Back To Cuddly Robots


Our pets give us unwavering support and at times of pressure or stress help to lower our cortisol levels. Of course, there are other times when they get into something that they’re not supposed to that they add to our stress levels, but by and large, companion animals are good for us and are recommended to improve our quality of life as we age.

It is not always possible to have our own cat or dog so what are we going to do? We can of course talk to the passing dogs as they are being walked. Mostly they appreciate the attention, but not always. Anyway, these brief encounters are no real substitute.

The alternative is the touchy-feely robot. Previous posts have talked about Paro last year. Paro is the baby Harp seal robot that comes in white (mostly) or dark gray so it doesn’t show the dirt quite so much.

Paro is a very responsive robot who likes being stroked, talked to and picked up and held. It wriggles with pleasure, flapping its flippers appreciatively and squeaking like a baby Harp seal should, bring our cortisol levels crashing with each cuddle.

 He (or maybe she, whichever you feel is appropriate) does come through the mail at quite a high price though. At close to $7k he is a more serious commitment than anything but the most successful show animal, but unlike them there is no chance of stud fees or offspring to sell off to recoup the outlay.

An article in Discovery News reports that about a 19,000 people are still living in temporary housing, which was erected in a baseball stadium in northern Japan after the tsunami that occurred about one year ago (1). Paros are being offered to help reduce depression and as replacement for drowned pets that they can’t bear to replace. There are also Paros that are available for short term loan, rather like a library book.

Perhaps we should adopt this idea and have surgeries prescribe short term Paro house guests as an alternative to antidepressant drugs. It may prove a cheaper option in the long-term.


  1. http://news.discovery.com/tech/robot-seal-paro-japan-120217.html


Time To Eat


Our body or circadian clocks regulate the ebb and flow of hormones in our bodies and we readily become creatures of habit. Waking up at the same time in the morning even when we don’t have to or feeling it’s time to eat are just two examples.

Our cats and dogs have even better clocks and your cat will let you know in no uncertain terms if she thinks that you are being slovenly by laying about in bed instead of busying yourself with her dish of cat food. Dogs are so good at anticipating your arrival at home at the end of the day that some people attribute that to doggie ESP.

So what about the nightly life of rats? They are nocturnal and tend to move around nibbling their way through the hours of darkness. However, they can be assigned to the day shift and Mistlberger et al from Simon Fraser U have set about checking the workings of their clocks after they’ve been acclimatized to daytime activity (1).

Now, they were housed indoors and at 2:10 P.M. precisely the lights were switched on when the researchers had finished their lunch breaks. Their first meal was given 3 hours after lights on and their second meal 10 hours after the first.

It didn’t take them long to get used to the timing and they would get into their exercise wheels prior to feeding to work up an appetite. The jogging started about an hour prior to the first meal and about an hour and a half before their second meal. The rats were quite precise about their exercise schedule and didn’t have to be reminded.

The question asked was did their circadian clocks set alarms for this or were they working on a separate interval timer independent of their body clock? A variety of tricks were played on them such as changing the interval between meals, leaving the lights out and not feeding. Of course the tricks weren’t played over long durations so starvation didn’t come into it, just a little healthy fasting.

The results were clear. The rats’ workout schedules were strictly adhered to regardless of changes of feeding practice, clearly showing that they were simply using their inbuilt clocks with a multiple alarm function and not using a separate interval timer or picking up on external clues, and there was certainly no ESP involved.

There is no information about whether the rats are currently unemployed or are engaged in some other major project.


  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031772

Counted Out


Recognizing the numerousness of a group is an important skill. Of course, we can spend time counting the individuals in a group if we want to be certain of the accuracy, but this is time consuming and laborious, not to say soporific as we claim counting sheep can be.

With up to about four, we don’t have to count. When there is a large group it's much more difficult to tell the exact number, but we can readily tell which group is the larger if we are confronted with two groups containing markedly different numbers. The bigger the difference, the more certain we are.

What this means is that we work with two numerical systems automatically and on an everyday basis, even if we claim to be horrified at anything mathematical. Some other species have been shown to have some numerical ability also.

In this week’s Public Library of Science, Agrillo et al pose the big question “Are their undergraduates more or less capable of counting than guppies?”(1). Female guppies were chosen because they are gregarious and go around in groups rather like some of our undergraduates.

Note that neither the undergraduates nor the guppies were required to attend any dry mathematical lectures during this study. Guppies especially don’t like things dry.

The mainly female group of undergraduates was asked to look at pairs of groups of dots and say which image had the most dots. Some had large numbers in and some had small (up to 4) in them. Their accuracy was plotted against the ratio of the numbers of the pairs.

Nobody was found that could speak Guppy, so experienced and very young guppies were given the choice of joining one of two shoals of different numbers of fish. Like the pictures of dots, large and small shoals were offered. As guppies are very fond of guppies, they were expected to join the bigger of the two shoals. Their accuracy was also plotted against shoal number ratio.

The result? Not quite a dead heat. The undergraduates had slightly better results than the fish, but the trends were much the same. For small numbers, the accuracy was number ratio independent. With big numbers, the accuracy fell as the groups approach similar sizes.

The conclusion drawn was that in estimating numbers, undergraduates operate in a very similar manner to guppies.

Not that this is a bad thing, it just means that the roots of our mathematical ability go back a very long way in evolution as numerousness is an important life-skill.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031923


Bee Warned


Bees have a great deal to cope with. The vagaries of the weather and limited flowering seasons of their food plants are enough to keep them busy without the mites and diseases that they get from time to time, let alone having to cope with predators.

Hornets like bees, that is, to eat. The European honeybee lives in large colonies, but the Asian honeybee lives in smaller more mobile colonies. It co-evolved with the hornet and has developed a strategy for dealing with them. Tan et al report on this in the Journal of Animal Behaviour (1,2).

Hornets like to swoop down and abduct an unsuspecting worker bee for lunch. Now the Asian honeybees are quite vigilant and if an incoming hornet is spotted a large number of them at the colony entrance shake their abdomens wildly so the hornet sees this seething mass and thinks better of its escapade and high tails it to somewhere else.

The bee's warning is not an idle threat. It alerts the hornet to a mass of bees that know it’s there. If it presses home its attack, the bees cluster around it very tightly so that it is immobilized and with the press of bees, its temperature increases and it becomes too hot and expires.

So all those wagging tails tell it to buzz off as it has a better chance of overheating than overeating.

The investigators used tethered hornets and butterflies to test the bee’s reaction. They found it was hornet specific as the bees ignored butterflies. The European honeybee has failed to evolve the same procedure and can get picked of by swooping hornets. 
  1. http://www.bbc.co.uk/nature/16981702
  2. K. Tan, Z. Wang, H. Li, S. Yang, Z. Hu, G. Kastlberger & B.P, Oldroyd, J Anim. Behav. ,(2012). http://dx.doi.org/10.1016/j.anbehav.2011.12.031


Pony Up


Some women and some men with long hair tie it back in a ponytail. When I see a young woman walking down the street with her ponytail, my attention is drawn to her face as with the hair drawn back, the bone structure is more clearly visible.

However, some physicists are drawn to the shape of the ponytail and want to describe it in the purest poetic terms, that is, in terms of mathematics so that its essence can be captured by a single number.

Goldstein, Warren and Ball have been discussing ponytails at length and have come up with the correct poetry, which they have released on an unsuspecting world via Physical Review Letters (1).

They waxed mathematically lyrical about the gravitational force on each hair producing a tension which is balanced by the restoring force from the elasticity of the hair along with the local density of hair in the bundle which forces the hairs to spread apart, an effect which is exacerbated by the average curliness of the hair.

The beauty of getting all these forces into perfect balance allows the shape to be defined by their ratio. That ratio is now called the Rapunzel Number. That number will go up or down as the hair grows, is cut or is treated with caring hands anointing it with expensive products.

I’ve no doubt that many physicist enjoy fairy tails and the tale Rapunzel’s golden locks hanging down from her tower, but I feel obligated to point out that she didn’t wear them in a ponytail, but in strong braids.

And where is Dame Gothell (the enchantress) and the prince in all this?

  1. http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.108.078101


Home, Sweet Smelling Home


Pharaoh ants are a small species with adults growing to about 2 millimeters, but they are rather different from many ant species in that they are quite happy with one colony living alongside neighboring colonies. Colonies are small thug, with a couple of thousand ants of which up to 10% may be queens.

They are more than happy to share our goodies, whether it is honey or toothpaste so we see them all over the place in our homes or places of work. The problem is that they produce more ants, but as they live in small colonies, this means that as one colony expands it splits into an additional colony and in a very short time you can find colonies all over your building once the first one takes a liking to it.

Our intuition would guide us to expect that the new colony group would rush off as far as they could before putting down roots to minimize foraging overlap and other sundry reasons for not having close neighbors, but that doesn’t seem to be a criterion for the Pharaoh ants. Evison et al from U of Leeds looked into their decision making process and published their results last week (1).

Ants mark their trails with pheromones so that they can get back home with their booty and not get lost. In the lab they were presented with trail choices for new nests. Some familiar trails led to new nest sites while other poorly marked ones led to even better nest sites in some cases, although some others were a bit down market.

Invariably the ants chose the familiar. If the new sites were indeed better, they would reconnoiter and decamp to take up residence later. They were rather conservative and liked their paths to have the familiar smell of their pheromones when making their corporate decisions. Not for them, the bold jump into the unknown.

  1. S.E.F. Evison, K.A. Webster & W. O.H. Hughes, J. Behav. Ecology & SocioBiol., (2012) doi: 10.1007/s00265-012-1319-2