Debroglie wavelength of a baseball

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The discussion centers on the application of the de Broglie wavelength to a baseball, weighing 1 kg, moving at an extremely low speed of 10^-34 m/s. The calculated wavelength of 6.63 meters suggests that a noticeable diffraction pattern should emerge when the baseballs pass through a double slit 12 meters apart. However, participants question the validity of this outcome, noting that the baseballs would likely collide with the space between the slits rather than create a diffraction pattern. Additionally, the uncertainty in the baseball's position and speed is highlighted, emphasizing that the uncertainty in speed is greater than that of position. Overall, the feasibility of observing a diffraction pattern from such a macroscopic object is critically examined.
michael879
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ok can someone please explain to me why this is wrong? debroglie of a baseball weighing 1kg is h/(1kg * v). You through this at a double slit at 10^-34 m/s which makes the wavelength equal to 6.63 meters. for a double slit its d*sin(theta) = m * (wavelength) so you get theta = sin^-1(6.63/d). If the distance between the slits is 12 meters, you get a theta of 33.5 degrees for the first maxima. After sending a lot of baseballs through there should be a very noticeable diffraction pattern right? I know this would take 3 * 10 ^26 years to get one baseball through, but it could be done with something smaller than a baseball that's still visible.. and anyway, it can't be true that there would be a diffraction pattern from this. I mean, baseballs being shot at two slit that's are 12 meters apart? theyre going to hit the part in between them right?
 
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michael879 said:
ok can someone please explain to me why this is wrong? debroglie of a baseball weighing 1kg is h/(1kg * v). You through this at a double slit at 10^-34 m/s which makes the wavelength equal to 6.63 meters. for a double slit its d*sin(theta) = m * (wavelength) so you get theta = sin^-1(6.63/d). If the distance between the slits is 12 meters, you get a theta of 33.5 degrees for the first maxima. After sending a lot of baseballs through there should be a very noticeable diffraction pattern right? I know this would take 3 * 10 ^26 years to get one baseball through, but it could be done with something smaller than a baseball that's still visible.. and anyway, it can't be true that there would be a diffraction pattern from this. I mean, baseballs being shot at two slit that's are 12 meters apart? theyre going to hit the part in between them right?

What's the uncertainty in position when you know that the baseball is moving at 10^(-34)m ?
 
you don't know exactly how fast it is moving. In fact, the uncertainty of the speed is higher than the position since u can see the thing.
 
Time reversal invariant Hamiltonians must satisfy ##[H,\Theta]=0## where ##\Theta## is time reversal operator. However, in some texts (for example see Many-body Quantum Theory in Condensed Matter Physics an introduction, HENRIK BRUUS and KARSTEN FLENSBERG, Corrected version: 14 January 2016, section 7.1.4) the time reversal invariant condition is introduced as ##H=H^*##. How these two conditions are identical?

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