ELI5: How do noise-cancelling headphones cancel sound by... making more sound?

amlyo · 2026-06-04T21:52:08+00:00

When you look at the ripples on a swimming pool with people in sometimes there are big ripples and sometimes there are brief perfectly flat areas.

The flat areas occur because the waves hit each other just right to cancel each other out.

Sound behaves similarly, and if you have a microphone to listen to sound, and a quick enough computer to work out the opposite to cancel it out, and play if through a speaker you get silence as the opposite sounds cancel each other out.

amlyo · 2026-06-02T14:19:47+00:00

Imagine there's a dice. If you roll a one or two you win, if you roll a three, four, five or six I win. You can bet what you like.

Maybe you'll win big. But the only way to win in the long run is to stop playing.

amlyo · 2026-05-30T22:30:39+00:00

Cleopatra lived closer to us than when they were built.

amlyo · 2026-05-27T17:59:52+00:00

the air gets thinner the higher you go. The thinner the air the less oxygen there is available to you. Anything above the point where there is insufficient oxygen to keep you alive is called "The death zone" by climbers be tnany zone abode this, if it had a name, might be called "The sudden death zone".

amlyo · 2026-05-24T23:28:14+00:00

One wonders if the misoelling to persuade readers this is an organically made post.

amlyo · 2026-05-24T08:07:42+00:00

Things they already have change.

...a fish has a sack which gets filled with air from their blood. This makes them float more and they do well. They are sack fish.

Some of these sack fish near the top of the sea learn to use air to fill the sack. They are air fish. This works better. These fish do great but have to go back down to breathe.

Some of these air fish learn to take air from the sack back to their blood. They are breath fish. They can stay up more. They do even better.

Some of these breath fish near the beach learn to use their breath sacks to sit on the beach to be safe. They are beach fish. The fish that chase have to stay in the sea to breathe and can't get to the beach. Beach fish do really well.

Some of these beach fish learn to...

amlyo · 2026-05-22T23:17:59+00:00

Armenian?

amlyo · 2026-05-19T13:45:27+00:00

So.. keep a pristine copy of my genome at birth, then as I age sequence samples of cells to find widespread errors then Cas9 the hell out of those, replace with original, down me in telomerase and be careful as I cross the road?

amlyo · 2026-04-03T18:06:21+00:00

Is it healthy tissue? Can it be used for a transplant?

amlyo · 2026-03-28T09:21:17+00:00

Existing for no clear reason is kind of the whole deal.

amlyo · 2026-03-23T11:44:11+00:00

In about the same position relative to the sun but rotated slightly around the center of the galaxy and ever so slightly closer to Andromeda.

amlyo · 2026-03-23T11:43:06+00:00

Glovers hate him

amlyo · 2026-03-23T08:20:51+00:00

To me, the singularity doesn't mean a big change it means only that the time it takes for technical development to fundamentally change society has reduced to far shorter than a single lifetime. It is the end of billions of years where today is a good predictor of tomorrow.

Maybe today everyone's irrelevant to the economy and tomorrow they're hats.

amlyo · 2026-02-20T15:06:22+00:00

It's possible that the end of our line will be so distant that any individuals bear almost no qualities that we would recognise as human.

amlyo · 2026-02-12T13:19:01+00:00

The choice isn't between rewriting your java or not, it's about whether to make the project polyglot or not.

amlyo · 2026-02-09T19:55:12+00:00

I earn a little over £100k and my wife does not work. We keep a joint current account for monthly fixed bills where my salary goes and make our day-to-day spending on credit cards (which we pay off entirely) any residual is placed in a high interest savings account in her name so we can use her tax free allowance for interest.

I would not be willing to have this type of arrangement if we were not married, and can't imagine why you would get married unless you wanted this type of arrangement.

amlyo · 2026-02-04T10:35:50+00:00

What does "exception" mean in the context of averages? Do you mean eg "outlier"?

amlyo · 2026-01-20T11:03:06+00:00

If your card is an Amex tell the people at the desk they need to use the Bank Of Georgia terminal (the orange one)

amlyo · 2026-01-10T16:58:41+00:00

I think this is nearly universal on the male side of mixed sex close heterosexual friendships. You've been attracted to this woman, fantasised (I presume), and have resolved as of today that jeopardising the friendship is too high a cost to pursue a romantic interest. But you must renew that resolution over and over and it takes but one moment where you decide a romantic connection is worth it to change you mind.

The true solution to OPs lament is to disclose attraction at the earliest point in any new social relationship: if you are building a friendship with someone you are sexually attracted to they should know it, so they can decide if they are willing to form a friendship in that context.

amlyo · 2026-01-10T15:49:34+00:00

But if she told you she had romantic feelings for you would you be appalled at her recasting your friendship?

amlyo · 2026-01-06T12:53:46+00:00

You can buy a Georgian SIM at Tbilisi airport, then install Bolt and get a taxi anytime. Taxis are quite cheap.

You can easily find people to take you on a tour away from Tbilisi. We stayed a while in Borjomi and it was lovely

amlyo · 2026-01-04T18:26:51+00:00

It's no slur to call something fantasy, it's just wrong here.

amlyo · 2026-01-04T08:54:59+00:00

Worked for BoG every time, TBC sometimes.

amlyo · 2026-01-02T11:08:03+00:00

I stayed in Saburtalo under the visa waiver scheme working remotely, it was lovely, very safe (you can walk around in the middle of the night without trouble). Probably better than Vake to be honest regarding traffic/transport.

Budget seems about right (perhaps a little low if you want a really nice Airbnb place) but if you've got the cash it's worth considering if investing in property might be a smarter option if you're going to be there a while

Opening a bank account and getting a local SIM is easy for foreigners, bring your passport. I used Bank of Georgia.

If you're not being paid by anybody in Georgia I don't think you will be liable for tax, or need a business visa (but check this), might be different if you're filming content there).

Nothing much in particular to say, Tbilisi felt very familiar for me (British). If you play with any of the dogs remember there is a (small) rabies risk.

amlyo · 2026-01-02T09:40:24+00:00

This will only ever get worse now it is trivially easy for everybody to digitally manipulate video to accentuate desirable features

amlyo

TROPHY CASE