Things you always wanted to know the answer to [Vol. 3]

[Silent1]

Willy Nilly said:

Vaud said:

AstonZagato said:

Three answers:
1. Moorland is a fantastic wildlife habitat that supports grouse, golden plover, peregrine falcons, hobbies, lapwings, oystercatchers, red deer, etc. Pine forests (particularly commercial ones) are virtually devoid of animal life.
2. Most of it is designated either an area of outstanding natural beauty or area of special scientific interest.
3. Grouse shooting (which pays for keeping it wild and unspoilt and therefore ensures that the first two reasons are preserved)

But given the UK used to be much more forested, aren't these, to some extent "artificial" environments?

That's my thinking. Man chopped all of the trees down, so why not replant them? They never seem that beautiful to me unless brown is you thing. Clearings could be left, ideally in rude shapes to amuse passing aircraft.

This is quite a good video about ancient forests and moorlands:
https://youtu.be/zVPUFMwm73Y

[Mr Snrub]

Dr Jekyll said:

If you had an infinite number of Shakespears and an infinite number of typewriters, would you get a script for Planet of the apes?

Or would they be able to come up with an ending that somehow makes less sense than Tim Burton's version?

[popeyewhite]

SpeckledJim said:

A figure moving steadily upwards is doing the same work as a figure maintaining position in a 'world' that is moving downwards.

I might have hinted at this a few pages back.
If you're wrong a large percentage the world's Olympic athlete's training is knackered before they even get to Brazil.

[Hugo a Gogo]

Ayahuasca said:

How much will it cost us to replace all postage stamps and coins, and pillar boxes.

Has Prince Charles already been photographed for the stamps / coins?

Does anyone still use pillar boxes?

there are still pillar boxes with VR on them, never mind GR

coins don't get taken out of use straight away either, just newly minted ones would have Charles on them

[popeyewhite]

Willy Nilly said:

Why not replant moorland with trees? The land isn't used for much and it could be done over a number of years using the money already paid to the people that farm there to plant and take care of the trees

A lot of it is private, also not all of it is suitable for farming or growing trees on. Moorland is typically rather wet, and the moorland above me (Peak District) is the source for numerous rivers, such as the Mersey, Dane, Don, Ouse and Trent. AFAIK mangrove wouldn't work either, not being an indigenous plant . A fair bit is also quite rocky. In exposed areas trees wouldn't be able to grow - they'd simply get ripped out in high winds. The forested areas of moorland that currently exist in the High Peak tend to be in valleys, such as the Goyt, Derwent etc.

[popeyewhite]

Vaud said:

But given the UK used to be much more forested, aren't these, to some extent "artificial" environments?

Yes, absolutely. A lot of the UK's moors have been changed by agriculture in the last 1000 years, however many areas have always been moor. When forest first began to be adapted to farming in Roman times this will have been relatively flat land, not the inaccessible high moors.

[SpeckledJim]

popeyewhite said:

SpeckledJim said:

A figure moving steadily upwards is doing the same work as a figure maintaining position in a 'world' that is moving downwards.

I might have hinted at this a few pages back.
If you're wrong a large percentage the world's Olympic athlete's training is knackered before they even get to Brazil.

Nobody could produce the maths to show where I was going wrong, and I couldn't produce the maths to show I was right, so I gave up.

Effort that in one case results in additional 'altitude' in the other case does useful work in propelling the staircase downwards.

What's the difference between doing the work to move from -2mph to 0mph and from 0mph to 2mph?

[P-Jay]

matchmaker said:

dci said:

Few train questions:

Why is that that freight trains in the uk are only about 17 carriages long but in the USA they can be many hundreds long?

Why are most trains (South Wales/ Valleys lines) so old? You don't get buses from the sixties still out on duty so why trains?

Why is everything related to the rails so expensive? I sometimes get involved with works for Network rail and they usually spec the most expensive equipment money can buy for no good reason.

I doubt that there are many (any?) 1960's passenger trains working in South Wales/Valleys!

The bulk are mid-80's, but you might be surprised when they decommissioned some of the older ones! They had one from 1958 running until 2013, and quite a few from the early 70's running until 2012.

One of my Friends drives trains for Arriva in South Wales, they're all old, but they work, break down surprisingly infrequently and new parts are still available.

The carriages are bloody awful, I used to commute by train into Cardiff, but at least the little branch line I was on (Penarth) was pretty quiet - the ones coming down from the Valleys looked like cattle trucks! I used one for the first time in 10 years the other day, it was exactly the same - nothing, not a single change in 10 years.

[singlecoil]

SpeckledJim said:

What's the difference between doing the work to move from -2mph to 0mph and from 0mph to 2mph?

That's the basis of your misunderstanding. If you stay in one place you are NOT going from -2mph to zero. You are already at zero. All you have to do is to move your legs to accommodate the movement of the escalator. The moving part of your legs is less than half your body weight, therefore the work done is less than half that of walking up a static escalator.

[popeyewhite]

singlecoil said:

All you have to do is to move your legs to accommodate the movement of the escalator.

Could you go to your local Leisure Centre and try your technique, then please report back? It would be an idea to do it while no one else is watching... .

[singlecoil]

popeyewhite said:

singlecoil said:

All you have to do is to move your legs to accommodate the movement of the escalator.

Could you go to your local Leisure Centre and try your technique, then please report back? It would be an idea to do it while no one else is watching... .

I've watched someone else doing it, so no need.

[SpeckledJim]

singlecoil said:

SpeckledJim said:

What's the difference between doing the work to move from -2mph to 0mph and from 0mph to 2mph?

That's the basis of your misunderstanding. If you stay in one place you are NOT going from -2mph to zero. You are already at zero. All you have to do is to move your legs to accommodate the movement of the escalator. The moving part of your legs is less than half your body weight, therefore the work done is less than half that of walking up a static escalator.

But Newton established that it takes no more energy to keep a body moving at 2mph than it does to keep it at -2mph or 0mph, so it isnt that simple.

By your rationale, not only is it harder to walk up a stationary escalator than a reversing one, but it is harder still to walk up a normal forwards moving escalator.

Genuine question to those who think there is a difference:

If the escalator was moving with you, instead of against you (ie, 4mph - 2mph from you, 2mph from the escalator) is that harder to walk up than a stationary staircase?

[popeyewhite]

singlecoil said:

popeyewhite said:

singlecoil said:

All you have to do is to move your legs to accommodate the movement of the escalator.

Could you go to your local Leisure Centre and try your technique, then please report back? It would be an idea to do it while no one else is watching... .

I've watched someone else doing it, so no need.

Uh-huh.





Sorry.

[singlecoil]

SpeckledJim said:

singlecoil said:

SpeckledJim said:

What's the difference between doing the work to move from -2mph to 0mph and from 0mph to 2mph?

That's the basis of your misunderstanding. If you stay in one place you are NOT going from -2mph to zero. You are already at zero. All you have to do is to move your legs to accommodate the movement of the escalator. The moving part of your legs is less than half your body weight, therefore the work done is less than half that of walking up a static escalator.

But Newton established that it takes no more energy to keep a body moving at 2mph than it does to keep it at -2mph or 0mph, so it isnt that simple.

By your rationale, not only is it harder to walk up a stationary escalator than a reversing one, but it is harder still to walk up a normal forwards moving escalator.

Genuine question to those who think there is a difference:

If the escalator was moving with you, instead of against you (ie, 4mph - 2mph from you, 2mph from the escalator) is that harder to walk up than a stationary staircase?

Newton's first law doesn't apply here, because there is an external force acting on the body i.e. gravity.

[Einion Yrth]

Just when we hadn't been bothered by the aeroplane and conveyor belt trope for a while...

[Einion Yrth]

It's basic relativity, principle of equivalence stuff; if you are in an elevator, in a gravity field, with no windows. How do you tell if the elevator is moving or not, unless it accelerates?

You can't; (Mike McCulloch's MiHsC theory notwithstanding, since it would only represent a minor correction anyway.)

Same effort is involved in climbing any set of stairs, unless they are undergoing acceleration, (note movement at a constant velocity is not acceleration, for the physically challenged.)

[singlecoil]

Einion Yrth said:

It's basic relativity, principle of equivalence stuff; if you are in an elevator, in a gravity field, with no windows. How do you tell if the elevator is moving or not, unless it accelerates?

You can't; (Mike McCulloch's MiHsC theory notwithstanding, since it would only represent a minor correction anyway.)

Same effort is involved in climbing any set of stairs, unless they are undergoing acceleration, (note movement at a constant velocity is not acceleration, for the physically challenged.)

An elevator is not an analogy because there is no way for the person in it to accommodate its downward motion without moving part of their body, but on an escalator there is.

[RobinOakapple]

Exactly

[deeen]

Einion Yrth said:

It's basic relativity, principle of equivalence stuff; if you are in an elevator, in a gravity field, with no windows. How do you tell if the elevator is moving or not, unless it accelerates?

You can't; (Mike McCulloch's MiHsC theory notwithstanding, since it would only represent a minor correction anyway.)...

You can if it's moving fast enough for your body to feel the apparant reduction in gravity. You can measure it at any speed. The only reason you might not feel it in a "normal" lift is that your body is not that sensetive to small variations in gravity.

[deeen]

singlecoil said:

That's the basis of your misunderstanding. If you stay in one place you are NOT going from -2mph to zero. You are already at zero. All you have to do is to move your legs to accommodate the movement of the escalator. The moving part of your legs is less than half your body weight, therefore the work done is less than half that of walking up a static escalator.

Imagine 2 down escalators next to each other, each with a man standing at the same point, near the top. Those men have the same potential energy from gravity.

One stands still, and ends up at the bottom of the escalator. The other climbs at the rate needed to match the speed of the escalator, and stays in the same place.

Now, those two men have different potential energy. The difference is the kinetic energy used by the man who "stays in the same place".