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Universe (Radiation (Visibe (Radio (Radio waves have frequencies as high…

- - - - Radio waves have frequencies as high as 300 GHz to as low as 3 kHz, though some definitions describe waves above 1 or 3 GHz as microwaves, or include waves of any lower frequency.
      - At 300 GHz, the corresponding wavelength is 1 mm (0.039 in), and at 3 kHz is 100 km (62 mi). Like all other electromagnetic waves, they travel at the speed of light.
      - Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light.
    - - Ultraviolet (UV) is an electromagnetic radiation with a wavelength from 10 nm to 400 nm, shorter than that of visible light but longer than X-rays.
      - UV radiation constitutes about 10% of the total light output of the Sun, and is thus present in sunlight.
      - Although it's not considered an ionizing radiation because its photons lack the energy to ionize atoms, long-wavelength ultraviolet radiation can cause chemical reactions and causes many substances to glow or fluoresce.
  - - - Bone x-rays are the fastest and easiest way for your doctor to view and assess bone fractures, injuries and joint abnormalities.
      - It is commonly used to diagnose fractured bones or joint dislocation
      - Bone x-ray uses a very small dose of ionizing radiation to produce pictures of any bone in the body
      - Doppler Effect
        
        The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave for an observer who is moving relative to the wave source.
        
        It is named after the Austrian physicist Christian Doppler, who described the phenomenon in 1842.
        
        A common example of Doppler shift is the change of pitch heard when a vehicle sounding a horn approaches and recedes from an observer.
- - - - Einstein is the father of modern physics. He revolutionised the way we look at the world.
      - Einstein showed that Newton was right about most things, but wrong about how gravity affected very large and very distance objects.
      - Einstein managed to do this without seeing an atom. Instead, he looked at pollen grains in water and realised that something smaller than pollen was making the pollen grains move around.
    - - His discovery of calculus led the way to more powerful methods of solving mathematical problems.
      - Besides his work on universal gravitation (gravity), Newton developed the three laws of motion which form the basic principles of modern physics.
    - - She found that the larger a Cepheid is, the slower it pulsates.
      - Since larger stars are brighter, this pulsation can be used to find the exact brightness of a cephid star
      - Hennrietta Leavitt discovered an important relationship concerning Cepheid variable stars, a type of star that pulsates in a regular pattern.
- - - - Evidence for the theory #
        
        if the universe was initially very, very hot as the Big Bang suggests, we should be able to find some remnant of this heat. In 1965, Radioastronomers Arno Penzias and Robert Wilson discovered a 2.725 degree Cosmic Microwave Background radiation #
        
        This observation supports the expansion of the universe and suggests that the universe was once compacted.
        
        we are reasonably certain that the universe had
        a beginning. galaxies appear to be moving away from us at speeds proportional to their distance. This is called "Hubble's Law," named after Edwin Hubble (1889-1953) who discovered this phenomenon in 1929.
        #
      - The only Plausible theory
        
        https://www.big-bang-theory.com/
        
        "Is the standard Big Bang theory the only model consistent with these evidences? No, it's just the most popular one. Internationally renown Astrophysicist George F. R. Ellis explains: "People need to be aware that there is a range of models that could explain the observations….For instance, I can construct you a spherically symmetrical universe with Earth at its center, and you cannot disprove it based on observations….You can only exclude it on philosophical grounds. In my view there is absolutely nothing wrong in that. What I want to bring into the open is the fact that we are using philosophical criteria in choosing our models. A lot of cosmology tries to hide that."4 In 2003, Physicist Robert Gentry proposed an attractive alternative to the standard theory, an alternative which also accounts for the evidences listed above.5 Dr. Gentry claims that the standard Big Bang model is founded upon a faulty paradigm (the Friedmann-lemaitre expanding-spacetime paradigm) which he claims is inconsistent with the empirical data. He chooses instead to base his model on Einstein's static-spacetime paradigm which he claims is the "genuine cosmic Rosetta." Gentry has published several papers outlining what he considers to be serious flaws in the standard Big Bang model.6 Other high-profile dissenters include Nobel laureate Dr. Hannes Alfvйn, Professor Geoffrey Burbidge, Dr. Halton Arp, and the renowned British astronomer Sir Fred Hoyle, who is accredited with first coining the term "the Big Bang" during a BBC radio broadcast in 1950."
      - Common Misconceptions
        
        there was (and continues to be) an expansion. Rather than imagining a balloon popping and releasing its contents, imagine a balloon expanding: #
        
        an infinitesimally small balloon expanding to the size of our current universe.
        
        There are many misconceptions surrounding the Big Bang theory. For example, we tend to imagine a giant explosion. Experts however say that there was no explosion;an infinitesimally small balloon expanding to the size of our current universe.
  - - - The starting point of our universe was very hot and dense with microwave waves #
      - 13.8 Billion years ago, it was created. Hubble said there was a single moment when the entire universe was held within a single zone
      - According to the standard theory, our universe sprang into existence as "singularity" around 13.7 billion years ago. What is a "singularity" and where does it come from? Well, to be honest, we don't know for sure. Singularities are zones which defy our current understanding of physics. They are thought to exist at the core of "black holes."