The There Are No Stupid Questions Thread

Radio signals travel way too slow, speed of light, to really go very far. Plus SETI is so new. Our early 20th century transmissions have gone much, much further. If we limit ourselves to there being intelligent life in our own galaxy, it could take 100,000 years for the signals to reach them and the same time for them to respond. We’d be gone and buried.

Maybe we will figure out communication like in Star Trek where it is through “sub space” and almost instantaneous. This would make things interesting. A bunch of aliens all talking on this shared “party line”. Travel would still be impossible, but maybe we will figure out how to make space/time our b!tch and just blink from one side of the universe to the other. Ah, sci-fi is cool.

Nah, we can have fun and theorize. :smiley:

The building blocks of Earth life are all based on super common elements. There is nothing rare about our chemical makeup. With hundreds of billions of possible planets out there I think it is hubris (or maybe religion?) that we would even think we are such special beings.

1 in a hundred billion is pretty small, huh? Maybe some folks want to feel special? I don’t think we are so special. There has to be other organisms out there. The statistical odds for other organisms is just too great. We will probably never find evidence due to the vast distances involved, so I just go by the odds.

Remember that I’m just talking about the odds of life being out there. I’m not talking about intelligent life that can hear us, communicate and maybe travel to us (Drake Equation). The odds of that are crazy, crazy smaller.

The building blocks are common but despite the many thousands of experiments attempted to explain the mechanism where by inanimate matter elements and compounds spontaneously create life has never been replicated or explained see miller experiment fact is we don’t know how life starts or what it takes we just have a Theory, it would be another assumption to believe just because other planets have the same elements it will happen.

We cannot form an assumption based only on a theory that isn’t how science works, that is the very definition of Pseudoscience. it has nothing to do with people wanting to feel special… (well maybe some do) but most people would prefer there to be life out there besides us but we don’t have any evidence at all to support that idea

Yes if we find one single life form or one piece of evidence to confirm it else where , even if its just an amoeba then the drake equation is confirmed and becomes Fact if we can demonstrate how life begins with the same common elements & conditions here then again the Drake equation becomes Fact, unfortunately without either we do sadly have to acknowledge that we could literally be alone.

Most people don’t take aliens too seriously. It is fun to believe. No need for sadness. :partying_face:

Yep. It doesn’t have to be intelligent or sophisticated. Just a handful of amino acids can be the basis for some virus a la the Andromeda Strain. One little whiff from space-dust, and all life here gets wiped out as it spreads and mutates.

Tenergy made flat top protected cells ...

If someone knows how to put a wrist strap on their light are they a modder, or do they have to actually put one on to qualify?

If you use a 30q on a light with a FET driver on turbo. Does that mean it will pull 15A since a 30q is rated an 15A?

I know how to make babies, does that make me a father, or do I need an actual child to qualify? :smiley:

No

The cell is able to deliver 15A

Any man can be a father, but it takes a real man to be a daddy :stuck_out_tongue:

:smiley:

To expand on this:
The cell is rated for 15A current draw. In theory, it can provide roughly 15A from full to empty without overheating. In practice, refer to HKJ’s tests.
What a light will actually draw from a cell depends. With “direct drive”, the actual power output is an intersection of the battery’s voltage vs. current curve and the voltage vs. current curve from the flashlight’s entire system (LED, driver, springs, contact resistances, etc.). So if you put a higher forward-voltage LED in a flashlight (XM-L2, for example) and a FET driver, you won’t get a ton of current. If you put the lowest Vf LED you can find, like a Luxon V or White Flat 2mm^2, and a very good battery, you could risk burning out the emitter from pulling too many amps! And if you put a bad battery, it would be risky because you could exceed the battery’s rating and/or where it’s been tested to perform safely (not always the same thing).

I think this has been answered, but I will go into more detail on battery ratings.

All batteries should have factory ratings. Besides continuous discharge there are charge rates for battery life, charge rates with reduced life, operating temperatures, storage temperatures and on and on. It’s pretty interesting to read factory battery specifications. I keep a lot of them in PDF form on my phone for quick reference. Here is the 30Q link.

The 15A 30Q rating is max continuous output without the cell going over its max rated surface temperature. Typical battery temperature upper limits are 60°C to 85°C. (High capacity cells tend to be on the lower side of this temp range and high drain cells tend to be on the higher temp side, generally speaking) The 30Q is in the middle at 75°C. These load tests take a lot of time to perform and really stress the cell so they are usually done in increments of 5A. HKJ and Mooch will test and record the output and temperature curve.

In HKJ’s test the 30Q made it from 4.2v to 2.8v without exceeding the 75°C temperature limit (71°C). It made it down to 3.15v at 20A before he stopped the test due to its temperature reaching 75°C.

Mooch tested the cell all the way down to 2.8v at 20A and 25A. His 15A test also recorded a temperature of 71°C. At 20A it got to 83°C and 25A got to 96°C. So it survived, didn’t burst in flames or anything, just got really hot. It can do these higher amps, but it’s not recommended as eventually it damages the cell and can be dangerous.

So you see there are a lot of variables in testing. We could probably say the 30Q should be rated at 16A as it would still stay under 75°C. 15A is good enough.

Some rewrap companies may list a 30Q with a max continuous current of 25A, because it really can do 25A, but they will put “up to 75°C” in the fine print. Some folks miss the fine print or maybe don’t understand it and just assume this is a better battery. You have to watch out for companies doing this. Find out what cell is under the wrapper and then find the specs for that cell.

A 30Q might even be able to do 40A for 5 seconds or something like that. Shorter durations can allow higher amps. Sometimes the factory will give these rating for 5, 10, 20 or 30 second bursts. I can’t remember what cells I saw these specs in, but they were factory specs.

I see it the other way, any man can be a daddy but it takes a man to be a father. A “father figure” is responsible for raising and providing care and safety for a child, a “daddy” is just responsible for getting someone pregnant.

Thanks for the explanation Scallywag! Sadly I still don’t understand most of what you said as I’m having a hard time understanding the engineering side of what goes on here. Hopefully soon I can. But I still got the answer to my question regardless! :partying_face:

Just because a flashlight uses a FET driver does not mean it’s like running a wire from the positive to the negative of the battery. This might produce 100+ amps! The led acts like a resistive load. The springs, FET model, led wires, body threads, etc… all create resistance.

With a particular battery, if you increase the resistance, the amperage goes down. If you decrease resistance the amperage goes up.

FET drivers can only be used with certain LEDs. Even then, you may be limited to certain batteries. It is a balancing act.

Hopefully this makes sense.

With lights which are both rated as having similar Lumens, why does one look like it
Has less flux, and the other casts a full bodied beam.

Would also appreciate the difference between candlepower, and Lumens.

I am thick af, so please shine a hefty, clear explanation. TIA!

Candela=intensity of the beam.

Lumens = how many photons the light can actually output.

Simple as that.

Candlepower is an old measurement not used any more.

Candela is about intensity or how light is spread out/concentrated. This is how we measure throw distance.

Lumens are about the total light that is scattering in all directions.

You’ve seen zoomy lights, right? It can change the angle of the beam. Changing the beam angle to be more narrow creates higher intensity or candela even though the led is still putting out the same lumens. So candela changes but lumens don’t.

(Note that zoomy lights are a tricky example to use because their optical efficiency changes a lot as the lens focus changes. The lumens going out the front does drop off a lot as you narrow the beam angle even though the led lumens don’t change)

To give another example, I had two lights with the same reflector size. One with a 70.2 and one with a 50.2 led. In order to get the same intensity, or brightness in the hot spot, I found the 70.2 light needed 1000 lumen while the 50.2 light only needed 600 lumen. So two different lumen levels, but the same intensity due to the different size of the hot spots.

From an earlier post in this thread: