| Doppler Red Shift |
| Time Dilation Red Shift |
| Dilation Effect on Apparent Temperatures |
| Conclusion |
The Time Dilation phenomenon has been popularly presented by the Twins Paradox. This is where one of a pair of twins remains on Earth, while the other twin boards a space ship that travels at nearly the speed of light. The space ship travels to Alpha Centauri, and returns. When the two twins meet again, they would now be rather different! The twin who remained on Earth aged 8.6 years during the trip, but the one on board only aged a few weeks.
The effect of Time Dilation is not noticeable to the traveling brother. It would only be visible to an observer who remained on Earth. A very strong telescope would be needed, which could look in the window of the space ship. It would show everything apparently happening in very slow motion. The passenger on the space ship would not be aware of this, and everything would seem normal to him.
In the reference frame of the traveling twin, ALL phenomena would seem to occur in compliance with our accepted laws of science. His watch would appear to him to be keeping correct time. An atomic clock he had along would also appear to be keeping precisely correct time. Any experiment he would perform would give the same results as if he were in a resting reference frame. Therefore, he could not do any experiment that would result in evidence that his ship was traveling away from the Earth (at a constant velocity) at nearly the speed of light. As far as he was concerned, his environment inside the spaceship would be as if the ship was still at rest.
Another consequence of the Theory of Special Relativity is that distances along the direction of motion appear to the traveler to be shortened. Thus, from his point of view, Alpha Centauri was only a few light-days away, and so he could logically get there in a week of travel. He would not have any sensation (or evidence) of violating the limitation of the speed of light as the fastest velocity that is theoretically possible. No logical contradictions would appear in his life. This is essentially what the word Relativity means. ALL frames of reference that are either motionless or moving with a constant velocity are effectively interchangeable.
These points are all firmly accepted by all physicists. They are correct but incomplete. There are two major consequences of these accepted facts that have not been considered until now. Recessional velocities of very distant objects are substantially less than generally now accepted, and the temperatures of those objects are much higher than previously thought.
If a radiation source is traveling toward you, MORE wave crests would arrive at your location per second, which would make it a Doppler Blue Shift.
At relativistic velocities, the Doppler Effect still exists, but it is modified as to the amount of Red Shift or Blue Shift observed for a particular line-of-sight velocity.
During the past several decades, several additional sources of Red Shift have been recognized. In all practical circumstances, these additional effects have a combined effect of a Red Shift that is less than one per cent of the Red Shift due to the Doppler Effect.
The current premise is that Time Dilation has an additional resultant effect of causing a substantial Red Shift effect. Where Doppler Shifts may be Red or Blue depending on the direction of motion, this Time Dilation shift is always a Red Shift, whether approaching or receding.
At some relativistic velocities, this effect is fully one-third the scale of the Red Shift due to the Doppler Effect. The importance of this is enormous. Presently, a given observed Red Shift is always interpreted as virtually completely a result of the relativistic Doppler Effect. Velocities of recession and therefore distances are always based on that assumption.
When accounting for the part of the observed Red Shift that is a result of Time Dilation, the consequence is that the relativistic Doppler Effect actually present is only about three-quarters of the previously accepted values. Calculated velocities of recession and actual distances of very distant objects in the Universe are therefore substantially smaller than previously thought. This results in an implication that the radius of the known Universe is only two-thirds of the commonly accepted value. THIS consequence greatly affects Hubble Constant analysis and whether the Universe has enough mass density to be open or closed.
Now, consider viewing a different piece of equipment aboard that space ship. In this experiment, Hydrogen gas is heated such that it glows. When the (traveling) experimenter directs a spectroscope toward this glowing Hydrogen, he observes the standard sequences of spectral lines (like the Balmer lines) unique to Hydrogen, each at precisely the wavelength known for Hydrogen gas.
When we observe this glowing Hydrogen from our Earth-based telescope, Time Dilation must apply. The atoms of the glowing Hydrogen gas appear move more slowly and to therefore oscillate more slowly. This means the frequency of the observed radiated light is lower, and the wavelength is longer. This result manifests itself as a Red Shift.
This Time Dilation Red Shift is ONLY a result of the apparent slowing of the passage of time, and can be easily calculated by the long-known Time Dilation equations. As shown in the examples below, this effect is independent of the relativistic Doppler Effect Red Shift component.
A first impression might be that this effect is just another way of describing the accepted Doppler Effect Red Shift. It is not. A very simple and obvious way to recognize this is the following. A Doppler Effect Shift is to the red for receding objects and to the blue for approaching objects. Time Dilation has the effect of slowing the apparent passage of time irrespective of the sign of the velocity. Time slows for BOTH receding and approaching objects. Therefore, the Time Dilation Red Shift is ALWAYS a Red Shift, even for approaching objects. Relativistically approaching objects would have a Doppler Blue Shift and a Time Dilation Red Shift.
Calculations (given in the second essay referred to below) show that at low relativistic velocities and at very high ones, the Doppler Effect greatly predominates. At intermediate relativistic velocities, the Dilation Effect becomes quite substantial. At z=3 or z=4, it is fully a third of the magnitude of the Doppler Effect Shift.
This means that the lower apparent average atom velocity gives us received light that appears to come from a source of lower surface temperature than it actually is. The actual object surface temperature can be substantially higher. Consider an object that is moving away from us at an ACTUAL velocity of 0.87c. For this recessional velocity, Time Dilation makes time appear to pass at exactly half of its normal rate. Molecular and atomic velocities would therefore appear to be half, as well. This means that effectively, we would see an object that indicates a surface temperature of half its actual rest-frame value.
Any text on thermodynamics tells that blackbody radiation rates go as the fourth power of the absolute temperature (the Stefan-Boltzmann law). This means that the object in question is actually radiating 16 times as much energy as previously thought.
This object would have an observed z = 3.8. (2.8 due to Relativistic Doppler and 1.0 due to Dilation). If the object had a higher total z than that, this temperature and radiation effect is even greater. An object that had z = 2.0 due to Dilation would be actually radiating 256 times as much energy as previously thought.
If the scale of the Universe is two-thirds the previously accepted value, then the volume of the Universe is less than one-third that previously thought. Given the accepted knowledge of masses of the objects in the Universe, this means the average density of the Universe is more than three times greater than previously thought. This result may resolve the ongoing Hubble constant arguments and eliminate the need to considering "missing mass" or numerous massive black holes or countless neutrinos to account for the gravitational interactions that are observed throughout the Universe.
Therefore, the possibility would seem to exist that the two new consequences of this new understanding eliminates the need for some of the assortment of exotic phenomena presently postulated for explaining observations of extremely distant objects. This seems like a nice benefit, to allow the explanations to be cleaner and more elegant and more traditional.
A more mathematical discussion of this is presented at http://mb-soft.info/public4/reltvty2.html on the Internet.
First Developed, Apr 1989,
First Published on the Web: Jun 8, 1997
This page is at: http://mb-soft.info/public4/reltvty3.html
( http://mb-soft.info/public4/othersci.html )
C Johnson, BA Physics, Univ. of Chicago
P.O. Box 301
Kingsbury, IN 46345