1

New Theories / Re: what is temperature?

« on: Yesterday at 22:35:15 »

Imagine we have sheep in a field. All wandering about in different directions and doing different things. Lots of entropy.

Now introduce an energetic dog who rounds them up into a pen, where they all stand still and face the same way. He has done work and reduced their entropy.

Therefore if you define temperature in terms of entropy, T = (dS/dE)^-1, he has reduced the temperature of the sheep by doing work on them, so T_sheep is negative.

2

Physiology & Medicine / Re: Can primates with longer necks and hips and shorter torsos take many roles?

« on: Yesterday at 22:20:56 »

The impressive characteristic of primates is their grasping hands and feet. Animals with long necks need them to feed, but primates carry the food to their mouths, so can wear a bigger head (hence bigger brain) with less musculature than swans or giraffes. 

Homo sapiens has proportionately longer legs than the other apes, that allow long-distance walking, striding over obstacles, and efficient bipedalism. But it comes at a cost - a huge amount of unconscious brain power  is involved in standing and walking upright.

A shorter trunk would compromise lung capacity or the ability of the digestive system to recycle water.

Gorillas and chimps have deeper skeletal ridges that provide anchors for more powerful upper body muscles: great for climbing trees and potentially amazing for playing wheelchair cricket or tennis, but they don't have the hips and brain capacity to play the able-bodied game.

Horses for courses! Design your environment, then optimise the species to exploit it.  Worked OK for God and Darwin!

3

The Environment / Re: Is global warming man-made?

« on: Yesterday at 22:05:14 »

a slope that's going up faster than ever before.

...than ever before Mauna Loa began to collect data, true.

If you remember vinyl records, you might recall that the microscopic scratches in an inch of one groove didn't look much like Beethoven's Sixth. At the time of recording, they may have been very important to the trombonist playing at that moment, but they don't tell you where Beethoven fits in the grand scheme of music.

4

New Theories / Re: An essay in futility, too long to read :)

« on: Yesterday at 18:48:27 »

Going by climate models, this wasn’t supposed to happen for a hundred years or more. And yet it’s happening now.” "

Yet another example of the difference between models (prejudice and arithmetic) and science (observation and explanation).

One to two billion people would be indefinitely sustainable with a western standard of living.

GDP is an awful parameter. It includes all financial transactions, with estimates for drugs, prostitution, and the price of houses, which is driven by speculation and shortage. It has absolutely nothing to do with human wellbeing.

5

Physiology & Medicine / Re: Can primates with longer necks and hips and shorter torsos take many roles?

« on: Yesterday at 18:35:39 »

Long necks have no aerodynamic advantage. A long tail, or a long neck furnished with vertical and horizontal stabilisers, reduces the force needed to maintain attitude and direction, but at the cost of increased weight and surface drag.

The length of the torso is unimportant. If you are going to fly by flapping, or even gliding, what matters is the quantity of muscle attached to the sternum, whci his why birds have a very deep sternum and humans can't fly by waving their arms.

Strong legs are used to propel man-powered flight. In various competitions it has proved easier to teach a racing cyclist to fly, than to train a glider pilot to generate 300 watts for more than a few seconds. But all these machines use an external propellor and gear system as no biological machine can have rotating parts.

You might consider rockets and pulse jets, as used by many aquatic animals, but you'd have a job to design a flying mammal that didn't look like a bat.

However if your fictional planet has a very dense atmosphere, you might find it already populated by whales and dolphins with gills instead of lungs.

6

The Environment / Re: Is global warming man-made?

« on: Yesterday at 18:22:13 »

No. Humans generate more CO2 in winter, not summer. That's what makes the Mauna Loa  data so  interesting: it suggests that CO2 is a thermometer, not a thermostat,

7

The Environment / Re: Will there be another ice age?

« on: Yesterday at 18:16:18 »

All depends on what you mean by "start"! The usual reference is the Vostok ice cores, which show how temperature and carbon dioxide have varied over the last 400,000 years. There are other ice core studies that show similar 100,000 year cycles in other parts of the world. What happens is that temperatures rise increasingly steeply of about 10 - 15,000 years to a fairly consistent maximum,  then decrease asymptotically towards an equally consistent minimum. The range is about 10 - 12 degrees.

Right now we are approaching the historic maximum, but "ice age" is not clearly defined: is it the point at which temperatures begin to decrease, or when the global mean temperature falls below the range mean, or when it is, say, within a degree of the minimum? 

The unmentionable truth is that the carbon dioxide level actually follows the temperature level, about 500 years later. It's currently out of sync a bit, thanks to farming and industry, but the historic record  suggests that it is irrelevant anyway.

8

New Theories / Re: How does Noether's theorem apply to moments of time?

« on: 10/08/2022 23:02:54 »

This is a public warning. Cool it, guys. Please stick to the subject and avoid personal accusations.

9

New Theories / Re: An essay in futility, too long to read :)

« on: 10/08/2022 20:28:18 »

Humans have directly modified 77% of the land surface and 87% of oceans (Watson et al., 2018).

That's pretty remarkable, considering that less than 25% of the land and less than 1% of the sea is inhabited or even regularly visited by humans.

We have indeed modified the 25% we occupy. It's called agriculture. Every animal modifies its environment. It's called living.   

10

Just Chat! / Re: Energy and healthwise, what is the best thing to eat for breakfast?

« on: 09/08/2022 21:13:51 »

Monday to Friday: Porridge, eggs, bacon, sausage, baked beans, black pudding, fried bread, coffee.

Saturday: Grapefruit, devilled kidneys,scrambled egg, white pudding, toast, champagne.

Sunday:  Orange juice, kedgeree, asparagus omelette, haggis, clouttie pudding, Guinness.

Substitute oysters, raw or cooked, for any item at any time. Add spinach and/or Hollandaise sauce to taste - eggs Benedict if you are in a hurry.

Breakfast is the key to good mental health. Best if it lasts for at least an hour, after which you spend the rest of the day outdoors digging, shooting or fishing for your dinner. Substitute coffee for alcohol if your weekend pursuit is flying: you can always turn up drunk at the office - nobody will notice.

11

Physiology & Medicine / Re: Is extreme lifestyle changes a primary cause of postpartum depression?

« on: 09/08/2022 20:59:10 »

The environmental factors are all important but to some extent also applicable to male partners, most of whom step up to the plate but a significant number run away. I wonder how the male statistics stand up against those for female PPD?

"Brain chemical imbalance" looks like pseudomedicine, to be followed by a list of ancient curative herbs and potions. There are certainly profound hormonal changes throughout pregnancy and early post-partum, but a species (or even a genetic line within that species) in which these ultimately led to the incapacity or unwillingness of the mother to nurture the baby,  would quickly  become extinct. We know of occasional rejections among farm animals but their lifestyle changes are far less profound than for humans, and the inherent commitment to the newborn is much shorter.

In summary, I've seen it, I don't know the answer, a bit of statistical analysis might be interesting, and I'd counsel against using language that might be construed as "alternative".

12

New Theories / Re: An essay in futility, too long to read :)

« on: 09/08/2022 11:08:31 »

And link those facts please.

google "gridwatch templar UK"

13

New Theories / Re: An essay in futility, too long to read :)

« on: 09/08/2022 11:07:18 »

World is a terrible place when not everyone plays cricket

My father used to point out that no cricketing nations had ever declared war on one another.

For the uninitated, the Indian Premier League is a major tournament between teams of world-class players who put themselves up for auction by the rival sponsors each year. The year after some Pakistan-based scum blew up a hotel in Bombay for the greater glory of their superstitions, nobody bought any Pakistani players. In response to such national humiliation, the Islamabad government swiftly issued an apology and began to crack down on religious terrorists. Equilibrium has been restored.

14

New Theories / Re: An essay in futility, too long to read :)

« on: 09/08/2022 10:55:27 »

" The UK receives hydroelectric power from Norway through a subsea interconnector cable running beneath the North Sea. However, water levels in southern Norway have been so low this year that the country’s government could put its own consumers ahead of international customers."

At this moment, the UK is actually supplying electricity to Norway, Ireland and France. The maximum capacity of each link is 1.5 GW in either direction. Sustainable? No, since nearly 50% of UK generation today (35 GW total demand) is fossil-powered.  Under blazing  sunshine we have  an estimated 6 GW of solar power (60% of installed capacity) and less than 3 GW of wind (12% of capacity).

So, in a nutshell, it seems that the most reliable renewable of all, Norwegian hydroelectricity, is not reliable.

15

New Theories / Re: what is temperature?

« on: 09/08/2022 10:42:20 »

Do laser cutters decrease entropy?

no.

16

New Theories / Re: An essay in futility, too long to read :)

« on: 08/08/2022 16:04:17 »

But yes, it could have gone the other way, a Japanese population believing in 'divine rights', refusing a surrender. And in that case, what would USA have done? I think I can guess it.

No need to guess. At the time, my dad was exercising tank squadrons in India and the Boss's dad was manning a "conventional" B29 somewhere in the Pacific, in preparation for the seaborne invasion of Japan. Like D-day and the march on Berlin  but a lot bloodier. The estimated casualty count was at least 3,000,000 in a 2 - 4 year campaign.

17

New Theories / Re: An essay in futility, too long to read :)

« on: 08/08/2022 15:59:38 »

It's the best way. And indeed the entire ethos of warfare - it's not like cricket. 

18

New Theories / Re: what is temperature?

« on: 08/08/2022 13:24:10 »

The concept of negative temperature derives from a definition of temperature in terms of entropy. All it means is a condition where adding energy to a system decreases its entropy.

19

New Theories / Re: An essay in futility, too long to read :)

« on: 08/08/2022 12:00:07 »

I don't think anyone can 'win' a nuclear war.

The western allies have already done so.

20

New Theories / Re: what is temperature?

« on: 08/08/2022 11:58:52 »

Gravitational potential is very real and always negative.