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General Science / Do we sense temperature?

« on: 03/10/2022 17:15:38 »

I just read this : https://www.thenakedscientists.com/get-naked/experiments/how-we-sense-temperature

Here it is explained how we sense temperature.
But this is wrong.

We dont sense temperature, we sense heat transfer.
Here some explanation from Veritasium :

2

New Theories / Is alzheimer a concequence or a cause ?

« on: 21/09/2022 18:39:46 »

Many studies show that alzheimer is multifactorial.
So like cancer.

But there is no evidence that the symptom (called "Alzheimer") is external to the brain.
We can also suppose that alzheimer is the concequence of "the misuse of ones brain".

To be more explicit.
If you sleep all the day, so you dont use your musculature, it is obvious that your musculature will disapear during time.

Same with the brain abilities.
If someone cant change his mind, and this is what we can call "learning", it is also obvious that if someone dont use his brain usefully this will make the neurones of the brain disapear.
This can be viewed as some physiological adaptation contrary of the actual dogma that say it is some  disease.

Some evidence is that peoples with higher education are likely not to developp Alzheimer.

The benefits of getting a good education may go beyond landing a good job, and continue to pay off long after retirement. Evidence has shown that formal education, like high school and college, may reduce a person’s risk of developing Alzheimer’s.

Research published in 2020 by The Lancet Commission that examined dementia interventions found 7% of worldwide dementia cases could be prevented by increasing early-life education. The study found higher childhood education levels and higher lifelong educational attainment could reduce dementia risk. Exactly how education helps is a mystery, but researchers have several theories.

Never stop learning
The majority of dementia risk studies have examined the benefits of obtaining education early in life. But Okonkwo says some studies have shown that learning new skills and working in jobs that are cognitively complex in mid and late life could also help protect the brain. For example, a 2015 study co-authored by Okonkwo found middle-aged adults who worked in mentally demanding occupations — especially dynamic jobs requiring frequent interaction and socialization with people — had higher cognitive reserve.

https://www.alz.org/news/2021/higher-ed-lower-risk

Where do you stand on the risk scale ?

3

Plant Sciences, Zoology & Evolution / Could a chicken fly?

« on: 20/09/2022 21:12:13 »

All is in the title: Could a chicken fly?

Could it be possible to select generations of chicken for their abilities to fly and finaly produce a "functionning" flying chicken ?

4

New Theories / New Theory - Why are black holes at the centre of galaxies?

« on: 30/08/2022 13:52:16 »

However, the universe is not old enough for the stellar-mass black holes to grow into supermassive black holes (millions to billions of times the mass of our Sun) by individual collisions
- So it is a mystery how the supermassive black holes grew so fast in the early universe, forming the quasars that are visible at high redshift

Yes you are right.

But perhaps this anomaly will be explained soon by some more advanced physic (some extension of the general relativity, the JANUS model of Jean-Pierre Petit).
The big bang model do not hypothesis negativ mass (some physicists tried but failed because they supposed that negative and positiv masses would have some run-away effect).

The paper can be found here : https://www.jp-petit.org/papers/cosmo/2022-HAL-incoherence-trou-noir.pdf
It is actually in french language and some people are actually working on the english translation.
It shows in the first place that the black hole object is not well understood because of initial errors into the schwarzchild formulas and because the full work of schwarzchild is unkwnown by most physicists (because there was no translation until 1990 from german to english after the dead of swharzchild of his second paper...).
In my opinion, every cosmologist should have at least read this new paper so as not to continue the errors.

5

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

« on: 08/08/2022 18:46:05 »

I dont think i really understand your explaination.
Not sure if it is right or wrong but at least you tried to answer the question.

Concerning the "now".
Is there a universal now ?

I think that yes,"everywherewhen" (a new word that should exist if we really understand relativity), there is a "now" that is unambiguous for every point of view.
The proof of that is that everytime someone that had some other point of view would approach the "local position" (in position and in time), he would agree with any other who had some other point of view, of the local reality (when he can understand the transformation from his point of view toward the local reality it would be more easy)

Saying this, the "now" we talk about in special realivity, is only "some illusion" (yes, an illusion has some real visual effect onto the far away observer)  of what happens localy.
But localy we have what we can tell "the now" : The full phenomenon.(not only the light related illusion).

It is not because light can travel the fatsest that it is representativ of the full local reality.

6

Marine Science / Can whales eat when they are in fresh water ?

« on: 07/08/2022 12:43:40 »

I wonder if whales, like dolphins, killer whales or beluga can eat fish when they are in fresh water instead of salty water.
We actually have a beluga in France that is swiming in the Seine river.
Here the video :

Many experts are trying actually to save his life because if he stay too long in fresh water he will die.
Furthermore it looks like he is not feeding.
They have injected the animal something so he will be more hungry.and they have throwed some dead fish so as he can feed. But he dont.
They are also trying to give him live fish, but this doesent work either.

I remember the last case, with some killer whales some month ago.
This whale was starving but he dident eat either.
This one could not be saved.
 
So this is why i ask this :
Is the whale willing to eat fish when the fish is in fresh water ?
Because, if he swallow the fish, so he will also swallow fresh water (i suppose).
Is fresh water toxic for the whale when swalowed in great quantity ?

If the problem is the fresh water, so we could find some solution to help him feeding.

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Physics, Astronomy & Cosmology / Why do we talk about light cones?

« on: 26/06/2022 20:58:56 »

Can someone explain me why we talk about "light cone"  ?
Why the particular angle of the cone and so forth ?

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New Theories / Did we really never observed white holes ?

« on: 19/06/2022 21:41:39 »

White holes are like the white rabbit a young fox has never meet.

They could exist, but nobody has ever seen one.

In general relativity, a white hole is a theoretical region of spacetime and singularity that cannot be entered from the outside, although energy-matter, light and information can escape from it. In this sense, it is the reverse of a black hole, which can be entered only from the outside and from which energy-matter, light and information cannot escape. White holes appear in the theory of eternal black holes. In addition to a black hole region in the future, such a solution of the Einstein field equations has a white hole region in its past.[1] This region does not exist for black holes that have formed through gravitational collapse, however, nor are there any observed physical processes through which a white hole could be formed.

Supermassive black holes (SBHs) are theoretically predicted to be at the center of every galaxy and that possibly, a galaxy cannot form without one. Stephen Hawking[2] and others have proposed that these supermassive black holes spawn a supermassive white hole.[3]

https://en.wikipedia.org/wiki/White_hole

But perhaps we see white holes everyday and we dont realize they are some.
Could it be possible that, as you enter a black hole, saying you reach the schwarzchild radius (i would not recommend this experience and i will explain why further), you would arrive in some special place where... :
If you look back, you see a star ! Instead of the walls of the black hole "like you should observe in a classical 3D hole".
What a surprise ! You realize that in a 4D spacetime, the inside of a hole is indeed  a sphere (like a star)
So you can go around the sphere (orbiting around the star) and in fact you are just orbiting inside, close to the walls of the black hole.

The interresting thing is that Stephen Hawking hypothetised that there could be some "Fire Wall" (this is why i do not recommend to travel trought the black hole) that is very dangerous for the matter.

So if you look at the Sun (yes our sun in our solar system) is it possible that this object is instead of what we think as  "a star" ,the walls seen from the inside of a black hole ?
And this is what we can call a White hole ?

The fire wall could be responsible of the strange behavior of the Sun corona.

Burning questions about the sun’s atmosphere

The visible surface of the sun, or the photosphere, is around 6,000 degrees Celsius (11,000 degrees Fahrenheit). But a few thousand kilometers above it – a small distance when we consider the size of the sun – the solar atmosphere, also called the corona, is hundreds of times hotter. The corona reaches a million degrees C or higher (over 1.8 million degrees F).

This spike in temperature, despite the increased distance from the sun’s main energy source, has been observed in most stars. It represents a fundamental puzzle that astrophysicists have mulled over for decades.

https://earthsky.org/sun/why-suns-atmosphere-hotter-than-its-surface/
 
Some possibility we have to verify this hypothesis could be to measure the gravity close around the sun.
Normaly, like for the earth, if we have what we call a classic star, we should have some slight difference in gravity.
But if it is some quantum object, (so a white hole) the hole should behave like one single object with no "details".
This could help Mercury to orbit so close around the sun.

Furthermore if you fall into a black hole, instead of "falling" toward the center (the singularity) you only enter using your inertia and then you are attracted by the "walls" of the hole if you cant escape the attraction of "the Sun".

What do you think about this ?