Recent content by rushikesh

Curvature of Space-time: What is it? General relativity talks about curvature of space-time due to mass. What does it actually mean by 'curve'. Is the space made of something that we can say is curving? If space is purely 'empty', then what is getting curve? Or is it that curving is just an...

ghwellsjr, btw what software do you use to draw these diagram??

I referred to the time dilation and length contraction. But not sure how it applied to that example. Equally confused. I don't think practically it is possible to do this, due to the high speed of light. Do you know experiments that are actually done? Do they have the same set up or some...

A very good animation. But I have a more general question. If for Rover, we show the expanding circle of light also moving/shifting along with Rover, (rover as always the center of light circles, outward or inward) we don't even need explanation of length contraction or time dilation. Isn't...

Yes, all experiments showed this and so we believe in this. But Special relativity did provide an answer for that. Length contraction and time dilation are nothing but an explanation for this phenomenon, is what I have known. Your instrument will calculate speed of light, by using distance...

I know about the Michaelson-Morley expt. trying to measure the speed of light, once in the direction of motion of the Earth and then perpendicular to it. But the source of light was a torch (or similar) which is (obviously) on earth. I have somewhere read that it was also done with the source...

So, this must be true even in case of sound. So, does the speed of sound also remain constant in such case?

If light from a moving away object, such as a star, would appear red-shifted (and blue in case of approaching object), why don't we conclude that the speed of light is affected from that. Doesn't it mean that since light from a moving away object appear red, then the speed of light with respect...

you can find more mathematical details on http://www.farmingdale.edu/faculty/peter-nolan/pdf/TOCRel.pdf Fifth Chapter

what is observers' 4 velocity you are talking about

I regret not being from a physics background to understand the above. Can you clarify it more?

Ok, I found out that I was talking about the Loedel's space-time diagrams and it is possible to explain time dilation in the tree example above. You can read more on it here: http://spacetime-blockuniverse.weebly.com/reciprocal-time-dilation.html

Ok, now let me put it different way. Let's forget about the space time diagrams and the coordinate system. Simply view time as a four dimensional space. Here it is a pure space and one dimension cannot have any distinctness with respect two any other dimension, just as in our three dimensional...

Taking one of your above spacetime diagrams, why should the green lines (moving observers) have longer distance between two time coordinates? can't they be the same as the blue line (still observer) or if they had to be longer then why not as shown in this below figure (and also tell me how...

And what about the figure (B), is it valid?