The video in the link does a pretty good job at explaining how the base si unit of mass (kg) is currently defined, and the issues that come with the current method
"The Fermi paradox or Fermi's paradox, named after physicist Enrico Fermi, is the apparent contradiction between the lack of evidence and high probability estimates, e.g. those given by the Drake equation, for the existence of extraterrestrial civilizations".
I have always failed to understand...
If the suggestion that all matter, or the vast majority of matter, that makes up the Earth and everything on it, including humans, was originally forged within dying stars and their resulting supernovae, meaning that we are literally constructed from stardust, would the following statement be...
Regarding your comment on the frame of a photon, I've always had trouble wrapping my brain around the following. If special relativity states that time approaches 0 as velocity approaches c, and photons are the only thing able to actually reach c, do photons not experience time? And if something...
From what I've gathered, this would be true for any outside observer who were not traveling at near light speeds. I guess a better way to put it, would be how close to the speed of light would you need to go in order to achieve a time dilation factor of 94billion:80 (traveller experiences time...
How close to the speed of light would you have to travel to be able to traverse the entire span of the known universe(94 billion light years i think?) in a persons 80 year lifetime?
They don't depend on them. But the laws of physics wouldn't be accurately measurable if one was using equations developed by a scientist who used a specific units to do so. I am just asking if there's any way to copy for certain, a unit of measurement such as the litre, kilo, metre etc..
Not sure where the best place to post this is, but here it goes.
Imagine you were sent back in time, far enough back when a lot of the now known scientific laws, rules equations etc, haven't been discovered yet. You're someone who is intelligible with many scientific fields, and you have...
The inital velocity in the downwards direction(ill state it as the y axis) would be 0, wouldn't it? Where as the inital velocity of the ball in the direction which you are moving(x axis) after the ball left your hand would be 2m/s, i think. Are you supposed to determine when the ball hits the...
I was just wondering is there any way to calculate what the airspeed would be, inside of a pipe with a known diameter and length, that lay with each end exposed to a known, different pressue than the other.
Was wondering if such a set up would be feasible for generating clean electricity by...
And a comparison from an observer on planet B will be just as true as planet A's observation? I just can't wrap my head around how both can be true, but they are. I understand how they both are completely true. But yet contradictory because they both see the other as the "slower" ones.
I...
why do you need to compare times in order for it to be true? i understand it would be undeniable evidence, but can't we just assume with the knowledge we have about time dilation, that two planets exist in different rates of time, if we know without a doubt that they are traveling at...
Not sure if i quoted correctly. So that means, for instance, if your in a ship going 0.999C, and you turn on your headlights, the light beam would still emit in front of you at the full magnitude of C? And if you were an observer watching the ship from a stationary position, on the ground let's...
Hey all,
Just a thought experiement here. With time dilation caused by gravity and relative velocity being a confirmed phenomena, do you think it's possible that other worlds that are extremely far away from each other, and are moving at a very high speeds relative to one another with...
Hey all,
This is a just for fun question, as I am sure there is no definitive correct answer. But here it goes
Blackholes to my knowledge, generate the strongest gravitational fields in the known universe. While thinking about gravitational time dilation, and the sheer magnitude that black...
Thanks again!
I think I understand how this frequency change is possible now, even with special relativity at play. I just figured one would not be able to catch up to something that is emitted at a constant speed, for whatever reason, call it a brainfart. But now I can clearly understand and...
Thanks Peter,
I figured that the answer was related to frequency not being the same as speed. But what I still don't fully understand, is how the light shifts frequencies (blue shift or red shift) based on the relative motion of the source and observer. If light is the same speed for all...
Hey all,
I was just wondering something which I couldn't get my head around tonight. If special relativity states that the speed of light is constant for all observers, regardless of the reference frame of any observer, then how is it possible for light to Doppler shift? Wouldn't the...