Hacker News new | past | comments | ask | show | jobs | submit login
Show HN: I was playing with fundamental constants and 13.8 b years popped out
56 points by sahil50 29 days ago | hide | past | favorite | 6 comments
I was playing around with fundamental constants and out popped 13.8 billion light years. What is going on?

the wavelength of an electron mass photon / (2pi) * the charge radius of a proton / the black hole radius of a proton = 13.8 billion light years

((h / (m_e * c * 2pi)) * (h / (m_p * c * pi/2)) / (2G * m_p / c^2)) = 13.8 billion light years

https://www.wolframalpha.com/input/?i=%28h+%2F+%28m_e++c++2pi%29%29++%28h+%2F+%28m_p++c++pi%2F2%29%29+%2F+%282G++m_p+%2F+c%5E2%29+to+light+years&assumption=%22UnitClash%22+-%3E+%7B%22G%22%2C+%7B%22GravitationalConstant%22%7D%7D&assumption=%22UnitClash%22+-%3E+%7B%22m_e%22%2C+%7B%22ElectronMass%22%7D%7D&assumption=%22UnitClash%22+-%3E+%7B%22c%22%2C+%7B%22SpeedOfLight%22%7D%7D&assumption=%22UnitClash%22+-%3E+%7B%22h%22%2C+%7B%22PlanckConstant%22%7D%7D




What's going on is that if you play around with enough numbers, you'll find one you like.

That 13.8 billion light years isn't a constant of the universe. It's a temporary condition, an accident of the particular instant in which you happen to be looking. There's nothing fundamental about it, so the fact that you got it out of an arbitrary arrangement of other values is a coincidence.


Sure there many coincidences that are meaningless.

I think this one stands out because it has to do with charge & gravity, and protons, electrons, & photons. Which are the stable & abundant "things" in the universe.


Right. Too stable. That's the problem.

The number you've "predicted" is "the age of the universe", which isn't constant. Unless you can show why this particular instant in time is especially interesting, then it's just another number, no more interesting than any of the other numbers you generated in the process.


Can we consider a few other possibilities?

As in, taking the point of view of cosmology about 100 years ago, before the redshift was attributed to the Doppler effect. And before the notion of a big bang was the default basis of reasoning.

- What if H is just a measure of redshift? Literally just redshift. Not expansion. Not an age. Just photons losing energy. At a rate of H.

- What if H actually is constant? Like G and like h and like k (Coulomb's constant).

- What if the universe doesn't have an age?

^ not rhetorical questions. Actually asking.


If you leave off the "to light years" conversion, you'll see that the units don't match up. A light year is a measure of distance (m). The result of this equation is 3.86×10^99 s^4/(kg^2 * m^3). How or why Wolfram decided to convert that into 13.82 billion light years is anybody's guess, but it's definitely wrong and nonsensical. You can't convert a s^4/(kg^2 * m^3) unit into just an m without more.


Heads up: click "Use Planck's constant", otherwise Wolfram Alpha assumes h is hours.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: