There is no direct conversion because they are used to measure two different things. Radiometric units are used to measure radiant energy across the entire spectrum, whereas photometric units are used to measure visible light as preceived by the human eye. As the eye's sensitivity varies across the visible spectrum (being most sensitive to green light, and least sensitive to red and violet light), the conversion between the two systems of measurement varies according to wavelength at which it they are being compared.
Sextant is used to measure the angle between any two visible objects.Its primary use is to determine the angle between a celestial object and the the horizon which is also know as objects altitude.
Were such a figure to be inscribed upon a plane such that the longest diameter of the object was equal to the extent of the visible universe, the sides would be far smaller than the diameter of a proton. Such an object would be, for all practical purposes, a circle, and any smaller copy would approach a circle even more closely.
If you can see it, it is visible. If you cannot it is not visible. Quite simple, really.
It is not visible.
yes
Yes it is.
Microscopic
An eleven letter word that means too small to be visible with the unaided is microscopic. This is in contrast with macroscopic.
The Andromedia.
H
The smallest size of a cell that can be seen with the unaided human eye is about 100 microns, which is roughly the size of a grain of sand. Anything smaller than that would generally require a microscope to be visible.
No. They are large and visible to the unaided eye.
No. They are large and visible to the unaided eye.
The term for visible with the unaided (naked) eye is "gross", as in gross anatomy.
Tracts of axons in the central nervous system (CNS) are visible to the unaided eye and are called white matter. In the peripheral nervous system (PNS), nerve bundles are visible and may appear as "cables" connecting different parts of the body.
In large amounts, yeast is visible to the unaided eye, but a single yeast plant is not.