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.


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…


Confirmation bias: confirmed as bias.

13 08 2011

I have this theory that ‘confirmation bias’ is a load of BS, so I looked on the net and found, after careful search, some people who clearly agree with me. Most don’t, but they must be idiots.


The compensation factor – or why shoes might just be bad for your feet

10 06 2011

There are many modern innovations around which we take for granted as good, that are, indeed, not.

Some interventions, such as seat belts, are shown by statistics to save lives, and as the cost of strapping in is not too high, so the case in favour is strong.

But what about modern running shoes? It may be turning out that nice cushiony running shoes actually cause more injuries than they prevent – and for a similar reason that taking out all the safety features from a traffic intersection may actually make it safer.

Why is this so?

It seems in these latter cases that making people safer only leads them to take more risks, sometimes cancelling out the benefit completely – this is has been termed “risk compensation” – but how does that apply to running shoes?

It turns out the cushioning makes us feel safe – safe to slam down our heels without feeling the shock. It also turns out that while it may feel ok, it allows us to use our foot in a way it was never intended, and results in far greater forces going up our legs.

Think for a moment about the foot of a cheetah, or a deer, or a dog. Ask yourself, where is the heel?

Of course, it is clear once you think about it, it’s way up the leg, far from the floor! And do you think a cheetah has thuds of force going up its spine? I don’t!

Ok, so someone could point out we did not evolve from gazelles and they could also point out that no other primates show a raised heel; true enough – but primates started off as rubbish runners, and it was only the humans that  started down the road to better feet for running during all those years hunting on the African savanna. Whenever there is selective pressure to run, that great engineer (evolution) eventually finds that a raised heel is the optimal solution – remembering of course that the engineer has only the stump of a redundant old fin to work with. Of course, the invention of shoes (and ultimately cars) has completely removed the shaping forces, so I guess our heels will fall once more.

Don’t agree? Ok, pop on those big comfy shoes, and just like a beemer driver cruising at 100mph, tell yourself its safe to slam down those heels 😉

Some interesting sources:

  1. Walking robot – gee look, to make it work, they abandoned heels:
  2. Walking robot “with heels” seems to need bizarre extra hip mobility:
  3. Even Nike, they who started the whole thing now seem to admit openly that bare is best, and sell you the shoe that does it for $90:
  4. Take a sneak-peek into the barefoot community:
  5. Oh, and I got put on the scent of this by Christopher McDougall’s excellent book, Born to Run:
  6. In the wiki for Risk Compensation it interesting to learn that in Sweden, traffic collision rates dropped for 18 months after they changed which side of the road they drove on. Wow!
  7. The classic tale about how making roads seem more dangerous made them safer:

Air Fresheners Exposed!

22 05 2011

Ok, so I know its not a conspiracy to take over the world, but my inner nerd has been provoked.

Have you ever wondered how air fresheners work?

Let’s take a sceptical look.


This cool pic is from

I’d love to think that AirWick / Glade / {insert preferred brand here} consist of an army of nano-bots that round up and deport any molecules without the right paperwork.

Although we aren’t there yet, it’s actually not too far from the truth!

Although many cheap deodorisers do simply mask the truth by overpowering our senses, I really like to give credit where credit is due, so I am happy to disclose that there are indeed certain substances that can detain odours – such as zeolites and silica gels, and there are also organic molecules that will react with a wide array or hydrocarbons rendering them odourless. These ideas are in fact used by several big brands today.


But that’s not the whole story, is it?

No, because none of that really means the substance (or it’s source) is ‘gone’; all they have done is disabled our ability to detect all that foreign matter around us!

The last time I looked, our sense of smell, just like our sight and hearing, was there to help us survive – to detect when there is something unsavoury in the vicinity and force us to deal with it. If your bed or sofa stinks, you should probably take it outside and try to remove to 5 lbs of skins flakes and  other sundry bodily oozings rather than spray the bed with an extra long burst of febreze.

You wouldn’t season rotten meat in curry then serve it to your in-laws, would you?

Now, to be fair, the purveyors of these products do not intend for you to use their product to allow you to live in filth disguised with the scent of lavender, and their scientists are smart people – however, there marketing departments do need to be brought to book for giving a few misleading impressions.

The world ‘fresh’ for example is used universally. I don’t know about you, but to me this should mean clean, pure and new. It may certainly allow for some sweet floral aroma, but it certainly doesn’t include ‘complex organics we cannot smell’.

Some solutions – like Resolve carpet cleaner, where an absorbent powder is applied liberally then hoovered up, deserve a break – but, as far as I can see there are the exception – most odour control is still in the form of the old “cover up”.

What we have to remember is that in order to claim a product is ‘absorbing’ an odour, one only need prove it absorbs ‘some’ odour – not necessarily the majority and very rarely “all”. Thus it can be that it absorbs 2% of the odour and the other 98% of the odour is still there but overwhelmed by the scent of a pine forest. The same is true with biocidal deodorisers (like Lysol) which may kill bacteria – a common source of odour. These products can actually kill germs – however the impression that a quick spray will effectively sterilise is falsely reassuring.


I sign off now by pointing out that the best way to avoid odours is by good hygiene, though not too good: remember that we humans co-evolved with this slimy little planet!


Reality: a hard sell

2 04 2011

I can’t help but wonder if doggedly debunking all spewings from the purveyors of woo is somewhat a fool’s errand.

There are a number of pseudo-scientific disciplines whose concepts are inherently highly attractive and contagious to the average Joe, saying things that make him feel good and making him want to pass on the good news. Think of how easy to sell these messages are:

  • organic food – frolicking chickens, steaming compost, happy farmers, healthy food – a return to basics, back to a purer time when humans actually had roots in the earth and cared for it; you too can go organic!
  • complimentary medicine – age-old wisdom, so long suppressed by big pharma is unlocked just for those open-minded enough to look. Are you open-minded! Yes? Here are your keys to healthy prosperity!
  • astrology – our fates, entwined with the universe, form a beautiful unity; enigmatic scholars have acted custodian to its cipher through the ages. Are you a spiritual soul? You too can share time’s secrets!
  • parapsychology – our minds are more powerful than science knows, and we all have potential beyond our wildest dreams! But hold on! Only those willing to break free from the trappings of conventional science will ever see the light…
  • and of course the big kahuna, religion – imagine for a minute the greatest most wonderful thing in all the world, and that is but nothing compared with the joys that await the believer, and for all eternity too!

It is little wonder the bible I had as a kid said “Good News” on the cover.

The issue is that the logical shredding of these pieces is often a sobering dose of reality that fills most people with instant sleepiness:

  • organic food is not always kinder to the planet and claimed health benefits are of the ‘hard to verify’ sort
  • alternative medicine actually does work, but only the level one would expect from getting time, care, attention and the placebo effect
  • the laws of physics do allow marvellous things (x-rays, computers, holograms) but it takes serious study to understand why they don’t allow for the positions of stars and planets to have predictable effects of the day-to-day ongoings in suburbia.
  • the mind is indeed fabulously clever and poorly understood, but those tedious laws of physics, and indeed dry, cold logic, are annoyingly sticky when it comes to clairvoyance, ESP, psychokinesis and precognition.

So YAWN! Boring!! Logic and analysis mean effort, work, thinking things through, totting up totals, cross-checking claims, testing, questioning and doubting. Pretty much the opposite of nice & easy. Accepting we are not all-powerful, we are not immortal and that we will all be forgotten someday is just no fun. These are not messages that will go viral, that will breed missionaries, that would generate a manic fervour. More like manic depression.


So the deck is stacked. Pseudo-scientific ideas persist because they are tenacious memes, and they are almost impossible to kill. They are contagious and sticky, and lovely and easy, and fighting them off requires not just the will, but also the ammunition.

And that is why it worthwhile to continue to fight the good fight – to keep trying to debunk poor thinking – to provide the ammunition to that small number, those that may be on their own, surrounded by superstition, but with that gift in their heart that is that first inkling of doubt.

I will do it for those that think they are alone as I once did.

We live in a time of unprecedented opportunity – people have better access than ever to the tools to arm themselves to achieve a new sort of ideal: to make life choices with full access to all the facts. We are after all free to choose to believe anything, the problem only comes when we are not given the choice. No information, no balance, no choice.


Hysteresis Explained

1 04 2011

Hysteresis (hiss-ter-ee-sis). Lovely word. But what on earth does it mean?

Hysteresis is one of those typically jargonny words used by scientists that instantly renders the entire sentence if not lecture lost on its audience. Sure, you can look it up on wikipedia, but you may die of boredom before you get to the point, so I am going to explain it here.


Hysteresis on the way to school

Let’s go for a walk. Let’s say we are ten years old and we are walking to school. The route is simple. The school is a few hundred yards down the hill on the other side of the road. Now consider the question: at what stage do we cross the road? Immediately? Or do we walk all the way to opposite the school before crossing – or somewhere between?

Assuming there are no ‘official’ crossing points, I bet you cross immediately, then walk down the far side of the road.

How can I make this prediction? Well, I assume that crossing the road requires there to be no traffic, so if there is no traffic as you start the journey, it is a good time to cross. If there is traffic, you just start walking down the road until a gap appears, then you cross. This strategy allows you to cross without losing any time. If your strategy had been to cross at the school there is a real risk you will need to wait, thus losing time. So it turns out the best strategy to avoid any waiting is to cross as soon as you can.

So now picture your walk home. Again, it makes sense to cross early on. The result is that the best route to school is not the same as the best route from school. This is an example of hysteresis – or a ‘path dependent phenomena’.

Hysteresis  everywhere

The dictionary will drone on about magnetism and capacitance and imaginary numbers. A much nicer example is melting and freezing of materials – some substances actually melt and freeze at different temperatures. This shows that the answer to the question: “is X a solid at temperature Y?” actually depends – on the path taken to that temperature. Just like what side of the road you are halfway between home and school will depend on whether you are coming or going.

It seems to me that falling asleep and waking up also bear some of the hallmarks of hysteresis; although they could be considered a simple state change in opposite directions, they feel very different to me – I  seem to drift to sleep, but tend to wake to alertness rather suddenly.

Now think of a golf club in mid swing. As the golfer swings, the head of the club lags behind the shaft. If the golfer where to swing in reverse, the club head would lag in the other direction – thus, you can  tell the direction of movement from a still photograph. We can therefore say the shape of a golf club exhibits hysteresis – and again you see see why it is so-called “path dependent”.

This logic can be taken further still – wetting is not the opposite of drying and likewise heating is rarely the inverse of of cooling. Let’s imagine for example that you want to make a chicken pie warm on the inside and cool on the outside. This is best done by warming the whole pie and then letting it cool a little. The temperature ‘profile’ inside your pie thus depends not only on the recent temperature but has a complex relationship with its more distant temperature history. This particular point is somewhat salient at the moment as we ask the question: is the earth heating up? 

So what?

Good question. I’m not a fan of jargon, and hysteresis is not a word I hope to need to use in my smalltalk. However, you can see that it encapsulates a rather specific and increasingly important concept that is pretty hard to replace with two or three simpler words; thus it passes my test of “words a scientist should understand that most don’t”. Please let me know your own additions to such a list!




Educational way to spend four minutes…

2 01 2011