beecee

Ancient man, in his/her ignorance and the absence of science, saw magical deities and gods in rivers, mountains, the Sun, Moon etc etc. Do yo still accept that? Of course you don,t! Because science has shown you, and given you logical explanations, models and theories as to how rivers came to be, how the Moon and Sun came to be, and how the Earth came to be. Science has in fact pushed the need for any supernatural/paranormal explanation of the universe back into near oblivion. And of course if you are genuine in your belief in some magical spaghetti monster/god or whatever as an explanation to have created the universe, please tell me who created that magical being? and who created him or her? and who created........ Let me add also that the evidence is so strong for the theory of evolution and the BB, that even the Catholic church have recognised it, although then they again move to their mythical deity. https://www.youtube.com/watch?v=Ag6fH8cU-MU Good for you...You are entitled to accept, or reject anything you like and accept whatever myth you like to give you that deep, warm inner glow and good feeling. So why did you came here to share it with us? I prefer science, logic and reason.

The speed of light in any medium is actually still the same as it is in a vacuum. In essence photons are reflected, refracted, absorbed and re-emitted and have longer paths to traverse, hence the "apparent" slowing in the observed speed of light from outside. My above reasoning and answer may need tidying up some, but I still believe in essence any photon of light can only ever traverse at "c'

Like near all that come to science forums, open to any Tom, Dick and Harry, to yet again claim some renowned incumbent theory is wrong, you do so on baseless and in your case misunderstood scenarios. Time certainly is relative, as is space. Neither fact detracts from the BB model of universal/spacetime evolution. Whether you are sitting where you are behind a computer screen on Earth, whether you are in a gigantic gravity well of a BH, each FoR and each calculation/s is as valid as any other. That's GR, and like the BB it still stands as the overwhelmingly supported model of the universe/spacetime we live in. The other point where you seem to err drastically is in claiming that one is ignoring some crucial part of reality due to some difference in precision. We still use Newtonian mechaics in near every operational aspect on Earth and near all space endeavours also. We simply do not need the precision as detailed in GR. Why? It seems from where I sit that you are shown to be wrong everyday. You are measuring a window frame in a house...Do you use a pair of Vernier calipers?

Like the OP, this post is riddled with silly assumptions and even sillier mistakes..... Firstly, we have known for quite a while now that science/cosmology has seen the need for some apparently unseen matter which we now call DM. Check out Fritz Zwicky around the early 1930's. Since then we have seen plenty of evidence of DM, not the least being "the bullet cluster" observation and gravitational lensing by DM. Secondly Einstein's theories actually are far more accepted now then they ever were, simply because they have continued aligning with experimental results and observations, and continue making successful predictions. Have you heard of gravitational waves? Thirdly, you seem rather confused as to what a scientific theory really is and what it entails. They can be modified, added to and continually reinforced by further evidence as per Einstein's theories which you appear to have no idea about. Fourthly I really think that what "knowledge" you apparently believe you do have re the OP and DM , has been gathered from tabloid press headlines, questionable u tube videos and other less then reputable wells of knowledge.

See https://www.scienceforums.net/topic/114532-witnessing-a-galactic-pileup/?tab=comments#comment-1049945

Vinaka Mordred, much appreciated.

And just to add my 2cents worth, doesn't light when traversing also warp/curve spacetime itself, albeit ever so slightly. So according to that 2 cents worth, it would be a different path. and which Mordred seems to be saying here.

https://phys.org/news/2018-04-astronomers-witness-galaxy-megamerger.html Peering deep into space—an astounding 90 percent of the way across the observable universe—astronomers have witnessed the beginnings of a gargantuan cosmic pileup, the impending collision of 14 young, starbursting galaxies. This ancient megamerger is destined to evolve into one of the most massive structures in the known universe: a cluster of galaxies, gravitationally bound by dark matter and swimming in a sea of hot, ionized gas. Read more at: https://phys.org/news/2018-04-astronomers-witness-galaxy-megamerger.html#jCp The results are published in the journal Nature. <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> the paper: https://www.nature.com/articles/s41586-018-0025-2 A massive core for a cluster of galaxies at a redshift of 4.3: Abstract Massive galaxy clusters have been found that date to times as early as three billion years after the Big Bang, containing stars that formed at even earlier epochs1,2,3. The high-redshift progenitors of these galaxy clusters—termed ‘protoclusters’—can be identified in cosmological simulations that have the highest overdensities (greater-than-average densities) of dark matter4,5,6. Protoclusters are expected to contain extremely massive galaxies that can be observed as luminous starbursts7. However, recent detections of possible protoclusters hosting such starbursts8,9,10,11 do not support the kind of rapid cluster-core formation expected from simulations12: the structures observed contain only a handful of starbursting galaxies spread throughout a broad region, with poor evidence for eventual collapse into a protocluster. Here we report observations of carbon monoxide and ionized carbon emission from the source SPT2349-56. We find that this source consists of at least 14 gas-rich galaxies, all lying at redshifts of 4.31. We demonstrate that each of these galaxies is forming stars between 50 and 1,000 times more quickly than our own Milky Way, and that all are located within a projected region that is only around 130 kiloparsecs in diameter. This galaxy surface density is more than ten times the average blank-field value (integrated over all redshifts), and more than 1,000 times the average field volume density. The velocity dispersion (approximately 410 kilometres per second) of these galaxies and the enormous gas and star-formation densities suggest that this system represents the core of a cluster of galaxies that was already at an advanced stage of formation when the Universe was only 1.4 billion years old. A comparison with other known protoclusters at high redshifts shows that SPT2349-56 could be building one of the most massive structures in the Universe today. ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Three questions arising from this article and paper. I have highlighted the relevant sentences. [1] Is this further evidence for DM? [2]Forming stars up to a 1000 times faster than our own galaxy....because of the abundance of accreting hydrogen [and helium] gas I presume? [3] Re all these starburst galaxies lying at 4.31 redshift....I'm pretty sure we have observed galaxies at far greater redshifts...up to 7, 8 and 9 in fact. Awesome cosmological science sure, but other then the observation of a galactic pileup, what is the real significance of this? [I'm probably missing something]

https://phys.org/news/2018-04-team-aims-nasa-telescope-capture.html Team aims to use new NASA telescope to capture light from the first stars to be born in the universe About 200 to 400 million years after the Big Bang created the universe, the first stars began to appear. Ordinarily stars lying at such a great distance in space and time would be out of reach even for NASA's new James Webb Space Telescope, due for launch in 2020. However, astronomers at Arizona State University are leading a team of scientists who propose that with good timing and some luck, the Webb Space Telescope will be able to capture light from the first stars to be born in the universe. Read more at: https://phys.org/news/2018-04-team-aims-nasa-telescope-capture.html#jCp <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> the paper: http://iopscience.iop.org/article/10.3847/1538-4365/aaa760/meta On the Observability of Individual Population III Stars and Their Stellar-mass Black Hole Accretion Disks through Cluster Caustic Transits: Abstract: We summarize panchromatic Extragalactic Background Light data to place upper limits on the integrated near-infrared surface brightness (SB) that may come from Population III stars and possible accretion disks around their stellar-mass black holes (BHs) in the epoch of First Light, broadly taken from z 7–17. Theoretical predictions and recent near-infrared power spectra provide tighter constraints on their sky signal. We outline the physical properties of zero-metallicity Population III stars from MESA stellar evolution models through helium depletion and of BH accretion disks at . We assume that second-generation non-zero-metallicity stars can form at higher multiplicity, so that BH accretion disks may be fed by Roche-lobe overflow from lower-mass companions. We use these near-infrared SB constraints to calculate the number of caustic transits behind lensing clusters that the James Webb Space Telescope and the next-generation ground-based telescopes may observe for both Population III stars and their BH accretion disks. Typical caustic magnifications can be , with rise times of hours and decline times of year for cluster transverse velocities of km s−1. Microlensing by intracluster-medium objects can modify transit magnifications but lengthen visibility times. Depending on BH masses, accretion-disk radii, and feeding efficiencies, stellar-mass BH accretion-disk caustic transits could outnumber those from Population III stars. To observe Population III caustic transits directly may require monitoring 3–30 lensing clusters to mag over a decade.

https://phys.org/news/2018-04-blocks-life-space.html How the building blocks of life may form in space April 25, 2018, American Institute of Physics Low-energy electrons, created in matter by space radiation (e.g., galactic cosmic rays, GCR, etc.), can induce formation of glycine (2HN-CH2-COOH) in astrophysical molecular ices; here, icy grains of interstellar dust (or ices on planetary satellites) are simulated by ammonia, methane and carbon dioxide condensed at 20 K on Pt in UHV, and irradiated by 0-70 eV LEEs. CREDIT: Public domain image from NASA, Hubble, STScI. Star forming region (Pillars of Creation) in the Eagle Nebula. Credit: American Institute of Physics (AIP) In a laboratory experiment that mimics astrophysical conditions, with cryogenic temperatures in an ultrahigh vacuum, scientists used an electron gun to irradiate thin sheets of ice covered in basic molecules of methane, ammonia and carbon dioxide. These simple molecules are ingredients for the building blocks of life. The experiment tested how the combination of electrons and basic matter leads to more complex biomolecule forms—and perhaps eventually to life forms.Read more at: https://phys.org/news/2018-04-blocks-life-space.html#jCp >>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<< the paper: https://aip.scitation.org/doi/10.1063/1.5021596 Glycine formation in CO2:CH4:NH3 ices induced by 0-70 eV electrons ABSTRACT Glycine (Gly), the simplest amino-acid building-block of proteins, has been identified on icy dust grains in the interstellar medium, icy comets, and ice covered meteorites. These astrophysical ices contain simple molecules (e.g., CO2, H2O, CH4, HCN, and NH3) and are exposed to complex radiation fields, e.g., UV, γ, or X-rays, stellar/solar wind particles, or cosmic rays. While much current effort is focused on understanding the radiochemistry induced in these ices by high energy radiation, the effects of the abundant secondary low energy electrons (LEEs) it produces have been mostly assumed rather than studied. Here we present the results for the exposure of multilayer CO2:CH4:NH3 ice mixtures to 0-70 eV electrons under simulated astrophysical conditions. Mass selected temperature programmed desorption (TPD) of our electron irradiated films reveals multiple products, most notably intact glycine, which is supported by control measurements of both irradiated or un-irradiated binary mixture films, and un-irradiated CO2:CH4:NH3 ices spiked with Gly. The threshold of Gly formation by LEEs is near 9 eV, while the TPD analysis of Gly film growth allows us to determine the “quantum” yield for 70 eV electrons to be about 0.004 Gly per incident electron. Our results show that simple amino acids can be formed directly from simple molecular ingredients, none of which possess preformed C—C or C—N bonds, by the copious secondary LEEs that are generated by ionizing radiation in astrophysical ices

Earth travellers would certainly have a far more involved and difficult task in slowing down for a Martian landing [as various probes have shown] then taking off again.

https://www.youtube.com/watch?v=MO0r930Sn_8

I have often thought of the same scenario. Also obviously if any future Earth space traveller wanted to land on a super Earth, he would have double trouble in trying to slow down enough for a safe landing, and then obviously far more then the 9.8mtrs/sec2 to overcome when taking off again.

Light is what we describe as the part of the EMS that is visible to the eye. The speed of light "c" most certainly is the universal speed limit. This essentially means that there is no universal "NOW" and what you see now of the Sun for example, is light that left it 8.25 minutes ago. We are looking into the past at varying degrees, every time we look at the stars in the night sky. The rate of expansion the last time I looked was about 70kms/sec/Mega parsec. While all matter in the universe including BHs will decay to their most fundamental parts, it is unknown as to whether the universe/spacetime is infinite or finite. We can say with some certainty that the universe we observe, is around 48 billion L/years in radius, and it extends well beyond this to that part of the universe we are unable to observe.

I'll certainly accept that correction to what I posted. The mere fact that life exists, is actually scientific evidence of abiogensis

Wrong. The current overwhelming accepted cosmology of the universe called the BB says nothing about any multiple universe. At this stage that is just speculation. Science/cosmology is a discipline in continued progress...the further we see, the more we see, the better access to instruments etc are a result of advancing technology. What we observe today certainly has changed our picture of the universe, compared to past epochs that lacked the technological equipment to delve deeper. eg: Hubble and his new "scope showed that the MW was not the whole universe, and that it [the universe] was also expanding. It also has added on and reinforced past cosmological thought. eg: we once only hypothesised about possible planets orbiting distant star systems like our own Sun. Now we know there is in excess of 3000 extra solar planets that we have observed so far. The fact that science is a discipline in eternal progress is why it is our greatest aspect of human endeavour and is responsible for the advancement and knowledge today and surpasses and replaces the old myths of creationism and other supernatural nonsense of the past.

My assertions are not my assertions. They are simply the theoretical application of overwhelming observational evidence. But as per usual, and as is evidenced in the vast amount of evidenced based cosmology that you reject and infest with your nonsensical remarks, it is obvious you are here, simply to preach and infer your mythical supernatural nonsense. The only misrepresentation being undertaken is by yourself, driven by what you see as some evangelistic crusade against the evils of science for extinguishing your mythical supernatural deity in explaining the universe. Your assumption as usual would be incorrect since it is not based on science nor the scientific methodology. Pot, kettle black....I'm really not sure about who you believe you are fooling, other then yourself and your baggage. You are the only one responsible for the stupidity you post. The only struggle I observe is your own inner struggle and angst in the fact that observational cosmology, astronomy and science in general has demoted the creationist myths that still plague you.

The evidence is overwhelming and concrete thus far that stars are simply distant Suns at various stages of their life and of various sizes, and your usual baseless doubts on this scientific issue among the many others you have, actually mean nothing. http://www.astro.keele.ac.uk/workx/starlife/StarpageS_26M.html

We have no evidence of there existence but they are a prediction of GR. And if they did exist, we would have great difficulties and problems in using them as a time machine.

What he is saying is interesting to say the least, and certainly food for thought. I would like to see him in a debate with, say Laurence Krauss.

My crack re being a hard task master was in reference to the theory of evolution. That can be said to be done and dusted. How life first arose, is another matter: On Earth? Either some mechanism in relation to an ancient pond of goo and possible lightning strike, or some other variation, or via Panspermia: ie, Life arose elsewhere in the universe and was transported to Earth via asteroids/comets etc. But certainly as yet we have no evidence for any form of Abiogenesis, although as I said, scientifically speaking, it is the only answer .

Firstly, with regards to the thread title, I would say that at least in the "hay day" of UFO sightings, there certainly was scientific research into the phenomena. Then as people's imaginations were stirred, many started to see so called UFO's in ever increasing numbers. You obviously also agree that 95% or thereabouts have been explained away by unusual weather events and astronomical sightings such as the planet Venus. So can you really blame scientists when their attitude is "here we go again" and the usual when someone reports a supposed sighting? Again as I said in the other thread, started by an obviously very impressionable type of character, why do these Alien characters [if Aliens are involved] keep flittering in and flittering out again, grabbing the odd individual for some anal probing, and generally scaring the daylights out of people, and not make themselves officially known? And then we have the time and distance barriers, while you yourself doubted we could ever achieve any type of warp travel.Thirdly of course is that often confusion by imressionable people of equating "unidentified or unknown with Alien. Extraordinary claims require extraordinary evidence: Carl Sagan. And obviously over the many years of these sightings, that extraordinary evidence has never been forthcoming, rather the usual blurry images of objects and second hand accounts. Can we reasonably expect science to keep on wasting manpower and time on supposed sightings by any Tom, Dick or Harry? Here are some photos that could be mistaken for UFO's and many more here..... https://www.google.com.au/search?q=photos+of+weird+weather+phenomena&tbm=isch&source=iu&ictx=1&fir=I1x2bU_MTxJU7M%3A%2CGP12OkT1wxXoJM%2C_&usg=__9XrxEFelLtNa3Fqv44B976jzSGA%3D&sa=X&ved=0ahUKEwiXocqcnMzaAhXKT7wKHTdTDyEQ9QEIOzAJ#imgrc=I1x2bU_MTxJU7M: then we have.... from...https://www.space.com/39200-spacex-rocket-launch-not-ufo-spectactular-photos.html and this.... from...http://www.mlive.com/news/us-world/index.ssf/2017/05/military_flares_over_lake_onta.html and the Queen of mistaken UFO claims! http://www.astronomyufo.com/UFO/Venusufo.htm Let me finish off by saying that as an old bastard, my two greatest wishes before I kick the bucket are [1] Manned Mars Landing, and [2] Confirmation [extraordinary evidence or contact] of some form of extra terrestrial life.

I,m an optimist Moontanman...truly! I certainly am of the opinion that avoiding any catastrophic astronomical event, and our own Earthly follies, and given the time, we should be able to achieve most of what is allowed for by the laws of physics and GR. That includes possible warp travel by manipulating spacetime. JPL also has this a a future production means, but they still realize that it is probably a millenium off as yet, if it is at all possible to achieve...Dyson spheres, space elevators, etc are also futuristic human dreams and possibilities. Asteroid mining another, although this maybe just around the corner. All are theoretically possible, but all [other then asteroid mining] still a fair way off as yet.

Here is an interesting article, pertaining to the many "would be's if they could be's" who claim Einstein is wrong..... https://phys.org/news/2014-01-einstein-wrong.html Why Einstein will never be wrong: One of the benefits of being an astrophysicist is your weekly email from someone who claims to have "proven Einstein wrong". These either contain no mathematical equations and use phrases such as "it is obvious that..", or they are page after page of complex equations with dozens of scientific terms used in non-traditional ways. They all get deleted pretty quickly, not because astrophysicists are too indoctrinated in established theories, but because none of them acknowledge how theories get replaced. Read more at: https://phys.org/news/2014-01-einstein-wrong.html#jCp extract from article...... "To begin with, Einstein's gravity will never be proven wrong by a theory. It will be proven wrong by experimental evidence showing that the predictions of general relativity don't work. Einstein's theory didn't supplant Newton's until we had experimental evidence that agreed with Einstein and didn't agree with Newton. So unless you have experimental evidence that clearly contradicts general relativity, claims of "disproving Einstein" will fall on deaf ears. The other way to trump Einstein would be to develop a theory that clearly shows how Einstein's theory is an approximation of your new theory, or how the experimental tests general relativity has passed are also passed by your theory. Ideally, your new theory will also make new predictions that can be tested in a reasonable way. If you can do that, and can present your ideas clearly, you will be listened to. String theory and entropic gravity are examples of models that try to do just that". Read more at: https://phys.org/news/2014-01-einstein-wrong.html#jCp

Yep, but at this time, we do not have the necessary technology to achieve anything like it. Let me sum up at this time... I'm not debating whether life exists elsewhere....I'm sure it does I'm not debating that individuals and/or groups have witnessed UFO's...I'm sure they have, including myself. I am being critical that some seem to automatically equate unidentified with Alien origin. I am being critical of the fact that some claim Earth has been visited by Aliens: That may well be true, but we do not have the necessary extraordinary evidence to support that supposed visitation. The greatest educator of our time, Carl Sagan was renowned for debunking supposed UFO's and Aliens, but the same man also firmly believed we were/are not alone. It was his idea of the plaques on the Voyager probes. https://www.youtube.com/watch?v=YEaucytiEwM