Star Talk: Dark Matter and Dark Energy

We know it by it's gravity

How do you mean? The expansion of the universe is accelerating. That isn't a fluke.

 

That's what I said.

We observe that. But we have no idea why, in fact it's in direct contradiction to known theory.

So to "explain" it, we abuse the equations of General Relativity by adding a "cosmological constant" that represents a uniform density of "dark energy" which would make the Universe expand faster.

In fact, there's dark energy all around us. Kind of like the Force.

We're entering the real of speculative physics where nobody knows what they're doing

 

I mostly agree, though we don't know that dark energy is homogeneous throughout space. The expansion appears to be greatest in areas void of mass, in the regions between galactic clusters.

It contradicts a theory based on a false premise due to an assumption. Ironically, the error for the rate of change of the expansion was always greater than the rate of change itself. From the first measurement, it was within the margin of error that the rate of the expansion was increasing. But since we had no way to account for that result, it was assumed that the acceleration was negative.

I used to argue with other scientists that our confidence in the existing models is far too great. Many people seemed to believe that physics was about complete. Then we discovered that we not only missed 95% of the universe, but also there is some force that dominates the entire universe at large scale, that can't begin to explain. HAH!!!

I happened to be going through Atlanta airport on my way back from a job in Peru, when I ran into a group of physicists who had just attended one of the major gatherings of physicists. They had just heard the first papers presented showing evidence for the increasing rate of expansion. I told them my background is in physics and joined the discussion. So I found out about it completely by chance, right from the horse's mouth, only hours after the evidence was first presented. How cool is that?!

 

PS. Also on a fluke, I was there when Fleischmann and Pons first presented their "cold-fusion" paper to the AES. How cool is that?!

 

I don't know the answer, but it's a valid question.

 

Look, I say stuff you don't want to hear because it makes you realise that they're making an idiot of you, and I can quite understand your intemperate outburst; but don't blame me for your childlike gullibility ffs, blame yourself. If it's any consolation to you though, you're not alone - there are more of your kind than mine, many many more: and as to that, read one of my signatures? I don't need to tell you which one, I presume? Oh and I don't troll science threads, I troll fake-science posts. See the difference?

 

Fire off an email to NASA - they'll tell you what the answer is.

 

Published by NASA or some other 'space agency' is it. Is there nothing these disciples won't believe?

 

I find this kind of stuff fascinating. I just wish I could understand it more. I have a hard time understanding the dark matter, black holes, etc. Maybe you have to be an expert in physics or something to understand. To me, once they start to get technical, I am totally lost. Lol! I think the universe is incredibly interesting and fascinating though. I love the pictures of constellations and stuff that NASA puts out. They are just AMAZING.

 

What a load of crap. How can anyone say if the universe is expanding? How can they measure whether it's expanding, contracting, or stable - answer me that?

 

red shift.

 

And your opinion means something because... you have vodka?

 

I'm tee-total. Take another guess?

 

Agreed the universe is interesting and fascinating. Much of the science stuff is above my education level, but we don't have to understand how satellite WiFi works for us to use it. NASA has done a lot of great work and provided nearly immeasurable benefits to mankind.

https://www.nasa.gov/content/benefits-for-humanity-changing-lives/
Here are 15 ways the space station is benefiting life on Earth:

Commercializing low-Earth orbit
An exciting new commercial pathway is revolutionizing and opening access to space, fostering America’s new space economy in low-Earth orbit. For the first time, the market is expressing what research can and should be done aboard the microgravity laboratory without direct government funding. The Center for Advancement of Science in Space, or CASIS, manages half of the crew research time via the ISS National Laboratory and is filling the pipeline with a wide variety of commercial research and payloads. More than two-thirds of these projects to date have required zero funding from CASIS, and that trend is increasing. In addition, a significant portion of the commercial research taking place aboard the station is made possible by NanoRacks hardware. The company has invested privately and raised capital to provide laboratory facilities for small payloads, including CubeSats deployed from the space station, that make research faster and more affordable. NASA’s move to purchase commercial cargo resupply and crew transportation to the space station enables U.S. businesses to develop a competitive capability they also can sell as a service to others while freeing NASA resources for deep space exploration. Private sector participation provides a new model for moving forward in partnership with the government.

Supporting water purification efforts worldwide
Whether in the confines of the International Space Station or a tiny hut village in sub-Saharan Africa, drinkable water is vital for human survival. Unfortunately, many people around the world lack access to clean water. Using technology developed for the space station, at-risk areas can gain access to advanced water filtration and purification systems, making a life-saving difference in these communities. Joint collaborations between aid organizations and NASA technology show just how effectively space research can adapt to contribute answers to global problems. The commercialization of this station-related technology has provided aid and disaster relief for communities worldwide. The Water Security Corporation, in collaboration with other organizations, has deployed systems using NASA water-processing technology around the world.

Growing high-quality protein crystals
There are more than 100,000 proteins in the human body and as many as 10 billion in nature. Every structure is different, and each protein holds important information related to our health and to the global environment. The perfect environment in which to study these structures is space. Microgravity allows for optimal growth of the unique and complicated crystal structures of proteins leading to the development of medical treatments. An example of a protein that was successfully crystallized in space is hematopoietic prostaglandin D synthase (H-PGDS), which may hold the key to developing useful drugs for treating muscular dystrophy. This particular experiment is an example of how understanding a protein’s structure can lead to better drug designs. Further research is ongoing.

Bringing space station ultrasound to the ends of the Earth
Fast, efficient and readily available medical attention is key to survival in a health emergency. For those without medical facilities within easy reach, it can mean the difference between life and death. For astronauts in orbit about 250 miles above Earth aboard the International Space Station, that problem was addressed through the Advanced Diagnostic Ultrasound in Microgravity (ADUM) investigation. In partnership with the World Interactive Network Focused on Critical Ultrasound (WINFO-CUS), ADUM principal investigator Scott Dulchavsky, M.D., is taking techniques originally developed for space station astronauts and adapting them for use in Earth’s farthest corners by developing protocols for performing complex procedures rapidly with remote expert guidance and training. Medical care has become more accessible in remote regions by use of small ultrasound units, tele-medicine, and remote guidance techniques, just like those used for people living aboard the space station.

Improving eye surgery with space hardware
Laser surgery to correct eyesight is a common practice, and technology developed for use in space is now commonly used on Earth to track a patient’s eye and precisely direct the laser scalpel. The Eye Tracking Device experiment gave researchers insight into how humans’ frames of reference, balance and the overall control of eye movement are affected by weightlessness. In parallel with its use on the space station, the engineers realized the device had potential for applications on Earth. Tracking the eye’s position without interfering with the surgeon’s work is essential in laser surgery. The space technology proved ideal, and the Eye Tracking Device equipment is now being used in a large proportion of corrective laser surgeries throughout the world.

Making inoperable tumors operable with a robotic arm
The delicate touch that successfully removed an egg-shaped tumor from Paige Nickason’s brain got a helping hand from a world-renowned arm—a robotic arm, that is. The technology that went into developing neuroArm, the world’s first robot capable of performing surgery inside magnetic resonance machines, was born of the Canadarm (developed in collaboration with engineers at MacDonald, Dettwiler, and Associates, Ltd. [MDA] for the U.S. Space Shuttle Program) as well as Canadarm2 and Dextre, the Canadian Space Agency’s family of space robots performing the heavy lifting and maintenance aboard the International Space Station. Since Nickason’s surgery in 2008, neuroArm has been used in initial clinical experience with 35 patients who were otherwise inoperable.

Preventing bone loss through diet and exercise
In the early days of the space station, astronauts were losing about one-and-a-half percent of their total bone mass density per month. Researchers discovered an opportunity to identify the mechanisms that control bones at a cellular level. These scientists discovered that high-intensity resistive exercise, dietary supplementation for vitamin D and specific caloric intake can remedy loss of bone mass in space. The research also is applicable to vulnerable populations on Earth, like older adults, and is important for continuous crew member residency aboard the space station and for deep space exploration to an asteroid placed in lunar orbit and on the journey to Mars.



Understanding the mechanisms of osteoporosis
While most people will never experience life in space, the benefits of studying bone and muscle loss aboard the station has the potential to touch lives here on the ground. Model organisms are non-human species with characteristics that allow them easily to be reproduced and studied in a laboratory. Scientists conducted a study of mice in orbit to understand mechanisms of osteoporosis. This research led to availability of a pharmaceutical on Earth called Prolia® to treat people with osteoporosis, a direct benefit of pharmaceutical companies using the spaceflight opportunity available via the national lab to improve health on Earth.

Developing improved vaccines
Ground research indicated that certain bacteria, in particular Salmonella, might become more pathogenic (more able to cause disease) during spaceflight. Salmonella infections result in thousands of hospitalizations and hundreds of deaths annually in the United States. While studying them in space, scientists found a pathway for bacterial pathogens to become virulent. Researchers identified the genetic pathway activating in Salmonella bacteria, allowing the increased likelihood to spread in microgravity. This research on the space station led to new studies of microbial vaccine development.

Providing students opportunities to conduct their own science in space
From the YouTube Space Lab competition, the Student Spaceflight Experiments Program, and SPHERES Zero Robotics, space station educational activities inspire more than 43 million students across the globe. These types of inquiry-based projects allow students to be involved in human space exploration with the goal of stimulating their studies of science, technology, engineering and mathematics. It is understood that when students test a hypothesis on their own or compare work in a lab to what’s going on aboard the space station, they are more motivated towards math and science.

Breast cancer detection and treatment technology
A surgical instrument inspired by the Canadian Space Agency’s heavy-lifting and maneuvering robotic arms on the space station is in clinical trials for use in patients with breast cancer. The Image-Guided Autonomous Robot (IGAR) works inside an MRI machine to help accurately identify the size and location of a tumor. Using IGAR, surgeons also will be able to perform highly dexterous, precise movements during biopsies.

Monitoring water quality from space
Though it completed its mission in 2015, the Hyperspectral Imager for the Coastal Ocean (HICO) was an imaging sensor that helped detect water quality parameters such as water clarity, phytoplankton concentrations, light absorption and the distribution of cyanobacteria. HICO was first designed and built by the U.S. Naval Research Laboratory for the Office of Naval Research to assess water quality in the coastal ocean. Researchers at the U.S. Environmental Protection Agency (EPA) took the data from HICO and developed a smartphone application to help determine hazardous concentrations of contaminants in water. With the space station’s regular addition of new instruments to provide a continuous platform for Earth observation, researchers will continue to build proactive environmental protection applications that benefit all life on Earth.

Monitoring natural disasters from space
An imaging system aboard the station, ISS SERVIR Environmental Research and Visualization System (ISERV), captured photographs of Earth from space for use in developing countries affected by natural disasters. A broader joint endeavor by NASA and the U.S. Agency for International Development, known as SERVIR, works with developing nations around the world to use satellites for environmental decision-making. Images from orbit can help with rapid response efforts to floods, fires, volcanic eruptions, deforestation, harmful algal blooms and other types of natural events. Since the station passes over more than 90 percent of the Earth’s populated areas every 24 hours, the ISERV system was available to provide imagery to developing nations quickly, collecting up to 1,000 images per day. Though ISERV successfully completed its mission, the space station continues to prove to be a valuable platform for Earth observation during times of disaster.

Describing the behavior of fluids to improve medical devices
Capillary Flow Experiments (CFE) aboard the space station study the movement of a liquid along surfaces, similar to the way fluid wicks along a paper towel. These investigations produce space-based models that describe fluid behavior in microgravity, which has led to a new medical testing device on Earth. This new device could improve diagnosis of HIV/AIDS in remote areas, thanks in part to knowledge gained from the experiments.

Improving indoor air quality
Solutions for growing crops in space now translates to solutions for mold prevention in wine cellars, homes and medical facilities, as well as other industries around the world. NASA is studying crop growth aboard the space station to develop the capability for astronauts to grow their own food as part of the agency’s journey to Mars. Scientists working on this investigation noticed that a buildup of a naturally-occurring plant hormone called ethylene was destroying plants within the confined plant growth chambers. Researchers developed and successfully tested an ethylene removal system in space, called Advanced Astroculture (ADVASC). It helped to keep the plants alive by removing viruses, bacteria and mold from the plant growth chamber. Scientists adapted the ADVASC system for use in air purification. Now this technology is used to prolong the shelf-life of fruits and vegetables in the grocery store, and winemakers are using it in their storage cellars.

 

Trolls don't need vodka.....they just like it.

Some people are just angry, I don't understand why. Life, like sex, is good even when it's bad. Why some people are always negative is a mystery to me but they are. Although they are rare at work, they're there.

 

I don't know your background but mine is in physics. I make a living as an engineer and programmer. Perhaps the most striking aspect of the educational experience was to realize just how smart these people are. In physics especially, everyone wants the top positions and there are very few of them. The ones who make it are scary smart. They are so far beyond the average person that unless you've been there, you really can't appreciate the power of their intellect.

In physics you often go back and retrace the footsteps that led to a discovery or theory. For example, I remember first deriving the famous E = MC^2 equation. I remember going through the logic that led Werner to recognize Werner complexes. I remember going through the earlier work of people like Newton. As students we are guided to these solutions. But time and time again, one has to sit back and wonder how in the world these people came up with these works from scratch. Such great minds! Humbling in the extreme.

It is sickening to see so many people going off half-cocked with crackpot objections to things they don't understand. Science is the purest form of truth humans have ever developed. Those who scoff at science are embarrassing themselves more than they can ever know. It is a sad comment on the pathetic state of the country these days.

 

I'm not trying to fool you. That's emotional reasoning IF you think that esp from me. You don't appear to understand what a black hole is and hole isn't the operative word. Extremely large mass is though.

 

Nope. It's there because the gravity reveals it. What's the difference in a black hole and dark matter? Or what are the similarities?

 

Gravity or the interpretation of observations reveal something.
And mythic figures makes the arithmetic balance.
Voila, Dark Matter.

Reminds me of Mr. Higgs boson science. Hardly impartial.
I remember when the neutrino was without mass and charge but still a particle. Early seventies.
Not today's neutrino. Where is my particle with no mass nor charge? GWTW.

Next up, Anti Dark Matter.

Moi
Show Me.
No stinkin' numbers.
Show Me.
Oh that's the beauty of Dark Matter .
They can't Show It. They have faith backed up by math.


r > g

I Can Show YOU. Search most likely to over stay their visa. #1
Across an immense, unguarded, ethereal border, Canadians, cool and unsympathetic,
regard our America with envious eyes and slowly and surely draw their plans against us.​

 

Sry got caught doing something else and unable to get reply posted in time.

You have numbers reflecting gravity created by non baryonic sources for certain amongst other phenomena. I can't make you accept them nor count them as reality based. You'll need to connect the dots.

 

You do know that the cosmological constant is no longer relevant to the theory don't you? In fact Einstien calls it his biggest blunder?

In Theoretical physics, speculation is not remotely equivalent to nobody knows what they are doing. But you knew that (i hope)

 

You're still living in the 30's.

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

 

Not quite. It was reintroduced when the accelerating expansion was first realized, roundabout 1992. Einstein assumed it was needed because he at first assumed the universe is static. But then Hubble came along and measured the red shift.

The equations of physics aren't being bastardized. They are seeking a model that agrees with observations. That is what physicists do.

 

Black holes are completely understandable, and having them collide would seem inevitable. This talk of dark matter and such is based purely on theory without evidence. If it just ended there it would be ok, but in this day and age accepted 'theory' tends to be taken as gospel and any naysayer is shouted down. I don't get why it can't simply be empty space, that seems to annoy people and they invented something to fill the 'empty' to make themselves sound smarter or something...