Things You Didn't Know Before

[Praxit]

I don't completely rule out the possibility of aliens visiting us, however, I think it's very unlikely.

First, for them to even know we exist, radio waves and/or evidence of life here (such as might be detected through spectroscopy of the light through our atmosphere) would have to have reached them. We've only been advanced enough for that to happen since around 1900, which means the aforementioned light or radio waves would have only traveled about 125 light years. Even if an alien civilization were to detect us and be interested, and have the ability to travel at light speed, their planet (or ship, or whatever) would have to be within about 60-65 light years from us, in order to receive the information and travel here

Now consider how long it took, since the Big Bang, for life to form here on Earth, then how many mass extinction events took place before intelligent life had the opportunity to come about. Not only do we have the whole "Goldilocks Zone" thing, but we have Jupiter clearing a lot of potential Earth killing asteroids and such. Most of the star systems we've seen don't seem to have that advantage.

There are many other considerations as well, so what I'm saying is that, while I certainly believe there's plenty of life, and much of it intelligent, out there, I doubt there's any close enough and intelligent enough and interested enough to visit us.

Just my opinion.

..I agree, I also think some type of life form exists. Its just to far from us.

But if they have visited us, that's some serious technology they are using.

 

[triplets_93]

The Drivecast with Joel Feder

I Reported on Flock’s Cameras. Now I’m One of the System’s Mistakes

How a typo entered 2,000 miles away triggered Flock's cameras — and led four police officers to surround me.

Typically I report the news, but sometimes, rarely, I am the news. That time just came. Millions of people saw the story about my wife and I getting surrounded by the police after errors made by law enforcement and Flock Safety’s systems led authorities to believe I had performed grand theft auto with a $155,000 Range Rover. The body cam footage of the situation went viral.

The reason this story became a lightning rod placing my face on countless news programs and my voice on a laundry list of radio shows and podcasts isn’t a secret: It landed in the middle of a heated debate around the country about Flock Safety’s, among others, growing network of AI-powered surveillance cameras, which police and the feds can tap into to track people’s lives.

https://www.thedrive.com/news/i-reported-on-flocks-cameras-now-im-one-of-the-systems-mistakes

 

[shabazz]

I didn't know that Nigerians have a recipe for dog meat called "404"

It consists of heavy, spiced pepper soup or local porridge using dog meat, pepper soup spice, and scent leaves.

My only question is if it leaves one still hungry an hour after eating it?

 

[Vtwin]

I didn't know that Nigerians have a recipe for dog meat called "404"

It consists of heavy, spiced pepper soup or local porridge using dog meat, pepper soup spice, and scent leaves.

My only question is if it leaves one still hungry an hour after eating it?

No. In fact I wouldn't recommend eating it if you have anything more active then holding down the couch on your schedule for the rest of the day. It really sticks to your ribs.

Definitely don't go swimming.

 

[triplets_93]

Now, I understand Oil . . .

 

[Creeper]

In the Laws of Physics, there is a law called the Law Of Conservation of Energy. That law states:

The law of conservation of energy states that energy cannot be created or destroyed. It can only be transformed or transferred from one form to another. This means the total energy within an isolated system remains constant over time.​

​

This law actually fails, yet it is still considered a law of physics.

While energy conservation is a cornerstone of classical physics, it relies on a mathematical principle called Noether's Theorem. This theorem states that every conservation law is the result of a specific symmetry in the universe:

• Conservation of energy specifically requires time-translation symmetry. The idea that the laws of physics and the backdrop of space stay the same from one moment to the next.
• Because the universe is expanding, space itself is changing over time. This breaks the time symmetry required for energy to be perfectly conserved on a cosmic scale.

Visible Evidence:

The most common example of this is cosmological redshift. As light travels through expanding space, its wavelength stretches. Since longer wavelengths have lower energy, the individual photons literally lose energy as they travel. In a non-expanding universe, that energy would have to go somewhere else; in an expanding one, it simply vanishes because the "rule" of conservation no longer strictly applies.

Similarly, dark energy (the postulated force driving the expansion) appears to have a constant density. As the universe expands and creates more space, the total amount of dark energy in the universe increases, meaning energy is being created out of nothing to fill the new volume.

Finally, we have the "Hubble Tension" Crisis

Beyond energy conservation, recent data from the James Webb Space Telescope has confirmed a major discrepancy known as the Hubble Tension. Different methods of measuring the universe's expansion rate are giving conflicting results that current physics cannot reconcile, leading some scientists to suggest we are on the verge of a "new physics" to explain how space-time evolves.

Is it possible that we cannot yet detect where the "lost energy" goes so we assume if just disappears? Maybe someday we will discover that that energy is somehow converted to a different form of energy that we previously could not detect.

 

[YosemiteSam]

Is it possible that we cannot yet detect where the "lost energy" goes so we assume if just disappears? Maybe someday we will discover that that energy is somehow converted to a different form of energy that we previously could not detect.

That is a great question. It's similar to the hidden variable theory around quantum mechanics with entangled particles. ...but that is another discussion!

As to your question, in ordinary mechanics, we expect it to have been transferred into something else. But in an expanding universe, (and to your question) there is generally no identifiable object or field that receives the missing energy. The photon simply has lower energy when measured by an observer at a later "cosmological" time. That sounds like a violation because we are trying to apply ordinary global conservation to a geometry (cosmological) where it doesn't necessary apply.

That said, local conservation actually still holds. Einstein's General Relativity uses a local conservation equation. Within a sufficiently small region of spacetime, energy and momentum do not simply disappear. Energy flowing out of one part must flow into another part, or be exchanged with matter and fields. ie, Locally the conservation law works fine. The problem appears when we try to add up the energy across the entire expanding universe at two different times. The geometry of spacetime itself has changed, so there is no universal way to compare those two totals.

The primary cause is that for ordinary energy conservation is closely tied to symmetry of the background remaining the same as time shifts forward. In a cosmological scale, that symmetry does not exist over time because as stated. The geometry of the universe 100 million years ago, is not the same as it is today thereby breaking that symmetry. Basically, there is no global time-translation symmetry.

That is where my reference to Neother's theorem came in the previous post. It states, time-translation symmetry gives energy conservation. An expanding universe lacks that global symmetry, therefore a global conserved cosmic energy need not exist.

There is a notion out there that the photon is "doing work" against the expansion of the universe and that definitely seems plausible to your point, but there is no generally defined container, wall, piston, or gravitational-energy reservoir that receives exactly the photon's lost energy. (that we are aware of anyhow)

An even stronger point to that would be dark energy. If dark energy is a cosmological constant that Einstein alluded to and it's constant, yet the universe is expanding. The funny distinction is the cosmological constant (dark energy) density remains unchanged while the universe's volume increases. It's why dark energy eventually becomes dominate and matter and radiation thin out.

Just to be clear, dark energy is enormously more energy that what is lost in a photon via redshift. So, dark energy definitely does not account for the "lost energy" from expansion / redshift. It's primarily around vacuum energy which is a part of spacetime itself. More space means more vacuum energy.

It like quantum mechanics. It is deeply unintuitive.

 

[Reverend Conehead]

On Kiss Alive II, released in about 1978, the new songs All American Man and Larger Than Life featured Bob Kulick on lead guitar, not Ace Frehley. Frehley (RIP) was going through some substance abuse problems, so they brought in Kulick as a ghost guitarist. He had actually auditioned for Kiss on the same day Frehley did, and was the runner up. Those two songs were a small taste of what Kiss would have been like if Kulick had gotten the job. Later, after Ace left the band, they went through a few lead guitarists and ended up with Bob's brother, Bruce Kulick, playing lead for them.

 

[Runwildboys]

I'm Batman...Shhhhhhhh!

 

[Reverend Conehead]

When The Knack released their smash hit single, My Sharona, in 1979, they had the photo of an attractive woman on its cover. That woman literally was Sharona Alperin who the song was written for. Doug Fieger, who co-wrote the song, had met her somewhere and was attracted to her, but she wasn't his girlfriend when he wrote the song or when they released the single. (He got together with her later on.) I remember seeing that picture and thinking they had hired a cute model, but it literally was the girl in the song. I was going to post the picture, but it's probably a little too risqué for CZ's rules. You won't have any trouble finding it if you want to see it.