Is Length Contraction Real? The Genuine answer (Special Relativity)

The phenomenon of special relativity called length contraction is probably the most tricky one in the whole theory. Can solid object shrink just because someone is moving relative to it? or is it just an illusion caused by the limited speed of light? what it really is? and what impact it has on the observer?
All the answers you can find in this video :)

Attributions:

[nikospitr]

i really love your videos man.
You are trying to give us real science, not attempts to impress and get views and money.

[derwegweiser]

awesome video. just one thing i dont understand: why would an observer always measure the front of the ship first and the rear later (from the perspective of an observer moving with the ship)? at 3:58

[Gabriel-mfwh]

Have you ever read John Bell's paper on how to teach relativity? He has the exact opposite view from yours. He sees both length contraction and even time dilation as actual mechanistic effects, and *because* of this, do you measure the speed of light to be the same in all frames of reference

[massimilianodellaguzzo]

Thanks, I really enjoyed this video ... 🥰

[m.c.]

I also think the front and back of the object are measured at different times, but where I disagree is that you think "it is" shorter , where as I think it "appears" shorter .
Question, an experiment can only give one result, if the car and garage paradox thought experiment was done as an actual experiment, do you think the garage doors would close or not ?

[marky]

Thank you! Would you say this means all of relativity can be derived from giving up absolute simultaneity? And that would mean you can understand all relativistic spacetime structure just from accepting time dilation.

This gives me the idea that time is very fundamental and maybe creates to space.

[tokajileo]

does the lorentz contraction apply to planck length? can observer see length smaller than planck length this way?

[macfrankist]

You do not require 2 simultaneous measurements to measure the length of a moving object. Simply obtain the time duration (in proper time) that a vehicle appears to pass through a single point via infrared sensor if you know the proper length relative to your rest frame S as well as the relative speed of the car as seen in S you can determine if in actuality some length contraction physically took place.

[philoso]

Did we know that length contraction is derived from c is universal constant in all inertial frame?

Did we know that c is universal constant based on absence of Aether?

Did we know that MMX fail to detect Aether?

Did we also know that just because MMX fail to detect Aether that doesn’t mean it doesn’t exist?

Did we know that Aether can be detected with simple experiment?

[leokovacic]

What do you think about the submarine paradox ?
A submarine with the same density as water either sinks or rises diet to lengh contraction in different frames .

The solution is tgat it always sinks, and but the explanations are quite nin trivial mathematicaly .
Could you just take the earth to be infinately long compared to the sub and have uts density alsi increase in the frame of the sub therby compensating for the increase of water density

[helifynoe]

Okay, we start with a 4D Space-Time environment. Two events can be located at the exact same place in the time dimension of Space-Time, but be apart from each other spatially. These two events will therefore truly be simultaneous events. However, different observers in different frames of reference, each will not see this as being simultaneous events. But the point is, unless one is a complete bonehead, one realizes that a set of events relative to Space-Time occurs, which is then being observed differently from the lessor mere 3D frames of reference. So in physics today, the absolute cause of the Special relativity phenomena, is basically never ever spoken of. Moving on. Okay, so you can have a ruler that is entirely in motion across the time dimension, and is at true rest spatially. Here your entire ruler extends across space. But if you change your rulers direction of travel within the 4D Space-Time environment, then rotation has obviously been required to do so, and thus in turn less of the ruler now extends across space, now that it partially extends across the time dimension. So there is no real length contraction taking place here, but simply less of the ruler now extends across space.

[paulg]

He is really good ! But length like time is not a thing that is, like momentum and energy.. it is a thing that is perceived.

[seetharama]

If the length contraction is not real, Michelson-Morley experiment would have given positive result, that is there will be some drift in the interference pattern. Length contraction in the direction of motion is real but not detectable by observer in the same frame because his measuring scale will shrink proportionately in the direction of motion. I have mathematical proof for it.

[zenastronomy]

I still don't get why it isn't considered an illusion. proper length seems to be the only valid length. everything else is relative.

[DuchAmagi]

It seems to me that I understand the issue of Lorentz contraction and the lack of absolute simultaneity, and yet I still cannot understand that there is no contraction in reality (?), and at the same time it is not an illusion? 😅

[RolanRoyce]

Here's where a problem appears with SR. Suppose you have a square box moving at 0.866 c. The length would be contracted by 50%, making it a 1:2 rectangle box, and time would be dilated to half speed. If a laser was fired from the upper rear corner to the lower front corner, meaning diagonally, the beam would be directed at a 45 degree angle as seen from inside the box but at a 26.5650512 degree angle as seen by a stationary observer. Its length would change from 1.4142 times the height of the box to 1.118 times, a reduction of 20.943%. A vertical beam would be 100% of its normal stationary length, a horizontal beam would be 50% of its normal length but the diagonal beam would be 79.057%, which is not the average of 100% and 50%, which would be 75%.

Now Einstein has a serious conundrum, because how could he make all three beams work out correctly using the same time dilation and clock desynchronization factors? The desynchronization of the rear and front clocks can't work with both the horizontal and diagonal beams at the same time, you would require two different amounts of desynchronization. That's why you never see a thought experiment involving a diagonal beam.

[jnhrtmn]

This is all born of scientists trying to CREATE an absolute velocity reference frame. But, each velocity is infinitely relative which says that there is NO definition for any velocity. The INSTANT that it changes, there is acceleration, and ALL OBSERVERS AGREE. Theory is simply focused on the wrong aspects of science -the vague useless relative aspects. Einstein was wrong in that you CAN differentiate between linear acceleration and gravity acceleration. The gravity frame will squeeze inward, but the linear acceleration frame will not. With absolutes, you don't need frames. Dimensions are not real and are created and manipulated by math (transforms), which also creates a lot of fools by trying to CREATE an absolute frame for v. Length contraction and time dilation probably cancel out, and the only real physics in modern science is the mass increase. Space certainly has an affect on inertia by gravity, photoelectric effect, clocks, and anything you consider to be a force. The Strong force was invented to maintain the established concept of electric charge, so if electric charge changes when positive particles are crammed into a nucleus, then the Strong force don't exist, and apparent mass changes are suddenly associated with the changing mechanism of electric charge (whatever that is). That Strong force bandage has hidden a lot of physics. That is its only job. It is funny that neutrons are invisible. They may be massive photons for all we know, but science has never gone there. Most spend their time trying to master this crap. Question it, it falls apart.

[philoso]

Mathematics in physics problem solving is just like problem solving with gymnastics in a gymnasium. Once we step out of the gymnasium we face the real world.

The problem is we can’t challenge our professor even if we are right to receive his appraisal towards our graduation.

[philoso]

What happens in mathematics doesn’t mean it always happens in this universe. That including selective dimensional variance caused by speed.

[philoso]

I don’t believe length contraction. It is an artifice based on light c is constant in all reference frame, as a consequence of a faulty MMX experiment to a false conclusion. Concluding that Aether isn’t a medium of light.