Is light what we think of as dark matter?

AI Thread Summary
Light has gravity and is abundant in space, but it does not explain dark matter or dark energy, which are fundamentally different phenomena. Dark matter contributes to gravitational effects on a large scale, yet lacks direct physical evidence. Theories about dark matter include it being a weakly interacting particle or the result of gravity from a parallel universe. Despite various plausible ideas, there remains no conclusive evidence to support any specific theory. The discussion highlights the ongoing mystery surrounding dark matter and the need for further research.
jeik
Messages
3
Reaction score
0
Since light has gravity, and there is an abundance of it in any given space (this is easily observable by being at anyone spot in space with objects around you), would it be possible to explain what 'dark matter' seems to be?
 
Science news on Phys.org
no, we can see light(radio, ir, visual, etc) and so we can account for its energy contribution as well. dark matter is something else that's contributing to gravity but outside of the gravitational effect that dark matter has on the large scale, we have no physical evidence that this stuff is even there (afaik)
some people think its a weakly interacting particle with a large mass
other people think its gravity leaking in from another universe that is parallel to us separated from us by some distance in a higher dimension
there's many more ideas all plausible still but sadly no evidence :(

i'd give these sites a quick read
http://en.wikipedia.org/wiki/Dark_matter
http://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy/
 
Thread 'A quartet of epi-illumination methods'
Well, it took almost 20 years (!!!), but I finally obtained a set of epi-phase microscope objectives (Zeiss). The principles of epi-phase contrast is nearly identical to transillumination phase contrast, but the phase ring is a 1/8 wave retarder rather than a 1/4 wave retarder (because with epi-illumination, the light passes through the ring twice). This method was popular only for a very short period of time before epi-DIC (differential interference contrast) became widely available. So...
I am currently undertaking a research internship where I am modelling the heating of silicon wafers with a 515 nm femtosecond laser. In order to increase the absorption of the laser into the oxide layer on top of the wafer it was suggested we use gold nanoparticles. I was tasked with modelling the optical properties of a 5nm gold nanoparticle, in particular the absorption cross section, using COMSOL Multiphysics. My model seems to be getting correct values for the absorption coefficient and...
After my surgery this year, gas remained in my eye for a while. The light air bubbles appeared to sink to the bottom, and I realized that the brain was processing the information to invert the up/down/left/right image transferred to the retina. I have a question about optics and ophthalmology. Does the inversion of the image transferred to the retina depend on the position of the intraocular focal point of the lens of the eye? For example, in people with farsightedness, the focal point is...
Back
Top