∂T∂t=xgT∂3T∂3t
∫∂T=xgT∫∂3T∂3t∂t
T(t)T(x)=xgT(∂2T∂t2+C(x)+C) ---(*)
where C(x) is a function only in x and C is a numerical constant.
If we insist that T propagate as a wave at velocity v,
∂2T∂t2=v2∂2T∂x2
Substitute the above into (*)
T(t)T(x)=xgT(v2∂2T∂x2+C(x)+C)
when we let T=T(t)T(x).
If T(t) has no constant term,
C(x)=C=0,
T(t)T(x)=v2xgTT(t)d2T(x)dx2
gT=v2xT(x)d2T(x)dx2
The biggest assumption here is that T propagate as a wave at velocity v. We know that gT→0 as x→∞. Thermal gravity is positive, and points away from higher temperature. It is in the same direction as x. T(x) as a product with T(t) satisfies the wave equation. Just on the boundary of the hot spot, gT is maximum. Thereafter, gT decreases monotonously.
Still looking for gT(x)...
Because the immediate answer is,
T(x)=e−Ax
where
A=1v√gTL
which leads right back to
gT=v2x(1v√gTL)2
gT=xgTL
x=L
which is undeniable. Very Hot...
Because the immediate answer is,
T(x)=e−Ax
where
A=1v√gTL
which leads right back to
gT=v2x(1v√gTL)2
gT=xgTL
x=L
which is undeniable. Very Hot...