Quote from: SteveKelsey on 10/26/2018 10:29 amhttps://phys.org/news/2017-03-expansion-universe-dark-energy.htmlInteresting results if any other researchers could confirm, but it sounds like they made a mistake somewhere. Dark matter is additional mass, and therefore more reason that everything in the universe should be more attracted to each other, which is the exact opposite of what is needed to explain the universe having accelerating expansion. I only read the news article and not the original, so may be something important got lost in between.
https://phys.org/news/2017-03-expansion-universe-dark-energy.html
Quote from: meberbs on 10/26/2018 08:10 pmQuote from: SteveKelsey on 10/26/2018 10:29 amhttps://phys.org/news/2017-03-expansion-universe-dark-energy.htmlInteresting results if any other researchers could confirm, but it sounds like they made a mistake somewhere. Dark matter is additional mass, and therefore more reason that everything in the universe should be more attracted to each other, which is the exact opposite of what is needed to explain the universe having accelerating expansion. I only read the news article and not the original, so may be something important got lost in between.The paper is about cosmological backreaction, i.e. the effect of inhomogeneity on expansion. It has been argued that such inhomogeneity can lead to apparent accelerating expansion without any dark energy. It's a very difficult question (one needs to deal with the full non-linear GR) and still actively debated.
What you have described is how Doppler radar works, an application of the Doppler effect, not the Doppler effect itself. Absorption and emission are not required. The Doppler effect is the change in frequency of a wave in relation to an observer moving relative to the wave source. Cosmological redshift looks like the Doppler effect, but it's not. It's due to the expansion of space, not the motion of an individual body.
No re-emission is needed for there to be a Doppler shift. Paint an object black and you can still measure the effect as the difference between the energy and momentum from the frame of the source to the energy and momentum imparted to the receiver in its own frame.
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Somebody here .(I'm too polite to say who) is posting the most ridiculous load of scientific crap since the last Flat Earth Society meeting.
Quote from: Nomadd on 10/26/2018 08:55 pmSomebody here .(I'm too polite to say who) is posting the most ridiculous load of scientific crap since the last Flat Earth Society meeting.I'll say it, its meberbs.
The Doppler Effect with electromagnetic waves is a result of a receiver not being calibrated.
Quote from: RonM on 10/26/2018 05:30 pmWhat you have described is how Doppler radar works, an application of the Doppler effect, not the Doppler effect itself. Absorption and emission are not required. The Doppler effect is the change in frequency of a wave in relation to an observer moving relative to the wave source. Cosmological redshift looks like the Doppler effect, but it's not. It's due to the expansion of space, not the motion of an individual body.The "Doppler Effect", as you've described, is an observation with causes as diverse as the waves. The Doppler Effect with electromagnetic waves is a result of a receiver not being calibrated. Once calibrated, Doppler Radar is possibly by measuring the frequency change of re-emitted energy (there's no such thing as reflecting as a change in energy will always occur). Eliminating re-emittance is the basis of stealth. With photons, re-emittance is required for any frequency change to occur -or- your device hasn't been calibrated and is giving false readings.
Quote from: meberbs on 10/26/2018 05:32 pmNo re-emission is needed for there to be a Doppler shift. Paint an object black and you can still measure the effect as the difference between the energy and momentum from the frame of the source to the energy and momentum imparted to the receiver in its own frame.How the heck does "painting something black", assuming it will then absorb all light, become a means to measure a photonic Doppler Effect? And if it "can still be measured", assuming with radar, what was the point of painting it. What are you inferring or attempting to talk about?
1) As this thread suggests "New Physics" to explain all conventional theories to date being incapable of describing the Universe, I would suggest correcting the use of existing theories rather than make up fantastic energies or matter to fill the void of ignorance. All science starts with "I don't know", but if that is replaced with mythical, unmeasurable "things" - it's not really science.
2) I would suggest avoiding the crutch of theoretical mathematics. Math is a language with rules. But one can just as easily assemble a meaningless word-soup (as mentioned above) as assemble a meaningless equation of jibberish.
This disparity between reality and mathematics doesn't just occur in astronomy, but also subatomic particle physics (often ridiculously renamed "Quantum") and complex systems like fluid dynamics.
Quote from: Propylox on 10/28/2018 01:47 amQuote from: Nomadd on 10/26/2018 08:55 pmSomebody here .(I'm too polite to say who) is posting the most ridiculous load of scientific crap since the last Flat Earth Society meeting.I'll say it, its meberbs.Incorrect.meberbs has a very good understanding of physics and is known around here for very good posts on the topic.Quote from: Propylox on 10/28/2018 01:47 amThe Doppler Effect with electromagnetic waves is a result of a receiver not being calibrated.Incorrect.This is one of many, many things you've said in this thread that are so completely wrong that most people on this forum will just give up on you and not even try to help you understand where you are wrong.I admire meberbs for trying to help you understand what you're getting wrong. I wish you were more respectful of that.
Just saw this. You better believe incorrect. I respect few people more than meberbs when it comes to understanding and explaining physics.
For about a decade, the biggest machine on the planet has been the Large Hadron Collider (LHC), situated on the border between Switzerland and France. The main body of the collider is a giant ring over five miles in diameter and the entire facility employs thousands of people. But according to a new announcement from China’s Institute of High Energy Physics, it might not be the world’s largest machine for long.The Chinese institute announced plans to build its own particle accelerator over the next decade, and it’s designed to surpass the LHC in every way. According to the report authored by the institute, the upcoming collider will be over five times more powerful and over 20 miles in diameter.