Hey my mom makes lasagna all the time and we freeze the leftovers. It will last a good two weeks in the freezer. My advice is to take it out of the fridge and stick it in the freezer. Lasagna is always better the day after it was made, i.e. as leftovers.
Thus, the part of the Universe we can observe (the Visible Universe) lies within a sphere with a radius of 13.7 billion light years centered around the Earth. 1  We can only observe 13.7 billion light years of the Universe. 2  We are only able to see the parts of the Universe whose light has had time to reach us.
Light is a form of electromagnetic radiation. Visible light is a narrow range of wavelengths of the electromagnetic spectrum. By measuring the wavelength or frequency of light coming from objects in the universe, we can learn something about their nature. Since we are not able to travel to a star or take samples from a galaxy, we must depend on electromagnetic radiation to carry information to us from distant objects in space. The human eye is sensitive to a very small range of wavelengths called visible light.