was to add to relative motion the idea of a limiting speed, which would be the same for everyone no matter how fast they were moving.  The idea of this limiting speed came from the work in the 1800's on electromagnetism, as there was a constant relating electric charges to magnetic forces, and that constant involved the speed of electromagnetic waves - the speed of light.

Einstein insisted that electromagnetism (and everything else about physics) should work the same no matter how fast you are moving relative to anything else - you should not be able to perform an experiment to determine some absolute speed at which you were moving.

So, if the speed of light was the same for everyone, what would be the result?  It would be that speeds would not add up simply.  If someone travelling at 20km/h turned on a torch and projected the beam of light ahead, both that person, and someone stationary relative to that person, should measure the speed of the beam as the speed of light (not the speed of light + 20km/h).   A vast number of experiments show that this is the case.  Other effects would be that lengths of objects moving close to the speed of light will appear shortened, and time should appear to move more slowly for such objects.  These effects have all been measured.

What with everything changing depending on speed, is there something that everyone will agree on?  Yes, there is - it is called the 'spacetime interval' between two events.  You may remember that the distance between two points A and B in space is given by sqrt((Ax - Bx)2 + (Ay - By)2 + (Az - Bz)2): the square root of the squares of the distances along three axes between A and B.

Special Relativity deals with points in 'spacetime' - the 4-dimensional combination of space and time (known as 'Minkowski space').  However, Relativity also has to deal with time being a different kind of dimension than those of space.  This difference results in changes of signs.  The equivalent of distance in Minkowski space is the 'spacetime interval' s, and it's calculated like this

s = sqrt((Ax - Bx)2 + (Ay - By)2 + (Az - Bz)2 - c2(At- Bt)2 )

It's the normal Pythagorean calculation, but with the difference in time squared multiplied by the square of the speed of light subtracted.

A speed (the speed of light) comes into the equation because it converts the units of time to units of distance.

No matter how something is moving, all observers will get the same value of 's' for that thing.  That's what stays the same in Einstein's Special Relativity.

By the way, you might be wondering what happens if the term involving times gets bigger that the sum of the terms involving space, giving a negative number to be square rooted.  This gives a perfectly acceptable 'imaginary number'.  'imaginary' spacetime intervals connect events which can be causally connected - one event could possibly be the cause of another.  Non-imaginary intervals are between events which cannot be causally linked, as faster-than-light speeds would be needed to get from one event to the other.

Sunday, 25 August 2013

You can go faster than the speed of light

You can go faster than the speed of light.  This seems to be a strange thing to claim, because isn't the speed of light the ultimate speed limit?  It is, but speed only makes sense as relative to something else, and during an actual journey.  It's possible to have travelled faster than light, but only in a very special way.

Imagine you are setting off to the centre of the galaxy, about 30,000 light years away, and you have no limit to the amount of fuel you can use.  Suppose you travel with an acceleration of 1g to make it comfortable on your spaceship.  You could reach the centre of our galaxy in 20 years.  That's an average of 1,500 times the speed of light.

But no-one will actually see you travel at this speed because they will see you take about 30,000 years to reach the centre.  You won't see the distance to the centre of the galaxy as 30,000 light years as you are travelling because speed compresses length - it will appear very much shorter.  However, when you stop at the centre, you can, in hindsight, work out how far you have gone and how long it took.  You can travel faster than the speed of light so long as no-one sees you do it, not even you!

How relativity makes magnetism

An electric current creates a magnetic field.  That's been known for a long time, but when physics is taught this is one of those things which is just stated, which I find a shame because the explanation is both simple and amazing.

First, we have to accept the consequences of there being a universal speed of light, observed by anyone no matter how they are moving.  Given that, things that are seen to be moving relative to an observer will show various effects.  Firstly, time will appear to slow for these things.  Secondly, lengths in the moving objects will seem to be shorter in the direction of movement.  Thirdly, moving objects will seem heavier than when they are at rest.  What matters for magnetism is the second effect - the contraction of length.

Now, imagine two parallel wires, each with an electric current flowing in the same direction.   First, let's look from the point of view of the positive nucleii of atoms on one of the wires.  Electrons in the opposite wire will be seen to be moving, and because of this distances between them will seem to be shorter, and so there will appear to be an increased density of negative charge.  Now let's look from the point of view of the moving negative electrons in one of the wires.  Nucleii in a second, opposite wire will be seen to be moving (backwards relative to the electrons in the first wire), and so there will seem to be an increased density of positive charge.

The increased densities of charge because of relativistic length contraction results in an attraction between two wires carrying electric currents in the same direction.  This is what magnetism consists of - a very, very, very tiny excess of electrostatic forces.  It's small because the movement of electrons in an electric currents we use to generate magnetism is extremely small - it's typically measured in metres per hour.  (Electricity is the signal for electrons to start moving, and that can travel very quickly).  That we can make magnetism at all with our technology shows how incredibly strong electrostatic forces are.

Saturday, 24 August 2013

Dinosaurs did not go extinct

Dinosaurs were not wiped out at the end of the Cretaceous era when some asteroid or comet hit the Earth and the result send most species into extinction.  The reason why it used to be said that dinosaurs disappeared was because the relationship between dinosaurs and their descendants today was not well understood.  That changed years ago when it was discovered that a considerable number of dinosaur species that were though to look much like reptiles were, in fact, covered in feathers.  It's now thought that the majority of certain groups of dinosaurs were either feathered all over or were born feathered and lost that covering later in life.

The existence of very well-preserved fossilised feathers can allow us to do something that was thought to be forever impossible - to find out the likely colours of some dinosaurs.  This can be done because the colours of feathers can be due to their very fine structure.  As a result we can know that some early gliding dinosaurs (such as Microrapter) were a combination of yellows and browns.

More detailed analysis of fossils is showing us more about how the species we call 'birds' arose from, and although it's not sorted out fully, there is little doubt that birds are members of a group of dinosaurs called Maniraptora, which includes the fearsome Velociraptors.

The so-called 'dinosaur killer' collision did no such thing.  The celestial impact had a dramatic effect on life because what it killed across the world was animals above a certain size.  Large land animals could not hide from the fires and impact heat that spread across the world, and in the aftermath large animals could not survive on the limited food that would have been left.  What survived were small-bodied species - small reptiles, small mammals, and small dinosaurs, and the dinosaurs that happened to survive were a one group that we now call birds.

Friday, 23 August 2013

Do black holes mean that the universe is safe?

The universe isn't safe?  It's a frightening thought, but let me put your mind at rest, at least a bit.  According to some ideas about physics the universe could collapse into a different type of universe at any time.  This is astronomically unlikely to happen while humans are around, and it would not be all at once.  A tiny flicker of a quantum event at one point in space could start it off, and then it would spread at the speed of light.  However, the universe is extremely big and expanding at an accelerating rate.  If the collapse happens in a distant part of the universe it may never reach us.  But really, don't worry, it's so very, very unlikely to happen while anyone is around.

What could make it happen fast is having vast amounts of energy concentrated in one place, kicking space around enough to make it able to flip into a different state.  But, there isn't anywhere around in the universe where that kind of concentrated energy can be found.  Or is there?

Black holes are only black because we aren't close.  Very strange things happen at the edge of a black hole if you can get very close to that edge and hover there, or if you can observe very close to that edge from a distance - things will get very, very hot, if current theories are right.  All the information associated with whatever falls into the black hole appears as thermalised radiation at the event horizon, and that radiation is very hot indeed, perhaps the hottest thing possible in our universe.

And so, if theories are true about black holes, it may be that close to their surfaces space is blasted with such intense heat that if it was going to collapse, it would have, and there are so many black holes around us that the universe should have been destroyed.

Perhaps the intense heat of black holes means we are safe from any possible collapse of the universe, no matter how incredibly unlikely!

Thursday, 22 August 2013

Relativity: why time slows with increased speed and with gravity

What I'm going to do is explain a way of looking at relativity that should give a feel for what is going on.   Some physicists may cringe at what I am going to write, but I have no shame!

First, let's take a look at Special Relativity.  Einstein realised that there was a speed that was constant for everyone, no matter what they are doing.  That speed is the speed of light.  The constant isn't defined by what light does, but it is the ultimate speed, and light goes at that speed in empty space, as does anything massless.  One way to look at why this speed is a constant is to consider it as the universal speed, the speed at which everything moves.  This makes no sense until we think of the speed as being in 4 dimensions, with time as one of those dimensions.  When something appears to be standing still (relative to you) in space it will not seem to be slowed in time.  The reason is that something standing still (relative to you) in space is moving at the ultimate speed, but only through time.  If something is moving relative to you, you will see its time slowed down.  The reason is that that thing is now moving through space as well as time, so some of its speed through time has been diverted to speed through space.  What happens as things speed up and slow down is that they are merely changing direction in the four dimensions of space and time; they aren't actually changing speed at all.

If something moves at the ultimate speed through space, as light does, it has no speed through time at all, and so its clocks (if it has any) appear stopped.

Now, General Relativity.  Imagine you are sitting alone in the dark, and you turn on a light.  A sphere of light will rush away from you in all directions, and (obviously) at the speed of light.  If you are weightless, floating in empty space, then that sphere of light will stay centred on you, as it speeds towards the stars.  That sphere of light will always be the furthest anything could have possibly moved away from you, because nothing can outrun light.

Gravity bends space and time.  If you are on the surface of a planet, in the dark, and you turn on a light, a sphere-like shape of light will rush away from you, but it won't remain centred on you.  Gravity drags down even light.  The centre of that globe of light will drift, just a tiny bit, down towards the centre of the planet.  If you were close to a very, very massive object such as a neutron star or black hole then the shape of the globe of light coming from you would be very distorted indeed.

The bending of space and time does this:  it's constantly telling things that they should be somewhere else.  The gravity of the Earth is nagging at your atoms, insisting that they really should be lower down.  The surface of the Earth pushes back up on your body and your house, car and furniture, to make sure you don't fall downwards, but that nagging continues which is why you feel gravity as a force.

Remember from Special Relativity that everything moves at the ultimate speed through space and time.  What gravity does can be though of as constantly moving space, and it's that movement of space that is telling your atoms that they should move.  Because your atoms are experiencing a movement of space, they can't be moving at the ultimate speed through time any more.  So, gravity's effect on space results in things being seen slowed down from a point of view where gravity is less.

At the edge of a black hole (the event horizon), we can consider that space is moving towards the centre of the hole at the speed of light.  This has two effects.  Firstly, than nothing can experience being stationary there, and secondly, time dilation will be infinite - clocks will appear stopped.

Everything moves at the universal speed, and gravity makes space move - that's an easy way to get some idea of how Special and General Relativity work.

Wednesday, 21 August 2013

Origins, explanations, and anti-explanations

Some really interesting questions have been asked on Twitter about what is reasonable and unreasonable when it comes to the origin of our universe.

One question is about what is likely and unlikely.  It may be that origins of universes are unlikely, but does that matter when we are dealing with origins?  There are ideas about the physics of the origin of our universe that can help us think about this.  The physicist Sean Carroll suggests (in his book From Eternity to Here) that our universe may be the result of a quantum fluctuation in an earlier universe.  That quantum fluctuation may have been astronomically unlikely, but that earlier universe may have got into a boring static state and have been around for trillions of trillions of years, and given enough time, the most unlikely things will happen.

Related to likelihood is the matter of complexity.  The reason is that complex things are hugely less likely to appear out of nothing than simple things, because there are so many random possibilities of which the complex things are a tiny fraction.  It's physically possible for a clock to appear out of nothingness by quantum fluctuations, but that is vastly less likely to happen than for an atom to appear out of nothingness.

Then there is the question of what we mean by 'explanation'. This is also linked to likelihood and complexity.  Evolution shows how apparently unlikely complex organisms can arise from much, much simpler systems through simple processes.  There is no 'conservation of complexity' in the universe - complexity can grow (and shrink).

What we mean by explanation is to try and find a simple and likely reason for something happening.   Our explanations may be wrong, but simplicity and likelihood are the criteria we use when we look for explanations.  This is why gods are not good at all as explanations - indeed they are 'anti-explanations', as introducing a god leaves more to explain that we started with.

Tuesday, 20 August 2013

Complex creators

Without wanting to wander too much into theism, I want to explore a common idea and show how it can be easily shown to be wrong, no matter what your belief system.  This idea is that a creator can be simple.  Some sort of vague mindless creative influence might possibility be simple, but a creator with a mind absolutely cannot.  Why?  Because of the things we insist a mind can do.  A mind can think, it can respond, it can remember, and it can change.  These things that a mind can do necessarily involve complexity.

Let's consider memory.  Memory requires storage of things separately so that they aren't confused - if you have a memory of red, and a memory of blue, then recalling these memories will recall each separately, and not some purple mess of combination.  There are many, many ways of storing such things, but method doesn't matter, what matters is that by any measure of complexity being able to remember has to involve complexity, such as the ability to assign storage to memories and later recall them based on some form of identification (such as the word "red" for the colour red).

Similar arguments for the requirement of complexity apply to the process of thinking, the changing of mind, the making of decisions.  All these things involve a mind changing states, and the existence of such states is part of what we call complexity.

The problem of complexity can't be avoided by labelling a creator 'supernatural', because in the above discussion no mention of physics has been made.  A 'supernatural' being has the same necessity for memory and thinking, no matter that the mechanism is forever unknowable.

Mind is complex, and if mind seems so complex that it surely needed a creator, then the mind of a creator is then so complex that a further creator is needed, and so on forever.  This is why the idea of a creator is never a satisfactory explanation for the existence of mind.

Monday, 19 August 2013

I'm fan of Roger Penrose

One of the greatest physicists, and still active in research in his 80s, is Roger Penrose.  Penrose has been working mostly behind the scenes for a long time, never having got the exposure of his friend and collaborator Stephen Hawking, and yet Penrose is at least Hawking's equal.  

When the theory behind black holes were being examined in the 60s and 70s, there were still many questions about what happened inside them (there still are), and one of those questions was whether or not anything that fell into a black hole could ever miss being crushed to destruction at the centre of the hole.  Penrose showed that no object could ever miss the centre of a simple black hole, and he did it using not physics but topological mathematics, a stunning achievement.  Penrose is one of those who revolutionised our understanding of these strange collapsed stars.

Penrose seems to like sometimes standing on the sidelines of physics, challenging established ideas and coming up with amazing new ways of looking at reality.  One of his challenges to such ideas is his rejection of the idea of inflation, the idea that the universe expanded incredibly fast right at its origin.  This expansion is supposed to have smoothed out the universe, creating a state of very low entropy, from which the universe we see around us could have formed.  Penrose says that inflation solves little, as inflation itself requires such special conditions that it's more unlikely than the smoothness it's supposed to explain.  Instead, Penrose has come up with some fascinating ideas of what the universe may have started like and what it may end up like, as discussed in his latest book "Cycles of Time".  As the physicist Lee Smolin says, only Penrose could write phrases like "after eternity" and really mean it!

Penrose does have some strange ideas, such as that minds can do things that computers can't, or that consciousness may be a quantum phenomenon.  However, he does have the honesty to admit in his writings that his views aren't mainstream.  I find that honesty both endearing and important.

His books can be dense with information, and hard to get through, but if you can, it's really worth it.  You will always learn something new, and get an exciting perspective on physics from one of the greats.

Saturday, 17 August 2013

Forget Mars - go to Titan!

I can remember the feeling of excitement I felt when the Huygens probe touched down on the surface of Titan, the biggest moon of Saturn.  Suddenly, we saw a landscape: shades of pale orange, rounded boulders scattered here and there.  So much more data came back from this mission, but the image of the rounded boulders told us so much.  Rounded meant eroded, rocks tumbling in a river, ground down by collisions.  This could have been an Earth landscape if not for the orange light, and the temperature.  The rocks were not the familiar minerals of Earth, but ice - water ice frozen into hardness.  The river that tossed the rocks around was not one of water, but methane.

So much of Titan looks familiar.  Mountains, rivers, seas, volcanoes,  dry land with dunes.  Titan was a stage on which the same stories where told but with different players.  Mountains of ice, rivers of hydrocarbons, volcanoes from which water/ammonia lava flowed.  This is becoming a familiar story - cold doesn't seem to be a barrier to interesting and beautiful things happening: Freezing Neptune has the strongest winds of anywhere in the Solar System!

Does the similarity with Earth stop with landscapes?  Does the existence of water lava mean that there might be life?  Perhaps.  Titan is literally dripping with complex chemistry, as energy from the distant sun reacts with Titan's atmosphere.  It's definitely worth looking.

There is another advantage to Titan for humans.  Strange as it may seem, it could be a great place for a colony.  Titan has an atmosphere - not thick enough to be harmful to people, but thick enough to mean that humans could walk on Titan's surface without space suits.  Heated clothing would be vital, but all that would be needed to breathe would be an oxygen mask.  The atmosphere would protect against cosmic and solar radiation.  Titan has all the resources a colony would need - plenty of water as ice and vast amounts of hydrocarbons to make food and fuel.

There is no other place away from our planet that we could walk in the 'open air', without fear of radiation or decompression.  And just think of the views of Saturn!

Friday, 16 August 2013

What possible evidence can there be for gods?

I see that some rationalist non-believers (such as Jerry Coyne) say that unlike some other rationalist non-believers (such as PZ Myers), they believe that there can be evidence for the existence of gods.  I'm really trying to understand this position, because it seems to me that the supposed nature of gods necessarily includes attributes that are beyond any evidence, ensuring that there is a vast difference between an enormously powerful being who can manipulate the world and a god.

Some of the attributes that may be assigned to gods are:

1. Being an avatar in some way of Nature - Poseidon isn't just good at making storms, he the personification of the sea.   Poseidon and seas are somehow bound together.

2. Being the source of what otherwise would be an abstraction - Yahweh is the source of morality, not just a good being.  Some say Yahweh is the reason for mathematics working.

3. Having creative power.  A god may not be a being within Nature, but may instead be the source of Nature, in some sort of 'ground of being' way.

4. Having magic abilities - being able to work miracles.

I'm at a loss to understand how any of these attributes can be supported by evidence.  A powerful being might be able to do very dramatic things, and might say that they are the source of morality and logic, but there is no way I can see that such claims can in any way be demonstrated by evidence.

This matters, because the difference between a hugely powerful being and a god is that in religion a god gets to define what is right and wrong, and people live their lives accordingly.

I can see how there might be evidence that a powerful being performed various acts that were interpreted as miracles by the authors of holy books.  But that still doesn't get us to that being having the kind of moral authority that should influence lives.  Godhood matters, and yet it seems to be that godhood is clearly beyond any possibility of demonstration by evidence.

Thursday, 15 August 2013

10 reasons not to be a dick

In 2010 Phil Plait gave his now famous "Don't be a dick" speech at The Amazing Meeting.  I thought it was silly, and that people should not need to calm down about matters that were important to them, matters of fact and reason and fairness.  But since that time I have realised Plait's wisdom.  "Don't be a dick" is good advice, for many reasons:

1. Being a dick is tiring.  It really is.  Emotional reactions can run out of steam and it can take a lot of effort to maintain the full dick persona.

2. Most people aren't very good at being a dick.  Being snarky and satirical can sometimes be effective but only if done really well.  When not done well you will come across simply as dickishly mean and spiteful.

3. Not being a dick is a good debating tactic, gaining you support, especially if your opponent is definitely being dickish.

4. Not being  dick can actually unsettle an opponent, particularly if they have usually had to deal with dicks.  It gives you an advantage.

5. Not being a dick leads to calmer thinking, allowing you to respond more thoughtfully and effectively in discussions and debates.

6. You are going to be wrong about something - it happens to everyone.  If you are wrong while being a dick you will be thought of as having been an ass.  Better to be wrong while not being a dick, because it only takes a few words to correct yourself in a way that others will think better of you for changing your mind.

7. Being a dick is unimaginative - it limits how you can approach an issue, and can paint you into a corner.

8. Being a dick isn't always easy.  You may think you are being a dick but no-one may actually notice.  That's hugely embarrassing.

9. You will feel better about yourself.  You really won't want to look back at dickish you in a few years time.  You don't want to fill your life with awkward memories.

10. The "don't be a dick" meme is supported by Wil Wheaton.  You want to be like Wil Wheaton, don't you?

Unless you are sure you are the next Oscar Wilde or Dorothy Parker, just don't be a dick - even if you like the idea, leave it to the few who are good at it.  

Science can be sure of many things

Science does keep changing, what with Newton's ideas being replaces by those of Einstein, and quantum mechanics messing up simple ideas of what matter was made of.  But not really.  This isn't the way science works.

Science involves two things which are combined to try and help understand reality:  the first is an hypothesis, an idea about what is happening and the second is data.  What is seen to happen - the data - is used to test ideas about what is actually happening.  Science keeps progressing in terms of what is seen to happen, and once enough reliable data has been gathered what is seen to happen rarely changes, whereas ideas about what is actually happening can often change.

For example, in the study of genetics and inheritance data about the way inherited characteristics behave has been known for a long time.  It has been known that the basis of inheritance has to be digital, not continuous, because individual characteristics don't blend, they retain their existence from generation to generation: this is why features present a grandparent can re-appear in grandchildren while not visible in the children of the grandparents: a feature can require two copies of inheritance material to be visible.  This feature can be only present in one copy in the first generation, but two copies can randomly come together in the second generation. We know based on data that genetic material in humans is paired up in most cells, and that it contains digital information.

There were all kinds of hypotheses about what the genetic material consisted off, and eventually even more data showed that it was DNA.  Once found, DNA became a new part of the data, part of the known.  It's a fact about human existence: science isn't going to find humans that don't have DNA.

Another example is gravity.  Newton's model of gravity was based on data about planetary (and other) movement.  We knew that the Earth orbited the Sun at that time.   More precise data was one of the things that led to Einstein's model of gravity, but that was never going to show that the Earth did not orbit the Sun.

Science does progress, and does lead to things that it is entirely reasonable for us to consider true and not provisional.  What changes in science is the understanding of mechanism, of what is happening behind the scenes.  In 1000 years we will still be saying that the Earth orbits the Sun (unless we have moved the Earth!).    

Tuesday, 13 August 2013

"Quine" and Consciousness

A friend, who is known online as "Quine", posted this link to a blog post of his about consciousness.  It's really worth reading.

Quine has provided me with some really useful ways to think about consciousness, especially in response to those who who insist that there must be some non-physical aspect, such as that consciousness develops, both through evolution and in the life of an animal.  There is a point where growth and organisation of the brain allows for some consciousness, and that is certainly a physical change of state.

Monday, 12 August 2013

What actually is the Hard Problem?

One of the great unsolved problems of philosophy is the Hard Problem of Consciousness.  It's usually defined as something like the following: "Why do we have subjective experience?", or "Why do qualia exist?", or "Why does red look like THAT?".  It's the question of how the physical activity of brain cells can lead to conscious experiences which seem to have properties that can't have anything to do with brain cells.  The Hard Problem involves very common questions, as being puzzled about the origins of one's experiences is a widespread human experience.  But what actually is the problem?  Does it even exist?

What can it mean for such a problem not to exist?  It means that what is going on in terms of mind and experience isn't what we think is going on and because of this the questions being asked aren't the right ones.  An analogy is wondering why the rain god is allowing crops to wilt - this is begging the question about the supernatural origin of rain.  There is a question - why isn't it raining? - but it's a different one.

A possible way to try and understand what the Hard Problem is about is to take a look at why we ask it - what are the reasons for asking the question, for thinking there is a problem.  This is where it gets a bit murky.  We can have certain beliefs about the nature of our consciousness, such as that various things we experience are being experienced at the same time, but it can be easily show through psychological tests that such beliefs are not always true.  Our feelings about our experiences involve memory, and memory is built and rebuilt as time passes - it's not as reliable as we might think.  The problem is that we are trying to use a facility we don't understand - our minds - to analyse something we find mysterious - conscious awareness.  There are none of the usual tools of scientific investigation available.  It may be hard to see how conscious experience is the result of brain cell activity, but without having encountered conscious experience that definitely isn't the result of brain cell activity we have no evidence to support the position that conscious experience can't be the result of brain cell activity.  We don't even know if there is a real problem or if it's just a mistake.

We can't use a feeling of mystery to make judgements about the nature of something we don't yet understand, and yet that seems to be the basis for so many statements about the Hard Problem of Consciousness.  We have no evidence that the problem even exists.

Black holes aren't dangerous

Black holes have a bad press.  They are seen as cosmic vacuum cleaners, sucking up everything in space, as the end of everything, as places where physical laws break down.

This is all wrong, all of it, in interesting ways.

Black holes don't suck up everything.  Black hole gravity is no different from any other kind of gravity.  If the Sun were changed instantly into a black hole of the same mass, the orbits of the planets would not shift at all, not even an inch.  If the Moon were made into a black hole the nights would be darker, but that's all that would happen.  The tides would be the same.

Things do fall into black holes, but it's really quite hard to do, as they are so very small on a cosmic scale.  If you fall towards a black hole, by far the most likely thing to happen is that you will miss it and either be flung away or end up in orbit.

Black holes are dangerous if you get too close, but then just about anything in the skies is dangerous too.  You would be killed by tidal forces close to a typical black hole, but you would be destroyed by heat long before you got to the equivalent distance of the centre of a star.

Physical laws don't break down in black holes - we just don't understand what is going on.  To say physical laws break down is like saying that the laws of landscape break down at edge of a map.  The real world doesn't care about the shape of our maps.

Even tiny black holes that might be made in a particle accelerator are harmless - they would disappear extremely rapidly in a tiny burst of radiation, but even if they didn't, it wouldn't matter - such black holes are so incredibly small that there is no chance an atom could randomly fall into one as they are so much smaller than atoms.  The chance of even a single particle ending up in the hole is remote.

Black holes aren't at all like science fiction usually portrays them - they are amazing and fascinating and strange, but almost always harmless.


Saturday, 10 August 2013

Why curved space makes things move

I have been doing some more reading up about General Relativity, and I thought it would be fun to post something more about why things end up moving towards sources of gravity.

The idea is that matter and energy curve space, but as we can't see space, it can be a unclear what is supposed to be happening.  One way to see what is happening is to consider where something in space will end up when it's moving or standing still.  The way this is often done in relativity is to consider the "light cone"of the object.  I'm going to simplify this and talk about a "light angle".  This is a light angle:

There is a single dimension of space, and time increases upwards.  An object that starts at the centre of the space line and that isn't moving will stay where it is as time moves on.  There are two diagonal lines in this figure.  They represent two light rays which are sent off left and right.  As time passes they will move further and further away from the central object at the speed of light.  By convention the scale of these drawing is such that movement at the speed of light gives 45 degree angles between space and time, but the angle is not that important - what is important is to realise that points on the left and right lines at a given time are always the same distance as each other from the centre of the figure, the position of the object that isn't moving.  Nothing can move any direction closer to the horizontal than the light ray lines as that would indicate movement faster than light.

What happens when space is curved by gravity is that this whole thing is twisted, like this:

The light ray lines are no longer equal distances from the upward time direction, and there is a new dotted line on the figure.  The dotted line is what happens to an object from which two light rays are sent off left and right, and is not moving at the start.  What the dotted line shows is that a stationary object will, paradoxically, end up in a different position that it started at after a length of time! The angles of the light rays show that it's harder to get away to the left than to the right.

This second figure is what gravity does to space and time if there was a massive object off to the right.  By twisting space and time gravity leads to things that would otherwise be standing still moving towards the source of gravity.  It's worth nothing that no force is involved!  Someone falling under (gentle) gravity feels no difference than if they were stationary in space.  Gravity is not a force, it's more like an instruction to things in space and time to move.

Friday, 9 August 2013

The science of Muslims and science

It's not easy when someone you respect makes statements that you feel the need to defend because of that respect. One such statement is Dawkins' comments about the lack of Nobel Prizes amongst Muslims. 

It's not that this is factually wrong, it's that one should surely be precise about the point that is being made and back that point with clear evidence and analysis. When a group consists of over a billion people, members of that group will live in such a range of cultures and environments it's much harder to show scientifically which factor or factors are responsible for a lack of scientific progress. It's hard enough even with a smaller group. Let's pick one - Americans:

The USA has produced many, many Nobel Prize winners and yet the USA is a highly religious country with much science denial. So what does this statistic say? Nothing unless you can focus, with factorial analysis, on the causes. Does religious belief influence acceptance of science? Yes, it does. 

Do certain modern Muslim cultures have a particular issue with this? Yes, they do. But sweeping statements about 'Muslims and Nobel Prizes' don't do anything to illustrate what the specific problems are - such statements are, in my view, meaningless. 

I can't defend such statements, and as a supporter of science, I won't, because scientists should be open about their disagreements with friends and those they respect, not apologists for certain views because of who expresses them.

So, I respectfully disagree with the validity of Dawkins' statement.

Thursday, 8 August 2013

Why don't we expand with space?

It's often said that space is expanding, and that raises the question of why we don't expand with space.   The thing is that space is not expanding.  Instead, gravitational fields are kind of telling everything to move apart.  It's easier to think of thing when dealing with gravitational attraction, so... what exactly is gravitational attraction?

According to Einstein, gravitational attraction is what happens when space is curved in a way that means that something that isn't doing anything - not changing direction or accelerating off somewhere - will move towards a gravitational source.   Gravitation attraction is when the default action of something is to move.  If you are in free fall in space and you get near a planet or a star you will find yourself moving towards that object without feeling anything at all.  That's gravitational attraction.  But - when you hit the surface of a planet (or land safely) then you do feel a force.  That force is not gravity, but the surface of the planet pushing back.  It feels like an acceleration, because that is what it is - your default action is to speed up towards the centre of the planet but the planet is constantly slowing you down.

So, if the universe is filled with an expansion force (as it seems to be), and this force is repulsive gravity (which it seems to be), then the default action of everything will be to separate.  However, the repulsive gravity force is EXTREMELY small, so small that your body has no problem at all resisting it.  But, it has an effect:  just like you are a tiny bit smaller on the surface of the Earth because of the resistance to gravity than you would be if you were in free fall, you are a very tiny bit larger than you would be if there was no expansion effect of the universe.  You don't continue to expand for the same reason that you aren't crushed by gravity on the surface of the Earth - your body can easily maintain its shape against such forces.

So, you don't expand with the universe, you, and the Earth, and the Solar System, and the galaxy, are all just a tiny bit larger than you would be if the expansion force wasn't there.

What I'm not - OK?

I'll tell you what I'm not:  I'm not part of any atheist community.  A community based on a conclusion seems a bit silly to me when what matters is how you think about the world, not that you have a certain view.  I have friends who are Christians and Muslims and who believe in rationality.  I disagree with their conclusions, but I truly love their support for rationality.  I'm not part of any skeptical community.  This may be more laziness than anything else, but also because, in Britain, 'skeptic' does come across rather like 'cynic'.  I support what many skeptics do, but I also know of some skeptics who aren't skeptical much at all.

What I am, I hope, is a science and philosopher amateur, where 'amateur' means 'lover'.  I'm madly in love with science, and have been since I was a small child.  I have grown to love philosophy after an introduction from a friend, Michael, many years ago.  Philosophy and I go on dates.  Occasionally one or other of us storm off in a sulk, but we always make up, and I admire his awesome beauty.

I'm also a feminist because I believe that society has a long way to go before women are treated with equal value and respect, and I'm also an individualist, because anyone who talks about groups of people as if that grouping has any value is an utter plonker.  Heck, we can't even say 'Nazis are all..'.  Remember that Oskar Schindler, the rescuer of so many Jews, was a member of the Nazi  party.

Anyway, it's not just atheism/skepticism that has major falling outs - as any programmer can tell you, Java and C developers can't be left in a room together; As any science fiction fan can tell you, the legacy/new Doctor Who battles are fierce; any comedian can tell you about the great Miranda wars of 2012.

I have privileges that I have not earned - I have an ability to think and understand, and I want to share that privilege by writing, if I can.  I'll have to do better at ignoring vicious people, and I apologise for my occasional lack of ability.

Wednesday, 7 August 2013

Why Creation is logically wrong

The idea of a creator, even some intelligent alien culture, starting things off is so bad that we don't even need to involve evolution to provide an alternative.  The idea is wrong even on its own terms.

The reason is that a creator is said to be necessary because of the complexity of the world in general, and us in particular.  We have complex bodies, we have brains and we have minds.  There is no doubt that a mind needs to be complex because minds can hold memories, have thoughts, be changed.  Those are not possible attributes of anything simple - the endless possible states of mind rule out mind's simplicity.

So, there is a question about how such amazing complexity can arise by itself.  That's a reasonable question.  What's not a reasonable answer is the suggestion that amazing complexity has to originate from the from the actions of another mind.  The key word here is 'originate'.  It's just feasible that our universe was made by aliens, but then we are left with the question of the origin of those aliens. The concept of a creator is of a being who was at the very start of things, not just the designer of our universe.

So, saying a mind is needed to originate minds doesn't solve anything.  We end up back where we started in terms of questions.  As explained above, trying to say that the original mind was simple is logically incorrect because minds are necessarily complex because of what we insist minds must be capable of doing.  Trying to say that a creator mind is beyond the bounds of nature doesn't help because complexity doesn't have to have material form: it's about possible states, not type of substance.

The idea of a creator to solve the problem of complexity is logically incorrect.  It doesn't even need to be refuted by science.  We don't need to introduce evolution as some alternative explanation, because Creation isn't even an explanation.

Tuesday, 6 August 2013

The Failure of "Many Worlds"

Quantum Mechanics is strange.  Particles seem to exist in states of uncertainty, an uncertainty that collapses when we try and take a look at what they are doing.  This oddness has led to all kinds of ways of looking at quantum mechanics to try and understand what is the reality 'behind the scenes' of it all.

The most commonly described way of looking at quantum mechanics is called the 'Copenhagen Interpretation', which states that there is something that happens when a quantum situation is somehow 'observed' which forces the state into a defined value as against uncertainty.  This interpretation has led to all kinds of nonsense, such as the idea that human minds are necessary to act as observers, but it's still widely used as a way of dealing with quantum situations.

Another way of looking at quantum mechanics which is supposed to remove the failings of the Copenhagen Interpretation is called the "Many Worlds Interpretation".  This interpretation takes the view that quantum uncertainty doesn't collapse into certainty in the way we might think it does.  Instead, all quantum possibilities actually happen, but because we are involved in the quantum world too, each of us is split into copies, one of which will see each of the the possibilities.

"Many Worlds" is quite popular, and often thought to be more reasonable than the idea of quantum probability collapse.  I'm going to try and show that this isn't the case.

One objection to "Many Worlds" is that it results in an unimaginable number of parallel universe, and that is though to be excessive.  This isn't really a sensible objection, because an hypothesis should be supported because of the simplicity of its premises and logic, not the number of outcomes.

I don't object to "Many Worlds" because of the number of parallel worlds.  My objection is quite different.  My objection is that it doesn't add any explanatory value.

Consider a quantum state which can be one of two values: V1, and V2.  This might be the polarization of a photon or the spin of an electron, for example.  Now imagine a person, A, who does an experiment to determine the quantum state.  According to Many Worlds the result of the experiment is that there are two copies of A, A1 and A2, who see two different values:  A1 sees V1 and A2 sees V2.

Now, suppose A1 asks the question 'why do I see value V1?'.   The Copenhagen Interpretation says "the quantum state collapsed and randomly selected V1".  The Many Worlds Interpretation says "don't worry - there is another you, A2, who sees V2".  Effectively, what Many Worlds says is "there is another you, and somehow it was randomly decided that between you and other you, one would see V1 and the other would see V2".  So, each copy of A could justifiably ask why they were not seeing what the other copy was seeing, and the answer to both would be "it's random".

The Many Worlds Interpretation gives the impression that there is no collapse of quantum states, but that isn't true.  Each person will see a history of quantum observations, each of which could have given an alternative result.  That there are other copies of that person does not add any explanatory value when it comes to trying to explain why one person sees a particular history.

Many Worlds is excessive, not because it introduces parallel words per se, but because those parallel worlds don't add any explanatory value.  It's more reasonable to say that there are many alternatives, but only one actually exists.

Monday, 5 August 2013

Space expands and contracts!

I have done it ... finally understood how General Relativity works.  It's a lot simpler than it usually sounds, and I have to explain what I have found out, as it's so very cool!

The problem with Newton's model of gravity was that it didn't cope with relativity - the idea that the laws of physics should work the same no matter what you are doing.  Einstein's Special Relativity sorted out the business of the laws working the same in what are called 'Inertial Frames' - situations where you don't feel any force.  Special Relativity showed how things could be the same no matter how you are moving as long as you are moving in a straight line and not changing speed.  That the speed of light always had to be seen as the same led to the strangeness of time passing at different speeds and lengths appearing to change, but the idea was very simple even though the consequences appeared strange.

General Relativity allows for the laws of physics to appear the same no matter how you are moving - you could be standing still, falling under gravity, accelerating, spinning - anything.  The vast number of possible types of motion and changes of motion mean that the equations of General Relativity are complicated involving things called 'Tensors', which represent relationships between changes of directions.  But the ideas behind General Relativity are simple: space is distorted by mass and energy resulting in the effects on movement that, in situations where gravity isn't too strong, result in the same effects as described by Newton.  This distortion is called 'curvature', but it's actually more complicated that just a distortion of space.  Space and time are both distorted.  This distortion changes the future position of an object that isn't subjected to any force.  If an object is close to a source of gravity such as the Earth the distortion will mean that the object will move towards Earth.  One way to look at the effects of the distortion is to think of space as contracting towards the centre of the Earth, as a kind of flow of space.   If you are on the Earth but not falling towards it you must be experiencing a force of some kind, such as from the Earth's surface.  This feels exactly the same as if the surface of the Earth was accelerating upwards while trying to leave you behind!  In terms of the flow of space, this is exactly what is happening.

In my view, it makes things much easier to understand if you think of what is happening to space as flows rather than expansion and contraction:  space is flowing towards the centre of the Earth and your inertia means you are trying to follow it there, but the surface is getting in the way.  In certain situations such as the very early universe gravity can become repulsive, and that leads to expansion of space - things that don't feel any force will all move away from each other:  it's as if space is seeping into the universe at every single point, resulting in a universal flow outwards from each point.

The mathematics of General Relativity is hard, but the ideas behind it are wonderfully simple.

Sunday, 4 August 2013

Fear of Twitter

The media is making a fuss about twitter trolls.  I have great sympathy for those who have to face frightening messages, and I'm glad that legal action is starting to be taken against those who threaten.  But I'm also surprised that anyone is shocked that such messages are sent.  Honestly, what did you expect?  

It didn't use to be like this.  Users of the Internet used to be largely academics who had access to the service at work, and hobbyists who would occasionally connect on expensive and slow modems from home.  Things were slower, and the internet was much more like thousands of islands as against a huge continent.  You could connect to mailing lists, or a channel on IRC (Internet Relay Chat) and you might deal with dozens of others, perhaps even hundreds.  Such discourse could be easily moderated if needed, to keep things calm.

Twitter is about as different from that as it's possible to be.  It a single chatroom, always on and with millions of users.  If you get even slightly well-known you can have thousands of regular readers of your comments, and all it takes is a fraction of a percent of those readers to be unpleasant or nasty and you end up with a bad experience.  Twitter's design was always going to fail this way.  The problem is with the reaction that takes the actions of a fraction of a percent as being representative of millions of others, when it just isn't.  Journalists rarely understand statistical sampling, and for them Twitter is a gold-mine of controversy, as self-selecting idiots and cowards are there for all to see.

Yes, some people are vicious and even criminal.  That should be dealt with.  But it's hopelessly naive to think that Twitter is going to be a pleasant experience for all.  

Friday, 2 August 2013

I'm a 'Caitlin Moran' socialist

I'm close to tears, but in a good way.  I thought that Caitlin Moran would be one of those jolly columnists who would write vaguely funny gossipy columns that would make a distracting read.  She can be.  But, she can also write with a poetic passion about suffering and poverty that can move me close to tears.  She lives a happy life now, with husband and children, but she was raised in deep poverty.  Others she knows aren't that fortunate: there is the the story of her schizophrenic friend struggling as benefit cuts means he has to try to find somewhere new to live on £75 per week.  She writes of the desolation of trying to live on benefits as governments slowly erode the system.

Moran makes me proud to be a socialist, because that is what I am.  I believe we have a moral duty to pay tax to ensure everyone can live with a decent roof over their heads and with enough to eat.  I believe we have a duty to ensure that no-one need live in constant fear of benefit cuts and means testing.  I believe that no-one should ever get ill because they are poor.