I never heard of the Planck length before. Interesting concept. But why does the known laws of physics end there? I would’ve thought it ends at the width of a neutrino.
In physics, the Planck length, denoted ℓP, is a unit of length, equal to 1.616229(38)×10−35 metres. It is a base unit in the system of Planck units, developed by physicist Max Planck. The Planck length can be defined from three fundamental physical constants: the speed of light in a vacuum, the Planck constant, and the gravitational constant.
One more thing on this… There seems to be a problem with the definition of “observable”. If the distant galaxy or quasar we see is 12 billion light years away, but has moved much farther away in the meantime, that does not make its current distance (or state) something we are now observing! We are seeing it as it was 12 billion years ago— when it was that far away, not 90 billion light years away.
An interesting thing about our planet: In this unimaginably vast universe the Earth is equivalent to one grain of sand in the Sahara desert. We are not a big deal.
Bilan almost 8 years ago
I never heard of the Planck length before. Interesting concept. But why does the known laws of physics end there? I would’ve thought it ends at the width of a neutrino.
Ida No almost 8 years ago
Love the science stuff, Dr. Mel. Now, can we put this to practical use and find a way to mass-produce bacon-flavored frosted cereal?
Say What Now‽ Premium Member almost 8 years ago
A sting measures 10 to the minus 33 centimeters long, if you want to consider that.
Night-Gaunt49[Bozo is Boffo] almost 8 years ago
What I found a Wikipedia:
In physics, the Planck length, denoted ℓP, is a unit of length, equal to 1.616229(38)×10−35 metres. It is a base unit in the system of Planck units, developed by physicist Max Planck. The Planck length can be defined from three fundamental physical constants: the speed of light in a vacuum, the Planck constant, and the gravitational constant.
sherbert almost 8 years ago
Okay, you savvy Rockiteers…what does Dr. Mel mean by “from our position the universe is smaller than larger” ????
brain Les almost 8 years ago
There is a mistake here, the smallest known item is Brewster’s brain measuring -4.3 to 343 nanogram.
pcolli almost 8 years ago
As thick as two short Plancks?
NeedaChuckle Premium Member almost 8 years ago
I thought the observable universe was 26 Billion light years. Learned something.
gantech almost 8 years ago
But is it bigger on the inside?
Rev Phnk Ey almost 8 years ago
Another mistake — not all neutrinos are yellow.
corzak almost 8 years ago
Great chart.
stamps almost 8 years ago
So, most of the universe is NOT bigger than a breadbox.
Dirty Dragon almost 8 years ago
A bit outdated, but search YouTube for “Powers of Ten”. Always a highlight of my trips to the Science Museum back in the day…
Astroman007 almost 8 years ago
So, how can the observable universe be 93 billion light years across when the universe is estimated to be 13.8 years old?!
The farthest objects we can see are closer than 14 billion light years.
Hope Rickard did more than Google and take the first source— Wikipedia!
Try these on for size [pun unintentional, but left in!]
https://futurism.com/how-can-the-diameter-of-the-universe-the-age/
https://www.quora.com/How-can-it-be-understood-that-the-universe-is-93-billion-light-years-across-and-yet-only-13-8-billion-years-old-1
In contrast, this tries to explain that it is larger, but arrives at around 45.7 billion light years.
http://www.pbs.org/wgbh/nova/blogs/physics/2012/10/how-large-is-the-observable-universe/
This, though, gets us there
http://www.space.com/24073-how-big-is-the-universe.html
I feel like Brewster!
Astroman007 almost 8 years ago
One more thing on this… There seems to be a problem with the definition of “observable”. If the distant galaxy or quasar we see is 12 billion light years away, but has moved much farther away in the meantime, that does not make its current distance (or state) something we are now observing! We are seeing it as it was 12 billion years ago— when it was that far away, not 90 billion light years away.
“Dr. Mel, paging Dr. Mel!”
“Pam, do you have something for my headache?!”
Stephen Gilberg almost 8 years ago
And the sun is 93 million miles from Earth. Coincidence? :-P
Spider-UK almost 8 years ago
If the universe is expanding, does that mean that there is an edge to it? If so what would happen if you passed it?
Nuliajuk almost 8 years ago
Is this a logarithmic scale?
BobCu almost 8 years ago
An interesting thing about our planet: In this unimaginably vast universe the Earth is equivalent to one grain of sand in the Sahara desert. We are not a big deal.