If we can move at the speed of light, can we pass a small hole?

[beste ulusoy]

If we can motion at speed of light,can we pass a small hole like a keyhole? Of course in suitable conditions...

 

[Chronos]

The speed of light is only achievable by massless particles. It would be fascinating to see what a massless particle sees, but, we haven't figured out how to mount a massless camera on one to observe what happens.

 

[Essence]

If we can motion at speed of light,can we pass a small hole like a keyhole? Of course in suitable conditions...

The short answer is no.

So you probably know that moving at the speed of light is not considered possible (for something with mass). This is related to the fact that as you get faster your mass increases, which makes it harder to go even faster (requires more energy) until it will actually require an infinite amount of energy to increase your speed even more.

However, let's pretend we are really close to the speed of light. In this case there is something called length contraction which will make an object very skinny in the direction that it is moving when observed by someone who is watching it pass by at that really fast speed (close to the speed of light). The object will get skinnier but it will not get shorter (or less wide) so it will not fit through through the key hole. By the way in this case

---------> If this is the direction the object is moving in
-------------> this is the dimension of the object that is "skinny"

if an object looked like this (and was moving right very fast) :
--------------------
--------------------
--------------------

it could start to look like this (at high enough speeds):

------
------
------I should tell you that I have not taken unusually advanced physics yet. It is possible outside of normal special relativity that there is a theory somewhere that suggests otherwise, but I am 99% confident in my answer.

 

[beste ulusoy]

i just ask my question out of all rules.this is just a think.if we can move at speed of light(assume),can we pass a little hole
for example how to fit these huge stars to our eyes,how can we see them

 

[Drakkith]

i just ask my question out of all rules.this is just a think.if we can move at speed of light(assume),can we pass a little hole
for example how to fit these huge stars to our eyes,how can we see them

I cannot understand you. Are you asking how we can see stars?
Are you asking if we can fit large objects through small holes while traveling at near-light speed?

 

[phinds]

... if we can move at speed of light(assume) ...

It is unacceptable to assume we can move at the speed of light.

Your question is like asking "if the laws of physics do not apply, what do the laws of physics say about <insert nonsense of your choice>"

 

[ZapperZ]

If we can motion at speed of light,can we pass a small hole like a keyhole? Of course in suitable conditions...

This is a typical "When did you stop beating your wife?" question.

Secondly, even with applying length contraction, the contraction is only along the direction of motion, not in the transverse direction! Your transverse size is still the SAME!

Zz.

 

[Orodruin]

So you probably know that moving at the speed of light is not considered possible (for something with mass). This is related to the fact that as you get faster your mass increases, which makes it harder to go even faster (requires more energy) until it will actually require an infinite amount of energy to increase your speed even more.

The truth of this sentence is conditioned on "mass" meaning "relativistic mass", a concept most physicists tend to avoid. For the reasons why, see our FAQ on the subject: https://www.physicsforums.com/threads/what-is-relativistic-mass-and-why-it-is-not-used-much.796527/

 

[DaveC426913]

I'm still trying to figure out what he means by "can we pass a small hole like a keyhole".

 

[phinds]

I'm still trying to figure out what he means by "can we pass a small hole like a keyhole".

I think he's totally confused about length contraction and thinks that things set skinnier along their line of travel and if they get skinny enough they could pass through a keyhole.

 

[A.T.]

I'm still trying to figure out what he means by "can we pass a small hole like a keyhole".

You can pass almost everything if you move fast enough... and don't care about surviving it.

 

[Drakkith]

Perhaps we should wait and see what the OP says instead of trying to guess.

 

[DaveC426913]

I think he's totally confused about length contraction and thinks that things set skinnier along their line of travel and if they get skinny enough they could pass through a keyhole.

Ohhhh. Pass through the keyhole.
Because of length contraction.

OK, I get what he's asking now.

 

[phinds]

Perhaps we should wait and see what the OP says instead of trying to guess.

Yeah, but guessing is so much more fun ... and apparently none of us have anything better to do anyway

 

[bahamagreen]

"pass a small hole like a keyhole"

I think this means pass through a slot... the OP may be confused about the dimension of contraction, unless he is thinking of something like this:

The object's path has two components, vertical Y and horizontal X, so the observed contraction may be in the X dimension, but that contraction allows the object to slip in the Y direction though a slot with its long axis oriented in the Z dimension, so as to accept passage of the X contracted object "sideways" ...

Kind of like throwing a loaf of bread fast enough that it contracts to the thickness of a single slice, and then that slice takes on a vertical component to fall into the slot of an awaiting toaster oriented sideways...

But yeah, let's see if the OP can clarify...

 

[phinds]

I think the OP's a drive-by and we're just flailing around

 

[DaveC426913]

I think the OP's a drive-by and we're just flailing around

It's only been 18 hours...

 

[phinds]

It's only been 18 hours...

Yeah, but patience is not one of my virtues

 

[OCR]

and apparently none of us have anything better to do anyway

Well, you could edit your typo... ...

...thinks that things set skinnier along their line of travel...

 

[phinds]

Well, you could edit your typo... ...

an innocent slip of the figner

 

[OCR]

an innocent slip of the figner

Understood... ✓

 

[jimgraber]

Just for fun, let's try to put a photon, an electron and a proton through that small hole.

The photon does not get any faster, but as it gets more energetic, it gets “skinnier” sideways (transversely) as well as longitudinally.

If I understand what I have read correctly, the electron-electron collision cross section also shrinks with increasing energy.

The proton-proton collision cross section, on the other hand increases with increasing energy.

(For nice pictures, google electron electron cross section images and also proton proton cross section images.)

Comments or corrections?

Thanks.

Jim Graber

 

[beste ulusoy]

Comments or corrections?

Thanks.

do you understand me? and do you agree with me partially?

 

[beste ulusoy]

what's the reason of a big object can not go through in a small hole? i guess, it is the distance between them and the elapsed time. because when the object is far away, it is as small as can go through in a small hole. but as long as the object approach the hole, namely, as long as it passes the road and the time, the possibility of the object's ability to go through in the hole gets low. if this object moves as fast as speed of light the distance between the hole and the object disappears instantly. so can the object go through in the hole?

 

[Dale]

how to fit these huge stars to our eyes,how can we see them

when the object is far away, it is as small as can go through in a small hole

This is a truly bizarre comment. Do you actually believe that a star can go through a hole the size of your pupil because it is far away and therefore small enough? I must be really misunderstanding you, because this is the type of geometrical idea that even a very young child knows is wrong.

if this object moves as fast as speed of light the distance between the hole and the object disappears instantly. so can the object go through in the hole?

No.

 

[Wim Nobel]

If… If you assume something that's impossible, you can conclude anything. So yes, if massive objects can move the speed of light, they can also pass through small holes.

 

[DaveC426913]

If… If you assume something that's impossible, you can conclude anything. So yes, if massive objects can move the speed of light, they can also pass through small holes.

Let's not mislead the OP here. The latter does not follow from the former.

If one supposed a massive object to go the speed of light, it does not follow that it can pass through a small hole. (I don't think you were implying that it does; I just wanted to state it for the OP's edification.)

You could suppose multiple, independent impossibilities, such as:
- massive objects can move at c, and/or
- large objects can fit through tiny holes, and/or
- they turn into unicorns.

They are all equally - and independently - impossible.

(OK, #2 is an exception. A large object could fit through a tiny hole if it were very thin and very long.)

 

[Dale]

On that good note, thread closed.