Evidence Definition and 355 Threads

Where can I find direct experimental evidence that Snell's law is correct for at least three of the typical spectral colours (say RGB). Thank you.

Science news article by their dog domestication guy (David Grimm). Fossils of dogs, bred for use on sleds 9000 years ago, found on Siberian island.

https://arxiv.org/pdf/1412.2777.pdf I have always thought that Dark matter and Dark energy do not interact, but this paper says otherwise. Just because both are called Dark as a' place name for them' people think they must be akin to one another, I have always been told this is incorrect One...

This question was triggered by the fact that Adam Riess is making his lecture rounds at a local University. So, wanting to be prepared, I pulled out his old Nobel lecture, which nicely described the techniques used for the high-z s/n measurements. I was particularly interested in how they...

I have been looking online and in other resources for some answers to no avail. Thought I would sign up on astrophysics forums to find the answer.What is the evidence and data for the period before the cosmic microwave background (CMB) in the early universe? In other words, is the idea of energy...

present time we just knew that US Government legalized the use of marijuana cigarettes. Is there any proven that marijuana can heal parkinson disease and also can heal cancer.

Hi guys. I hope Scientists are at the same time civilized. Because science is civilization. Firstly I'm sorry about language. In Turkey, Our education system does not adequately support English. Anyway. What is the evidence about gravity is exist. Wait. I mean, we know something pushing...

That pesky 3.5 keV line just won't go away. The authors note that it's compatible with dark matter composed of 7.02 keV sterile neutrinos. If such is the case, the Majorana mass scale of the seesaw mechanism needn't coincide with the GUT scale (if such a scale even exists).

What is the prevailing opinion among astronomers about the most plausible explanation for the Wow! signal? I was just reading that Jerry Ehman, the man who discovered the anomaly in 1977, believes the most likely explanation is a signal from an extraterrestrial civilization...

Do we need more proof of dark matter than this?: https://en.wikipedia.org/wiki/Weak_gravitational_lensing

Could this possibly be what the inside of a black hole looks like? aka our Universe resides in a black hole and this area is the event horizon slowly becoming more desolate as Hawking radiation occurs on the opposite side.

For centuries, scientists argued whether light was waves or particles. Light scattering with other light would favor the particle concept. Today we know both models are wrong, but quantum electrodynamics also predicts this scattering - just with an incredibly tiny rate, so it has never been...

http://www.nature.com/articles/srep35596

This paper; https: //arxiv.org/abs/1609.05216, Measurement of matter-antimatter differences in beauty baryon decays, provides the first evidence for CP violation in the baryon sector. This potentially explains a longstanding mystery - why the universe became dominated by matter while anti matter...

Despite of my attempts of trying to find the evidence pointing towards the extra dimensions many new theoretical physics theories suggest, i haven't been able to find one. Still many of the theoretical physicists seem to think that this is indeed the case - that we actually live in a universe...

Is there any experimental evidence that pure energy (massless) can curve spacetime?

Bulk viscosity is a factor now claimed to support the big rip scenario. Its nearly a year old, but an intriguing story nonetheless, as detailed in the guardian: https://www.theguardian.com/science/2015/jul/02/not-with-a-bang-but-with-a-big-rip-how-the-world-will-end and for any with access...

I am aware of the theory of stellar nucleosynthesis, but what evidence do we have to support this theory? Sources are very much appreciated. Thanks!

This is just an oddball question that's been rattling around in my head. What evidence do we have that the Coulomb force of, say, a spherical charge distribution Q, is actually nonzero at very large distances? I can easily imagine that the inverse square law is very accurate out to some...

I heard the holographic principle is a sham and that there is no evidence to back it up and that 99% of physicists don't accept the idea as credible. Is this true?

Hello, my name is sergio , I'm from mexico and am a student of psychology . My studies are based on behavior modification , evidence-based treatments , CBT and third wave therapies . I'm interested in physics, chemistry , biology, genetics . Greetings from mexico , I hope to share with you, and...

Homework Statement I wasn't sure where the most appropriate place to post this question is. But anyway. Which of these, if any, can be used as evidence that the Earth revolves around the sun. 1. The phases of the moon 2. The seasons 3. analemma of the sun 4. solar and lunar eclipses 5. the...

We know electrons can act as waves because of Young's Double split experiment, but what evidence is there to suggest they are particles?

Is there any observation evidence for the expansion of the universe besides redshift?

I've been looking for the specific experimental evidence as to why we know mass increases with velocity. The only way I can think of is with gravitation. If so how do we experimentally know that (as I've been told) increase in observed mass relies on the total relative velocity of the moving...

So I always see in the news that the curiosity rover or some NASA study of previous data discovered evidence of water like its actually news. Wasn't it shown a decade ago that there is conclusive evidence that lots of water existed on mars? I don't get why they're still spending so much time...

Do you know of a resource that expunges all theory and all mathematics and focuses solely on observable facts? Example: This resource would list Faradays experiments but leave out Maxwells equations.

How is the sharpness of shadows evidence for the propagation of light in a straight line ?

http://physics.princeton.edu/~steinh/lambda16.pdf In this research article the authors suggest a cyclic universe, specifically one involving collisions of higher dimensional branes (an idea taken out of string theory), could indirectly explain why the observed cosmological constant is so small...

I want to put this thread in the right context. After reading a plethora of physics literature for many years I have no doubt the people with advanced degrees in physics who work on this stuff are much smarter than me. I don’t believe my observations haven’t already been considered and dismissed...

I don't know much about gauge/gravity duality but I know that its a conjecture coming from superstring theory and one of its examples is AdS/CFT duality. Now I have two questions: 1) As I said, I know that gauge/gravity duality and superstring theory are related but I don't know how much. Is it...

Oxygen is not definitive evidence of life on habitable extrasolar planets The Earth's atmosphere contains oxygen because plants continuously produce it through photosynthesis. This abundant supply of oxygen allows life forms like animals to flourish. Therefore, oxygen had been thought to be an...

Can someone please point me to an experiment (photons/electrons/whatever) where detectors were placed on both slits, this seems like a really big hole in the experiment if they stopped at having just the one detector. (Excuse the pun)

Looking for research on the destruction of biological evidence due to the subduction and destruction inherent to plate tectonic activity. One, are there any places on Earth that have not been affected by tectonic activity? And two, what is our chronological limitation in looking back at...

What evidence is there that time and space began at the instant of the big bang rather than, on the other hand, that space and time existed before the big bang and that the universe simply popped into existence into preexisting space because of Murphy's law; or has this been dis-proven somehow...

I personally think that acupuncture is nonsense but my spouse thinks it is legitimate. She says that she has "heard" that some studies have shown an effect (without having any specific reference). Being a scientist I am open to being disproven. Does anyone know of serious studies that have...

A paper was published on today's ArXiv that questions the empirical basis of the acceleration of the expansion of the universe: Marginal evidence for cosmic acceleration from Type Ia supernovae . The authors are: Jeppe Trst Nielsen1, Alberto Guanti1, and Subir Sarkar1;2 (1Niels Bohr...

I've been teaching physics at a community college in California since 1996. Starting around 2010, I seem to have noticed a change in the behavior of my students, which is that much larger numbers of them seem to be dropping the course because although they're passing, they want a higher grade...

I heard a claim bacteria can exist within human mitochondria, is there any evidence that is true ?. mitochondria"']https://www.google.com/search?q="bacteria+within+mitochondria"[/URL] only gets one hit, and the examples given are not human.

We know that there are 3 generations of neutrinos, namely the electron neutrino, muon neutrino and the tau neutrino. The masses are all very small compared to their respective leptons. What evidence is there that these neutrinos of different generations are distinct?

Newton, Poincare, Lorentz and Einstein (around 1921) believed that there is a preferred frame of reference. Einstein changed his mind when he saw that he is going against mainstream. Michaelson Morley experiment and subsequent experiments are regarded by most people as proof that there is no...

I'm not sure where to post this but it is technically homework but it doesn't follow the template and its less of a math question and more of a conceptual thing anyways. I have to write an English paper on a problem in a future career and it has to be big. I'm thinking about physics so I wanted...

Definition 1: Ghosts are the "creatures" which might be made of particles as we are, but unseen (with the use of photons). Premise 1: We are made of particles or atoms which enable us to think and make us what we are (human creatures). Premise 2: Their might exist creatures which are made...

in classical mathematics plane is taught as an axiom, I question whether the plane can be a proof, let's start from the assumption that there are n ( n>1) line that intersect at a single point in space , from them can be proved that the plane can be used as evidence, ..

Homework Statement (a) What are their vertex and propagator factors? (b) Find the value of R. (c) Explain the peaks at 3, 10 and 100 GeV. Homework EquationsThe Attempt at a Solution Part (a) They have the same propagator factor ##\frac{1}{P \cdot P}##. Vertex factor for muon production is...

Is the red shift evidence enough to define accelerated expansion

This article about a recent experiment was just published the other day: http://phys.org/news/2015-02-hindsight-foresight-accurately-quantum-state.html I can't help but think that this is at least weak evidence in favour of the retrocausal interpretation. Of course other interpretations aren't...

This just in: http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3233.html

I have always wondered if spacetime is actually smooth, or if it is granular such as a quantized spacetime. I remember learning that if you draw the smallest possible square around a circle, you will, of course, get a perimeter, 8 times the radius of the circle. Then if you draw in the...

Direct experimental evidence of time slowing down for moving clocks is well-known. With the advent of atomic clocks, round trip journeys taken by these clocks on slow moving(compared to light speed) jets show time differences with clocks that have not taken the journey. But is there...