Astronomy and Cosmology

Is the more than 3 dimensions often discussed mere mathematical models or do they really eXist

Base on my post in computer engineering, about chatplace technics: ORBITAL SPACE ARRAY With the same kind of device, we could expect to reach Mars by telecommunication system with great bandwidth by only few step, the result will be an array of satellites (at least 6, for redundancy) to be placed in orbit around the Sun, our star, between Earth and Mars. My first estimation gives to me, with an array of 9 X 18-packed coloured LASER, distanced by 115 km. The power will be produced in every single devices, because the power requirement is low, by the detection rate that need only about less than 1E-12 J. We could achieved that without the use of massiv…

https://arxiv.org/pdf/1504.07627.pdf A New Area Law in General Relativity: "We report a new area law in General Relativity. A future holographic screen is a hypersurface foliated by marginally trapped surfaces. We show that their area increases monotonically along the foliation. Future holographic screens can easily be found in collapsing stars and near a big crunch. Past holographic screens exist in any expanding universe and obey a similar theorem, yielding the first rigorous area law in big bang cosmology. Unlike event horizons, these objects can be identified at finite time and without reference to an asymptotic boundary. The Bousso bound is not used, but it…

How are gravitational waves affected by gravitational fields and matter through which the waves pass? What interactions are predicted by mainstream theories? I’m interested in discussing such predictions even if observations or experiments are not (yet) possible. I have some (limited) understanding of how space and matter are affected by a passing gravity wave*. But not the other way around, how matter (and gravity) can affect a gravity wave. *) LIGO

We speculate that stars are moving away. They seem to merge to a single point if we reverse their motions. My question is which of the following caused the moving away. 1) The big bang is an explosion, such that they are moving away due to the explosion 2) They are accelerated away due to a force, the imaginary dark energy 3) It's due to a space expansion. That even the stars can be stationary, it gives a moving effect along with the expansion of universe. This is used to be illustrated by dots on the surface of a balloon. So which one or more than one of the above caused the moving away of the stars.

How big of an object and at what speed is required to majorly f*** the world up?

Is this correct? Just a thought triggered by a another current thread.

That say for example we had the technology to get to mars in hour and the cost of plane ticket!! A mars colony of 500,000 people or million people may not be enough to support it self on mars!! Why? You need. doctors and surgeons nurses dentist construction workers maintenance workers office workers factory workers electrician plumper engineer of all types of fields buildings, bridges, electrical so on water and road workers drug companies people skilled in biology people skinned in chemistry people skilled in physics people skilled in computers and technology teache…

This is how I think humans can best adapt to outer space. What you need for survival is just water-ice. If you can find a large supply of ice on an asteroid of maybe 100 miles in diameter, you can start building your space station there. You can also get a centrifuge rotating at one g gravity for crew quarters. How many g's of gravity would the workers experience working on a 100 mile diameter asteroid? If a 10 mile diameter asteroid has about ONE NANO G. Then a 100 mile diameter asteroid would have about 10 to 20 NANO G's? Anyhow it is so low a gravity that very massive volumes of ice could be moved and processed with minimal amounts of energy. You excavate the i…

I. Star…………………….Type………………Mass Sun=1……Temperature °K EZ Canis Majoris..WN3-hv………….19…………………..89.100 Centaurus X-3………O……………….20.5 ± 0.7………….39.000 η Canis Majores…..B…………………19,19……………….15.000 HD 21389…………….A…………………19,3………………….9.730 Kappa Pavonis……..F………………..19 – 25…………..5,250 - 6,350 V382 Carinae……….G…………………20…………………5,866 S Persei……………….M…………………20……………….3.000-3.600 DH Tauri b..Planet; dist. 330 AU..12 M Jupiter….2.750 HIP 78530 b..Planet; dist. 740 AU..24 M Jup…….2.700 (2.800) II. galaxies....................type galaxies................Speed of galaxies Fast-rotating galaxies RX J1131-1231.......…

I can't understand why heat is transfered differently in low and high mass stars. I read that radiation is more efficient when the gaz is already ionized, meaning it's really hot, then I understand why the core of the Sun is a radiative zone. But I don't see why it wouldn't apply to high mass star? why in this case is the core convective?? Thank you for your help!!

It seems like it may be a nasty fly in the ointment for GR. I know little about the subject and this is probably a stupid question...Could it be regions of negative spacetime curvature? I have heard it described as perhaps something akin to an anti gravity so would that imply negative spacetime curvature? Apologies for the level of ignorance edit: on reflection isn't Dark Energy everywhere and not confined to regions (unlike Dark Matter)? If so ,it couldn't be negative spacetime curvature,could it?

https://www.space.com/astronauts-cancer-space-radiation-risk.html Space Radiation Doesn't Seem to Be Causing Astronauts to Die from Cancer, Study Finds: By Rachael Rettner 2 days ago Human Spaceflight Outer space is a notoriously harsh environment, exposing astronauts to high levels of radiation. And radiation exposure can increase cancer and heart disease rates in earthbound humans. But a new study has some good news: Space radiation doesn't seem to increase astronauts' risk of death from cancer or heart disease, at least not at the doses they experienced during historical missions. Still, longer missions — such a mission to Mars — will likely come w…

"On April 10th 2019, the Event Horizon Telescope (EHT) Collaboration will present its first results in multiple simultaneous press conferences around the world, and many satellite events organized by its stakeholder and affiliated institutions. Press conferences will be held simultaneously in Brussels (in English), Lyngby (in Danish), Santiago (in Spanish), Shanghai (in Mandarin), Tokyo (in Japanese), Taipei (in Mandarin), and Washington D.C. (in English), starting at 13:00 Universal Time [...] Major press conferences will be streamed live online via the following channels: Brussels: European Comission Youtube Channel Tokyo: National Astronomical Observatory o…

https://phys.org/news/2019-07-light-sensing-distant-galaxies-unprecedented.html Light-sensing system could show distant galaxies in unprecedented detail: Researchers at the UCLA Samueli School of Engineering have developed an ultra-sensitive light-detecting system that could enable astronomers to view galaxies, stars and planetary systems in superb detail. The system works at room temperature—an improvement over similar technology that only works in temperatures nearing 270 degrees below zero Celsius, or minus 454 degrees Fahrenheit. A paper detailing the advance is published today in Nature Astronomy. The sensor system detects radiation in the terahertz band of…

I have a theory on why the speed changed on Oumuamua. The object was observed to change speed which is seen as something only intelligent life forms can do,But if Oumuamua were lighter on one side then it may speed up because of light particles pushing off of it.If one side was darker it would absorb light which would slow it down. Maybe i'm wrong i don't know.

Hi! I would like to share with you guys some facts you might not know about antimatter: 1º - Recent studies suggest that an antimatter spacecraft could achieve up to 70% the speed of light, reaching Proxima b in just about 6 years. 2º - The maximum time that antimatter has been stored is 405 days. 3º - According to the former Fermilab physicist Gerald Jackson, antimatter rockets could become a reality by 2050. SPAM DELETED What are your thoughts about antimatter propulsion?

I have come to believe the universe is effectivily a virtual reality machine, but the administrators say its pie in the sky without explaining why, the thread is always closed just as we are getting to the critical juncture. Anyway, if you think I what I am suggesting is fairy tales, fine you are entitled to your own beliefs, but what does science say the universe *is* exactly?

I have just watched "Can We Make it to Mars?" , a Nova DVD from Netflix. My focus of the several problems that hazzard space travel, are cosmic rays. We here on earth are protected from cosmic rays via the magnetic field surrounding earth. However, in a space ship, there is no protection and such rays are of concern to scientists. My question is relative to the anticipated Ion engine (radio waves stimulating Argon gas to ionize, producing a speed that would allow the ship to get to Mars in 39 days instead of the 9 or so months). The program stated that the ion engine would produce such high heat that it must be enclosed in a magnetic field. If that is so, and the…

I refer to this: https://physicsworld.com/a/was-the-universe-born-spinning/ (shortly: as galaxies prefer, by 7%, to spin in a counter-clockwise direction, it means that the overall universe should have a rather large net angular momentum. Since angular momentum is conserved, it seems it [the universe] must have been “born” spinning.). Two questions: 1. Can big bang spin explain slight flatness of Universe? 2. Can somebody calculate, what was the spin speed? Thanks, Kaido

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During what period of time were these planets found? Are these the most recent discoveries? Of all the terrestrial planets found, how many of them are so much like Earth that we could survive on the surface without help from space suits? As far as I know, we have not discovered any Earth 2.0. Maybe that explains the Fermi Paradox?

Hello I want to know which theory is more preferable among astrophysicists about the current expansion of the universe? i mean between cosmological constant or quintessence or something else? and one more thing. what represents the expansion in equations for examining long distances ( megaparsec level ) ? Q? hubble constant? cosmo constant? (and i mean the accelerating expansion. the parameter for accelerating space)

I'm neither thin skinned or religious despite being an ex Catholic Altar Boy! But while parallel universes and simulations etc may be unfalsifiable at this time, they are still scientific speculations...and as far as my knowledge goes, falls into the same category as Hawking Radiation. It has been speculated that various anomalies in spacetime, are evidence for other universes.https://www.space.com/32728-parallel-universes.html Whereas any concept of god or other divine deity, falls under the banner of the supernatural and/or paranormal which is unscientific. But hey, my thinking on the matter could be wrong, so I'm open for correction/s. And of…

https://www.extremetech.com/extreme/227126-neil-degrasse-tyson-says-its-very-likely-the-universe-is-a-simulation At the most recent Isaac Asimov Memorial Debate, recently held at New York’s Hayden Planetarium, scientists gathered to address the question for the year: Is the universe a computer simulation? It’s an older question that you might imagine, and if we interpret it a bit more broadly then it’s really one of the oldest questions imaginable: How do we know that reality is reality? And, if our universe were a big, elaborate lie, could we ever devise some test to prove that fact? At the debate, host and celebrity astronomer Neil deGrasse Tyson argued t…