# Relation of time dilation with Biological clock

I have completely understood the time dilation topic along with its mathematical derivation and consequences. And we know due to time dilation a person's biological clock slows down.So I am not getting that point how slowing down of time in physical clocks affects the slowing down of our biological clock. I don't think that rate of metabolism inside our body is dependent on frame of reference.Please explain this.Are there any kind of biological explanation to this?

• The explanation is not biological. It is purely physical. The biology merely overlays on top of the physical behaviors. Of course, no living creature has ever moved at a speed sufficiently high with respect to another to cause a measurable change in metabolism as measured from the ground. The effects of time dialation are lost in the noise compared to the other sources of variability in metabolism. We talk of Mark and Scott Kelley(twins) getting older or younger with respect to each other when one is orbiting in space, but practically it is not measurable. Commented Jul 26, 2019 at 6:50

Your body is essentially a clock, ticking at the rate at which you age. Regardless of what reference frame you are in, you always find yourself to be aging at the same rate, so your "biological clock" does not slow down at all. This is your "proper" rate of aging. If however you are in motion with respect to some other observer, the observer will see you aging more slowly than the "proper" rate. So your "biological clock" will appear to have slowed down relative to this observer, and it is in this sense that your "rate of metabolism" depends on the observer.

• Good answer. When it comes to (special) relativity, most of the misconceptions come from the fact that people tend to omit saying "according to your frame of reference" or "according to other frame of reference". An observer will not see or experience anything different in his/her own frame regardless of how fast he/she is going. It is always about what an observer will see and think about other observers in other frames of reference. Commented Jul 26, 2019 at 11:55

A common misconception concerning special relativity is that moving clocks 'slow down', which is nonsense. What time dilation means is that an interval between two events that occur in the same place in one inertial frame is always shorter than the interval between the same two events in another inertial frame in which they occur in two different places.

Note it is the length of the interval that changes. If the length is 4 seconds in one frame and 5 seconds in another, that does not mean the clocks in the first frame have slowed down or that the clocks in the second frame have speeded up- the clocks are simply measuring different intervals.

Suppose your heart beats once a second on Earth, where successive beats occur in the same place (more or less). In the frame of a passing muon, in which you are time dilated by a factor of sixty, say, each beat of your heart occurs a huge distance from the previous one owing to your speed of motion, and the interval between successive beats of your heart is a minute as measured in that frame. If you really do 'completely understand time dilation' you will know the the reason why the interval between two beats in the muon frame is one minute is because time in the muon frame is out of synch with time in your frame. If you don't understand that, you should ask a separate question about it.

It’s all biological in terms of application to humans or monkeys or whatever organism you send. The aging process is an entropy process, not time. Aging of all things is entropy not time. You can overlay all aging processes with our concept/tool of time, as expressed in our mathmatics. But that doesn’t change “aging”.

Similarly clocks have no communication or interaction with time. They measure the decay of energy that we put inside them, influenced only by motion and gravity. Once again you can overlay the phenomena of delta entropy retardation or acceleration as the case may be, with the mathematics tool of time.

Since our Diurnal rhythms are also entropy based there would be an expected biological affect at extended high speeds/acceleration.