Astronomy/Space Exploration

Buster15

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Yup all fair, plus water itself is a great radiation shield. Supposedly next gen telescopes (ground based as well as Webb) will be able to detect life signals from atmospheres.

But the problem remains that half the variables are basically untestable, you need extensive data on other civilisations in the galaxy which is what you're trying to find out in the first place. It's interesting as a thought experiment, plugging your own guesses in and seeing what comes out, but you can't really use it beyond that.
Agreed. In principle an Equation should give you a specific answer.
But as you quite rightly say, it would be the discovery of other civilizations that is the key thing.
It is nonetheless a well defined set of variables within the equation. Someone has to start somewhere.
Have you by any chance read Brian Cox book the Human Universe. Reason I ask is that he covers the number of key stages or more specifically bottlenecks that life had to go through to go from single cell organisms through to humans. Very interesting to understand.
 

Invictus

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https://www.theguardian.com/science/2019/oct/11/alexei-leonov-space-walk-human-death-cosmonaut-russia

Alexei Leonov, the legendary Soviet cosmonaut who became the first human to walk in space 54 years ago, has died in Moscow at 85.

The Russian space agency Roscosmos announced the news on its website on Friday, but gave no cause of death. Leonov had health issues for several years, according to Russia media.

Showing just how much of a space pioneer Leonov was, Nasa interrupted its live televised coverage of a spacewalk by two Americans outside the International Space Station to report Leonov’s death.

“A tribute to Leonov as today is a spacewalk,” Mission Control in Houston said.

Leonov was an icon both in his country as well as in the US, so much so that the late science fiction writer Arthur C Clarke named a Soviet spaceship after him in his 2010 sequel to 2001: A Space Odyssey.

The Russian president, Vladimir Putin,sent his condolences to Leonov’s family, calling him a “true pioneer, a strong and heroic person”.

Leonov staked his place in space history on 18 March 1965, when he exited his Voskhod 2 space capsule secured by a tether.

“I stepped into that void and I didn’t fall in,” the cosmonaut recalled years later. “I was mesmerised by the stars. They were everywhere – up above, down below, to the left, to the right. I can still hear my breath and my heartbeat in that silence.”

Spacewalking always carries a high risk but Leonov’s pioneering venture was particularly nerve-racking, according to details of the exploit which only became public decades later.

His spacesuit had inflated so much in the vacuum of space that he could not get back into the spacecraft. He had to open a valve to vent oxygen from his suit to be able to fit through the hatch.

Leonov’s 12-minute spacewalk preceded the first US spacewalk, by Ed White, by less than three months.
 

Ubik

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Casual gif of a planet twice the size of Jupiter orbiting its star, 97 light years away.
 

Buster15

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There is much conjecture as to whether Gravity is actually a force. But in principle there is no specific reason why additional forces should not exist. In particular Dark Energy and Dark Matter constitute the majority of the known universe.
Reading the article, the Electron is a hugely interesting particle despite its quantum size.
 

Buster15

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PedroMendez

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Fascinating. I can't see the theory of everything being too far off at this point.
nvm the clickbaity nature of the article, the chances of this paper holding up are close to zero.

On a different note, the minimal requirement of "a theory of everything" is a cohesive description of gravity and QM and nobody can seriously predict when/how this is going to happen.
 

Raoul

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nvm the clickbaity nature of the article, the chances of this paper holding up are close to zero.

On a different note, the minimal requirement of "a theory of everything" is a cohesive description of gravity and QM and nobody can seriously predict when/how this is going to happen.
Very negative Pedro. Sad! :(
 

rcoobc

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Venus beautiful right next to the moon tonight. Just gone over the horizon for us on the UK
 

Buster15

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Fascinating. I can't see the theory of everything being too far off at this point.
That assumes that there is a theory about everything waiting to be discovered.
We have to accept that the laws of physics including quantum mechanics are not there for our convenience and don't have to be understood. They are what they are be it understandable or totally elusive.
 

Raoul

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That assumes that there is a theory about everything waiting to be discovered.
We have to accept that the laws of physics including quantum mechanics are not there for our convenience and don't have to be understood. They are what they are be it understandable or totally elusive.
True, but I don't think its particularly wise to approach things from the "what if it doesn't exist at all" perspective. We have to follow the facts and research to where they lead us, and given rapid advancements in technology, it wouldn't at all be outside the realm of possibility that we are nearing a point of breaking through to another level of understanding. Also, these things often happen by accident - just look at Suskind's' supposition that String Theory shouldn't have even existed until the 2030s or beyond, if not for an improbable series of events that happened in the 1960s.
 
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Buster15

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True, but I don't think its particularly wise to approach things from the "what if it doesn't exist at all" perspective. We have to follow the facts and research to where they lead us, and given the rapid advancements in technology, it wouldn't at all be outside the realm of possibility that we are nearing a point of breaking through to another level of understanding. Also, these things often happen by accident - just look at Suskind's' supposition that String Theory shouldn't have even existed until the 2030s or beyond, if not for an improbable series of events that happened in the 1960s.
That is very fair.
I wasn't trying to be pessimistic.
But due to the vagaries and uncertainty principles of QM, even a full understanding of QM could be difficult.
But you are right that given time and human ingenuity anything is possible.

Quick question. What is your primary scientific interest.
Mine is a better understanding of the event termed the big bang.
 

Raoul

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That is very fair.
I wasn't trying to be pessimistic.
But due to the vagaries and uncertainty principles of QM, even a full understanding of QM could be difficult.
But you are right that given time and human ingenuity anything is possible.

Quick question. What is your primary scientific interest.
Mine is a better understanding of the event termed the big bang.
I'm generally all over the map in terms of interests.

- Cosmic inflation and whether our perceptions of the Universe (observable and beyond) is a result of inflation (in the Alan Guth sense) that created repulsive gravity and the conditions of the universe today - or whether there's an alternative explanation.

- Black Holes - what they really are (an evolving topic) and how it applies to our (also evolving) understanding of the Universe.

- QM and String Theory - There's been a bit of recent work by a few Israeli researchers looking into whether temporal entanglement is a real phenomenon. The idea that particles are entangled across space has been around for decades, the idea that they are also entangled over time is fairly new and would have some fascinating repercussions.

- Also interested in more research into Bohmian Mechanics (Pilot Wave Theory).
 

PedroMendez

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Very negative Pedro. Sad! :(
https://arxiv.org/abs/2001.00101

it might or might not interest you. Its about physics in general. The author is a very accomplished high energy physicist. Its in the form of a paper on arxiv, but it really is just his opinion about the state of parts of physics. Its easy to understand with the exception of p.7/8-11, where a lot of technical terms are getting used. (he describes very specific areas, where progress is made)

Some excerpts below

The seven years that have elapsed since [1] brought new perspectives: (...) I would say that the most important message we have received is the absence of dramatic or surprising new results. In HEP no significant experimental findings were reported,2 old ideas concerning Beyond the Standard Model (BSM) physics hit dead-ends one after another and were not replaced by novel ideas. Hopes for key discoveries at the LHC (such as superpartners) which I mentioned in 2012 are fading away. Some may even say that these hopes are already dead. Low energy-supersymmetry is ruled out, and gone with it is the concept of naturalness, a basic principle 3 which theorists cherished and followed for decades.
(In Fig. 1 I present a simplified picture of the Quantum Tree.)
Particle physics and HEP gave birth to string theory. At birth the baby was christened “Veneziano amplitude” [5]. It grew into a powerful branch which made many believe that the “theory of everything” is around the corner. Well... it never happened and – I will risk to say – never will.
The theorists involved went far beyond exploring our world. One can say that today’s theorists mainly investigate imaginary worlds, the worlds which might have existed as an alternative to our world being somewhat similar to ours.9 The degree of similarity may vary, from very similar to our world (e.g. changing the number of colors and space-time dimensions is quite fruitful, so we are happy) to mildly fantastic (e.g. adding supersymmetry), to those which – I am afraid – could be characterized as “El sueño de la razón produce monstruos.”
I hope that young people currently entering the area will focus more on the established mysteries of nature (e.g. dark matter) than in the 1990s’ and early 2000s. I expect that on the way they will discover new mysteries (Fig. 3). Perhaps, they will come to a new scientific paradigm. Thinking boldly, why not imagine that quantum mechanics gives place to something else at shorter distances? Or a milder statement: why not replace the concept of naturalness by the following: As we move in the UV all interactions (including gravity) must remain weak? Perhaps, the information loss paradox in evaporating black holes might be solved, perhaps...

Its quite astonishing how influential the idea of naturalness has been and still is. As far as I understand it, its not required by anything.
 

Edgar Allan Pillow

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https://www.universetoday.com/144618/a-second-planet-may-have-been-found-orbiting-proxima-centauri-and-its-a-super-earth/

A Second Planet May Have been Found Orbiting Proxima Centauri! And it’s a Super Earth.

Astronomers have discovered another candidate exoplanet orbiting our neighbor, Proxima Centauri. A paper announcing these results was just published in the journal Science Advances. If confirmed, it will be the second exoplanet orbiting the star. The discovery of a second planet, even though it’s likely too far away from its star for liquid water, is intensifying interest in the PC system.