I have an historical artefact. It is a laser pointer come control unit for PowerPoint presentations. Around two decades ago I was accustomed to talking to PowerPoint slide packs.

The laser emits a deep red beam which creates a small red filled-in circle on the floor or on the wall. The beam is not too divergent. I can move the circle around using the hand held pointer for the cat to chase. She enjoys this for a while. She will run from side to side and jump up the wall. After a while it fries her brain because no matter how hard she tries she never catches anything tangible. In the end she shrugs her shoulders, mutters and gives up. It is a waste of time.

Her instinct knows to chase. Her brain kicks in eventually that it is futile. At one level the cat understands the laser pointer. She learns.

When I used to do “A” level physics tutorials I would use the laser pointer in conjunction with a ruled diffraction gating projector slide. At normal incidence it would give a transmission line and first and second order diffraction spots.

d sine (theta) = n lambda

Using a DIY measuring tape and knowing the number of lines per millimetre on the grating I would get the students to use a little trigonometry and calculate the wavelength {lambda} of the laser pointer diode laser. They would invariably get to within 2% of the correct wavelength from a fairly rough experiment. I would hand them the pointer upon which the manufacture output wavelength was written. The numbers would agree well. This made them happy and gave belief in the above equation. They were happy that light can be explained as a wave.

Bibi the cat does not care about this. She can easily see three spots when I shine the laser through the grating.

At one level I understand the emission process in a semiconductor diode laser and how such a laser beam may be output coupled. I understand the semiconductor physics, the laser optics and the diffraction of visible light. I could even comment on the means of manufacture of the laser.

Bibi does not give a shit.

In her world that is unimportant and she is unaware as to where her knowledge and understanding ceases. She does not even know that she does not know.

I cannot control my body with the efficacy and speed she can. I can understand how to hunt like her but I have no practical experience. I know better where my knowledge starts to fail. I could catch and dismember mice. I too am not fond of fresh kidney so I might leave these on the pavement like she does.

In her world what I know is of little importance to her provided I give her Sheba on demand and open the door when requested.

She is blissfully unaware of some aspects of my world and largely does not give a toss about it…

She does not know where her knowledge and understanding stops…she is like many humans in this respect.

She does not give a shit about this…

If I was hunting her, given time I would catch her. I know more about cat behaviour than she knows about human behaviour and know how…

If I turn on the laser pointer she will chase it for a while until she remembers…