How to show 400 neutrinos are present?

Thread starter hraghav
Start date Nov 18, 2024
Tags

Calculation Detection Neutrinos

AI Thread Summary

To demonstrate the presence of 400 neutrinos, the calculation starts with detecting 12 neutrinos per 3 million kg of water, resulting in a detection rate of 4*10^-6 neutrinos per kg. When scaled to the weight of a human eyeball, approximately 0.01 kg, this equates to 4*10^-8 neutrinos per eyeball. The poster struggles to scale this data effectively to reach a total of 400 neutrinos, having arrived at values of either 3.69*10^9 or 4*10^-8 neutrinos. The discussion also touches on the number of human eyeballs present in 1987, indicating a broader inquiry into neutrino detection methods. Assistance is requested to clarify the scaling process to achieve the target of 400 neutrinos.

Nov 18, 2024

hraghav

Homework Statement: Twelve electron neutrinos from SN 1987A were detected at Kamiokande in Japan. This
experiment consisted of a tank filled with 3x10^6 kg of water and surrounded by photomultiplier tubes to detect the Cerenkov radiation. Scale this to show that about 400 neutrinos could have been “seen” by humans, if we assume that eyeballs are composed primarily of water and weigh about 10 g each.

Relevant Equations: 12/3*10^6 kg
4*10^-6 neutrinos * 0.01kg

Number of neutrinos detected per kg of water = 12/3*10^6 kg = 4*10^-6 neutrinos
Neutrinos detected by 1 eyeball = 4*10^-6 neutrinos * 0.01kg = 4*10^-8 neutrinos

I am not sure how to scale this to get 400 neutrinos. I did try multiple ways but either ended up with 3.69*10^9 or 4*10^-8 neutrinos. Could someone please help me with this. Thanks!

Physics news on Phys.org

Nov 18, 2024

Orodruin

Staff Emeritus

Science Advisor

Homework Helper

Insights Author

Gold Member

2024 Award

How many (human) eyeballs in 1987?

Nov 18, 2024

WWGD

Science Advisor

Homework Helper

Roll call on neutrinos.

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .

View full post »

Thread 'Voltmeter readings for this circuit with switches'

TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...

View full post »

Thread 'Trying to understand the logic behind adding vectors with an angle between them'

My initial calculation was to subtract V1 from V2 to show that from the perspective of the second aircraft the first one is -300km/h. So i checked with ChatGPT and it said I cant just subtract them because I have an angle between them. So I dont understand the reasoning of it. Like why should a velocity be dependent on an angle? I was thinking about how it would look like if the planes where parallel to each other, and then how it look like if one is turning away and I dont see it. Since...

View full post »