Requirements for Promoting a New Scientific Theory

25 04 2013

I have been reading some pretty strange stuff this week about Gravity recently. It seems there are some pretty odd folk out there who have taken thinking about physics to a new, possibly unhealthy, level.

Gravity: It's the Law

Basically, they are crackpots. Well I guess it’s a slippery slope – one day you wonder why the earth is sucking down on you, the next you decide to spend some time on the knotty question. Soon enough you think you’ve got it, it is clearly that the earth is absorbing space which is constantly rushing down around us dragging us with it. Or similar.

So yes, its true, Einstein did not ‘solve’ Gravity, and there is still fame and fortune to be had in thinking about gravity, so this is the example I shall use today.

The trouble with Gravity is that Einstein’s explanation is just so cool! He explained that mass warps space and that the feeling of being pulled is simply a side effect of being in warped space. It sounds so outlandish, but also so simple, that it has clearly encouraged many ‘interesting’ people to have a crack at doing a better job themselves.

So, as a service to all those wannabe physics icons, I offer today a service, in the form of a checklist – what hoops will your new scientific theory have to jump through to get my attention, and that of the so-called ivory tower elite in the scientific community?

Requirement 1: Your theory needs to be well presented

presentation counts!Yes, it may sound elitist to say, but your documentation/website/paper/video should have good grammar. Yes, yes, one should not use the quality of one’s english to judge the quality of one’s theory, and I know prejudice is hard to overcome, but this is not my point. My point is that in order to understand a complicated thing like a physics theory it needs to be unambiguous. It needs to be clear. It needs to use the same jargon the so called ‘elite’ community uses. Invented acronyms, especially those with your own initials in them, are out.

Requirement 2: Your proposal needs to be respectful

Image courtesy of Wikimedia Commons

Image courtesy of Wikimedia Commons

Again, this is not about making you bow to your superiors in the academic world. Indeed in the case of Gravity, the physics community is one of the most humble out there. While I agree academia is up it’s arse most of the time, this is about convincing the reader that you know your stuff. In order to do that, you need to show that you know ‘their stuff’ too. If you have headings like “Einstein’s Big Mistake” it is a bit like saying to the reader ‘you are all FOOLS!’ and cackling madly. Don’t do it!

Respect also means you need to answer questions ‘properly’. That means clearly, fully, and in the common language of the community. You cannot say “its the responsibility of the community to test your theory”. This is a great way to piss people right off. It is your responsibility to make them want to. This usually means dealing with their doubts head-on, and if you can do that, I promise you they will then want to know more.

Requirement 3: You need to develop credibility

Sorry, as you can see we have yet to consider the actual merit of the theory itself. I wish it were not so, but we are humans first and scientists second. We cannot focus our thoughts on a theory if we doubt the payback. And if you say that aliens came and told you the scientific theory, then people are unlikely to keep listening, unless, perhaps they’re from Hollywood.

But seriously, credibility is the hidden currency of the world, it opens doors, bends ears and gets funds. It takes professionals decades to build and it is really rather naive to waltz into a specialism and expect everyone to drop their tools and listen to you.

That said, the science world is full of incomers, it is not a closed shop as some would you believe. If you follow requirements 1 and 2, and are persistent (and your theory actually holds water) then you are very likely to succeed.

Penrose_triangleRequirement 4: Your theory needs to be consistent

I have seen some pretty strange stuff proposed. Gravity is a manifestation of the flow of information, or the speed of light is determined by a planet’s density. Find your own at crank.net. Let’s look at this peach as an example: http://www.einsteingravity.com/.

This exhibit is great example of how not to go about promoting your theory. “Monumental   Scientific   Discovery  !” it screams across the top, then the first claim is this:

1) The Acceleration of earth’s Gravity x earth orbit Time (exact lunar year) = the Velocity of Light.
(9.80175174 m/s2 x 30,585,600 s = 299,792,458 m/s)

Now this is rather remarkable. Can it really be that you can calculate the speed of light to 9 significant figures from just the earth’s gravitational acceleration and the length of a year? Intuitively I suspect you could (eventually), but then I started to think, well, what if the earth was irregularly shaped? The gravitational constant is actually not all that consistent depending on where you are either. So I checked, then I noticed he said ‘lunar year’. What? Why? What is a lunar year? Then I calculated that the time he used was 354 days, which isn’t even a lunar year. Add to that that he gives the acceleration of gravity on earth to 9-figures despite the fact that nobody knows it that well (like I said it is location dependent). Does he does the same test for other planets? No. Well what if they have no moon!

So, 0/4 for on our checklist for einsteingravity.com!

Requirement 5: The theory needs to be be consistent with well-known observationsevidence

Now if your theory has got past requirements 1-4 , well done to you, you will be welcome to join my table any time. Now is when you may need some more help.

Once a theory is consistent with itself, it now needs to agree with what we see around us. It needs to explain apples falling, moons orbiting, light bending and time dilating. This is the hardest part.

It cannot leave any out, or predict something contrary to the facts. It cannot be vague or wishy-washy. It needs the type of certainty we only get from the application of formal logic – and that old chestnut – mathematics.

No you cannot get away without it, there is no substitute for an equation. Equations derived using logic take all the emotion out of a debate. And they set you up perfectly for requirement #5.

crystal-ballRequirement 6: The theory needs to make testable predictions

If your theory has got past the 5 above, very nice job, I hope to meet you one day.

We are all set, we have a hypothesis and we can’t break it. It has been passed to others, some dismiss it, others are not so sure. How do you create consensus?

Simple, make an impressive prediction, and then test that.

Einsteins field equations for example, boldly provide a ‘shape’ of space (spacetime actually) for any given distribution of mass. With that shape in hand you should then be able to predict the path of light beams past stars or galaxies. These equation claimed to replace Newton’s simple inverse square law, but include the effects of time which creates strange effects (like frame dragging), which, importantly could be, and were, tested.

The beauty of these equations, derived via logical inference from how the speed of light seems invariate, and now proven many times, is that they moved physics forward. Rather than asking, ‘what is gravity’, the question is now ‘why does mass warp space’. It’s a better question because answering it will probably have implications far beyond gravity – it will inform cosmology and quantum theory too.

Conclusion

So if you are thinking of sharing with the world at last your immensely important insights, and want to be listened to, please remember my advice when you are famous and put in a good word for me in Stockholm. But please, if, when trying to explain yourself, and are finding it tough, please please consider the possibility that you are just plain wrong…

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Jarrod Hart is a practicing scientist, and wrote this to shamelessly enhance his  reputation in case he ever needs to peddle you a strange theory.

Further reading:

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Quote of the day:

22 05 2012

“A theory is something nobody believes, except the person who made it. An experiment is something everyone believes, except the person who made it.” – Albert Einstein





Exceeding the Speed-Of-Light Explained Simply (and the Quantum riddle solved at no extra cost)

27 09 2011

It has recently been in the news that some particle may have exceeded the legal speed limit for all things : 299,792,458 metres per second.

Of course, this will probably turn out to be a bad sum somewhere or perhaps waves ganging up, but the whole hubbub has raised my hackles, and here’s why.

Because Albert Einstein at no time said what they say he said (see here for example). They misunderstand relativity! Things can move at any speed we want, and I will try to explain the fuss now.

So let’s get to it!

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First, we have to consider the way space warps when we move.

The problems started when people realised that light always seems to have the same speed, regardless of the speed you were moving when you saw it. This seems to be a contradiction, because surely if you fly into the light ever faster, it will pass you ever faster?

Well the tests were pretty clear, this does not happen. The speed is always c.

For several years, people were unsure why – until they were told by Einstein in 1905. In the meantime, another ponderer of the problem (Lorentz) decided to write down the maths that are required to square the circle.

The so-called Lorentz equations show, unequivocally, that space and/or time need to warp in order for relative speeds of c not to be exceeded, even when two items are going very close to c in opposite directions to one another.

So something needed to give, and it was space and time!

So, newsflash! it was not Einstein that first published on space and time warping. His contribution (along with Henri Poincaré and a few others) was to explain how and why. His special theory showed that because there is no ‘preferred’ frame of reference, a speed limit on light was inevitable. The term ‘relativity’ come from this – basically he said, if everything is relative, nothing can be fixed.

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Ok, so we have some nice observations that nothing seems to go faster than the speed of light  – and we have a nice maths model that allows it. So why do I persist in saying things can go faster than the speed of light?

Let me show you…

There is a critical difference between ‘going’ faster than light and being ‘seen to be going’ faster than the speed of light, and that is where I am going with this.

So lets take this apart by asking how we actually define speed.

If a particle leaves point a and then gets to point b, we can divide the distance by the time taken and get the mean speed (or velocity to be pedantic).

The issue with relativistic speeds are that the clock cannot be in both point a and point b. So we need to do some fancy footwork with the maths to use one or other of the clocks. So far so good. This method will indeed never get a result > c.

The nature of space forbids it – if the Lorentz transformations that work so well are to be taken at face value, then for something to exceed c by this method of measurement, is much the same as a number exceeding infinity.

So all is still well. Until you ask, what about if the clock is the thing that travelled from a to b?

In this case, the transformations cancel! The faster the movement, the slower time goes for the clock, and you will see its ticks slow down, thus allowing its speed to exceed c.

The clock will cover the distance and appear to have tavelled at c on your own (stationary) clock, but the travelling clock will have ticked fewer times!

If you divide the distance by the time on the travelling clock, you see a speed that perfectly matches what you would expect should no limit apply. Indeed, the energy required to create the movement matches that expected from simple Newtonian mechanics.

The key point here is that while the clock travelled, the reader of the clock did not. If you do choose to travel with the clock, you will see it tick at normal speed, and see the limit apply – but see the rest of the universe magically shrink to make it so.

Some have argued that I am not comparing apples with apples, and that by using an observer in a different frame to the clock I am invalidating the logic.

To those who say that, I have to admit this is not done lightly. I have grown more confident that this inference is valid by considering questions such as the twin paradox over and over.

The twin paradox describes how one twin who travels somewhere at high speed and then returns will age less than his (or her) stationary twin.

Now if we consider a  trip to Proxima Centauri (our nearest neighbour) the transformations clearly show that if humans could bear the acceleration required (we can’t) and if we had the means to get to, say, 0.99c for most of the trip, that yes, the round-trip would take over 8 years and no laws would be broken. However the travellers themselves will experience time 7 times slower (7.089 to be precise). Thus they will have aged less than 8 years. So, once they get home and back-calculate their actual personal speed, it will exceed all the live measurements.

This has bothered me endlessly. Although taken for granted in some sci-fi books (the Enders Game saga for example) this clear ‘breakage of the c-limit’ is not discussed openly anywhere.

Still uncertain why people were ignoring this, I read a lot (fun tomes like this one) learned more maths (Riemann rules!) and also started to look at the wider implications of the assertion.

On the one hand, the implications are not dramatic, because instant interstellar communication is still clearly excluded, but that whole issue of needing a 4 years flight to get to Proxima Centauri is just wrong. If we can get closer to c we can indeed go very far into the universe, although our life stories will be strangely punctuated, just as in the Ender books.

But what about the implications for the other big festering boil on the body of theories that is physics today – quantum theory?

Well, if one is bold enough to assert that it is only measurement that is kept below c and not ‘local reality’, then one can allow for infinite speed.

In this scenario, we are saying measurement is simply mapping reality through a sort of hyperbolic lense such that infinity resembles a limit. Modelling space with hyperbolic geometry is really not as unreasonable as all that, I don’t know why we are so hung up on Euclid.

With infinite speed at our disposal, things get really interesting.

We get things like photons arriving at their destination the same tme they leave their source. Crazy of course… but is it?

Have we not heard physicists ask – how is it the photon ‘knows’ which slit is blocked in the famous double slit experiment? It knows because it was  spread out in space all the way from it’s source to it’s final point of absorption.

If you hate infinities and want to stick with Lorentz, you can equally argue that, for the photon, going exactly at c, time would stand still. Either way, the photon feels like it is everywhere en route at once.

If the photon is indeed smeared out, it probably can interfere with itself. Furthermore, it is fitting that what we see is a ‘wave’ when we try to ‘measure’ this thing.

A wave pattern is the sort of thing I would expect to see when cross sectioning something spread in time and space.

Please tell me I’m wrong so I can get back to worrying about something useful. No, don’t tell me – show me – please! 😉





Fun Physics Questions: Does time flow in baby steps?

21 08 2011

Question: is it possible time flows in little steps?

At some small scale, could it be, that time is simply a ‘symptom’ of a sequence of events, or states, that there is no actual time passage ‘between’ those states?

This scenario has interesting implications – it suggests life is a bit like a movie – a series of pictures on a strip of celluloid, or pages in a book, and like a book, while the story may unfold to you at whatever speed you read it, it does not matter how fast you read the story itself still has its own pace.

This doesn’t mean the book has to be pre-written, it can still unfold with utter unpredictability, the book is unfinished if you like – the important point is that we are stuck experiencing the passage of time at a rate determined internally – by the rate of chemical reactions in our brains. The drum beat of those reactions would feel the same no matter how fast or slow they seems to an outside observer. They could even be paused for a few minutes – we could not tell!

Now physicists studying energy balances of sub-atomic particles have seen that energy often seems to come in little chunks (the ‘quanta in’ quantum), and that can imply that time may also be chunky (maybe Planck time?); alas, time chunking has contradictory implications – contradictory to common sense anyway- like infinite energy flux, not to mention infinite speeds, but hey if you can just get your head around some of the workarounds physicists have dreamed up (quantum tunnelling for example) everything’s all right again. I am personally highly suspicious of workarounds, and that is what I think they are!

Anyway, even if you try to get away from quantum weirdness, you get sucked back in – take for example this geometrical example. Consider the relative positions of three point objects (small particles?) moving freely in space: they could, for an instant, line up perfectly, but if your measurement were infinitely accurate, this could only occur for an infinitely small duration so long as the particles are moving. If you try to explain this by saying space is divided up into chunks (like ‘snap to grid’ in MS Powerpoint) you get into geometrical issues that three points cannot always be integer increments apart  (nor even rational increments apart) without breaking the most basic number axioms.

So even if space isn’t chunked, it turns out you can appeal to the uncertainty principle, which handily says you can only measure the position of anything infinitely accurately if you allow its momentum to be anything at all, including infinite – and infinite momentum is exactly what you (temporarily) need if you are bold enough to let time ‘leap’.

So none of these issues with time chunking turn out as solid proofs against the possibility, they just make things more slippery!

Aside: rather than a book, I like to think of our universe as being a bit like a computer program  – I like to think about Pac-man when it plays itself in ‘demo mode’ – in demo mode, used to allure people at the arcade, the computer controls both the ghosts and pac-man. In the computer, a sequence of commands is run in the CPU and the speed of the computer (like the reader of the book) controls the rate at which we ‘see’ the ghost-chase on the screen, but this speed is invisible to pac-man himself – yes the ghosts chase faster across the screen, but he can run faster too.

Question: Does a time-increment universe allow time travel?

Well I don’t think we can ‘skip’ events out (we have to experience them all), but if we can go somewhere where events are more or less ‘dense’, maybe we can. We will not feel the difference, we will not get any extra life-span, our cells will age just the same – but if a friend had gone to another place is space-time, where events have bigger gaps, he may have aged at a different rate, and when you meet your friend again one of you will have time travelled forward and the other backward relative to one another.

Is this really possible? Well, yes, I think so – this model ties in very well with relativistic time travel: if you assume events are more spaced out (less dense, with bigger ‘leaps’ between them) in areas with more mass nearby. or when moving vary fast, it maps perfectly.

Conclusion

That’s it for now! Of course, maybe time does not leap, I don’t know, but its something I love to think about! Please let me know your thoughts…





Stuff I Wish I Had Read When I Was Younger

6 11 2010

Over the years I have supervised and mentored several PhD students, and recently our firm started to award scholarships to undergrads, and I was asked to support one such scholar. These scholars are from the best and brightest and so I got to thinking…

Graduates today have it tough, competition is tough, people work longer and harder than ever and stress is hitting us earlier and earlier in life – or so it seems. I would argue that, to some real extent, things have always been getting worse, and therefore by induction, we can prove that they have haven’t really changed at all.

No, the graduates of today have unparalleled opportunity to learn, to travel and to experience. The brightest graduates have the world at their feet and will be its commanders when we are are all retired and done for.

So what could I do to support this scholar? In the end it was easy – I asked myself – what do I know now that I wish I had known sooner? Most of this is in attitudes and is deep in my psychology, and is the result of direct experience – but it turns out that a healthy chunk of my scientific learning experience can be re-lived – by reading some of the books I think steered my course.

So I made a point to summarize some of the best science related books I have read (and some of the most useful internet resources I have found), and dumped the list complete with hyper-links in an email to the scholar. I hope she goes on to be president!

Now having gone to the effort, it would be a crime to keep this email secret, so here it is, (almost) verbatim!

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As promised, here is a list of useful resources I wish I had known about when I was an undergrad. I am glad I got round to this, it should be useful for several other students I work with, and has also led to me revisiting a few things! I think I may brush it up and pop in on my blog if you don’t mind…obviously I won’t mention you!
Anyway, back to the business. To me, science is not all about chemistry, molecules, atoms, valence electrons and so on. To me, is is the process of trying to understand the world, and this set of materials I have hand picked, should you get through even a part of it, will not only educate but inspire.

This may not be the very best list, and I am sure there are many great books I have not read, but I have stuck with ones that I have, so you will have to rely on other people for further recommendations.

Jarrod’s reading list: science/psychology/economics & so on

  • I’ll start with something really easy, relevant and engaging – an excellent (if quirky) summary of material science: The New Science of Strong Materials – Prof Gordon  has written another on Structures that is also worth reading.
  • Ok, this next one is not a book, but a paper; I like it because it shows that many stuffy professors are wrong when they prescribe boring scientific prose for papers. This paper uses the criminal “us” and “we” and discusses subjects as if with a friend. Shocking form, especially for a junior scientist. This paper by an unknown, changed the world.
  • Guns, Germs and Steel” – this is large-scale scientific thinking at its best- the book looks at how we can explain why the world is the way it is (especially the inequality) by looking at how technology spreads through societies.
  • Mistakes were made…but not by me” – this is required reading if you want to work with other people, so its basically for everyone then…
  • Then to take it to the next level – “How the mind works…” – Stephen Pinker‘s other books are also good if you like this one.
  • “Flatland”, (full text here) was written in 1884, and is essential reading because it defines the cliche “thinking outside of the box”.
  • To make your upcoming economics courses more interesting, first read this easy-to-read popular book: “The Undercover Economist“.
  • Also, Freakonomics– it’s shameless self promotion by egotistical authors, but hell they are smart, so put up with it.
  • The Tipping Point –  Malcolm Gladwell is a current thinker I really like; he’s not satisfied to focus on one thing for very long – his other books are on totally different stuff, but are equally thought provoking.
  • The selfish gene” – Obviously I would firstly recommend “On the Origin of Species”, (full text here) but if you are short of time (which you should be as an undergrad), you can learn most of the basics, and also get updated (well up to the 1970’s at any rate) by reading Dawkins’ classic.
  • I couldn’t ignore statistics, so I will include two – one classic, “How to Lie with Statistics”  and a more modern one “Reckoning with Risk“, they are quite different, but either will get the important points across.

Alas, books are perhaps becoming obsolete, so I better include some other media:-

  • The first one is so good I can’t believe its free – try watch at least one a week, but the odd binge is essential too. http://www.ted.com/
  • Next, an excellent physics recap (or primer) – but  you need lots of time (or a long commute!) to get through this lot – look on the left menu for Podacts/Webcasts on this webpage: http://muller.lbl.gov/teaching/physics10/pffp.html – I cannot begin to praise the worthwhileness of this enough. It used to be called “Physics for future presidents” because it teaches you enough to understand the risks of nuclear energy, and the likelihood that we will all run our cars on water – and let you know when you are being duped or dazzled by big words.
  • When I was somewhat younger there was a TV show called Cosmos, hosted by Carl Sagan, you may know of it. You could watch in now here, though obviously it is dated, so perhaps you shouldn’t; the reason I mention it, is because it was key in creating a generation of scientists, people who were inspired by Carl to be inspired by the universe. The previous generation had the space race and the moon landings to inspire them, but since then science has been on a downhill, with 3-mile island, global warming, etc, etc, and we have had no more Carl Sagans to cheer for us; Cosmos was a rare bit of resistance in the decline of the importance of science in society. You may also know that there have been battles in society (well in the circles on intelligentsia at any rate) about science – on the one had the ‘two cultures debate‘ and more recently, the ‘anti-science’ movement (suggested in books like “The Republican War on Science“. I do not wish to indoctrinate you, but rather make you aware that being a scientist used to be cooler and used to be more respected and something is indeed rotten in the state of Denmark.
  • Getting back on track, here is an excellent guide to critical thinking (something else sadly lacking in the world) – don’t read it, listen to the podcast versions (also on itunes):
    “A Magical Journey through the Land of Logical Fallacies” – Part 1 and Part 2
    I think this should be taught in school. Brian Dunning’s other Skeptoid podcasts put these lessons into practice showing how a scientific approach can debunk an awful lot of the nonsense that is out there (alternative medicine, water dowsers, fortune tellers, ghost hunters, etc etc).
  • If you do happen to have any time left, which I doubt, there are several other podcasts on critical thinking – that use a scientific approach to look at the world and current affairs: –

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Postscipt – Dear readers, please feel free to append your own recommendations to my letter in the comments section below. If there is one thing I know well, and that’s how little I know. I feel I only started to read ‘the good stuff’ far too late in life, and so those with more years than me (or better mentors), please do share. But bear in mind, this is principally a science oriented list, and is meant to be accessible to undergraduates – I left out books like Principia Mathematica (Newton) because it is really rather unreadable – and the Princeton Science Library (though awesome) is probably a bit too intense. Also, in the 30 minutes since I sent the email, I have already thought of several others I sort of, well, forgot:

That’s it for now…





How to prove that space is curved…

26 10 2010

Question: if you lived in flatland (a 2-d world), how could you tell if the land was curved in the third dimension?

Answer: geometry!

It turns out many of the mathematical rules we learned at school ‘fall apart’ if the working surface is curved. For example, can you draw a square on the surface of a sphere? No!

So can we use this insight to tell if our 3-d world is curved in a mysterious fourth dimension? Yes!

If we set off from earth, went in straight line for, say 1 light-year, then turned 90º, went 1 light-year, turned 90º again, and then did this yet again, you should have traced a perfect square, and be back exactly where you started. If you aren’t, something is amiss!

 

Now it turns out that it we do this, we will indeed discover an error; but why? And how do we know this?

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Newton told us that a massive object in motion will continue to travel in a straight line, unless acted upon by external forces. Some people think that Einstein overturned this insight, but he didn’t; indeed he extended it: he said that the force of gravity is not actually a force, and thus objects falling under gravity are actually going in straight lines! Indeed this makes sense, as anyone ‘falling’ does indeed not sense any acceleration, but rather feels ‘weightless’. Thus they are not actually accelerating, they are going straight – in curved space.

Now anyone who has thrown a ball can see this is absurd on the face of it, but Einstein was serious, and he is right, from a certain perspective. The ball is not going in a straight line through ‘regular’ space, but is going on a straight path in a 4-d construct called ‘space-time’. Likewise, he would argue that the planets are tracing straight lines around the sun; and indeed the ‘parabola’ of a baseball is actually not a parabola, but a very small part of the enormous ellipse that would be traced in the baseball could fall though the earth and go into ‘orbit’ §.

Anyway, Einstein’s model says that light travels in straight lines, but we have seen that light bends when it passes near to the sun (this can most easily be tested during an eclipse) – so… if one of the sides of your ‘perfect square’ were to pass near the sun, it would also be bent and if you followed the above rule to draw the square, you would not end up where you started.

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Physicists have grown used to Einstein’s model, and better tests for the flatness of space have been developed. For example, if you drew a circle on the surface of a sphere, the area would not equal Πr2, but would be less. Likewise, in 3-D space, we could plot a sphere and then measure the volume and if it did not equal 4/3Πr3, we would know something was amiss.

So physicists have looked at how light bends, and how the planets move, and found out, amazingly (but predicted by Einstein) that the error in this spherical volume calculation is directly proportional to the mass of matter within the sphere – proving that the warpage in space is proportional to (and thus caused by) ‘mass’.  Thus mass warps space.

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MC Escher: 'Grid'

But is space really warped in some ‘extra’ dimension?

Well, this is a good question. Maybe it is some extra ‘spacial type’ dimension, but you could also look at time as a fourth dimension, and argue that this space is not ‘curved’ at all, but rather that space and time simply vary in density in different locations. I personally like this way of looking at it, it eliminates the need for some vague ‘extra dimension’, and therefore swiftly removes the possibility that space could be ‘closed’ or fold back on itself in this extra spacial dimension. Occam’s razor thus prefers the ‘density’ model!

Footnotes:

§. In Wikipedia, they state that balls bounce in perfect parabolas, but note they also mention a ‘uniform’ gravitation field, and it is well to remember that the earth gravitational field is not uniform, but radial. Thus I stand by my assertion that missiles follow elliptical paths just like planets and comets. Of course, an ellipse is a close relative of both the parabola and the hyperbola, so this is not really that dramatic.





What exactly is ‘science’?

14 05 2010

I used to think science was the practice of the scientific method; i.e. you propose a hypothesis, you develop a test of the hypothesis, execute it and prove the hypothesis.

That worked for me until the end of high school.

At university, I was a true nerd. I read all my textbooks cover to cover (mainly because as I was too shy for girls and too poor for booze). During this time, the definition above started to fail. So much of the science was maths, statistics, observation, pattern recognition, logic and quite a bit of rote learning. Not all of it fitted into my definition of science. I became a fan of a new definition: science is the study of the nature of reality .

But then I did post-grad, and I realised that not much in science is ‘proven’ (I guess this is the point of post grad study). Evolution, for example, is not proven. That the sun revolves around the earth is not ‘proven’. I discovered that the only things that could be proven were ‘ideas’ about ‘other ideas’. Bear with me on this one.

Let us say we define the number system – this is an ‘idea’ or conceptual construction. Within this construction we can ‘prove’ that one and one is two. Because we ‘made’ the system, with rules, then we can make factual and true statements about it. We can’t do this about the real world – we cannot say anything with absolute certainly because we rely on flaky inputs like our own highly fallible perception.

It’s like that old chestnut: how can you be sure you are not living in a giant simulation? Of course you can argue that it is pretty unlikely and I would agree, and right there we have a clue to a better definition of science.

It turns out that much of modern science deals in ‘likelihood’ and ‘probability’ rather than proof and certainty. For example, we can say that the theory of evolution is very likely to be more-or-less right, as there is a lot of corroborating evidence. Science cannot be run like a law court – where the prosecution only need to reach a threshold of reasonable doubt to ‘prove’ someone guilty.

Aside for nerds: Science says you can use logic to prove things absolutely, but logic only works with ideas, and there is a breakdown between ideas and reality, so one can never prove things in reality. So it is thoroughly wrong for a court to say that someone has been proven guilty. The courts use this language as a convenience, to “draw a line under” a case as they have not found a moral way to dole out punishments based on probabilities. Imagine a world in which a murder suspect gets a 5 year sentence because the was a 20% chance he was guilty! Sports referees often operate in this decisive way, perhaps because it saves a lot of arguing!

Anyway, good science cannot just give up and say once there is consensus something passes from theory to fact. This is sloppy. We have to keep our options open – forever.

Think for example of Newton’s Laws of Motion. They are called ‘Laws’ because the scientific community had so much faith in them they passed from theory (or a proposed model) to accepted fact. But they were then found wrong. Strange that we persist in calling them laws!

It took Einstein’s courage (and open mindedness) to try out theories that dispensed with a key plank of the laws – that time was utterly inflexible and completely constant and reliable.

So it is that the canon of scientific knowledge has become a complex web of evidence and theories that attempt to ‘best fit’ the evidence.

Alas, there are still many propositions that many so-called scientists would claim are fact or at least ‘above reproach’. Evolution is attacked (rather pathetically), but the defenders would do well to take care before they call it ‘fact’. It is not fact, it is a superbly good explanation for the evidence, which has yet to fail a test of its predictions. So it is very very likely to be right, but it cannot be said to be fact.

This is not just a point of pedantry (though I am a bit of a pedant) – it is critical to keep this in mind as it is the key to improving our model.

Two great examples of models people forget are still in flux…

1) The big bang theory

2) Quantum theory

I will not go into global warming here though it is tempting. That is one where it doesn’t even matter if it is fact, because game theory tells you that either way, we better stop making CO2 urgently.

Back to the big bang.

I heard on the Skeptic’s Guide podcast today about an NSF questionnaire that quizzed people about whether they believed the universe was started with a massive explosion, and they tried to paint the picture that if you didn’t believe that, then you were ignorant of science. This annoyed me, because the big bang theory is now too often spoken of as if it were fact. Yes, the theory contributes viable explanations for red-shifted pulsars, background radiation, etc, etc, but people are quick to forget that it is an extrapolation relying on a fairly tall pile of suppositions.

I am not saying it is wrong, all I am saying is that it would be crazy to stop exploring other possibilities at this point.

You get a feeling for the sort of doubts you should have from the following thought experiment:

Imagine you are a photon born in the big bang. You have no mass, so you cannot help but travel at ‘light speed’. But being an obedient photon, you obey the contractions in the Lorentz equations to the letter, and time thus cannot pass for you. However, you are minding your own business one day when suddenly you zoom down toward planet earth and head straight into a big radiotelescope. Scientists analyse you and declare that you are background radiation dating from the big bang and that you have been travelling for over 13 billion years (they know this because they can backtrack the expansion of the universe). Only trouble is, that for you, no time has passed, so for you, the universe is still new. Who is right? What about a particle that was travelling at 0.999 x the speed of light since the big bang? For it, the universe is some other intermediate age. So how old is the universe, really?

This reminds us of the fundamental proposition of relatively – time is like a gooey compressible stretchable mess, and so is space, so the distance across the universe may be 13.5 billion light years, or it might be a micron (how it felt to the photon). It all depends on your perspective. It is much like the statement that the sun does not revolve around the earth and that it is the other way around. No! The sun does revolve a round the earth. You can see it clearly does. From our perspective at least.

Now, quantum theory.

Where do I start? String theory? Entanglement? Please.

The study of forces, particles, EM radiation and the like is the most exciting part of science. But being so complex, so mysterious, so weird and counter intuitive, it is super vulnerable to abuse.

Most people have no idea how to judge the merits of quantum theories. Physicists are so deep in there, they have little time (or desire or capability) to explain themselves. They also love the mystique.

I do not want to ingratiate myself with physicists, so I will add that the vast majority have complete integrity. They do want to understand and then share. However, I have been working in the field for long enough to know that there are weaknesses, holes and downright contradictions in the modern theory that are often underplayed. In fact these weaknesses are what make the field so attractive to people like me, but is also a dirty little secret.

The fact is that the three forces (weak nuclear, strong nuclear and magnetic) have not been explained anything like as well as gravity has (by relativity). And don’t get me started on quantum gravity.

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Anyway, thinking about all these issues, I concluded that science was (definition #3) the grand (platonic) model we are building of reality, ever evolving to best fit our observations.

My man, Plato

That works well for me. However, I recently came across a totally different definition for science:

# 4) “Science is a tool to help make the subjective objective.”

OK I paraphrased it to make it more snappy. It was really a discussion about how science was developed to overcome the fallibility of the human mind. Examples of weaknesses it needs to overcome are:

  1. The way our perception is filtered by preconceptions
  2. How we see pattern where there is none
  3. How we select evidence to match our opinion (confirmation bias)
  4. How we  read too much into anecdotal evidence
  5. etc etc.

I could go on. So ‘science’ is the collection of tricks we use to overcome our weaknesses.

I like this definition. We are all going about, and in our heads we are building our model of the world… and its time for an audit!