1

Physics, Astronomy & Cosmology / Re: Can we ever truly describe space as empty?

« on: 20/10/2021 09:00:05 »

Maybe as we learn more about the universe we will need new words to describe new relationships and phenomena. But for now, we don't need to quibble about which word we will use to describe "everything"

I think, we need new words and terms for many notions and concepts, some of them waiting 100 years ('time', 'space', nothingness' and so forth).
Oxford and Webster dictionaries do the job, searching new words around the world, and if a word is new and used and understood in the same way and mostly in many countries (in English), they put it as a candidate to be added to the dictionary.
Scientific definitions look as waiting something new to happen (as we might expect always).
Until then questioning of the terms and definitions are travelling throughout minds and discussions.

2

Physics, Astronomy & Cosmology / Re: What is TIME?

« on: 09/10/2021 09:27:23 »

Isaac Newton presented a point in space and time separately. Meeting someone needs: address (3 - dimensional coordinates) and time - the fourth dimension.
After 200 years Albert Einstein merged spacetime as a 3-dimensional model. Without time as a 4th dimension.
And after 20 years more we’ve got the concept of ‘arrow of time’ by Arthur Eddington.

Arrow of time depending on the stuff in the universe, the microscopic matter and the configurations. Entropy started to grow and will continue to grow for the future.
Arrow of time gives us an impression that time passes, flows, and we progress through different moments.
Past is not more real than the future, the past is that we know more about (any book, memory, fossil, that we can look at) that we believe gives us reliable knowledge of the past. There are no history books written about the future.
We have different access to the past and the future.

A movement in time as in space would presuppose the possibility of moving backwards in time and remaining still in it.
But you cannot remain absolutely still in time (only in relation to some reference systems), and you cannot go back in time (until proven otherwise).

There is no ‘earlier’, ‘now’ and ‘later’. Clock is just doing the same thing over and over again. We might have lived in a universe with the existence of things that are doing the same thing over and over again in a predictable way, which is not taken for granted. Clocks are something that can measure a passage of time. And there are many clocks in the universe, showing different time to a distant observer.

There should not be a confusion of terms and concepts, while going through theories.

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Physics, Astronomy & Cosmology / Re: Astronomy VS astrology

« on: 30/09/2021 09:08:09 »

Reminds me of Timothy Leary or someone trying to sell you a hippy ethos.

It is always possible to dive into Jung and history, to get rid of the sense (in this case).

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Physics, Astronomy & Cosmology / Re: Astronomy VS astrology

« on: 29/09/2021 11:38:48 »

Thanks Tommy J. I find Jordan Peterson very interesting and have watched many of his presentations this one is very informative reveling more than I have considerd befor.

Thank you.
I am glad that it came to the point that right. Likewise I am quite a fan of him

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Physics, Astronomy & Cosmology / Re: Astronomy VS astrology

« on: 29/09/2021 09:15:18 »

‘Astrology has not demonstrated its effectiveness in controlled studies and has no scientific validity,  and is thus regarded as pseudoscience.’ - Wikipedia

But at the same time, for ancients, it was first of all the way of finding regularities, and the way of going beyond the observance and exact knowledge.
 
I like this scientific explanation:

Nowadays, probably, this is a manipulation with known regularities, patterns, an algorithm, which one may jungle in front of the public and show ‘predicted’ things to become true, make people believe in them.

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Physics, Astronomy & Cosmology / Re: Does gravitational time dilation/GTD really cause gravity?

« on: 24/09/2021 10:21:02 »

Everything above helped from all of the participants (Not for me only, I believe).

How much do you simplify at an early age, how much do some teachers really understand their subject?

I have no experience of my own that is enough to compare the oversimplification between generations in physics. But for other key disciplines I would confirm, it is there.

Which is enough to suggest that any quantum field theory for gravity would be unlike anything else you've seen.

Unfortunately, whatever it would be, it is pushed outside the physics’ focus (if I am correct). The vector of physics is about making more precise predictions, not understanding quantization of GR deeper.
It worked for electromagnetism with patches, but didn’t work for gravity.
And gravity is at some point simplified to unknown yet, with the list of ideas.

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Physics, Astronomy & Cosmology / Re: Does gravitational time dilation/GTD really cause gravity?

« on: 23/09/2021 13:14:39 »

Thank you for amendment, Halc.
Right.

The LIGO gravitational waves detection verified that neutron stars merging produced gravitational wave signals during 2 seconds.
The first signal itself was detected as a vibration of the distance between mirrors four kilometres apart. Is it 4 km - for the amplification of the ripples?

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Physics, Astronomy & Cosmology / Re: Does gravitational time dilation/GTD really cause gravity?

« on: 23/09/2021 10:50:06 »

1. Does gravitational time dilation/GTD really cause gravity?
2. "What causes gravity, really"?

1. Gravitational time dilation is a form of time dilation, an actual difference of elapsed time between two events as measured by observers situated at varying distances from a gravitating mass.

Gravity [..] is a consequence of masses moving along geodesic lines in a curved spacetime caused by the uneven distribution of mass.
(Wikipedia)

2. ‘Mass’ here is not necessarily a rest-mass.

Photons have energy, ‘relativistic mass’, which is the source of gravity, not ‘rest mass’. Hence, the energy is the source of gravity.

It is proposed that particles called gravitons cause objects to be attracted to one another. But gravitons have never actually been observed.

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Physiology & Medicine / Re: How Do Isolated Tribes Survive Inbreeding Birth Defects ?

« on: 23/09/2021 09:53:29 »

1. Inbreeding is a problem for tribes with populations near to 50 or below.Tribal customs keep partners' relations far enough.
The European royal lines would be in the endangered group of 50 less.
2. Survivorship bias  has studies on that.
3. They might not be so isolated yet, throughout their history.

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General Science / Re: Do you know where the water you drink has been?

« on: 22/09/2021 13:14:17 »

According to what we know about the Earth formation and extraterrestrial influence of asteroids, comets, etc., during our planets' life, the whole water that we have has been always here.
Hence, we drink the same molecules as our not so far ancestors as well hundreds of millions ones.
Human and not human thirsty species ever inhabited the Earth.

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Physics, Astronomy & Cosmology / Re: Can someone mine 102 tons of coal in 5 hours and 45 minutes w/ 1935 technology?

« on: 17/09/2021 16:08:07 »

I think this whole thing is a Russian attempt to push workers to work harder and achieve the goal of achievement steam power was an industrial achievement long before 1935 in all civilized countries and coal is the main source of fire.

I think so.
By one local example they pushed the industry with hands. That former united area is reach in coal and workers and its output in the end.
Trying to understand leads to depths of history)

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Physics, Astronomy & Cosmology / Re: Can someone mine 102 tons of coal in 5 hours and 45 minutes w/ 1935 technology?

« on: 09/09/2021 13:30:12 »

Commenting the news André Gide asked if that could mean that previously the miners were working just 14 times worse?

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Physics, Astronomy & Cosmology / Re: Lagrangian Mechanics - Why is Nature lazy?

« on: 02/09/2021 19:52:01 »

Why is Nature lazy?   Why does it always want to minimise something?
   What actually makes you so sure there is always a thing, the action, that we can define and Nature would want to minimise that?

Thank you, for understanding and clarifying the question.
My first explanation was rather 'project management' approach: where we are, were we need to get (result), and what time we have to get the result?
Nice that many things in other areas come to differential equations.

The question on the level of biology/chemistry/physics is deeper. Probably they went with experience, knowledge and trials, and the nature of viruses just follows the nature.
1. Do the biologists and chemists use similar equations? (I was always trying to escape with math from that) - needs answer.
2. Why Nature evolution goes like this 'lazy' way and if it does it all the time? - needs answer (probably or approximate hypothesis comes to some of 'energy conservation' and entropy answers?).

14

Physics, Astronomy & Cosmology / Re: How does a diffraction grating really work?

« on: 28/08/2021 13:42:14 »

- Explain that in this case a beam of light is a wave. For the 2 slit demonstration it could be done with 2 wave sources of water (e. g. in a bath). So it means each slit is an identical source.
- Let them know the scale: length for each colour of light-wave.
- CD, laser or holographic sticker sheets might be somewhere near.

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Physics, Astronomy & Cosmology / Re: ESA and NASA are gonna make a partnership in some environmental campaign

« on: 28/08/2021 11:12:07 »

Yes, Goggles translates boggles!
👍
Agreed!

Muscles have a lil memory.
& Tissues too.

But holding meaningful conversation & being clearly communicatively receptive is the art field of the brain.

Ps - The brain is survival, the heart brings meaning & the mind simply exists.
Brains must have evolved for a purpose, other than to simply survive.
🤔

Mark Manson and Rahul Jandial books comprehension (from a glimpse of my bookshelf) might save this argue of P.S.: 'being clearly communicatively - [must have been communicative - my humble opiniion]'.

16

Technology / Re: How to make MILLIONS of people, robots and drones TETHERED

« on: 23/08/2021 09:57:33 »

Bizzare because they try to show up with something that might be surprising. But it need to be developed yet.
Everyday agricultural, 'smart home' things are working.
'Smart city' is working:)
Electroencephalography (EEG) can be obtained by a gadget and sent to your smartphone.

Sending thoughts experiment was much told about. But even sending 'ciao' from brain to brain took too much effort.
It is far from the first whoa (hello) by the telephone.

17

Physics, Astronomy & Cosmology / Re: ESA and NASA are gonna make a partnership in some environmental campaign

« on: 20/08/2021 15:41:08 »

Such kinds of satellites has already been involved in the environmental preservation campaign. Some small space agencies from Europe and from other countries all over the world manufacture microsatellite in order to observe the land

Yes, they have already done.
https://en.wikipedia.org/wiki/List_of_private_spaceflight_companies
From which I checked operational:
Skyrora (Europe)
Rocket Lab (New Zealand)
Virgin Orbit (US)
Northrop Grumman Innovation Systems (US)

18

Physics, Astronomy & Cosmology / Re: If sound could travel through space, what would the Sun sound like?

« on: 16/08/2021 18:47:38 »

How is the sound detected and collected and is the sound that is heard a simulation or the actual sound of the sun?

The Sun’s internal and external plasma movement create the turbulence vibrations, which are captured by Solar and Heliospheric Observatory (SOHO). Data from SOHO, sonified by the Stanford Experimental Physics Lab.
Columns of gases swirl, rise and fall (same way as gases and liquids on Earth), these processes are being tracked inside the Sun.

When we hear sound in the air, we hear vibrations of turbulence (in audible range).
Under water detected sounds are also sped up in order to come to audible range.

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Physics, Astronomy & Cosmology / Re: Is "Space" distinct from "nothingness"? (and the Vacuum)

« on: 10/08/2021 15:28:28 »

  If we take a lead box and it is fully sealed and suck all the air out of it what do we have only the inside walls of the box in space

We would have gravitational attraction between the pieces of lead  that detach themselves from the wall and the remaining walls.(and themselves)

So something is happening within the space .
You make a very interesting point but then again I would expect there are different forms of radiation in the led box and throughout the whole universe so we can not escape there being something But this is the best definition for nothing now not before the big bang or whatever created everything. Mater created time and time creates mater this is the passage of reality before that there was no time no matter no empty space. As incredible as it is that there is a universe at all I think it is just as incredible if not more so that there was nothing at all but that seems to be the way it goes.

Can be also an alternative approach.
Attempts to unify space, time, and matter beyond general relativity introduce additional interactions and extra space-time dimensions.

The Casimir effect is a small attractive force that acts between two close parallel uncharged conducting plates.  It is caused by quantum vacuum fluctuations of the electromagnetic field. The vacuum contains virtual particles which are in a continuous state of fluctuation.
According to the theory, the total zero point energy in the vacuum is infinite when summed over all the possible photon modes. The Casimir effect comes from a difference of energies in which the infinities cancel.
https://math.ucr.edu/home/baez/physics/Quantum/casimir.html

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General Science / Re: Shouldn't we worry about Earth before we try to conquer Mars?

« on: 09/08/2021 09:55:31 »

But do We have a Choice?
Placing all eggs in one basket?
No plan B?

This is always reasonable.
We cannot forget the impact of the 'Planet B' research effort and effect. Actually, it serves the both plans. Space exploration benefits not only colonization, but also observation and the Earth security from cosmos factors (the most like, asteroids danger). The procedures of launches, safety and human adaptation is also important contribution.