Evidence Definition and 367 Threads

Hi, Here's a http://blogs.discovermagazine.com/cosmicvariance/2011/03/04/fractal-black-holes-on-strings/" ). Basically, they showed that if http://en.wikipedia.org/wiki/Black_string" is to be expected. However naked singularities would be such a strange thing that it seems safe to...

There is a picture on this site that I don't understand. http://csep10.phys.utk.edu/astr162/lect/cosmology/darkmatter.html It is used as evidence that dark matter exists, but what is it? Is it a MACHO, a WIMP or something else? Can someone also explain what a MACHO or a WIMP is without...

Hi all, First let me say that I'm not an astrophysicist but that I have some understanding of classical physics. So it has been said that the universe is expanding, but what evidence is there of this other than the fact that things seem to be drifting apart? Since much of the universe is...

Is there any hard evidence that the inside of a black hole is simply an empty oblivion of nothingness? I've been mulling over some thoughts on time, and this has been grinding progress. I'm currently trying to find if the possibility of its center being a negative index of timespace is indeed...

I wanted to ask if there are any tests that CMB primary anisotropies are ancient? Or to put it differently can we exclude possibility that they are forming somewhere not far from Solar system say on some spherical horizon? Just thought that black body spectrum is what you would expect from...

In a recent paper http://xxx.lanl.gov/abs/1101.1083 Don N. Page presents a very interesting statistical anthropic argument for the reality of many worlds. It is not only an argument against the collapse hypothesis, but also against (my favoured) Bohmian interpretation. What do you think?

The standard (popular) explanation about big bang goes like this: "We observe red shift in distant galaxies in all directions. One might think that this means that we are in the center of the universe, where some explosion occured, but there exists a more likely explanation: The universe is an...

Is there any evidence that M-theory (where M may stand for Matrix, Membrane, or whatever ...) could be UV finite? I am not asking for a proof (because I know there is none), but only for a piece of evidence or an argument which is more than a pure wish. If you know about such evidence, an...

On the web are some informed-sounding discussions saying that the various videos showing the appearance of the dots on the photo-sensitive surfaces can by no means guarantee that only one photon got through. A lot hinges on that, thanks for referring me to other posts which show certainty of a...

http://arxiv.org/abs/1012.1268 http://arxiv.org/abs/1012.1305 These papers seem to claim that the circles found by Penrose and Gurzadyan in the WMAP data, which were presented as evidence of pre-big bang activity, are entirely consistent with what we would expect the CMB to look like from...

What is the empirical evidence that the red dwarves we observe nowadys were once like our sun in magnitude and luminosity? Thanks in advance for any reference.

All the buzz is that NASA has found out something important. http://www.nasa.gov/home/hqnews/2010/nov/HQ_M10-167_Astrobiology.html

Here's some strange stuff coming from Penrose... An article on Universe Today: http://www.universetoday.com/79750/penrose-wmap-shows-evidence-of-%E2%80%98activity%E2%80%99-before-big-bang/ And the paper: http://arxiv.org/abs/1011.3706 Okaaaay... Granted, I need to actually pore over...

I am doing my science coursework on the Big Bang Theory. Do you know any reliable websites where i can use quotes from scientists to help back up the information i have gathered? Thankyou

I have two questions: which subatomic particles do we have empirical evidence for? And which are postulated but never been detected or doesn't have any evidence yet. Thanks in advance.

Life on Mars? The question is not whether there is life on Mars, but whether life existed on Mars long ago.

I have a 5mm diameter, 10mm long magnet, a short (6mm) coil of 50mm diameter, and an oscilloscope. When I move the magnet through the coil, the oscilloscope shows that the signal (voltage) looks pretty much like the derivative of a Gaussian function. So there must be magnetic flux maximum when...

Yet another question about the evolution of life, likely in the Archaen or Proterozoic eons. As I understand it, the genomes of all life - archaea, bacteria, eukaryotes - is based on DNA, even that of eukaryote organelles, such as plastids and mitochondria. Are there any counter-examples, in...

I was reading through Wikipedia under 'String Theory' recently and discovered that within the lest week a Theoretical Physicist by the name of Kremlic Dormac has found evidence of String Theory within Isolated Monopoles. - http://en.wikipedia.org/wiki/String_theory This is extremely interesting...

Evidence of extraterrestrial "biochemistry"? The linked article claims the apparent depletion of H2, acetylene and ethane from the surface of Titan might be evidence of "life" since (the authors claim) there seems to be no likely simple set of chemical reactions that would account for for this...

I am A Ph.D em Chemistry and not so good in High Mathematics than most of you. Therefore forgive me if, if my idea is a little bit naive. Superparticles as an evidence are dificult to create, because of hughe energy ammounts necessary for it. But I was told that our STRINGS are much, much...

Do we have evidence to support gravity is a wave (like the interference pattern for em wave)? Do we have evidence to support the gravity waves travel at the same speed of em waves?

Symbolize "Absence of evidence is not evidence of absence" This isn't homework. I was bored and ran across a blog that claimed the statement, "Absence of evidence is not evidence of absence" wasn't logical. It seems like common sense to me, so I was going to try prove it to be valid with...

Hi, I'm dean Mullen aged 14, now the other day in school, well a few weeks back or so, I was at PE, basically excercise class, anyway there is a test called the bleep test, we have to run from one end of the hall to the other, I've never got too near completing it, yet this time i tried an...

Homework Statement To find magnetic monopole. Homework Equations I need to know whether or not there is The Attempt at a Solution I have searched around and i can't see to find any SOLID evidence p.s. I am so sorry if this the wrong forum. I am a newbie.

I was wondering if studies of individual galaxies predict the same amount and distribution of dark matter as do studies of galactic super-clusters.

Hello everyone, does anybody of you know, whether there are some publications/blog entries/ideas/anything on possibilities of experimental verification/falsification of Loop Quantum Gravity at collider experiments? I know, there are predictions that can be tested with astrophysical...

In electrostatic case, Gauss's law can be derived from Columb's law, so we can regard experimental evidence for Columb's law as evidence of Gauss's law. But what about non-static case? In this case we know columb's law is no longer valid, so we need experimental evidence to justify Gauss's law...

Quantum mechanics does not take gravity into account at all. So when the energy levels of the hydrogen atom are calculated, the results should be exact only in flat spacetime (no gravitational fields). Energy levels of an H atom in a gravitational field should require a quantum gravity theory...

http://arxiv.org/abs/1001.4090"

So now, do big most bang beleivers and non beleivers think the COBE satelite really proves one way or another the validity of the big bang theory as opposed to the theory that the universe has always existed and that time is a man made concept? Essentially, Is the argument swayed one way or...

If the universe is shown to have angular velocity, is this evidence of a physical universe prior to the "Big Bang"? Several studies are being undertaken currently to determine the rotational velocity of the universe. So far they have all indicated a positive velocity although the values...

Well, if we consider the universe as a closed, isolated system, then the law of conservation of momentum should kick in. P = MV We know that Hubble's law states that the velocity of bodies on an astronomical scale is increasing and P is a constant, so that means M must be decreasing...

Are there any evidence that universe is expanding other then redshifting of EM radiation?

How do we know that the force of gravitation continues indefinitely with respect to distance? Is there any evidence to support it? Could it be possible that it works on a large scale, but drops to zero at a certain distance much like other forces eg. strong nuclear?

I came across the following quote on the home page of a cosmology professor and I have seen similar statements in other contexts: "Although the rate of expansion of the observable Universe is constant at one light year per year, and the local rate of expansion is more or less constant at one...

Is there a 'proof' for this law? or is it experimentally derived..Thanks for reading

As somebody with considerable immunological knowledge and a great interest in the field, I am very curious to see what evidence is in support of the anti-vaccine movement. Personally, I believe in the practice of vaccination because of what I have learned regarding the human immune system...

I've stumbled upon a website that claims that he has created a hollow spherical electromagnet that could contain plasma. http://justodians.org/SphericalMagnet/PatentApp.htm I don't know the credibility of his claims but I would appreciate an analysis of his "invention". Does this device...

Space-time is supposed to be one unity making time in a way equivalent to spatial dimensions. Of course in the metric for time has a different sign though. But what if it's just a mathematical accident that space and time take very similar positions in physical equations? What is the best...

Not sure where better to place this thread, here or gr. Is there direct evidence photons attract one another gravitationally? I am aware of the arguments that GR couples to the energy-stress tensor so photons should attract one another gravitationaly but I wonder if Gravity needs an inertial...

I think QMers may know something about this.

I am fascinated with this idea.

No evidence for dark energy---------- http://arxiv.org/PS_cache/arxiv/pdf/0908/0908.3186v1.pdf We use a variant of principal component analysis to investigate the possible temporal evolution of the dark energy equation of state, w(z). We constrain w(z) in multiple redshift bins, utilizing the...

Is it generally true that the further away a galaxy is (and more red-shifted), the more it tends to contain lower metal content stars? I'd always assumed this was one of the main bits of evidence for the Big Bang, but I've also read that the globular clusters that surround (and are...

What evidence is there that at light speed things such as time dilation, and mass/energy, actually reach infinity?

NuTeV "anomaly" : evidence for in-medium nucleon modification Dear HEP folks, maybe some of you have missed it : Isovector EMC Effect and the NuTeV Anomaly From http://www.jlab.org/news/releases/2009/NuTeV.html

I'm having trouble finding an article or paper on the observational evidence for dark energy being a cosmological constant. I'm looking at this Living Review by Sean Carroll http://relativity.livingreviews.org/Articles/lrr-2001-1/ and he only describes how supernova data constrain the...

Homework Statement what experimental evidence is there for the number of different colour charges? this was on one of our past papers but i don't really understand a few of the answers found online and hyperphysics.com seems to have some of the info missing from the page... all i know is...

Homework Statement What are jets, and how do they provide evidence for quarks. Homework Equations The Attempt at a Solution High energy collisions between hadron can cause quarks within hadrons to fly apart from each other at high energies. Before being observed as quarks, these...