

 Bump - wglb
http://www.tbray.org/ongoing/When/201x/2010/04/21/Bump

======
biotech
The first time I ever used Bump, I "bumped" in the air (just moved the phone
back and forth). It asked me if I wanted to exchange contact info with someone
who I had never met; I tried it again and it asked me to accept contact
exchange with another unknown person.

All of my attempts since had no effect. Granted, I haven't tried to bump
_that_ many times.

My theory is that they use a GPS location to determine where you are. Then
when the phone senses a particular type of motion, it considers that a "bump".
The server looks to see if anyone else is "bumping" in that GPS location, and,
if so, they connect and exchange contact info or whatever.

If this is true, it explains my original success with bumping into strangers:
these two people were probably in a nearby house trying to bump! The server
thought they were close to my GPS location, and connected me to the stranger.

------
samratjp
Second thoughts and notes: 1) Clearly, bluetooth has its place. But, Bump is
for the rest of us who'd rather get things done quickly. Ask a random iPhone
user how they'd share a file or contact with you using Bluetooth. But Bump is
easier to explain and it works fine. The bump is a mere ritual for explanation
sake and coordinating accelerometer data and is probably not meant to be phone
shattering (And seriously, why did anyone pay $600 for a phone these days?)

2) No, the bumping together seems to be perhaps calculating two similar
accelerometer signatures within a certain probability (of course location
seems to be their secondary heuristic).

3) I don't see why this should this insecure. They are probably using Diffie-
hellman for some pretty badass security measure -
[http://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exch...](http://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange)

4) To those who don't think this is not going to make any money on the
"business" side, maybe you should tell Sequoia, one of Bump's funders, that.

~~~
tewks
If you look at Apple's recent earnings report or listen to the conference
call, you'll find that the ASP for the iPhone was exactly $600. This does not
include any additional carrier payments.

~~~
samratjp
True, but I mean at a consumer level :-)

------
nreece
_This is the kind of technology I like; a simple effect, instantly
understandable, that requires rocket science under the covers to pull off._

Historically, _most_ "rocket science" grade technical implementations in
software/Web fail, except for stuff by NASA (and the likes). Keep it simple
under the hood, but no simpler than what's absolutely required.

~~~
nsfmc
I think dropbox is an app that is instantly understandable and takes quite a
bit of work to get functioning _seamlessly._

The big thing isn't the literal "rocket science" part, just the "easy" part
where you don't realize that the problem might have been difficult at all.

------
jmillikin
Perhaps I'm old fashioned, but what's wrong with using Bluetooth? The last
thing I want to do with a $600 phone is smack it into somebody else's $600
phone just to transfer some pictures.

~~~
jmintz
Bluetooth doesn't work very well or reliably between two of the same phone
(such as iPhone to iPhone). And lots of people have Bluetooth turned off to
save battery (you can't turn it on programmatically, users have to leave your
app and goto settings). And it definitely won't work well between any two
different phones (such as iPhone to Android).

The official recommended bumping techniques is hold phones, and bump hands.
Like a fist bump. That eliminates the risk of damaging your phone and actually
works better.

The long-term goal is to bump more than contacts and pictures. For instance
you can bump money using the new PayPal app on iPhone.

~~~
jrockway
_you can't turn it on programmatically, users have to leave your app and goto
settings_

Uh, on Android? False:

[http://developer.android.com/reference/android/bluetooth/Blu...](http://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html#enable\(\))

~~~
jmintz
Yes that statement was about iPhone OS devices which are used by the majority
of our users.

------
eplanit
Ah, exchange personal information with somebody in immediate proximity to
you...oh, but through a central server. Wait, what?!

I'm sure the central server is and always will be benevolent and benign
regarding the knowledge it gains about its users, their associates, and the
information they convey.

------
jrockway
I like this idea a lot, though I'm not sure there is any possibility of making
money on the business side.

I think I might have to code up an implementation of this to see how well the
vibrations between phones match.

