Monday, August 22, 2011

QUESTIONS

     I'm going to use this posting space to keep track of some of the questions I have in reference to science and philosophy. One of the earliest questions I had was:

     CAN THERE BE A SMALLEST THING?

     It seems logical to me that there cannot be a smallest thing, but there is a smallest theoretical length at which new science would need to be developed in order to explain. That is called the Planck Length and it's many orders of magnitude smaller than atoms or their constituents.

     Another question I had formed, in my early 20s:

     SINCE MASS BECOMES INFINITE AT LIGHT SPEED, WHAT HAPPENS AT ZERO VELOCITY?

     Light speed makes no sense for objects that have mass, so my answer to this question is that zero velocity also makes no sense. Using logic, an object that came completely to rest would lose all its mass, have infinite length, and not last long enough to witness the birth of the universe. Since time slows as velocity increases, then that implies that time speeds up as velocity slows. If somehow, one could achieve zero velocity, then one would experience such a fantastic rate of time that the birth of the universe would never happen.
     One might wonder what I'm talking about, since zero velocity is so easy to achieve. But that is not the case. While you are reading this blog post, you are on the Earth (very likely). Since the Earth is moving around the Sun and the Sun is moving around the core of the galaxy and the galaxy is moving through space, you are not even remotely close to zero velocity. And it gets worse. Space itself moves.
     Gravity is definitely something to consider while pondering this question. The one thing that locks your velocity is gravity. You are "locked" at around 66,000 miles/hr because that is the orbital velocity of the Earth. You can escape that lock by leaving the influence of the Earth's gravitational field. But then you must escape the Sun, and then, you must escape the Milky Way.
     At what velocity would one be locked outside of the gravitational field of a galaxy? That is something I do not know. One thing is clear: from your point of view, everything would be moving. If you found something that was not moving, then you could determine your velocity to be zero, with respect to that object. But since everything is moving (in reality), you are automatically moving at the same velocity as that object. Your next task would be to determine the velocity of that object and then escape its lock. Good luck achieving absolute zero velocity!!!

     WHAT WOULD YOU SEE WITH X-RAY VISION?

      I am perturbed by the laziness of many writers for TV and movies, as well as with the developers of video games. But in their defense, I am also perturbed by the name given to energetic photons. In particular, the suffix -ray is what I find so bothersome. Photons of all energy levels are waves, whether we see them or whether they kill us. X-rays and gamma rays are "rays" as much as "fat" makes one fat. ("Fat" is another poorly understood word.) Why am I calling some writers lazy?
     Because they should know that our eyes collect photons; they do not emit photons. Anyone that thinks a person with x-ray vision could look through walls or see a woman's breasts has not advanced much beyond what the ancient Greeks thought. They thought that our eyes emitted light.
     Just like with visible light, if one wants to see anything with x-rays, then one needs an x-ray source. I am curious as to what one would see if they could detect x-rays. I wrote the following on 5-25-2010 and posted it at a physics website:

      "I couldn't sleep the other night because I was thinking about photons and their ability to penetrate materials. It can be argued that humans are photon detectors. This is true in more than just the sense of visible light because photons don't just enter our pupils. As an example, our bodies can detect x-rays (our bones stop them). But we can't form an x-ray map of our surroundings, as we can with visible light, unless computers assist us. 
     Imagine for a moment if our eyes were unable to detect visible light. For some reason we evolved to detect x-rays. If I were in a building, away from all windows, what would I see? Assume that all light sources (in this case the sources would emit x-rays) were turned off. Since x-rays have greater penetrating power than visible light, would I still see the Sun if I were inside a building? If one had eyes able to detect x-rays would there be a need to make artificial x-ray sources?
      But then I thought about much longer wavelengths. As you know, if you step outside of a building and shine a flashlight against the wall, the photons will not pass through the wall and be detected by any humans inside. Interestingly, I asked, 'Why can radio waves pass through the wall?'

      Since radio waves have less energy than light waves, how are they able to penetrate materials that absorb and reflect visible light? I used to think that radio waves were made of photons, but I read recently that they are not. It just seems logical to assume that the carriers of electromagnetic radiation, the photons, waved at all wavelengths.

      Since radio waves are not made of photons (are they made of electrons?) why are they put on the same chart as visible light, ultraviolet, x-ray, gamma-ray, etc.?
"

     Wow. Everything was fine until I got to the end of what I had typed. What made me think that radio waves are not made of photons? I must have read a really bad forum answer somewhere else. Luckily, someone responded to what I had typed....

      "Radio and Visible light are exactly the same phenomenon.

Long radio waves can be explained "classically" because the wavelength is so much larger than the size of atoms, and because they have low energy: you have many many many individual photons each very subtle so you only see the overall effect. The atoms of the radio antenna don't stop and absorb a photon and change state; instead, quantum effects mix displacements of the free electrons with the photons and when it all comes out in the end you say "electric field" etc.


Short visible waves don't do all that because they are very small compared to the atoms. Your eyes work by having a molecule stop (absorb) photons which causes a change to the electron's energy level in the atom. Visible light's energy is a good match for the available energy levels in organic molecules... so no coincidence that we use it to see with!


Just at the edge of visibility and into UV, individual photons knock individual electrons out of a metal, which is what lead to the realization that photons exist. Radio waves, in huge numbers, gently sway the electrons in the metal instead, like water molecules in the surf making small seashells dance on the edge of the beach.


The two things are extreme ends of a continuous range of phenomena. Just like water is "a liquid" in bulk, but individual hard and solid atoms on another scale. Radio and Visible light is like the difference between a pile of sand and a large slab of stone. Different things happen if you drop each one onto you.
"

     Honestly, I'm kind of embarrassed about my mistake. Anyway, I still want to know what would happen if our eyes could collect photons in the x-ray energy range. My guess is that hospitals would be sources of light, as well as dentist's offices. How many x-ray photons from the Sun penetrate down to ground level? Would the Sun even be visible?

    For now, this is my answer, based on my research. The sun would probably be hard to distinguish amongst the more powerful and unusually ubiquitous x-ray sources covering the entire sky. The whole sky would probably be "visible", but I can't even guess what "color" it would be. X-rays don't penetrate to the surface of the earth, so a life-form that could detect x-rays on the earth would need to develop artificial sources and carry around flashlights that emit x-rays. Even so, regular objects and other life-forms would look pretty odd. A lot of things would also be transparent.

     Updates to come randomly.

2 comments:

  1. This would be an object without energy or mass, correct? By definition, can this object even exist, or would we have to redefine the word itself?

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  2. Think of it this way. You have an object (with mass) at some time (T), moving at some velocity (V) that is not equal to 0 or c. If the massive object increases its V to c, then you have a problem. Its mass becomes infinite, which makes no sense. Now go backwards. Slow the object down until V = 0. In the world of "velocity", there are two extremes: c and 0. We all know about V = c.

    But I know nothing about V = 0! All I can do is speculate. My real question is what happens at the other end of velocity? Is it even possible to achieve zero velocity? If you suddenly achieved zero velocity, then, logically, the entire Milky Way galaxy would scream away from your feet at a fantastic velocity, some 552 km/s. Of course, the Milky Way is really big, so it would take a while for its spiral shape to be visible in total.

    To specifically tackle your question, if the object started out at zero velocity, then I suppose it would not have mass. Mass increases as velocity increases, which implies that something which has a velocity of 0 has a mass of 0. If that were not the case, then there would have to be some arbitrary baseline mass starting value for objects. After thinking about this, the only conclusion I can reach is that zero velocity doesn't make sense for objects that have mass.

    A massless particle, such as a boson, could achieve zero velocity, I suppose. Photons, for example, don't need to worry about velocity, since they have no mass. All velocities are the same to them and their energy increases with a decrease in wavelength.

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