A Question For The Lone Ranger

[Janet]

TLR,

Have you ever considered doing educational programs at libraries during your summers off? We often have speakers bring animals in or do science programs. This year the state Summer Reading Club theme is Dig into Reading and a local man has loaned us a gorgeous collection of fossils, mostly skulls, to display in the children's department. As I was looking at them today, I thought it might be something that you would really enjoy.

[LadyShea]

Summer Reading Club theme is Dig into Reading

Our library uses the same program outline, I guess, since we are Digging into Reading too. They have different things every week...music, puppets, one year they brought out a dairy cow. TLR doing something would be fun. I have first hand experience of his "program"

[Janet]

I wasn't sure if the theme was decided on a national or state level. I guess now I know. The connecting adult theme is Groundbreaking Reads, which is kind of an interesting way to go.

[The Lone Ranger]

I do some occasional programs with local schools (mostly at the elementary level), occasionally with 4-H programs, and sometimes at a nearby nature center. I must say that I do enjoy that sort of thing, and I've been thinking that maybe we could do more of that sort of thing, maybe in concert with the Scouts. (I used to do volunteer work as a "Camp Naturalist" for the Girl Scouts, and enjoyed it immensely.)


I'm still hoping that the Blue Ridge Parkway, or Great Smoky Mountains N. P. or Shenandoah N. P. will come to their senses and decide that they need to hire me as a naturalist!

Speaking of which, if I can arrange to get next Summer free, I'm toying with the idea of seeing if I can't arrange to do some volunteer work for the Park Service. Who knows? Maybe I can get a foot in the door. (And I've been told that a "Ranger Hat" looks good -- and natural -- on me. Go figure.)

[Janet]

For the rest of my life, I will be imagining you as Ranger Gord. I just want you to know that.

[thedoc]

Originally Posted by Janet

For the rest of my life, I will be imagining you as Ranger Gord. I just want you to know that.

I just hope he gets paid better.

[Megatron]

Originally Posted by Janet

For the rest of my life, I will be imagining you as Ranger Gord. I just want you to know that.

And now because of this post so will I

[The Lone Ranger]

I'm not Canadian, eh?

[Janet]

My best friend insists Red Green is a bunch of Canadians who spent too much time watching Michigan Outdoors. It makes him very happy that the Lansing PBS station shows them back to back.

[MonCapitan2002]

I have a new question that I recently though of. What determines the speed of light? Second question. if it were faster (say 3,000,000 KPS versuss 300,000 KPS), would that mean our universe as it is would not exist?

[thedoc]

Originally Posted by MonCapitan2002

I have a new question that I recently though of. What determines the speed of light? Second question. if it were faster (say 3,000,000 KPS versuss 300,000 KPS), would that mean our universe as it is would not exist?

We can measure the speed of light, but that speed is determined by the physics of light itself. A more detailed explination will no doubt be forth comeing from TLR.

On the second question, while the universe itself might exist it would be quite different, and the existance of matter and energy, as we know it, is doubtful. Astro physicists say that our universe can only exist within a very narrow range of parameters, the speed of light being one of them.

[Dragar]

Originally Posted by MonCapitan2002

I have a new question that I recently though of. What determines the speed of light? Second question. if it were faster (say 3,000,000 KPS versus 300,000 KPS), would that mean our universe as it is would not exist?

The 'speed of light' is not so much the speed of light, but the speed at which massless objects happen to travel (like light). The speed of light is also the speed of gravity, for example.

But to be more concrete, the notion of a fundamental constant associated with space and time arises from special relativity.

The basic notion is that when you describe locations in boring, Euclidean space (the sort of space you and I grew up with, and approximately in), you can specify the separation between two locations by their distance. If you write down a coordinate system for the three dimensions, (x,y,z) you can use Pythagoras theorem to sum up the squares of the separations in each dimension, and get their separation.

This quantity is called an invariant, because even if we have chosen different coordinate systems (say, rotated, or offset in one direction), we will still agree on how far apart two locations are.

Once we move to spacetime, things get a bit weirder - the spatial separation between events is not an invariant. It depends on how fast you are going. The same is true of temporal separation - simultaneity is relative.

Fortunately, there is another invariant. You sum the squares of the (x,y,z) differences, and subtract the square of the temporal separation. Since we measure distances in metres, or length units, and time in seconds, or some other time unit, we need a constant to multiply our time units to get all the units into the same one. The constant needs to have units of velocity (distance per unit time), hence there is a fundamental velocity in the theory.

So really, you can view the speed of light as nothing more than a conversion factor between space and time, allowing us to properly talk about separations in spacetime, rather than just space and time separately.

Asking what would change if the speed of light was different is a bit subtle. The speed of light is its value by definition. If you changed the 'number', all you're really doing is changing how long the distance we call a metre is, and how long the time is that we call a second. And that would propagate through, ultimately resulting in a universe that was indistinguishable from our own. If you want to consider changing the fundamental physical laws, you need to think about dimensionless numbers (like the fine structure constant, or ratios of particle masses, for example).

[ceptimus]

There are some fundamental constants, like c, the speed of light, that have 'dimensions'.

All we mean by 'dimensions' in this sense is that they include different types of measurement within them. As the speed of light is a speed and we measure speeds by distance divided by time, the dimensions of c are distance/time or meters/seconds if you want to work in SI units.

There are other fundamental constants that are 'dimensionless' - they are just pure numbers. One example is the mass ratio between a proton and an electron. The number is about 1836.15 which means a proton has slightly more mass (weight if you like) than 1836 electrons.

Physicists don't expect to be able to calculate these constants just using theory - the constants are something that have to be measured. There is a slight possibility that they may change over time (though there is no evidence for that). As you say, we can imagine other universes where the constants have different values - and those universes would be very different to our own, even if the constants were only tweaked a little.

[MonCapitan2002]

You guys are definitely smarter than I am (or at least better educated then I am with regards to physics), so some of that explanation goes over my head a bit. I do think I got the gist of it however. I do appreciate the time you took to answer my question, so thank you for answering.

I think I'll go over your answers again when I haven't been up for nearly 20 hours. It might make more sense after I've slept.

[S.Vashti]

I have a question for the Lone Ranger! (my expertise is fish, not hypotheses).

I want to test the self awareness of my dog. Here is what I know so far:

1. She ignores her image in a mirror. She looks at it, but does nothing.
2. She will bark and lunge at any dog, no matter the size, a few moments after she spots them.
3. She will bark at many dogs, even if she can't see them, but only hear them. Unfortunately, she doesn't always bark at dogs she just hears barking, and I don't know why.
4. Smell does not seem to be an issue, she barks and lunges at dogs that are over 50 yards away from her, and downwind. It seems to be a sight issue

So, my hypothesis is that she knows the reflection of herself in the mirror is of her, and I can test this by showing her a mirror with a reflection of another dog. If she barks and lunges at the mirror, will that show that she knows it's her reflection? If she turns around and looks behind her, (seems really doubtful that would happen) that would show she knows it's a reflection. If she lunges at the mirror (a first for her), or attempts to go around it, does that mean she sees the dog at a thing she should attack?

I'm awful at construction testable hypotheses, can you help with this?

[livius drusus]

What is differential friction?

[The Lone Ranger]

I'd have to give it some further thought, but my first thought would be to employ a one-way mirror. An incompletely-silvered mirror functions as either a window or a mirror, depending on the lighting conditions.

Ideally, you'd need such a mirror/window set into a wall, with a dog on the other side. That is, you'd want to make sure that there were no olfactory or auditory cues to alert your dog that another dog is nearby, if possible.

Then, by altering the light level on either side of the mirror/window, you could make it so that your dog sees either the other dog or itself, and observe the resulting behavior.

That's what comes up off the top of my head, anyway.



The null hypothesis would be that your dog does not distinguish between an image of herself and an image of another dog, I should think. If she clearly does respond differently to images of other dogs compared to images of herself, that could indicate self-recognition.

That's actually a very widely-studied phenomenon -- whether or not an animal is capable of self-recognition. One way to test self-recognition is to put a dab of paint on a part of an animal's body that it can't see, and then let it look at itself in a mirror. Most animals won't make a connection between the mirror image and themselves, but a chimpanzee will recognize that the image in the mirror is itself, and will immediately begin picking at the discolored fur.

Such self-recognition has been convincingly demonstrated in many primate species, in cetaceans, and in elephants. To my knowledge, it has never been demonstrated in dogs, however. This may be because most dogs are much less visually-oriented than are most primates, however.

[The Lone Ranger]

Originally Posted by livius drusus

What is differential friction?

Could you provide a bit of context? It could refer to several different things.

For instance, you sometimes hear the term in reference to automotives, when the different tires on an automobile experience different amounts of friction with the road surface. (This could be due to differing amounts of wear on the tires, for example.) If there is differential friction, then the tire experiencing the least amount of friction with the road surface is the one that's most likely to lose traction.

Some vehicles monitor traction and adjust the power going to the individual wheels, to compensate.

[S.Vashti]

Thanks, that might be doable! Tally is a terrier, very scent oriented-but for the fact that she detects dogs she shouldn't be able to smell (wind from the west, target dog in the east; windows closed up, windows drapes open). It's clear she uses her sight in these instances to work herself into a tizzy barking at the other dog.
I don't think she's self aware, I'm just curious as to why a mirror at her height, elicited nothing more than a glance. I wonder what would happen if I "painted" her face and let her see herself, would she think it's another dog or not?


(right now, she is inside a closed house, barking her head of and whimpering in agitation at a dog she saw on the street outside.)

[Ari]

Perhaps use a flat screen to simulate another dog.

[livius drusus]

Originally Posted by The Lone Ranger

Could you provide a bit of context? It could refer to several different things.

An Egyptian statue at the Manchester Museum moves on its own. It's just standing there on a shelf and gradually over the course of the day it rotates until its back is to the viewer. This has made the news because it's awesome, and a physicist said the cause is differential friction but the article doesn't really explain what that means and how it would make the statue move.

[The Lone Ranger]

Ah, I see. In that case, what he'd be referring to is the supposition that different parts of the statue's base have a different coefficient of friction with the support than others.

Picture a table with 4 legs. On 3 of those legs, the end is capped with grease, while the end of the fourth leg is capped with sandpaper. The fourth leg is going to experience much more friction with the floor than will any of the others.

So, if you vibrate the floor or otherwise subject the table to any sort of lateral stress, the fourth leg will be much more resistant to movement than will the other 3 legs. The result is that the table will have a tendency to rotate around that fourth leg.

I imagine that's what the physicist is referring to. If one part of the statue has greater friction against the support than do other portions (perhaps due to unevenness in either the statue base or the support, or because something sticky has somehow gotten attached to it), then vibrations will not cause the statue to move in a uniform manner. Where the statue is in contact with its support, whatever portion has the highest friction will be most resistant to movement, and so the statue will tend to rotate around that point.

Say the left side of the statue moves easily, but the right side is much more resistant to movement. In that case, the statue will tend to pivot around its right side.

That would explain not why it turns, but not necessarily why it always rotates in the same direction. After all, if it were on a perfectly level surface, it could rotate in either direction. But if it's inclined at all, then it will preferentially rotate in one direction, because of the Earth's gravity; the side that moves will tend to "fall" toward gravity.

Cheers,

Michael

[livius drusus]

That is a crystal clear explanation, thank you. Can you think of any reason why this would only recently have begun to happen? The article is deficient in details, but it does quote a curator being mystified that the statue suddenly starting turning even though nothing about the display has been changed.

[The Lone Ranger]

I dunno. Has the statue been changed in any way recently? Polished? Moved to a new shelf?

Maybe there's construction traffic nearby, and the increased vibrations are causing the movement?



ETA: If it's on an inclined surface, that could also explain why it stops rotating. Once the rotating side has "fallen" as far as it can, any further rotation would mean that it was rotating upward, against the pull of gravity. In effect, this would increase the amount of friction that surface experiences, preventing the rotation. (Though the whole statue might then slide downward, if there's enough vibration.)

[livius drusus]

Thanks again, Michael. I put your explanation to work on my blog.