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Amio
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Ok I am not serious here. I was just wondering - as for us, time always moves forward; doesn't that mean time have a direction? So why not call it a vector? :-)
phinds said:Mathematically, time is a vector
If we multiply velocity with time, we get displacement. How can we multiply two vector and get a vector? (I thought it is possible only under cross multiplication, but you reminded me that cross multiplication is only for 3D.) So how do we multiply the 'vector' time with any other vector?hilbert2 said:Multiplying with a 1D vector (like time) is called scalar multiplication.
Do you think there is a difference between a 1D vector and a scalar? If so, what is the difference? If not, why bother?Amio said:Ok I am not serious here. I was just wondering - as for us, time always moves forward; doesn't that mean time have a direction? So why not call it a vector? :-)
I am beginner intro physics student. So I might be lacking in concept. That said; when we study 1D kinematics don't we consider 1D quantity like 1D velocity. 1D acceleration as vectors?DaleSpam said:Do you think there is a difference between a 1D vector and a scalar? If so, what is the difference? If not, why bother?
Mathematically, time is a scalar. Scalars can go forwards and backwards. Since a 1D vector is equivalent to a scalar, one could also say that time is a vector. That's a bit tautological, though.phinds said:Mathematically, time is a vector (it can go forwards and backwards).
Sorry, but I don't understand this. For example: the unit vector along x-axis is a 1D vector. Did you mean to say that its actually a scalar? And also,D H said:a 1D vector is equivalent to a scalar
Amio said:when we study 1D kinematics don't we consider 1D quantity like 1D velocity. 1D acceleration as vectors?
Amio said:Actaully I don't understand this. For example: the unit vector along x-axis is a 1D vector. Did you mean to say that its actually a scalar? And also,
when we study 1D kinematics don't we consider 1D quantity like 1D velocity. 1D acceleration as vectors?
Hey, thanks a lot. :-)ModusPwnd said:I would guess that is done for convenience and/or as an aid into moving into 2 and 3 dimensions.
No! You have to look at the space of which that vector is a member. Aside: "Space" here does not mean three dimensional space. It means the set of all possible vectors. There are many different vector spaces. The Euclidean plane, the three dimensional space you learn about in physics, and abstract spaces invented by mathematicians.Amio said:Sorry, but I don't understand this. For example: the unit vector along x-axis is a 1D vector.
quantumnick said:There are quantity which have three, but also quantity that have four or more ( also infinite) number of component but still remain scalar.
D H said:You have to look at the space of which that vector is a member.
Agreed.Matterwave said:I don't think it's productive to confuse the OP by giving him the mathematical definition of a vector space, or more abstract definitions of vectors in terms of coordinate transformations, etc., at this point.
Agreed. I take it that it's the sign that was confusing the OP rather than the dimensionality. If that's the case, pointing the OP to the paper "On determinism and well-posedness in multiple time dimensions" by Craig and Weinstein would fall in the category of "not helping".It seems to me that the OP is a beginner in physics who's simple concept of physical vector at this point is "a quantity with both magnitude and direction (in space as is usually implied)" whereas a scalar is something "only with magnitude (usually implied to be positive, like speed, or distance)".
There is no benefit to doing so. None of non-trivial concepts of vectors are relevant to 1D motion. That is precisely why 1D motion is taught, because you can treat all of the quantities that are vectors in higher dimensions precisely as though they were scalars.Amio said:I am beginner intro physics student. So I might be lacking in concept. That said; when we study 1D kinematics don't we consider 1D quantity like 1D velocity. 1D acceleration as vectors?
A vector quantity has both magnitude (size) and direction, while a scalar quantity only has magnitude. Time has magnitude (in seconds) but does not have a specific direction, so it is considered a scalar quantity.
Time cannot be represented as a vector because it does not have a direction. Vectors are typically represented by arrows, but time does not have a specific direction that can be shown in this way.
No, time cannot be added or subtracted in the same way as a vector. Adding or subtracting time simply changes the value, while adding or subtracting vectors involves both magnitude and direction.
Yes, there are many other examples of scalar quantities, such as temperature, mass, and energy. These quantities have magnitude but do not have a specific direction associated with them.
In physics, time is often represented as a scalar quantity because it does not have a direction. However, in some cases, time can be treated as a vector when considering the change in time (i.e. delta t) between two points. This is often used in equations involving velocity and acceleration.